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Sample records for calcitonin-gene-related peptide stimulates

  1. Calcitonin Gene-Related Peptide (CGRP)

    PubMed Central

    Russo, Andrew F.

    2015-01-01

    Migraine is a neurological disorder that manifests as a debilitating headache associated with altered sensory perception. The neuropeptide calcitonin gene-related peptide (CGRP) is now firmly established as a key player in migraine. Clinical trials carried out during the past decade have proved that CGRP receptor antagonists are effective for treating migraine, and antibodies to the receptor and CGRP are currently under investigation. Despite this progress in the clinical arena, the mechanisms by which CGRP triggers migraine remain uncertain. This review discusses mechanisms whereby CGRP enhances sensitivity to sensory input at multiple levels in both the periphery and central nervous system. Future studies on epistatic and epigenetic regulators of CGRP actions are expected to shed further light on CGRP actions in migraine. In conclusion, targeting CGRP represents an approachable therapeutic strategy for migraine. PMID:25340934

  2. Inflammatory mediators release calcitonin gene-related peptide from dorsal root ganglion neurons of the rat.

    PubMed

    Averbeck, B; Izydorczyk, I; Kress, M

    2000-01-01

    The interactions between the inflammatory mediators bradykinin, serotonin, prostaglandin E(2) and acid pH were studied in rat dorsal root ganglion neurons in culture. For this purpose, the cultures were stimulated by inflammatory mediators (bradykinin, serotonin, prostaglandin E(2), 10(-5)M each) or acid solution (pH 6.1) for 5 min and the content of calcitonin gene-related peptide was determined in the supernatant before, during and after stimulation, using an enzyme immunoassay. Acid solution resulted in a threefold increase of the basal calcitonin gene-related peptide release which was entirely dependent on the presence of extracellular calcium. The release could not be blocked by the addition of the capsaicin antagonist capsazepine (10(-5)M). Bradykinin (10(-5)M) caused a 50% increase of the basal calcitonin gene-related peptide release which was again dependent on the presence of extracellular calcium, whereas serotonin and prostaglandin E(2) were each ineffective at 10(-5)M concentration. The combination of bradykinin, serotonin and prostaglandin E(2) led to a fivefold increase of the calcitonin gene-related peptide release which could not be further enhanced by acidification. The competitive capsaicin receptor antagonist capsazepine (10(-5)M) significantly reduced the release induced by the combination of bradykinin, serotonin and prostaglandin E(2). It is suggested that the inflammatory mediators co-operate and together may act as endogenous agonists at the capsaicin receptor to cause calcium influx and consecutive neuropeptide release. PMID:10858619

  3. Calcitonin Gene-Related Peptide: Key Regulator of Cutaneous Immunity

    PubMed Central

    Granstein, Richard D.; Wagner, John A.; Stohl, Lori L.; Ding, Wanhong

    2014-01-01

    Calcitonin gene-related peptide (CGRP) has been viewed as a neuropeptide and vasodilator. However, CGRP is more appropriately thought of as a pleiotropic signaling molecule. Indeed, CGRP has key regulatory functions on immune and inflammatory processes within the skin. CGRP-containing nerves are intimately associated with epidermal LCs and CGRP has profound regulatory effects on Langerhans cell antigen-presenting capability. When LCs are exposed to CGRP in vitro, their ability to present antigen for in vivo priming of naïve mice or elicitation of delayed-type hypersensitivity is inhibited in at least some situations. Administration of CGRP intradermally inhibits acquisition of immunity to Th1-dominant haptens applied to the injected site while augmenting immunity to Th2-dominant haptens, although the cellular targets of activity in these experiments remains unclear. Although CGRP can be a pro-inflammatory agent, several studies have demonstrated that administration of CGRP can inhibit the elicitation of inflammation by inflammatory stimuli in vivo. In this regard, CGRP inhibits the release of certain chemokines by stimulated endothelial cells. This is likely to be physiologically relevant since cutaneous blood vessels are innervated by sensory nerves. Exciting new studies suggest a significant role for CGRP in the pathogenesis of psoriasis and, most strikingly, that CGRP inhibit the ability of LCs to transmit the human immunodeficiency virus 1 to T lymphocytes. A more complete understanding of the role of CGRP in the skin immune system may lead to new and novel approaches for the therapy of immune mediated skin disorders. PMID:25534428

  4. Calcitonin Gene-Related Peptide: Physiology and Pathophysiology

    PubMed Central

    Russell, F. A.; King, R.; Smillie, S.-J.; Kodji, X.; Brain, S. D.

    2014-01-01

    Calcitonin gene-related peptide (CGRP) is a 37-amino acid neuropeptide. Discovered 30 years ago, it is produced as a consequence of alternative RNA processing of the calcitonin gene. CGRP has two major forms (α and β). It belongs to a group of peptides that all act on an unusual receptor family. These receptors consist of calcitonin receptor-like receptor (CLR) linked to an essential receptor activity modifying protein (RAMP) that is necessary for full functionality. CGRP is a highly potent vasodilator and, partly as a consequence, possesses protective mechanisms that are important for physiological and pathological conditions involving the cardiovascular system and wound healing. CGRP is primarily released from sensory nerves and thus is implicated in pain pathways. The proven ability of CGRP antagonists to alleviate migraine has been of most interest in terms of drug development, and knowledge to date concerning this potential therapeutic area is discussed. Other areas covered, where there is less information known on CGRP, include arthritis, skin conditions, diabetes, and obesity. It is concluded that CGRP is an important peptide in mammalian biology, but it is too early at present to know if new medicines for disease treatment will emerge from our knowledge concerning this molecule. PMID:25287861

  5. Superior Cervical Ganglia Neurons Induce Foxp3+ Regulatory T Cells via Calcitonin Gene-Related Peptide

    PubMed Central

    Szklany, Kirsten; Ruiter, Evelyn; Mian, Firoz; Kunze, Wolfgang; Bienenstock, John; Forsythe, Paul; Karimi, Khalil

    2016-01-01

    The nervous and immune systems communicate bidirectionally, utilizing diverse molecular signals including cytokines and neurotransmitters to provide an integrated response to changes in the body’s internal and external environment. Although, neuro-immune interactions are becoming better understood under inflammatory circumstances and it has been evidenced that interaction between neurons and T cells results in the conversion of encephalitogenic T cells to T regulatory cells, relatively little is known about the communication between neurons and naïve T cells. Here, we demonstrate that following co-culture of naïve CD4+ T cells with superior cervical ganglion neurons, the percentage of Foxp3 expressing CD4+CD25+ cells significantly increased. This was mediated in part by immune-regulatory cytokines TGF-β and IL-10, as well as the neuropeptide calcitonin gene-related peptide while vasoactive intestinal peptide was shown to play no role in generation of T regulatory cells. Additionally, T cells co-cultured with neurons showed a decrease in the levels of pro-inflammatory cytokine IFN-γ released upon in vitro stimulation. These findings suggest that the generation of Tregs may be promoted by naïve CD4+ T cell: neuron interaction through the release of neuropeptide CGRP. PMID:27022966

  6. A novel function of calcitonin gene-related peptide in body fluid Cl- homeostasis.

    PubMed

    Wang, Yi-Fang; Lafont, Anne-Gaëlle; Lee, Yi-Chun; Hwang, Pung-Pung

    2016-06-15

    Vertebrates need to maintain extracellular chloride (Cl(-)) concentrations to ensure the normal operation of physiological processes; the transition from aquatic to terrestrial environments necessitated the development of sophisticated mechanisms to ensure Cl(-) homeostasis in the face of fluctuating Cl(-) levels. Zebrafish calcitonin gene-related peptide (CGRP), unlike its splice variant calcitonin, does not respond to environmental Ca(2+) levels. This study aimed to test the hypothesis that CGRP is involved in the control of body fluid Cl(-) homeostasis. Acclimation to high-Cl(-) artificial water stimulated the mRNA expression of cgrp and the receptor (crlr1) when compared with low-Cl(-) CGRP knockdown induced upregulation of the Na(+)-Cl(-) co-transporter (ncc2b), while overexpression of CGRP resulted in the downregulation of ncc2b mRNA synthesis and a simultaneous decrease in Cl(-) uptake in embryos. Consistent with these findings, knockdown of either cgrp or crlr1 was found to increase the density of NCC2b-expressing cells in embryos. This is the first demonstration that CGRP acts as a hypochloremic hormone through suppressing NCC2b expression and the differentiation of NCC-expressing ionocytes. Elucidation of this novel function of CGRP in fish body fluid Cl(-) homeostasis promises to enhance our understanding of the related physiology in vertebrates. PMID:27306053

  7. Involvement of calcitonin gene-related peptide and receptor component protein in experimental autoimmune encephalomyelitis

    PubMed Central

    Sardi, Claudia; Zambusi, Laura; Finardi, Annamaria; Ruffini, Francesca; Tolun, Adviye A.; Dickerson, Ian M.; Righi, Marco; Zacchetti, Daniele; Grohovaz, Fabio; Provini, Luciano; Furlan, Roberto; Morara, Stefano

    2015-01-01

    Calcitonin Gene-Related Peptide (CGRP) inhibits microglia inflammatory activation in vitro. We here analyzed the involvement of CGRP and Receptor Component Protein (RCP) in experimental autoimmune encephalomyelitis (EAE). Alpha-CGRP deficiency increased EAE scores which followed the scale alpha-CGRP null > heterozygote > wild type. In wild type mice, CGRP delivery into the cerebrospinal fluid (CSF) 1) reduced chronic EAE (C-EAE) signs, 2) inhibited microglia activation (revealed by quantitative shape analysis), and 3) did not alter GFAP expression, cell density, lymphocyte infiltration, and peripheral lymphocyte production of IFN-gamma, TNF-alpha, IL-17, IL-2, and IL-4. RCP (probe for receptor involvement) was expressed in white matter microglia, astrocytes, oligodendrocytes, and vascular-endothelial cells: in EAE, also in infiltrating lymphocytes. In relapsing–remitting EAE (R-EAE) RCP increased during relapse, without correlation with lymphocyte density. RCP nuclear localization (stimulated by CGRP in vitro) was I) increased in microglia and decreased in astrocytes (R-EAE), and II) increased in microglia by CGRP CSF delivery (C-EAE). Calcitonin like receptor was rarely localized in nuclei of control and relapse mice. CGRP increased in motoneurons. In conclusion, CGRP can inhibit microglia activation in vivo in EAE. CGRP and its receptor may represent novel protective factors in EAE, apparently acting through the differential cell-specific intracellular translocationof RCP. PMID:24746422

  8. Calcitonin gene-related peptide targeted immunotherapy for migraine: progress and challenges in treating headache.

    PubMed

    Peroutka, Stephen J

    2014-06-01

    A role for calcitonin gene-related peptide (CGRP) in the pathophysiology of migraine has been established over the past 25 years. There have now been at least five different small-molecule CGRP antagonists that have demonstrated statistical proof of efficacy in the acute treatment of migraine. At present, multiple clinical trials are underway that are assessing the ability of long-acting antibodies against CGRP to prevent frequent migraine attacks. This review summarizes the existing data concerning the role of CGRP in migraine and attempts to highlight some possible outcomes from the ongoing anti-CGRP antibody trials. PMID:24452707

  9. Distribution of calcitonin gene-related peptide in vertebrate neuromuscular junctions: relationship to the acetylcholine receptor.

    PubMed

    Csillik, B; Tajti, L; Kovács, T; Kukla, E; Rakic, P; Knyihár-Csillik, E

    1993-10-01

    Calcitonin gene-related peptide (CGRP), regarded by several authors to be involved in maintenance of the acetylcholine receptor, is present in the motor axons of various striated rat muscles. It is present, however, only in motor endplates of several selected striated muscles, where it is located in presynaptic axon terminals of neuromuscular junctions. No immunoreactivity could be seen within synaptic vesicles themselves. In the non-human primate Macaca fasciculata, neuromuscular junctions, including those in the diaphragm, display an intense CGRP reaction. The structure of the simian motor endplates is more elaborate than that of the rat. Amphibian motor nerve endings, both in tetanic and tonic muscles, display CGRP immunoreactivity. In tetanic muscles the CGRP reaction outlines "terminaisons en placque" (true motor end plates) and weakly reacting "terminaisons en grappe" (grape-like endings) in tonic muscles. On supramaximal stimulation of the motor nerve, CGRP is depleted from the affected neuromuscular junctions. Wallerian degeneration of the motor axon results in complete disappearance of CGRP. In most rat muscles in which motor endplates do not normally exhibit CGRP immunoreactivity, e.g., the diaphragm and buccinator muscles, the pre-terminal motor axons are CGRP-positive. After immobilization of such muscles by local bupivacaine injection to rats under brief chloral hydrate anesthesia, CGRP immunoreactivity of the neuromuscular junctions can be elicited because blockade of neuromuscular transmission results in accumulation of CGRP in the endplates. Even more striking is the appearance of CGRP immunoreactivity in normally non-reactive motor endplates during axon regeneration after an experimentally induced Wallerian degeneration of the motor axons. We conclude that CGRP is a regular, genotypically determined component of neuromuscular junctions, present either in a manifest or in a latent form. The latter can be elicited by various experimental approaches

  10. Calcitonin Gene-related Peptide Inhibits Chemokine Production by Human Dermal Microvascular Endothelial Cells

    PubMed Central

    Huang, Jing; Stohl, Lori L.; Zhou, Xi; Ding, Wanhong; Granstein, Richard D.

    2011-01-01

    This study examined whether the sensory neuropeptide calcitonin gene-related peptide (CGRP) inhibits release of chemokines by dermal microvascular endothelial cells. Dermal blood vessels are associated with nerves containing CGRP, suggesting that CGRP-containing nerves may regulate cutaneous inflammation through effects on vessels. We examined CGRP effects on stimulated chemokine production by a human dermal microvascular endothelial cell line (HMEC-1) and primary human dermal microvascular endothelial cells (pHDMECs). HMEC-1 cells and pHDMECs expressed mRNA for components of the CGRP and adrenomedullin receptors and CGRP inhibited LPS-induced production of the chemokines CXCL8, CCL2, and CXCL1 by both HMEC-1 cells and pHDMECs. The receptor activity-modifying protein (RAMP)1/calcitonin receptor-like receptor (CL)-specific antagonists CGRP8-37 and BIBN4096BS, blocked this effect of CGRP in a dose-dependent manner. CGRP prevented LPS-induced IκBα degradation and NF-κB binding to the promoters of CXCL1, CXCL8 and CCL2 in HMEC-1 cells and Bay 11-7085, an inhibitor of NF-κB activation, suppressed LPS-induced production of CXCL1, CXCL8 and CCL2. Thus, the NF-κB pathway appears to be involved in CGRP-mediated suppression of chemokine production. Accordingly, CGRP treatment of LPS-stimulated HMEC-1 cells inhibited their ability to chemoattract human neutrophils and mononuclear cells. Elucidation of this pathway may suggest new avenues for therapeutic manipulation of cutaneous inflammation. PMID:21334428

  11. Calcitonin gene-related peptide immunoreactive (CGRP-IR) intradental nerves in the dog.

    PubMed

    Ngassapa, D; Narhi, M; Hirvonen, T; Markkula, I

    1998-03-01

    Calcitonin gene-related peptide (CGRP) is the most frequently occurring peptide in sensory neurons in the rat. Most of the Calcitonin Gene-Related Peptide Immunoreactive (CGRP-IP) nerves have been found to be Capsaicin-sensitive suggesting an involvement in certain types of pain. In the dental pulp CGRP-IR nerve fibres have been studied in the rat, guinea pig, cat, sheep, pig, cow and horse but not in the dog. Extensive sprouting of CGRP-IP intradental nerves has been demonstrated in the teeth with pulpal inflammation in rat molars. In the present investigation the occurrence and distribution of CGRP-IR intradental nerves both in the normal and the injured and inflamed teeth of the dog was studied. Immunolabelling was done by the Avidin-Biotin Complex (ABC) immunoperoxidase technique. CGRP-IR intradental nerves were demonstrated in the dog. The pattern of distribution was found to be similar to that in other animal species. However, the tip one third of the coronal pulp was sparsely innervated compared to that in the rat. Also much fewer fibres were seen to penetrate predentine and dentine, and this appears characteristic of the dog teeth. Sprouting phenomenon seen in the rat was not found in the dog teeth. It is suggested that there might be a species difference in the innervation pattern of CGRP-IR intradental nerves between the rat molar and the dog canine and incisor teeth. PMID:9640812

  12. Inhibition of Calcitonin Gene-Related Peptide Function: A Promising Strategy for Treating Migraine

    PubMed Central

    Durham, Paul L.

    2011-01-01

    The neuropeptide calcitonin gene-related peptide (CGRP) is implicated in the underlying pathology of migraine. Serum levels of CGRP, which are elevated during a migraine attack, have been reported to return to normal with alleviation of pain. In addition, CGRP administration has been shown to cause a migraine-like headache in susceptible individuals. Importantly, CGRP receptors are found on many cell types within the trigeminovascular system that are thought to play important roles in controlling inflammatory and nociceptive processes. Based on these findings, it was proposed that blockage of CGRP receptor function and, hence, the physiological effects of CGRP would be effective in aborting a migraine attack. This review will summarize key preclinical data that support the therapeutic potential of using CGRP receptor antagonists or molecules that bind CGRP within the context of current neurovascular theories on migraine pathology. PMID:18808507

  13. Microglial content-dependent inhibitory effects of calcitonin gene-related peptide (CGRP) on murine retroviral infection of glial cells.

    PubMed

    Malon, Jennifer T; Grlickova-Duzevik, Eliza; Vaughn, James; Beaulac, Holly; Vunk, Tyler R; Cao, Ling

    2015-02-15

    C57BL/6 (B6) mice develop peripheral neuropathy post-LP-BM5 infection, a murine model of HIV-1 infection, along with the up-regulation of select spinal cord cytokines. We investigated if calcitonin gene-related peptide (CGRP) contributed to the development of peripheral neuropathy by stimulating glial responses. An increased expression of lumbar spinal cord CGRP was observed in vivo, post-LP-BM5 infection. Consequently, in vitro CGRP co-treatments led to a microglial content-dependent attenuation of viral loads in spinal cord mixed glia infected with selected doses of LP-BM5. This inhibition was neither caused by the loss of glia nor induced via the direct inhibition of LP-BM5 by CGRP. PMID:25670002

  14. Peripheral amplification of sweating – a role for calcitonin gene-related peptide

    PubMed Central

    Schlereth, Tanja; Dittmar, Jan Oliver; Seewald, Bianca; Birklein, Frank

    2006-01-01

    Neuropeptides are the mediators of neurogenic inflammation. Some pain disorders, e.g. complex regional pain syndromes, are characterized by increased neurogenic inflammation and by exaggerated sudomotor function. The aim of this study was to explore whether neuropeptides have a peripheral effect on human sweating. We investigated the effects of different concentrations of calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and substance P (SP) on acetylcholine-induced axon reflex sweating in healthy subjects (total n = 18). All substances were applied via dermal microdialysis. The experiments were done in a parallel setting: ACh alone and ACh combined with CGRP, VIP or SP in various concentrations were applied. Acetylcholine (10−2m) always elicited a sweating response, neuropeptides alone did not. However, CGRP significantly enhanced ACh-induced sweating (P < 0.01). Post hoc tests revealed that CGRP in physiological concentrations of 10−7–10−9m was most effective. VIP at any concentration had no significant effect on axon reflex sweating. The duration of the sweating response (P < 0.01), but not the amount of sweat, was reduced by SP. ACh-induced skin blood flow was significantly increased by CGRP (P < 0.01), but unaltered by VIP and SP. The results indicate that CGRP amplifies axon reflex sweating in human skin. PMID:16931551

  15. Calcitonin gene-related peptide in migraine: intersection of peripheral inflammation and central modulation

    PubMed Central

    Raddant, Ann C.; Russo, Andrew F.

    2012-01-01

    Over the past two decades, a convergence of basic and clinical evidence has established the neuropeptide calcitonin-gene-related peptide (CGRP) as a key player in migraine. Although CGRP is a recognised neuromodulator of nociception, its mechanism of action in migraine remains elusive. In this review, we present evidence that led us to propose that CGRP is well poised to enhance neurotransmission in migraine by both peripheral and central mechanisms. In the periphery, it is thought that local release of CGRP from the nerve endings of meningeal nociceptors following their initial activation by cortical spreading depression is critical for the induction of vasodilation, plasma protein extravasation, neurogenic inflammation and the consequential sensitisation of meningeal nociceptors. Mechanistically, we propose that CGRP release can give rise to a positive-feedback loop involved in localised increased synthesis and release of CGRP from neurons and a CGRP-like peptide called procalcitonin from trigeminal ganglion glia. Within the brain, the wide distribution of CGRP and CGRP receptors provides numerous possible targets for CGRP to act as a neuromodulator. PMID:22123247

  16. Calcitonin gene-related peptide increases acetylcholine quantal size in neuromuscular junctions of mice.

    PubMed

    Gaydukov, Alexander E; Bogacheva, Polina O; Balezina, Olga P

    2016-08-15

    We used an intracellular microelectrode technique to study the mechanisms of action of two isoforms (human and rat) of calcitonin gene-related peptide (CGRP) on the evoked and spontaneous quantal secretion of acetylcholine (ACh) in mouse diaphragm motor synapses. Recordings of miniature endplate potentials (MEPPs) and evoked multiquantal endplate potentials (EPPs) in a cut neuromuscular preparation showed that CGRP increased the amplitude of EPPs without influencing their quantal content. Both isoforms of CGRP in a wide range of concentrations (1nM-1μM) provoked a similar considerable increase in MEPPs amplitude in a dose-dependent manner (up to 150-160% compared to control) without changing their frequency, rise-time, and decay. Inhibition of CGRP-receptors by truncated CGRP (CGRP8-37) completely prevented the potentiating effect of CGRP on the MEPPs amplitude. The effect of CGRP was not accompanied by changes in input resistance of muscle fiber membrane but was fully prevented by inhibition of vesicular ACh transport by vesamicol. Inhibition of protein kinase A (PKA) by H-89 also prevented CGRP action on the MEPPs amplitude. It is concluded that, in mammalian neuromuscular junctions, different isoforms of exogenously applied CGRP uniformly potentiate amplitudes of evoked and spontaneous postsynaptic potentials acting presynaptically via an increase in ACh quantal size. PMID:27288020

  17. Calcitonin gene-related peptide is a key neurotransmitter in the neuro-immune axis

    PubMed Central

    Assas, Bakri M.; Pennock, Joanne I.; Miyan, Jaleel A.

    2014-01-01

    The question of how the neural and immune systems interact in host defense is important, integrating a system that senses the whole body with one that protects. Understanding the mechanisms and routes of control could produce novel and powerful ways of promoting and enhancing normal functions as well as preventing or treating abnormal functions. Fragmentation of biological research into specialities has resulted in some failures in recognizing and understanding interactions across different systems and this is most striking across immunology, hematology, and neuroscience. This reductionist approach does not allow understanding of the in vivo orchestrated response generated through integration of all systems. However, many factors make the understanding of multisystem cross-talk in response to a threat difficult, for instance the nervous and immune systems share communication molecules and receptors for a wide range of physiological signals. But, it is clear that physical, hard-wired connections exist between the two systems, with the key link involving sensory, unmyelinated nerve fibers (c fibers) containing the neuropeptide calcitonin gene-related peptide (CGRP), and modified macrophages, mast cells and other immune and host defense cells in various locations throughout the body. In this review we will therefore focus on the induction of CGRP and its key role in the neuroimmune axis. PMID:24592205

  18. Structure–activity relationships for α-calcitonin gene-related peptide

    PubMed Central

    Watkins, Harriet A; Rathbone, Dan L; Barwell, James; Hay, Debbie L; Poyner, David R

    2013-01-01

    Calcitonin gene-related peptide (CGRP) is a member of the calcitonin (CT) family of peptides. It is a widely distributed neuropeptide implicated in conditions such as neurogenic inflammation. With other members of the CT family, it shares an N-terminal disulphide-bonded ring which is essential for biological activity, an area of potential α-helix, and a C-terminal amide. CGRP binds to the calcitonin receptor-like receptor (CLR) in complex with receptor activity-modifying protein 1 (RAMP1), a member of the family B (or secretin-like) GPCRs. It can also activate other CLR or calcitonin-receptor/RAMP complexes. This 37 amino acid peptide comprises the N-terminal ring that is required for receptor activation (residues 1–7); an α-helix (residues 8–18), a region incorporating a β-bend (residues 19–26) and the C-terminal portion (residues 27–37), that is characterized by bends between residues 28–30 and 33–34. A few residues have been identified that seem to make major contributions to receptor binding and activation, with a larger number contributing either to minor interactions (which collectively may be significant), or to maintaining the conformation of the bound peptide. It is not clear if CGRP follows the pattern of other family B GPCRs in binding largely as an α-helix. LINKED ARTICLES This article is part of a themed section on Neuropeptides. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.170.issue-7 PMID:23186257

  19. Adrenal responses to calcitonin gene-related peptide in conscious hypophysectomized calves.

    PubMed Central

    Bloom, S R; Edwards, A V; Jones, C T

    1989-01-01

    1. Right adrenal and various cardiovascular responses to an intra-aortic infusion of calcitonin gene-related peptide (CGRP; 4 micrograms min-1) have been investigated in the presence and absence of exogenous adrenocorticotrophin ACTH1-24 (2 or 5 ng min-1 kg-1, I.V.). The adrenal clamp technique was employed in conscious calves in which the pituitary stalk had been cauterized 3-7 days previously. 2. At the higher dose (5 ng min-1 kg-1) the I.V. infusion of ACTH raised mean plasma ACTH concentration by about 1000 pg ml-1 and mean right adrenal cortisol output by about 750 ng min-1 kg-1. Under these conditions the intra-aortic infusion of CGRP had no apparent effect on adrenal cortisol output by about 750 ng min-1 kg-1. Under these conditions the intra-aortic infusion of CGRP had no apparent effect on adrenal function, other than to produce moderate adrenal vasodilatation. In contrast, in the absence of exogenous ACTH, the same dose of CGRP produced a substantial rise in cortisol output, which rose steadily to a peak mean value of 409 +/- 31 pg min-1 kg-1 at 10 min. It also significantly inhibited the release of free, but not of total, met5-enkephalin-like immunoreactivity from the gland (P less than 0.001) together with a significantly greater fall in adrenal vascular resistance (P less than 0.001). 3. At the lower dose of ACTH (2 ng min-1 kg-1, I.V.) CGRP raised mean plasma cortisol output from 314 +/- 31 to 486 +/- 44 ng min-1 kg-1 (P less than 0.01) and this effect was not attributable to an increase in the adrenal presentation rate of ACTH. 4. It is concluded that this peptide exerts a steroidogenic action on the adrenal cortex which is manifest in the absence of exogenous ACTH in the functionally hypophysectomized calf. PMID:2555477

  20. Calcitonin/calcitonin gene-related peptide transcription unit: tissue-specific expression involves selective use of alternative polyadenylation sites.

    PubMed Central

    Amara, S G; Evans, R M; Rosenfeld, M G

    1984-01-01

    Different 3' coding exons in the rat calcitonin gene are used to generate distinct mRNAs encoding either the hormone calcitonin in thyroidal C-cells or a new neuropeptide referred to as calcitonin gene-related peptide in neuronal tissue, indicating the RNA processing regulation is one strategy used in tissue-specific regulation of gene expression in the brain. Although the two mRNAs use the same transcriptional initiation site and have identical 5' terminal sequences, their 3' termini are distinct. The polyadenylation sites for calcitonin and calcitonin gene-related peptide mRNAs are located at the end of the exons 4 and 6, respectively. Termination of transcription after the calcitonin exon does not dictate the production of calcitonin mRNA, because transcription proceeds through both calcitonin and calcitonin gene-related peptide exons irrespective of which mRNA is ultimately produced. In isolated nuclei, both polyadenylation sites appear to be utilized; however, the proximal (calcitonin) site is preferentially used in nuclei from tissues producing calcitonin mRNA. These data suggest that the mechanism dictating production of each mRNA involves the selective use of alternative polyadenylation sites. Images PMID:6334229

  1. Inotropic and lusitropic effects of calcitonin gene-related peptide in the heart

    PubMed Central

    Al-Rubaiee, Mustafa; Gangula, Pandu R.; Millis, Richard M.; Walker, Robin K.; Umoh, Nsini A.; Cousins, Valerie M.; Jeffress, Miara A.

    2013-01-01

    Previous studies have demonstrated positive-inotropic effects of calcitonin gene-related peptide (CGRP), but the mechanisms remain unclear. Therefore, two experiments were performed to determine the physiological correlates of the positive-inotropic effects of CGRP. Treatments designed to antagonize the effects of physiologically active CGRP1–37 included posttreatment with CGRP8–37 and pretreatment with LY-294002 (LY, an inhibitor of phosphatidylinositol 3-kinase), 17β-estradiol (E), and progesterone (P) were also used to modulate the effects of CGRP1–37. Experiment 1 was in vitro studies on sarcomeres and cells of isolated adult rat cardiac myocytes. CGRP1–37, alone and in combination with E and P, decreased sarcomere shortening velocities and increased shortening percentages, effects that were antagonized by CGRP8–37, but not by LY. CGRP1–37 increased resting intracellular calcium ion concentrations and Ca2+ influxes, effects that were also antagonized by both CGRP8–37 and LY. Experiment 2 was in vivo studies on left ventricular pressure-volume (PV) loops. CGRP1–37 increased end-systolic pressure, ejection fraction, and velocities of contraction and relaxation while decreasing stroke volume, cardiac output, stroke work, PV area, and compliance. After partial occlusion of the vena cava, CGRP1–37 increased the slope of the end-systolic PV relationship. CGRP8–37 and LY attenuated most of the CGRP-induced changes. These findings suggest that CGRP-induced positive-inotropic effects may be increased by treatments with estradiol and progesterone and inhibited by LY. The physiological correlates of CGRP-induced positive inotropy observed in rat sarcomeres, cells, and intact hearts are likely to reveal novel mechanisms of heart failure in humans. PMID:23585136

  2. Endosomal proteolysis regulates calcitonin gene-related peptide responses in mesenteric arteries

    PubMed Central

    McNeish, AJ; Roux, BT; Aylett, S-B; Van Den Brink, AM; Cottrell, GS

    2012-01-01

    Background and Purpose Calcitonin gene-related peptide (CGRP) is a potent vasodilator, implicated in the pathogenesis of migraine. CGRP activates a receptor complex comprising, calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1). In vitro studies indicate recycling of CLR•RAMP1 is regulated by degradation of CGRP in early endosomes by endothelin-converting enzyme-1 (ECE-1). However, it is not known if ECE-1 regulates the resensitization of CGRP-induced responses in functional arterial tissue. Experimental Approach CLR, ECE-1a-d and RAMP1 expression in rat mesenteric artery smooth muscle cells (RMA-SMCs) and mesenteric arteries was analysed by RT-PCR and by immunofluorescence and confocal microscopy. CGRP-induced signalling in cells was examined by measuring cAMP production and ERK activation. CGRP-induced relaxation of arteries was measured by isometric wire myography. ECE-1 was inhibited using the specific inhibitor, SM-19712. Key Results RMA-SMCs and arteries contained mRNA for CLR, ECE-1a-d and RAMP1. ECE-1 was present in early endosomes of RMA-SMCs and in the smooth muscle layer of arteries. CGRP induced endothelium-independent relaxation of arteries. ECE-1 inhibition had no effect on initial CGRP-induced responses but reduced cAMP generation in RMA-SMCs and vasodilation in mesenteric arteries responses to subsequent CGRP challenges. Conclusions And Implications ECE-1 regulated the resensitization of responses to CGRP in RMA-SMCs and mesenteric arteries. CGRP-induced relaxation did not involve endothelium-derived pathways. This is the first report of ECE-1 regulating CGRP responses in SMCs and arteries. ECE-1 inhibitors may attenuate an important vasodilatory pathway, implicated in primary headaches and may represent a new therapeutic approach for the treatment of migraine. PMID:22881710

  3. Skeletal muscle microcirculatory response to rat alpha-calcitonin gene-related peptide.

    PubMed

    Arden, W A; Fiscus, R R; Beihn, L D; Derbin, M; Oremus, R; Gross, D R

    1994-07-01

    We used in vivo video microscopy to determine the effect of increasing doses of rat alpha-calcitonin gene-related peptide (rCGRP) on rat cremaster muscle arterioles in the presence or absence of the nitric oxide synthase inhibitor N-omega-nitro-L-arginine (L-NNA). Male Sprague-Dawley rats (118-148 g) were anaesthetized with pentobarbital, and neurovascularly intact cremaster muscles were imaged. Changes in the diameter, erythrocyte velocity and volume flow in second-(A2), third-(A3), and fourth-(A4) order arterioles were determined. To produce uniform arteriolar tone, the cremaster preparation was challenged with norepinephrine (NE: 10(-7) M). L-NNA (10(-4) M), which was shown to inhibit acetylcholine-(ACh: 10(-6) M) induced arteriolar dilations, was added to 16 of the preparations. Preparations were then challenged by adding cumulative log concentrations of rCGRP (10(-12)-10-7) M; n = 16) or an equivalent volume of vehicle (n = 19) to the bath. Following rCGRP challenge, arterioles were maximally dilated with 10(-5) M nitroprusside (NP). rCGRP caused significant dose-dependent increases in erythrocyte velocity and volume flow in A2 arterioles, and in diameter, velocity, and volume flow in A3 and A4 arterioles, by 10(-8) M, when compared with vehicle-treated controls. L-NNA had no significant effect on rCGRP-induced responses. These data indicate that rCGRP causes dose-dependent dilation of skeletal muscle resistance arterioles at a concentration similar to that observed in larger vessels. This dilation does not appear to be dependent on the vascular production of nitric oxide from L-arginine. PMID:7526261

  4. Phospholipase C gamma mediates endogenous brain-derived neurotrophic factor-regulated calcitonin gene-related peptide expression in colitis-induced visceral pain

    PubMed Central

    Hashmi, Fiza; Liu, Miao; Shen, Shanwei

    2016-01-01

    Background Visceral hypersensitivity is a complex pathophysiological paradigm with unclear mechanisms. Primary afferent neuronal plasticity marked by alterations in neuroactive compounds such as calcitonin gene-related peptide is suggested to underlie the heightened sensory responses. Signal transduction that leads to calcitonin gene-related peptide expression thereby sensory neuroplasticity during colitis remains to be elucidated. Results In a rat model with colitis induced by 2,4,6-trinitrobenzene sulfonic acid, we found that endogenously elevated brain-derived neurotrophic factor elicited an up-regulation of calcitonin gene-related peptide in the lumbar L1 dorsal root ganglia. At seven days of colitis, neutralization of brain-derived neurotrophic factor with a specific brain-derived neurotrophic factor antibody reversed calcitonin gene-related peptide up-regulation in the dorsal root ganglia. Colitis-induced calcitonin gene-related peptide transcription was also inhibited by brain-derived neurotrophic factor antibody treatment. Signal transduction studies with dorsal root ganglia explants showed that brain-derived neurotrophic factor-induced calcitonin gene-related peptide expression was mediated by the phospholipase C gamma, but not the phosphatidylinositol 3-kinase/Akt or the mitogen-activated protein kinase/extracellular signal-regulated protein kinase pathway. Application of PLC inhibitor U73122 in vivo confirmed that colitis-induced and brain-derived neurotrophic factor-mediated calcitonin gene-related peptide up-regulation in the dorsal root ganglia was regulated by the phospholipase C gamma pathway. In contrast, suppression of the phosphatidylinositol 3-kinase activity in vivo had no effect on colitis-induced calcitonin gene-related peptide expression. During colitis, calcitonin gene-related peptide also co-expressed with phospholipase C gamma but not with p-Akt. Calcitonin gene-related peptide up-regulation during colitis correlated to the activation

  5. Calcitonin Gene-Related Peptide Enhances Release of Native Brain-Derived Neurotrophic Factor from Trigeminal Ganglion Neurons

    PubMed Central

    Buldyrev, Ilya; Tanner, Nathan M.; Hsieh, Hui-ya; Dodd, Emily G.; Nguyen, Loi T.; Balkowiec, Agnieszka

    2008-01-01

    Activity-dependent plasticity in nociceptive pathways has been implicated in pathomechanisms of chronic pain syndromes. Calcitonin gene-related peptide (CGRP), which is expressed by trigeminal nociceptors, has recently been identified as a key player in the mechanism of migraine headaches. Here we show that CGRP is co-expressed with brain-derived neurotrophic factor (BDNF) in a large subset of adult rat trigeminal ganglion neurons in vivo. Using ELISA in situ, we show that CGRP (1–1000 nM) potently enhances BDNF release from cultured trigeminal neurons. The effect of CGRP is dose–dependent and abolished by pretreatment with CGRP receptor antagonist, CGRP(8–37). Intriguingly, CGRP-mediated BDNF release, unlike BDNF release evoked by physiological patterns of electrical stimulation, is independent of extracellular calcium. Depletion of intracellular calcium stores with thapsigargin blocks the CGRP-mediated BDNF release. Using transmission electron microscopy, our study also shows that BDNF-immunoreactivity is present in dense core vesicles of unmyelinated axons and axon terminals in the subnucleus caudalis of the spinal trigeminal nucleus, the primary central target of trigeminal nociceptors. Together, these results reveal a previously unknown role for CGRP in regulating BDNF availability, and point to BDNF as a candidate mediator of trigeminal nociceptive plasticity. PMID:17064360

  6. Calcitonin gene-related peptide enhances release of native brain-derived neurotrophic factor from trigeminal ganglion neurons.

    PubMed

    Buldyrev, Ilya; Tanner, Nathan M; Hsieh, Hui-ya; Dodd, Emily G; Nguyen, Loi T; Balkowiec, Agnieszka

    2006-12-01

    Activity-dependent plasticity in nociceptive pathways has been implicated in pathomechanisms of chronic pain syndromes. Calcitonin gene-related peptide (CGRP), which is expressed by trigeminal nociceptors, has recently been identified as a key player in the mechanism of migraine headaches. Here we show that CGRP is coexpressed with brain-derived neurotrophic factor (BDNF) in a large subset of adult rat trigeminal ganglion neurons in vivo. Using ELISA in situ, we show that CGRP (1-1000 nM) potently enhances BDNF release from cultured trigeminal neurons. The effect of CGRP is dose-dependent and abolished by pretreatment with CGRP receptor antagonist, CGRP(8-37). Intriguingly, CGRP-mediated BDNF release, unlike BDNF release evoked by physiological patterns of electrical stimulation, is independent of extracellular calcium. Depletion of intracellular calcium stores with thapsigargin blocks the CGRP-mediated BDNF release. Using transmission electron microscopy, our study also shows that BDNF-immunoreactivity is present in dense core vesicles of unmyelinated axons and axon terminals in the subnucleus caudalis of the spinal trigeminal nucleus, the primary central target of trigeminal nociceptors. Together, these results reveal a previously unknown role for CGRP in regulating BDNF availability, and point to BDNF as a candidate mediator of trigeminal nociceptive plasticity. PMID:17064360

  7. [The pharmacological mechanism of gastrodin on calcitonin gene-related peptide of cultured rat trigeminal ganglion].

    PubMed

    Luo, Guo-Gang; Fan, Wen-Jing; Yuan, Xing-Yun; Yuan, Bo-Bo; Lü, She-Min; Cao, Yong-Xiao; Xu, Cang-Bao

    2011-12-01

    The Chinese herbal medicine Tianma (Gastrodia elata) has been used for treating and preventing primary headache over thousands of years, but the exact pharmacological mechanism of the main bioactive ingredient gastrodin remains unclear. In present study, the effects of gastrodin on calcitonin gene-related peptide (CGRP) and phosphorylated extracellular signal-regulated kinase1/2 (pERK1/2) expression were observed in rat trigeminal ganglion (TG) after in vitro organ culture to explore the underlying intracellular mechanism of gastrodin on primary vascular-associated headache. CGRP-immunoreactivity (CGRP-ir) positive neurons count, positive area, mean optical density and integrated optical density by means of immunohistochemistry stain were compared at different concentrations of gastrodin, which was separately co-incubated with DMEM in SD rat TG for 24 hours. Only at 5 or 10 mmol L(-1) concentration, gastrodin demonstrated significantly concentration-dependent reduction of CGRP-ir (+) expression and its action closed to 1.2 mmol L(-1) sumatriptan succinate. While at 2.5, 20, and 40 mmol L(-1) concentration, gastrodin did not show remarkable effects on CGRP-ir (+) expression. The optimal concentration of gastrodin (5 and 10 mmol L(-1)) similarly inhibited CGRP-mRNA expression level separately compared with 1.2 mmol L(-1) sumatriptan succinate and 10 micromol L(-1) flunarizine hydrochloride, which was quantitatively analyzed by real-time PCR (RT-PCR). pERK1/2 level was examined by Western blotting after co-cultured with optimal concentration of gastrodin and effective specific ERK1/2 pathway inhibitors PD98059, U0126. The result indicated that gastrodin significantly reduced pERK1/2 protein actions similarly to ERK1/2 pathway specific blockade. It suggests ERK1/2 signaling transduction pathway may be involved in gastrodin intracellular mechanism. This study indicates gastrodin (5 and 10 mmol L(-1)) can remarkably reduce CGRP-ir (+) neuron, CGRP-mRNA and pERK1

  8. Calcitonin gene-related peptide activated ATP-sensitive K+ currents in rabbit arterial smooth muscle via protein kinase A.

    PubMed Central

    Quayle, J M; Bonev, A D; Brayden, J E; Nelson, M T

    1994-01-01

    1. Whole-cell K+ currents activated by calcitonin gene-related peptide (CGRP) in smooth muscle cells enzymatically isolated from rabbit mesenteric arteries were measured in the conventional and perforated configurations of the patch clamp technique. The signal transduction pathway from CGRP receptors to activation of potassium currents was investigated. 2. CGRP (10 nM) activated a whole-cell current that was blocked by glibenclamide (10 microM), an inhibitor of ATP-sensitive K+ channels. Elevating intracellular ATP reduced glibenclamide-sensitive currents. CGRP increased the glibenclamide-sensitive currents by 3- to 6-fold in cells dialysed with 0.1 mM ATP, 3.0 mM ATP or in intact cells. The reversal potential of the glibenclamide-sensitive current in the presence of CGRP shifted with the potassium equilibrium potential, while its current-voltage relationship exhibited little voltage dependence. 3. Forskolin (10 microM), an adenylyl cyclase activator, Sp-cAMPS (500 microM) and the catalytic subunit of protein kinase A increased glibenclamide-sensitive K+ currents 2.1-, 3.3- and 8.2-fold, respectively. 4. Nitric oxide and nitroprusside did not activate glibenclamide-sensitive K+ currents. 5. Dialysis of the cell's interior with inhibitors of protein kinase A (synthetic peptide inhibitor, 4.6 microM or H-8, 100 microM) completely blocked activation of K+ currents by CGRP. 6. Our results suggest the following signal transduction scheme for activation of K+ currents by CGRP in arterial smooth muscle: (1) CGRP stimulates adenylyl cyclase, which leads to an elevation of cAMP; (2) cAMP activates protein kinase A, which opens ATP-sensitive K+ channels. PMID:8189394

  9. Demonstration of the neurotransmitter role of calcitonin gene-related peptides (CGRP) by immunoblockade with anti-CGRP monoclonal antibodies.

    PubMed Central

    Tan, K. K.; Brown, M. J.; Longmore, J.; Plumpton, C.; Hill, R. G.

    1994-01-01

    1. Monoclonal antibodies (MAbs) against rat alpha-calcitonin gene-related peptide (alpha CGRP) were produced. Those which bound CGRP in a radioimmunoassay and inhibited the binding of 2-[125I]-iodohistidyl10-CGRP in a receptor binding assay were selected for immunoblockade experiments. 2. The effect of MAbs on CGRP inhibition of electrically stimulated contractions of the rat isolated vas deferens was characterized. Four out of 11 MAbs tested shifted the concentration-response curve of CGRP to the right compared with vehicle or irrelevant MAb control. MAb C4.19 produced equipotent blockade of rat alpha CGRP and rat beta CGRP and was chosen for further studies. MAb C4.19 had no pharmacologically significant effect on the concentration-response relationship of isoprenaline, rat beta-endorphin or somatostatin. 3. We demonstrated that the pharmacological response to CGRP in the presence of MAb C4.19 could be predicted when the dissociation constant and concentration of binding sites of the antibody were known. Comparison of experimental and computer simulated data showed good agreement for EC50 and maximum effect of CGRP in the presence of MAb C4.19. 4. Capsaicin at 1 microM inhibited the electrically stimulated contractions by 60.8% (95% confidence interval 51.8% to 69.9%). This effect was significantly attenuated by MAb C4.19 to 26.0% (95% confidence interval 15.2% to 36.8%; P < 0.003). 5. The immunoblockade of exogenous and endogenous CGRP described here, together with complementary evidence from other studies, strongly suggest that CGRP has a major neurotransmitter role at the neuroeffector junction of the rat vas deferens. PMID:7912623

  10. Pharmacologic Characterization of AMG 334, a Potent and Selective Human Monoclonal Antibody against the Calcitonin Gene-Related Peptide Receptor.

    PubMed

    Shi, Licheng; Lehto, Sonya G; Zhu, Dawn X D; Sun, Hong; Zhang, Jianhua; Smith, Brian P; Immke, David C; Wild, Kenneth D; Xu, Cen

    2016-01-01

    Therapeutic agents that block the calcitonin gene-related peptide (CGRP) signaling pathway are a highly anticipated and promising new drug class for migraine therapy, especially after reports that small-molecule CGRP-receptor antagonists are efficacious for both acute migraine treatment and migraine prevention. Using XenoMouse technology, we successfully generated AMG 334, a fully human monoclonal antibody against the CGRP receptor. Here we show that AMG 334 competes with [(125)I]-CGRP binding to the human CGRP receptor, with a Ki of 0.02 nM. AMG 334 fully inhibited CGRP-stimulated cAMP production with an IC50 of 2.3 nM in cell-based functional assays (human CGRP receptor) and was 5000-fold more selective for the CGRP receptor than other human calcitonin family receptors, including adrenomedullin, calcitonin, and amylin receptors. The potency of AMG 334 at the cynomolgus monkey (cyno) CGRP receptor was similar to that at the human receptor, with an IC50 of 5.7 nM, but its potency at dog, rabbit, and rat receptors was significantly reduced (>5000-fold). Therefore, in vivo target coverage of AMG 334 was assessed in cynos using the capsaicin-induced increase in dermal blood flow model. AMG 334 dose-dependently prevented capsaicin-induced increases in dermal blood flow on days 2 and 4 postdosing. These results indicate AMG 334 is a potent, selective, full antagonist of the CGRP receptor and show in vivo dose-dependent target coverage in cynos. AMG 334 is currently in clinical development for the prevention of migraine. PMID:26559125

  11. Calcitonin gene-related peptide inhibits autophagic-lysosomal proteolysis through cAMP/PKA signaling in rat skeletal muscles.

    PubMed

    Machado, Juliano; Manfredi, Leandro H; Silveira, Wilian A; Gonçalves, Dawit A P; Lustrino, Danilo; Zanon, Neusa M; Kettelhut, Isis C; Navegantes, Luiz C

    2016-03-01

    Calcitonin gene-related peptide (CGRP) is a neuropeptide released by motor neuron in skeletal muscle and modulates the neuromuscular transmission by induction of synthesis and insertion of acetylcholine receptor on postsynaptic muscle membrane; however, its role in skeletal muscle protein metabolism remains unclear. We examined the in vitro and in vivo effects of CGRP on protein breakdown and signaling pathways in control skeletal muscles and muscles following denervation (DEN) in rats. In isolated muscles, CGRP (10(-10) to 10(-6)M) reduced basal and DEN-induced activation of overall proteolysis in a concentration-dependent manner. The in vitro anti-proteolytic effect of CGRP was completely abolished by CGRP8-37, a CGRP receptor antagonist. CGRP down-regulated the lysosomal proteolysis, the mRNA levels of LC3b, Gabarapl1 and cathepsin L and the protein content of LC3-II in control and denervated muscles. In parallel, CGRP elevated cAMP levels, stimulated PKA/CREB signaling and increased Foxo1 phosphorylation in both conditions. In denervated muscles and starved C2C12 cells, Rp-8-Br-cAMPs or PKI, two PKA inhibitors, completely abolished the inhibitory effect of CGRP on Foxo1, 3 and 4 and LC3 lipidation. A single injection of CGRP (100 μg kg(-1)) in denervated rats increased the phosphorylation levels of CREB and Akt, inhibited Foxo transcriptional activity, the LC3 lipidation as well as the mRNA levels of LC3b and cathepsin L, two bona fide targets of Foxo. This study shows for the first time that CGRP exerts a direct inhibitory action on autophagic-lysosomal proteolysis in control and denervated skeletal muscle by recruiting cAMP/PKA signaling, effects that are related to inhibition of Foxo activity and LC3 lipidation. PMID:26718975

  12. Effects of Voluntary Locomotion and Calcitonin Gene-Related Peptide on the Dynamics of Single Dural Vessels in Awake Mice

    PubMed Central

    Gao, Yu-Rong

    2016-01-01

    The dura mater is a vascularized membrane surrounding the brain and is heavily innervated by sensory nerves. Our knowledge of the dural vasculature has been limited to pathological conditions, such as headaches, but little is known about the dural blood flow regulation during behavior. To better understand the dynamics of dural vessels during behavior, we used two-photon laser scanning microscopy (2PLSM) to measure the diameter changes of single dural and pial vessels in the awake mouse during voluntary locomotion. Surprisingly, we found that voluntary locomotion drove the constriction of dural vessels, and the dynamics of these constrictions could be captured with a linear convolution model. Dural vessel constrictions did not mirror the large increases in intracranial pressure (ICP) during locomotion, indicating that dural vessel constriction was not caused passively by compression. To study how behaviorally driven dynamics of dural vessels might be altered in pathological states, we injected the vasodilator calcitonin gene-related peptide (CGRP), which induces headache in humans. CGRP dilated dural, but not pial, vessels and significantly reduced spontaneous locomotion but did not block locomotion-induced constrictions in dural vessels. Sumatriptan, a drug commonly used to treat headaches, blocked the vascular and behavioral the effects of CGRP. These findings suggest that, in the awake animal, the diameters of dural vessels are regulated dynamically during behavior and during drug-induced pathological states. SIGNIFICANT STATEMENT The vasculature of the dura has been implicated in the pathophysiology of headaches, but how individual dural vessels respond during behavior, both under normal conditions and after treatment with the headache-inducing peptide calcitonin gene-related peptide (CGRP), is poorly understood. To address these issues, we imaged individual dural vessels in awake mice and found that dural vessels constricted during voluntary locomotion, and

  13. Studies on rat and human thymus to demonstrate immunoreactivity of calcitonin gene-related peptide, tyrosine hydroxylase and neuropeptide Y

    PubMed Central

    KRANZ, ANDREA; KENDALL, MARION D.; VON GAUDECKER, BRITA

    1997-01-01

    The peptidergic and noradrenergic innervation of rat and human thymus was investigated by immunohistochemistry at the light and electron microscopical level (avidin-biotin-complex, sucrose-phosphate-glyoxylic-acid, and immunogold techniques). The distribution of noradrenergic neural profiles, and positive immunoreactivity for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH) and neuropeptide Y (NPY) is described in female rats during ageing, and in human children. In the neonatal rat thymus, the arteries and septa are well supplied by fine varicose nerves. In older animals (2 wk–1 y) the number of septa and blood vessels increase and consequently also the innervation. No nerves were found in the cortex. Apart from the innervation of the septal areas, immunoreactivity for CGRP and TH was present in thymic cells. Except for the young rats (neonatal–14 d), all rats showed CGRP positivity in subcapsular/perivascular epithelial cells (type 1 cells). All rat thymuses also contained a few TH positive cells in the medulla, which could only be confirmed as epithelial cells (type 6 cells) in children. Type 1 cells in the human thymus were not CGRP positive, but as in the rat, there were similar TH positive cells in the medulla. It was concluded that in addition to nerves containing CGRP, noradrenaline or dopamine, epithelial cells also contain these transmitters. They could therefore act on different cells (compared with neural targets) in a paracrine manner. PMID:9419001

  14. Control of calcitonin/calcitonin gene-related peptide pre-mRNA processing by constitutive intron and exon elements.

    PubMed Central

    Yeakley, J M; Hedjran, F; Morfin, J P; Merillat, N; Rosenfeld, M G; Emeson, R B

    1993-01-01

    The calcitonin/calcitonin gene-related peptide (CGRP) primary transcript is alternatively spliced in thyroid C cells and neurons, resulting in the tissue-specific production of calcitonin and CGRP mRNAs. Analyses of mutated calcitonin/CGRP transcription units in permanently transfected cell lines have indicated that alternative splicing is regulated by a differential capacity to utilize the calcitonin-specific splice acceptor. The analysis of an extensive series of mutations suggests that tissue-specific regulation of calcitonin mRNA production does not depend on the presence of a single, unique cis-active element but instead appears to be a consequence of suboptimal constitutive splicing signals. While only those mutations that altered constitutive splicing signals affected splice choices, the action of multiple regulatory sequences cannot be formally excluded. Further, we have identified a 13-nucleotide purine-rich element from a constitutive exon that, when placed in exon 4, entirely switches splice site usage in CGRP-producing cells. These data suggest that specific exon recruitment sequences, in combination with other constitutive elements, serve an important function in exon recognition. These results are consistent with the hypothesis that tissue-specific alternative splicing of the calcitonin/CGRP primary transcript is mediated by cell-specific differences in components of the constitutive splicing machinery. Images PMID:8413203

  15. Role of calcitonin gene-related peptide in cerebral vasospasm, and as a therapeutic approach to subarachnoid hemorrhage

    PubMed Central

    Kokkoris, Stelios; Andrews, Peter; Webb, David J.

    2012-01-01

    Calcitonin gene-related peptide (CGRP) is one of the most potent microvascular vasodilators identified to date. Vascular relaxation and vasodilation is mediated via activation of the CGRP receptor. This atypical receptor is made up of a G protein-coupled receptor called calcitonin receptor-like receptor (CLR), a single transmembrane protein called receptor activity-modifying protein (RAMP), and an additional protein that is required for Gas coupling, known as receptor component protein (RCP). Several mechanisms involved in CGRP-mediated relaxation have been identified. These include nitric oxide (NO)-dependent endothelium-dependent mechanisms or cAMP-mediated endothelium-independent pathways; the latter being more common. Subarachnoid hemorrhage (SAH) is associated with cerebral vasoconstriction that occurs several days after the hemorrhage and is often fatal. The vasospasm occurs in 30–40% of patients and is the major cause of death from this condition. The vasoconstriction is associated with a decrease in CGRP levels in nerves and an increase in CGRP levels in draining blood, suggesting that CGRP is released from nerves to oppose the vasoconstriction. This evidence has led to the concept that exogenous CGRP may be beneficial in a condition that has proven hard to treat. The present article reviews: (a) the pathophysiology of delayed ischemic neurologic deficit after SAH (b) the basics of the CGRP receptor structure, signal transduction, and vasodilatation mechanisms and (c) the studies that have been conducted so far using CGRP in both animals and humans with SAH. PMID:23162536

  16. Calcitonin Gene-Related Peptide Modulates Heat Nociception in the Human Brain - An fMRI Study in Healthy Volunteers

    PubMed Central

    Asghar, Mohammad Sohail; Becerra, Lino; Larsson, Henrik B. W.; Borsook, David; Ashina, Messoud

    2016-01-01

    Background Intravenous infusion of calcitonin-gene-related-peptide (CGRP) provokes headache and migraine in humans. Mechanisms underlying CGRP-induced headache are not fully clarified and it is unknown to what extent CGRP modulates nociceptive processing in the brain. To elucidate this we recorded blood-oxygenation-level-dependent (BOLD) signals in the brain by functional MRI after infusion of CGRP in a double-blind placebo-controlled crossover study of 27 healthy volunteers. BOLD-signals were recorded in response to noxious heat stimuli in the V1-area of the trigeminal nerve. In addition, we measured BOLD-signals after injection of sumatriptan (5-HT1B/1D antagonist). Results Brain activation to noxious heat stimuli following CGRP infusion compared to baseline resulted in increased BOLD-signal in insula and brainstem, and decreased BOLD-signal in the caudate nuclei, thalamus and cingulate cortex. Sumatriptan injection reversed these changes. Conclusion The changes in BOLD-signals in the brain after CGRP infusion suggests that systemic CGRP modulates nociceptive transmission in the trigeminal pain pathways in response to noxious heat stimuli. PMID:26990646

  17. Cells showing immunoreactivity for calcitonin or calcitonin gene-related peptide (CGRP) in the central nervous system of some invertebrates.

    PubMed

    Sasayama, Y; Katoh, A; Oguro, C; Kambegawa, A; Yoshizawa, H

    1991-09-01

    In the central nervous system of some species of several invertebrate phyla, including land planarians (Platyhelminthes), ribbon worms (Nemertina), slugs (Mollusca), polychaetes, earthworms and leeches (Annelida), pill bugs (Arthropoda), and beard worms (Pogonophora), salmon calcitonin-immunoreactive cells and rat calcitonin gene-related peptide (CGRP)-immunoreactive cells were found by immunohistochemistry. These immunoreactive cells were located in the region surrounding the neuropile, although the sizes of the cells varied according to species. Some of them were round or polygonal and regarded as apolar nerve cells because of their lack of cytoplasmic processes, whereas others were spindle-shaped or elongated, being comparable with unipolar nerve cells because of extension of their cytoplasmic processes in the direction of the neuropile. In some cases, it was noted that the cytoplasmic processes had complicated branches or formed loop-like structures at their ends. These observations suggest that a calcitonin-like or CGRP-like substance is extensively present in invertebrates as well as vertebrates. PMID:1936921

  18. Reductions in calcitonin gene-related peptide may be associated with the impairment of the contralateral testis in unilateral cryptorchidism

    PubMed Central

    ZHU, BAOPING; LIU, QING; LIN, LI; ZHENG, XINMIN

    2015-01-01

    The aim of the present study was to investigate the mechanism underlying the impairment of the contralateral testis in unilateral cryptorchidism in experimental rats using a molecular neurophysiological approach. Thirty-six male rats (21 days old) were divided into a cryptorchidism group, a cryptorchidism with division of the genitofemoral nerve (GFN) group and a control group (n=12/group). The distribution of the calcitonin gene-related peptide (CGRP) immunoreactive nerve fibers in the testes was studied using an immunohistochemistry technique. Germ cell apoptosis was detected using the terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling method. The concentration of malondialdehyde (MDA) in the testis tissue was evaluated using a spectrophotometric determination method, and the ultrastructure of Sertoli cells was observed using transmission electron microscopy. It was found that, 100 days after the surgery, the concentration of CGRP in the cryptorchidism group was decreased significantly, whereas the levels of MDA and the number of apoptotic germ cells were increased significantly compared with the control group (P<0.01). Following the division of the GFN, the damaging effects were decreased (P<0.01). The impairment mechanism may therefore be associated with a reduction in the level of CGRP in the contralateral testis. The reflex decrease in CGRP may be caused by germ cell apoptosis, decreased blood flow and oxygen levels, and the increase in reactive oxygen free radicals and lipid peroxidation. PMID:26136895

  19. Interaction of histamine and calcitonin gene-related peptide in the formalin induced pain perception in rats.

    PubMed

    Mobarakeh, Jalal Izadi; Torkaman-Boutorabi, Anahita; Rahimi, Amir Abbas; Ghasri, Shahrooz; Nezhad, Reza Mohammad Ali; Hamzely, Arash; Khoshkholgh Sima, Baharak; Takahashi, Kazuhiro; Nunoki, Kazuo; Yanai, Kazuhiko

    2011-06-01

    Histamine and calcitonin gene-related peptide (CGRP) contribute to the pain perception. The aim of the present study is to clarify the interaction of histamine and CGRP in the perception of inflammatory pain. The effects of a histamine H1 receptor antagonist (pyrilamine, i.p.), an H2 receptor antagonist (ranitidine, i.p.) and a CGRP antagonist (CGRP 8-37, i.t.) on the formalininduced pain was studied in rats. Pyrilamine and ranitidine produced a dose-dependent antinociceptive response in the first and the second phases of the formalin test. A single administration of pyrilamine (1 mg/kg, i.p.), ranitidine (10 mg/kg, i.p.) or CGRP 8-37 (10 µg/µL, i.t.) had no significant effects on the pain perception in the second phase. A combination of CGRP 8-37 and pyrilamine or ranitidine at these sub-effective doses, however, showed nociceptive response in the second phase. Moreover, a histamine (i.t.)-induced hyperalgesia was completely prevented by treatment with GGRP 8-37 at this dose. Our findings have raised the possibility that the CGRP system has interaction with histamine in the perception of inflammatory pain. PMID:21673449

  20. Immunohistochemical localization of the calcitonin gene-related peptide binding site in the primate trigeminovascular system using functional antagonist antibodies.

    PubMed

    Miller, Silke; Liu, Hantao; Warfvinge, Karin; Shi, Licheng; Dovlatyan, Mary; Xu, Cen; Edvinsson, Lars

    2016-07-22

    Calcitonin gene-related peptide (CGRP) is a potent vasodilator and a neuromodulator implicated in the pathophysiology of migraine. It binds to the extracellular domains of calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein (RAMP) 1 that together form the CGRP receptor. Antagonist antibodies against CGRP and its binding site at the receptor are clinically effective in preventing migraine attacks. The blood-brain barrier penetration of these antagonist antibodies is limited, suggesting that a potential peripheral site of action is sufficient to prevent migraine attacks. To further understand the sites of CGRP-mediated signaling in migraine, we used immunohistochemical staining with recently developed antagonist antibodies specifically recognizing a fusion protein of the extracellular domains of RAMP1 and CLR that comprise the CGRP binding pocket at the CGRP receptor in monkey and man. We confirmed binding of the antagonist antibodies to human vascular smooth muscle cells (VSMCs) of dural meningeal arteries and neurons in the trigeminal ganglion, both of which are likely sites of action for therapeutic antibodies in migraine patients. We further used one of these antibodies for detailed mapping on cynomolgus monkey tissue and found antagonist antibody binding sites at multiple levels in the trigeminovascular system: in the dura mater VSMCs, in neurons and satellite glial cells in the trigeminal ganglion, and in neurons in the spinal trigeminal nucleus caudalis. These data reinforce and clarify our understanding of CGRP receptor localization in a pattern consistent with a role for CGRP receptors in trigeminal sensitization and migraine pathology. PMID:27155150

  1. Nitric oxide synthase inhibitors can antagonize neurogenic and calcitonin gene-related peptide induced dilation of dural meningeal vessels

    PubMed Central

    Akerman, S; Williamson, D J; Kaube, H; Goadsby, P J

    2002-01-01

    The detailed pathophysiology of migraine is beginning to be understood and is likely to involve activation of trigeminovascular afferents. Clinically effective anti-migraine compounds are believed to have actions that include peripheral inhibition of calcitonin gene-related peptide (CGRP) release from trigeminal neurones, or preventing dural vessel dilation, or both. CGRP antagonists can block both neurogenic and CGRP-induced dural vessel dilation. Nitric oxide (NO) can induce headache in migraine patients and often triggers a delayed migraine. The initial headache is thought to be caused via a direct action of the NO–cGMP pathway that causes vasodilation by vascular smooth muscle relaxation, while the delayed headache is likely to be a result of triggering trigeminovascular activation. Nitric oxide synthase (NOS) inhibitors are effective in the treatment of acute migraine. The present studies used intravital microscopy to examine the effects of specific NOS inhibitors on neurogenic dural vasodilation (NDV) and CGRP-induced dilation. The non-specific and neuronal NOS (nNOS) inhibitors were able to partially inhibit NDV, while the non-specific and endothelial NOS (eNOS) inhibitors were able to partially inhibit the CGRP induced dilation. There was no effect of the inducible NOS (iNOS) inhibitor. The data suggest that the delayed headache response triggered by NO donors in humans may be due, in part, to increased nNOS activity in the trigeminal system that causes CGRP release and dural vessel dilation. Further, eNOS activity in the endothelium causes NO production and smooth muscle relaxation by direct activation of the NO–cGMP pathway, and may be involved in the initial headache response. PMID:12183331

  2. Flupirtine inhibits calcitonin-gene related peptide release from rat brainstem in vitro.

    PubMed

    Tringali, Giuseppe; Greco, Maria Cristina; Capuano, Alessandro; Guerriero, Giuseppe; Currò, Diego; Navarra, Pierluigi

    2012-01-11

    We have previously shown that the nonopioid analgesic flupirtine possesses analgesic activity in the orofacial formalin test in vivo in the rat. However, this paradigm does not allow to distinguish between central and peripheral site of action of the drug. In this study we used a recently characterized in vitro model, consisting in acute rat brainstem explants, to investigate whether flupirtine analgesia may be, at least in part, attributed to interference with neurotransmission between the first and the second order neurons of the trigeminal system, occurring within the brainstem. We used acute rat brainstem explants; CGRP released into the incubation medium was taken as a marker of CGRP release from central terminals of trigeminal ganglion afferent neurons within the brainstem. CGRP levels were measured by radioimmunoassay under basal conditions or in the presence of flupirtine, alone or with putative antagonist XE-991. We found that flupirtine inhibits in a concentration-dependent manner both basal and capsaicin-stimulated CGRP release from rat brainstem. This effect is mimicked by the flupirtine analogue retigabine, and is counteracted by the Kv7 blocker XE-991. These findings provide in vitro evidence that the analgesic activity of flupirtine may be related to interference with pain neurotransmission at the brainstem level. Pharmacological data suggests that such effect is related to opening of Kv7 channels on first-order neuronal nerve ending, and the subsequent inhibition of neurotransmitter release, since the effect is mimicked by the Kv7 opener retigabine and is counteracted by the Kv7 blocker XE-991. PMID:22155095

  3. Hydrogen sulfide inhibits opioid withdrawal-induced pain sensitization in rats by down-regulation of spinal calcitonin gene-related peptide expression in the spine.

    PubMed

    Yang, Hai-Yu; Wu, Zhi-Yuan; Bian, Jin-Song

    2014-09-01

    Hyperalgesia often occurs in opioid-induced withdrawal syndrome. In the present study, we found that three hourly injections of DAMGO (a μ-opioid receptor agonist) followed by naloxone administration at the fourth hour significantly decreased rat paw nociceptive threshold, indicating the induction of withdrawal hyperalgesia. Application of NaHS (a hydrogen sulfide donor) together with each injection of DAMGO attenuated naloxone-precipitated withdrawal hyperalgesia. RT-PCR and Western blot analysis showed that NaHS significantly reversed the gene and protein expression of up-regulated spinal calcitonin gene-related peptide (CGRP) in naloxone-treated animals. NaHS also inhibited naloxone-induced cAMP rebound and cAMP response element-binding protein (CREB) phosphorylation in rat spinal cord. In SH-SY5Y neuronal cells, NaHS inhibited forskolin-stimulated cAMP production and adenylate cyclase (AC) activity. Moreover, NaHS pre-treatment suppressed naloxone-stimulated activation of protein kinase C (PKC) α, Raf-1, and extracellular signal-regulated kinase (ERK) 1/2 in rat spinal cord. Our data suggest that H2S prevents the development of opioid withdrawal-induced hyperalgesia via suppression of synthesis of CGRP in spine through inhibition of AC/cAMP and PKC/Raf-1/ERK pathways. PMID:24824948

  4. Involvement of calcitonin gene-related peptide and CCL2 production in CD40-mediated behavioral hypersensitivity in a model of neuropathic pain

    PubMed Central

    MALON, JENNIFER T.; MADDULA, SWATHI; BELL, HARMONY; CAO, LING

    2014-01-01

    The neuropeptide calcitonin gene-related peptide (CGRP) is known to play a pro-nociceptive role after peripheral nerve injury upon its release from primary afferent neurons in preclinical models of neuropathic pain. We previously demonstrated a critical role for spinal cord microglial CD40 in the development of spinal nerve L5 transection (L5Tx)-induced mechanical hypersensitivity. Herein, we investigated whether CGRP is involved in the CD40-mediated behavioral hypersensitivity. First, L5Tx was found to significantly induce CGRP expression in wild-type (WT) mice up to 14 days post-L5Tx. This increase in CGRP expression was reduced in CD40 knockout (KO) mice at day 14 post-L5Tx. Intrathecal injection of the CGRP antagonist CGRP8–37 significantly blocked L5Tx-induced mechanical hypersensitivity. In vitro, CGRP induced glial IL-6 and CCL2 production, and CD40 stimulation added to the effects of CGRP in neonatal glia. Further, there was decreased CCL2 production in CD40 KO mice compared to WT mice 21 days post-L5Tx. However, CGRP8–37 did not significantly affect spinal cord CCL2 production following L5Tx in WT mice. Altogether, these data suggest that CD40 contributes to the maintenance of behavioral hypersensitivity following peripheral nerve injury in part through two distinct pathways, the enhancement of CGRP expression and spinal cord CCL2 production. PMID:22377050

  5. Identification of specific calcitonin-like receptor residues important for calcitonin gene-related peptide high affinity binding

    PubMed Central

    Banerjee, Sugato; Evanson, Janel; Harris, Erik; Lowe, Stephen L; Thomasson, Kathryn A; Porter, James E

    2006-01-01

    Background Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide whose biological activity has potential therapeutic value for many vascular related diseases. CGRP is a 37 amino acid neuropeptide that signals through a G protein-coupled receptor belonging to the secretin receptor family. Previous studies on the calcitonin-like receptor (CLR), which requires co-expression of the receptor-activity-modifying protein-1 (RAMP1) to function as a CGRP receptor, have shown an 18 amino acid N-terminus sequence important for binding CGRP. Moreover, several investigations have recognized the C-terminal amidated phenylalanine (F37) of CGRP as essential for docking to the mature receptor. Therefore, we hypothesize that hydrophobic amino acids within the previously characterized 18 amino acid CLR N-terminus domain are important binding contacts for the C-terminal phenylalaninamide of CGRP. Results Two leucine residues within this previously characterized CLR N-terminus domain, when mutated to alanine and expressed on HEK293T cells stably transfected with RAMP1, demonstrated a significantly decreased binding affinity for CGRP compared to wild type receptor. Additional decreases in binding affinity for CGRP were not found when both leucine mutations were expressed in the same CLR construct. Decreased binding characteristic of these leucine mutant receptors was observed for all CGRP ligands tested that contained the necessary amidated phenylalanine at their C-terminus. However, there was no difference in the potency of CGRP to increase cAMP production by these leucine mutant receptors when compared to wild type CLR, consistent with the notion that the neuropeptide C-terminal F37 is important for docking but not activation of the receptor. This observation was conserved when modified CGRP ligands lacking the amidated F37 demonstrated similar potencies to generate cAMP at both wild type and mutant CLRs. Furthermore, these modified CGRP ligands displayed a significant

  6. Effect of vasoactive peptides in Tetrahymena: chemotactic activities of adrenomedullin, proadrenomedullin N-terminal 20 peptide (PAMP) and calcitonin gene-related peptide (CGRP).

    PubMed

    Kőhidai, László; Tóth, Katalin; Samotik, Paul; Ranganathan, Kiran; Láng, Orsolya; Tóth, Miklós; Ruskoaho, Heikki

    2016-01-01

    Adrenomedullin (AMD), proadrenomedullin N-terminal 20 peptide (PAMP) and calcitonin gene-related peptide (CGRP) were studied for chemotaxis, chemotactic selection and G-actin/F-actin transition in Tetrahymena. The aim of the experiments was to study the effects of two different peptides encoded by the same gene compared to a peptide related to one of the two, but encoded by a different gene, at a low level of phylogeny. The positive, chemotactic effect of ADM and the strong negative, chemorepellent effect of PAMP suggest that in Tetrahymena, the two peptides elicit their chemotactic effects via different signalling mechanisms. The complexity of swimming behaviour modulated by the three peptides underlines that chemotaxis, chemokinesis and some characteristics of migratory behaviour (velocity, tortuosity) are working as a sub-population level complex functional unit. Chemotactic responsiveness to ADM and CGRP is short-term, in contrast to PAMP, which as a chemorepellent ligand, has the ability to select sub-populations with negative chemotactic responsiveness. The different effects of ADM and PAMP on the polymerization of actin networks show that the microtubular structure of cilia is more essential to chemotactic response than are transitions of the actin network. The results draw attention to the characteristic effects of vasoactive peptides at this low level of phylogeny. PMID:26481478

  7. Calcitonin gene-related peptide promotes the expression of osteoblastic genes and activates the WNT signal transduction pathway in bone marrow stromal stem cells

    PubMed Central

    ZHOU, RI; YUAN, ZHI; LIU, JIERONG; LIU, JIAN

    2016-01-01

    Calcitonin gene-related peptide (CGRP) is known to induce osteoblastic differentiation and alkaline phosphatase activity in bone marrow stromal stem cells (BMSCs). However, it has remained elusive whether this effect is mediated by CGRP receptors directly or whether other signaling pathways are involved. The present study assessed the possible involvement of the Wnt/β-catenin signaling pathway in the activation of CGRP signaling during the differentiation of BMSCs. First, the differentiation of BMSCs was induced in vitro and the expression of CGRP receptors was examined by western blot analysis. The effects of exogenous CGRP and LiCl, a stimulator of the Wnt/β-catenin signaling pathway, on the osteoblastic differentiation of BMSCs were assessed; furthermore, the expression of mRNA and proteins involved in the Wnt/β-catenin signaling pathway was assessed using quantitative PCR and western blot analyses. The results revealed that CGRP receptors were expressed throughout the differentiation of BMSCs, at days 7 and 14. Incubation with CGRP and LiCl led to the upregulation of the expression of osteoblastic genes associated with the Wnt/β-catenin pathway, including the mRNA of c-myc, cyclin D1, Lef1, Tcf7 and β-catenin as well as β-catenin protein. However, the upregulation of these genes and β-catenin protein was inhibited by CGRP receptor antagonist or secreted frizzled-related protein, an antagonist of the Wnt/β-catenin pathway. The results of the present study therefore suggested that the Wnt/β-catenin signaling pathway may be involved in CGRP- and LiCl-promoted osteoblastic differentiation of BMSCs. PMID:27082317

  8. Calcitonin gene-related peptide promotes the expression of osteoblastic genes and activates the WNT signal transduction pathway in bone marrow stromal stem cells.

    PubMed

    Zhou, Ri; Yuan, Zhi; Liu, Jierong; Liu, Jian

    2016-06-01

    Calcitonin gene-related peptide (CGRP) is known to induce osteoblastic differentiation and alkaline phosphatase activity in bone marrow stromal stem cells (BMSCs). However, it has remained elusive whether this effect is mediated by CGRP receptors directly or whether other signaling pathways are involved. The present study assessed the possible involvement of the Wnt/β‑catenin signaling pathway in the activation of CGRP signaling during the differentiation of BMSCs. First, the differentiation of BMSCs was induced in vitro and the expression of CGRP receptors was examined by western blot analysis. The effects of exogenous CGRP and LiCl, a stimulator of the Wnt/β‑catenin signaling pathway, on the osteoblastic differentiation of BMSCs were assessed; furthermore, the expression of mRNA and proteins involved in the Wnt/β‑catenin signaling pathway was assessed using quantitative PCR and western blot analyses. The results revealed that CGRP receptors were expressed throughout the differentiation of BMSCs, at days 7 and 14. Incubation with CGRP and LiCl led to the upregulation of the expression of osteoblastic genes associated with the Wnt/β‑catenin pathway, including the mRNA of c‑myc, cyclin D1, Lef1, Tcf7 and β‑catenin as well as β‑catenin protein. However, the upregulation of these genes and β‑catenin protein was inhibited by CGRP receptor antagonist or secreted frizzled‑related protein, an antagonist of the Wnt/β‑catenin pathway. The results of the present study therefore suggested that the Wnt/β-catenin signaling pathway may be involved in CGRP‑ and LiCl-promoted osteoblastic differentiation of BMSCs. PMID:27082317

  9. Identification of N-terminal receptor activity-modifying protein residues important for calcitonin gene-related peptide, adrenomedullin, and amylin receptor function.

    PubMed

    Qi, Tao; Christopoulos, George; Bailey, Richard J; Christopoulos, Arthur; Sexton, Patrick M; Hay, Debbie L

    2008-10-01

    Calcitonin-family receptors comprise calcitonin receptor-like receptor (CL) or calcitonin receptor and receptor activity-modifying protein (RAMP) pairings. Calcitonin gene-related peptide (CGRP) receptors are CL/RAMP1, whereas adrenomedullin (AM) receptors are CL/RAMP2 (AM1 receptor) or CL/RAMP3 (AM2 receptor). Amylin (Amy) receptors are RAMP hetero-oligomers with the calcitonin receptor (AMY1, AMY2, and AMY3, respectively). How RAMPs change G protein-coupled receptor pharmacology is not fully understood. We exploited sequence differences between RAMP1 and RAMP3 to identify individual residues capable of altering receptor pharmacology. Alignment of human RAMPs revealed eight residues that are conserved in RAMP2 and RAMP3 but are different in RAMP1. We hypothesized that residues in RAMP2 and RAMP3, but not RAMP1, are responsible for making CL/RAMP2 and CL/RAMP3 AM receptors. Using site-directed mutagenesis, we introduced individual RAMP3 residues into RAMP1 and vice versa in these eight positions. Mutant or wild-type RAMPs were transfected into Cos7 cells with CL or the insert-negative form of the calcitonin receptor [CT(a)]. Agonist-stimulated cAMP production and cell-surface expression of constructs were measured. Position 74 in RAMP1 and RAMP3 was critical for determining AM potency and affinity, and Phe93 in RAMP1 was an important contributor to alphaCGRP potency at CGRP receptors. Mutant RAMP/CT(a) receptor complexes displayed different phenotypes. It is noteworthy that RAMP1 S103N and W74E mutations led to enhanced rAmy potency, probably related to increased cell-surface expression of these complexes. This differs from the effect on CL-based receptors where expression was unchanged. Targeted substitution has emphasized the importance of position 74 in RAMP1/RAMP3 as a key determinant of AM pharmacology. PMID:18593822

  10. Impact of Food Components on in vitro Calcitonin Gene-Related Peptide Secretion-A Potential Mechanism for Dietary Influence on Migraine.

    PubMed

    Slavin, Margaret; Bourguignon, Julia; Jackson, Kyle; Orciga, Michael-Angelo

    2016-01-01

    Calcitonin gene-related peptide (CGRP) is a pivotal messenger in the inflammatory process in migraine. Limited evidence indicates that diet impacts circulating levels of CGRP, suggesting that certain elements in the diet may influence migraine outcomes. Interruption of calcium signaling, a mechanism which can trigger CGRP release, has been suggested as one potential route by which exogenous food substances may impact CGRP secretion. The objective of this study was to investigate the effects of foods and a dietary supplement on two migraine-related mechanisms in vitro: CGRP secretion from neuroendocrine CA77 cells, and calcium uptake by differentiated PC12 cells. Ginger and grape pomace extracts were selected for their anecdotal connections to reducing or promoting migraine. S-petasin was selected as a suspected active constituent of butterbur extract, the migraine prophylactic dietary supplement. Results showed a statistically significant decrease in stimulated CGRP secretion from CA77 cells following treatment with ginger (0.2 mg dry ginger equivalent/mL) and two doses of grape pomace (0.25 and 1.0 mg dry pomace equivalent/mL) extracts. Relative to vehicle control, CGRP secretion decreased by 22%, 43%, and 87%, respectively. S-petasin at 1.0 μM also decreased CGRP secretion by 24%. Meanwhile, S-petasin and ginger extract showed inhibition of calcium influx, whereas grape pomace had no effect on calcium. These results suggest that grape pomace and ginger extracts, and S-petasin may have anti-inflammatory propensity by preventing CGRP release in migraine, although potentially by different mechanisms, which future studies may elucidate further. PMID:27376323

  11. Impact of Food Components on in vitro Calcitonin Gene-Related Peptide Secretion—A Potential Mechanism for Dietary Influence on Migraine

    PubMed Central

    Slavin, Margaret; Bourguignon, Julia; Jackson, Kyle; Orciga, Michael-Angelo

    2016-01-01

    Calcitonin gene-related peptide (CGRP) is a pivotal messenger in the inflammatory process in migraine. Limited evidence indicates that diet impacts circulating levels of CGRP, suggesting that certain elements in the diet may influence migraine outcomes. Interruption of calcium signaling, a mechanism which can trigger CGRP release, has been suggested as one potential route by which exogenous food substances may impact CGRP secretion. The objective of this study was to investigate the effects of foods and a dietary supplement on two migraine-related mechanisms in vitro: CGRP secretion from neuroendocrine CA77 cells, and calcium uptake by differentiated PC12 cells. Ginger and grape pomace extracts were selected for their anecdotal connections to reducing or promoting migraine. S-petasin was selected as a suspected active constituent of butterbur extract, the migraine prophylactic dietary supplement. Results showed a statistically significant decrease in stimulated CGRP secretion from CA77 cells following treatment with ginger (0.2 mg dry ginger equivalent/mL) and two doses of grape pomace (0.25 and 1.0 mg dry pomace equivalent/mL) extracts. Relative to vehicle control, CGRP secretion decreased by 22%, 43%, and 87%, respectively. S-petasin at 1.0 μM also decreased CGRP secretion by 24%. Meanwhile, S-petasin and ginger extract showed inhibition of calcium influx, whereas grape pomace had no effect on calcium. These results suggest that grape pomace and ginger extracts, and S-petasin may have anti-inflammatory propensity by preventing CGRP release in migraine, although potentially by different mechanisms, which future studies may elucidate further. PMID:27376323

  12. Expression of calcitonin gene-related peptide, adenosine A2a receptor and adenosine A1 receptor in experiment rat migraine models

    PubMed Central

    LU, WENXIAN; LI, BIN; CHEN, JINBO; SU, YIPENG; DONG, XIAOMENG; SU, XINYANG; GAO, LIXIANG

    2016-01-01

    A migraine is a disabling neurovascular disorder characterized by a unilateral throbbing headache that lasts from 4 to 72 h. The headache is often accompanied by nausea, vomiting, phonophobia and photophobia, and may be worsened by physical exercise. The trigeminovascular system (TVS) is speculated to have an important role in migraines, although the pathophysiology of this disorder remains to be elucidated. Trigeminal ganglion (TG) and spinal trigeminal nucleus caudalis (TNC) are important components of the TVS. Several clinical cases have provided evidence for the involvement of the brainstem in migraine initiation. Electrical stimulation of the trigeminal ganglion (ESTG) in rats can activate TVS during a migraine attack. Calcitonin gene-related peptide (CGRP) is an important vasoactive compound produced following TVS activation. Numerous studies have revealed that adenosine and its receptors have an important role in pain transmission and regulation process. However, only a few studies have examined whether adenosine A2a receptor (A2aR) and adenosine A1 receptor (A1R) are involved in migraine and nociceptive pathways. In the present study, CGRP, A2aR and A1R expression levels were detected in the TG and TNC of ESTG models through reverse transcription-quantitative polymerase chain reaction and western blot analysis. Tianshu capsule (TSC), a type of Chinese medicine, was also used in the ESTG rat models to examine its influence on the three proteins. Results demonstrated that CGRP, A2aR and A1R mediated pain transmission and the regulation process during migraine and the expression of the three proteins was regulated by TSC. PMID:26998280

  13. Calcitonin gene-related peptide (CGRP), peptide YY (PYY) gastrin releasing peptide (GRP) and others in hamster lung and plasma

    SciTech Connect

    Ekman, R.; Keith, I.M.

    1986-03-05

    Rabbit antisera to CGRP, PYY, neuropeptide Y (NPY) and GRP were used for immunocytochemical localization of these peptides in lungs of neonate hamsters at birth and 6 d of age and young (70 gm) and adult (107 gm) hamsters. The peroxidase-antiperoxidase method was applied to paraffin sections of tissue fixed in Bouin's or Zamboni's solution. Furthermore, radioimmunoassay (RIA) was used to quantify these peptides in lung tissue and plasma from the young hamsters (n=13). Distinct CGRP-like immunoreactivity (IR) was noted in grouped (NEB) and individual (NEC) neuroendocrine cells at all ages including all airways from trachea (NECs only) to alveoli. In some NEBs this IR coexisted with 5-HT-like IR. PYY- and NPY-like Ir was mainly noted in NEBs and NECs at the level of bronchioles and alveoli, and weak GRP-like IR was present in neuroendocrine-like cells of small airways. Measurable quantities of all peptides were recorded by RIA. Females had higher lung and plasma levels of CGRP and plasma levels of PYY than males and tended to have higher lung levels of GRP. The neuropeptides CGRP, PYY and the analog NPY are putative regulators of local pulmonary blood flow by vasodilation (CGRP) and constriction (PYY, NPY), and GRP is known to regulate peptide release.

  14. Diverse Physiological Roles of Calcitonin Gene-Related Peptide in Migraine Pathology: Modulation of Neuronal-Glial-Immune Cells to Promote Peripheral and Central Sensitization.

    PubMed

    Durham, Paul L

    2016-08-01

    The neuropeptide calcitonin gene-related peptide (CGRP) is implicated in the underlying pathology of migraine by promoting the development of a sensitized state of primary and secondary nociceptive neurons. The ability of CGRP to initiate and maintain peripheral and central sensitization is mediated by modulation of neuronal, glial, and immune cells in the trigeminal nociceptive signaling pathway. There is accumulating evidence to support a key role of CGRP in promoting cross excitation within the trigeminal ganglion that may help to explain the high co-morbidity of migraine with rhinosinusitis and temporomandibular joint disorder. In addition, there is emerging evidence that CGRP facilitates and sustains a hyperresponsive neuronal state in migraineurs mediated by reported risk factors such as stress and anxiety. In this review, the significant role of CGRP as a modulator of the trigeminal system will be discussed to provide a better understanding of the underlying pathology associated with the migraine phenotype. PMID:27334137

  15. Calcitonin gene-related peptide contributes to peripheral nerve injury-induced mechanical hypersensitivity through CCL5 and p38 pathways.

    PubMed

    Malon, Jennifer T; Cao, Ling

    2016-08-15

    The role of calcitonin gene related peptide (CGRP) in neuropathic pain was investigated in a mouse model of neuropathic pain, spinal nerve L5 transection (L5Tx). Intrathecal injection (i.t.) of CGRP8-37, a CGRP antagonist, significantly reduced L5Tx-induced mechanical hypersensitivity and lumbar spinal cord CCL5 expression. i.t. injection of a CCL5 neutralizing antibody significantly inhibited L5Tx-induced mechanical hypersensitivity. Further, pre-treatment with a p38-inhibitor, SB203580, was able to reduce CGRP-induced mechanical hypersensitivity, but not CGRP-induced CCL5 production. Our data indicate that CGRP can play its pro-nociceptive role through both a spinal cord CCL5-dependent, p38-independent pathway, and a p38-depenented, CCL5-independent pathway. PMID:27397078

  16. Effects of rizatriptan on the expression of calcitonin gene-related peptide and cholecystokinin in the periaqueductal gray of a rat migraine model.

    PubMed

    Yao, Gang; Han, Ximei; Hao, Tingting; Huang, Qian; Yu, Tingmin

    2015-02-01

    Triptans are serotonin 5-hydroxytryptamine receptor 1B/D agonists that are highly effective in the treatment of migraine. We previously found that rizatriptan can reduce the expression of proenkephalin and P substance in the rat midbrain, suggesting that rizatriptan may exert its analgesic effects by influencing the endogenous pain modulatory system. Calcitonin gene-related peptide (CGRP) and cholecystokinin (CCK) are mainly responsible for antagonizing the analgesic effects of opioid peptides in the endogenous pain modulatory system. In this study, we investigated the effects of rizatriptan on the expression of CGRP and CCK in the periaqueductal gray (PAG), a key structure of the endogenous pain modulatory system, in a rat migraine model induced by nitroglycerin. We found that the mRNA and protein levels of CGRP and CCK in the PAG of migraine rats were significantly increased compared to those in control rats, and these levels were significantly reduced upon treatment with rizatriptan in migraine rats (P<0.05). Our results suggest that the expression of CGRP and CCK in the endogenous pain modulatory system may be increased during migraine attacks, which further antagonizes the analgesic effects of endogenous opioid peptides and induces sustained migraine. Rizatriptan, however, significantly reduces the levels of CGRP and CCK to enhance the inhibition of pain signals via the endogenous pain modulatory system, resulting in effective treatment of migraine. PMID:25524408

  17. Calcitonin gene-related peptide erases the fear memory and facilitates long-term potentiation in the central nucleus of the amygdala in rats.

    PubMed

    Wu, Xin; Zhang, Jie-Ting; Liu, Jue; Yang, Si; Chen, Tao; Chen, Jian-Guo; Wang, Fang

    2015-11-01

    Calcitonin gene-related peptide (CGRP) is a 37 amino acid neuropeptide, which plays a critical role in the central nervous system. CGRP binds to G protein-coupled receptors, including CGRP1, which couples positively to adenylyl cyclase (AC) and protein kinase A (PKA) activation. CGRP and CGRP1 receptors are enriched in central nucleus of the amygdala (CeA), the main part of the amygdala, which regulates conditioned fear memories. Here, we reported the importance of CGRP and CGRP1 receptor for synaptic plasticity in the CeA and the extinction of fear memory in rats. Our electrophysiological and behavioral in vitro and in vivo results showed exogenous application of CGRP induced an immediate and lasting long-term potentiation in the basolateral nucleus of amygdala-CeA pathway, but not in the lateral nucleus of amygdala-CeA pathway, while bilateral intra-CeA infusion CGRP (0, 5, 13 and 21 μM/side) dose dependently enhanced fear memory extinction. The effects were blocked by CGRP1 receptor antagonist (CGRP8-37 ), N-methyl-d-aspartate receptors antagonist MK801 and PKA inhibitor H89. These results demonstrate that CGRP can lead to long-term potentiation of basolateral nucleus of amygdala-CeA pathway through a PKA-dependent postsynaptic mechanism that involved N-methyl-d-aspartate receptors and enhance the extinction of fear memory in rats. Together, the results strongly support a pivotal role of CGRP in the synaptic plasticity of CeA and extinction of fear memory. Calcitonin gene-related peptide (CGRP) plays an essential role in synaptic plasticity in the amygdala and fear memory. We found that CGRP-induced chemical long-term potentiation (LTP) in a dose-dependent way in the BLA-CeA (basolateral and central nucleus of amygdala, respectively) pathway and enhanced fear memory extinction in rats through a protein kinase A (PKA)-dependent postsynaptic mechanism that involved NMDA receptors. These results support a pivotal role of CGRP in amygdala. PMID:26179152

  18. High arterial compliance in cirrhosis is related to low adrenaline and elevated circulating calcitonin gene related peptide but not to activated vasoconstrictor systems

    PubMed Central

    Henriksen, J; Moller, S; Schifter, S; Abrahamsen, J; Becker, U

    2001-01-01

    BACKGROUND AND AIMS—Static and dynamic functions of the wall of large arteries are largely unknown in cirrhosis in vivo. The present study was undertaken to determine arterial compliance (COMPart) in relation to vasodilator and vasoconstrictor systems in patients with cirrhosis. In addition, vasoactivity was manipulated by inhalation of oxygen.
STUDY POPULATION AND METHODS—In 20 patients with alcoholic cirrhosis and 12 controls we determined COMPart (stroke volume relative to pulse pressure), cardiac output, plasma volume, systemic vascular resistance, central circulation time, plasma catecholamines, renin activity, endothelin-1, and calcitonin gene related peptide (CGRP) at baseline and during oxygen inhalation.
RESULTS—COMPart was significantly increased in cirrhotic patients compared with controls (1.32 v 1.06 ml/mm Hg; p< 0.05) and inversely related to plasma adrenaline levels (r=−0.53; p<0.02) but positively related to circulating levels of CGRP (r=0.58; p<0.01). No significant relation was found for plasma noradrenaline, renin activity, or endothelin-1. COMPart was positively related to plasma volume (r=0.50; p<0.02) and inversely to systemic vascular resistance (r=−0.69; p<0.001) and central circulation time (r=−0.49; p<0.02). During oxygen inhalation, COMPart decreased (−13%; p<0.005) and systemic vascular resistance increased (+10%; p<0.001) towards normal values without significant changes in mean arterial pressure. Plasma adrenaline (−16%; p<0.01) decreased and the relation to COMPart disappeared. The relation of COMPart to CGRP and circulatory variables remained unchanged.
CONCLUSION—Elevated arterial compliance in cirrhosis is related to low adrenaline, high CGRP, and systemic hyperdynamics but not to indicators of the activated vasoconstrictor systems (noradrenaline, renin, endothelin-1). Thus the altered static and dynamic characteristics of the wall of large arteries are intimately associated with circulatory and

  19. Calcitonin gene-related peptide is a key factor in the homing of transplanted human MSCs to sites of spinal cord injury.

    PubMed

    Zhang, Yu; Yang, Jinhua; Zhang, Peng; Liu, Tao; Xu, Jianwei; Fan, Zhihai; Shen, Yixin; Li, Wenjie; Zhang, Huanxiang

    2016-01-01

    Mesenchymal stem cells (MSCs) can be used to treat many diseases, including spinal cord injury (SCI). Treatment relies mostly on the precise navigation of cells to the injury site for rebuilding the damaged spinal cord. However, the key factors guiding MSCs to the epicenter of SCI remain unknown. Here, we demonstrated that calcitonin gene-related peptide (CGRP), a neural peptide synthesized in spinal cord, can dramatically aid the homing of human umbilical cord mesenchymal stem cells (HUMSCs) in spinal cord-transected SCI rats. First, HUMSCs exhibited chemotactic responses in vitro to CGRP. By time-lapse video analysis, increased chemotactic index (CMI), forward migration index (FMI) and speed contributed to this observed migration. Then, through enzyme immunoassay, higher CGRP concentrations at the lesion site were observed after injury. The release of CGRP directed HUMSCs to the injury site, which was suppressed by CGRP 8-37, a CGRP antagonist. We also verified that the PI3K/Akt and p38MAPK signaling pathways played a critical role in the CGRP-induced chemotactic migration of HUMSCs. Collectively, our data reveal that CGRP is a key chemokine that helps HUMSCs migrate to the lesion site and thereby can be used as a model molecule to study MSCs homing after SCI. PMID:27296555

  20. Calcitonin gene-related peptide is a key factor in the homing of transplanted human MSCs to sites of spinal cord injury

    PubMed Central

    Zhang, Yu; Yang, Jinhua; Zhang, Peng; Liu, Tao; Xu, Jianwei; Fan, Zhihai; Shen, Yixin; Li, Wenjie; Zhang, Huanxiang

    2016-01-01

    Mesenchymal stem cells (MSCs) can be used to treat many diseases, including spinal cord injury (SCI). Treatment relies mostly on the precise navigation of cells to the injury site for rebuilding the damaged spinal cord. However, the key factors guiding MSCs to the epicenter of SCI remain unknown. Here, we demonstrated that calcitonin gene-related peptide (CGRP), a neural peptide synthesized in spinal cord, can dramatically aid the homing of human umbilical cord mesenchymal stem cells (HUMSCs) in spinal cord-transected SCI rats. First, HUMSCs exhibited chemotactic responses in vitro to CGRP. By time-lapse video analysis, increased chemotactic index (CMI), forward migration index (FMI) and speed contributed to this observed migration. Then, through enzyme immunoassay, higher CGRP concentrations at the lesion site were observed after injury. The release of CGRP directed HUMSCs to the injury site, which was suppressed by CGRP 8–37, a CGRP antagonist. We also verified that the PI3K/Akt and p38MAPK signaling pathways played a critical role in the CGRP-induced chemotactic migration of HUMSCs. Collectively, our data reveal that CGRP is a key chemokine that helps HUMSCs migrate to the lesion site and thereby can be used as a model molecule to study MSCs homing after SCI. PMID:27296555

  1. [Suppressing effect of the serotonin 5HT1B/D receptor agonist rizatriptan on calcitonin gene-related peptide (CGRP) concentration in migraine attacks].

    PubMed

    Stepień, Adam; Jagustyn, Piotr; Trafny, Elzbieta Anna; Widerkiewicz, Krzysztof

    2003-01-01

    Calcitonin gene-related peptide (CGRP) is one of the neuropeptides most abundant in the nervous tissue. Recent studies indicate that local cranial release of CGRP from the trigeminal nerve perivascular endings within arachnoidea plays an important role in the pathophysiology of migraine attacks and cluster headaches. Elevated CGRP levels in cranial venous blood (in the jugular vein) during an acute spontaneous migraine attack have been reported in rather few studies so far. Sumatriptan--a selective serotonin 5HT1B/D receptor agonist, highly effective in terminating migraine attacks, decreases the elevated CGRP level back to normal. The aim of our study was to determine the effect of rizatriptan (a drug from a new generation of triptans) on CGRP release in migraine attacks. In 45 patients suffering from migraine attacks with and without aura, plasma CGRP levels were assessed during an attack twice: before treatment and two hours after rizatriptan administration. In the group under study the plasma CGRP level before treatment was significantly higher than that measured two hours after rizatriptan administration. The decrease in CGRP levels was associated with subsidence of the migraine attack. There was no difference between migraine patients with and without aura. These results suggest that triptans as serotonin 5HT1B/D receptor agonists decrease CGRP plasma concentration in migraine attacks. PMID:15174248

  2. Lafutidine, a novel histamine H2-receptor antagonist, increases serum calcitonin gene-related peptide in rats after water immersion-restraint stress.

    PubMed

    Sato, Hiroshi; Kawashima, Kousaku; Yuki, Mika; Kazumori, Hideaki; Rumi, Mohammad Azharul Karim; Ortega-Cava, Cesar Francisco; Ishihara, Shunji; Kinoshita, Yoshikazu

    2003-02-01

    Lafutidine is a novel histamine H(2)-receptor antagonist with a potent and long-lasting anti-acid secretory effect that has also been found to have a potent gastroprotective effect. We investigated the effect of lafutidine on gastric mucosal injury induced in rats with the use of water-immersion restraint stress (WRS) by examining serum calcitonin gene-related peptide (CGRP) concentrations, which we measured with the use of an enzyme immunometric assay. WRS-induced mucosal erosive injury in the stomach was reduced significantly by both lafutidine and famotidine pretreatment (from 7.79 +/- 2.02 mm(2) to 3.09 +/- 0.74 mm(2) and 4.05 +/- 1.18 mm(2), respectively). A single administration of lafutidine or famotidine did not change the serum CGRP concentration from the control value when these drugs were administered without WRS. Lafutidine pretreatment before WRS caused a significant increase in serum CGRP concentration compared with famotidine (lafutidine, 86.64 +/- 9.52 pg/mL; famotidine, 47.55 +/- 4.35 pg/mL; control, 58.43 +/- 6.07 pg/mL). Our results suggest that lafutidine augments CGRP release from the rat stomach when administered before the induction of WRS. PMID:12577045

  3. Rapid nitric oxide- and prostaglandin-dependent release of calcitonin gene-related peptide (CGRP) triggered by endotoxin in rat mesenteric arterial bed.

    PubMed Central

    Wang, X.; Wu, Z.; Tang, Y.; Fiscus, R. R.; Han, C.

    1996-01-01

    1. Our objective was to determine whether endotoxin (ETX) could directly trigger the release of calcitonin gene-related peptide (CGRP) from perivascular sensory nerves in the isolated mesenteric arterial bed (MAB) of the rat and to determine whether nitric oxide (NO) and prostaglandins (PGs) are involved. 2. ETX caused time- and concentration-dependent release of CGRP, and as much as a 17 fold increase in CGRP levels in the perfusate at 10-15 min after the administration of ETX (50 micrograms ml-1). 3. CGRP-like immunoreactivity in the perfusate was shown to co-elute with synthetic rat CGRP by reverse-phase h.p.l.c. 4. Pretreatment of MAB with capsaicin or ruthenium red inhibited ETX-induced CGRP release by 90% and 71%, respectively. ETX-evoked CGRP release was decreased by 84% during Ca2(+)-free perfusion. 5. The release of CGRP evoked by ETX was enhanced by L-arginine by 43% and inhibited by N omega-nitro-L-arginine (L-NOARG) and methylene blue by 37% and 38%, respectively. L-Arginine reversed the effect of L-NOARG. 6. Indomethacin and ibuprofen also inhibited the ETX-induced CGRP release by 34% and 44%, respectively. No additive inhibition could be found when L-NOARG and indomethacin were concomitantly incubated. 7. The data suggest that ETX triggers the release of CGRP from capsaicin-sensitive sensory nerves innervating blood vessels. The ETX-induced CGRP release is dependent on extracellular Ca2+ influx and involves a ruthenium red-sensitive mechanism. Both NO and PGs appear to be involved in the ETX-induced release of CGRP in the rat mesenteric arterial bed. PMID:8864557

  4. Structure–activity relationships of the N-terminus of calcitonin gene-related peptide: key roles of alanine-5 and threonine-6 in receptor activation

    PubMed Central

    Hay, Debbie L; Harris, Paul WR; Kowalczyk, Renata; Brimble, Margaret A; Rathbone, Dan L; Barwell, James; Conner, Alex C; Poyner, David R

    2014-01-01

    Background and Purpose: The N-terminus of calcitonin gene-related peptide (CGRP) is important for receptor activation, especially the disulphide-bonded ring (residues 1–7). However, the roles of individual amino acids within this region have not been examined and so the molecular determinants of agonism are unknown. This study has examined the role of residues 1, 3–6 and 8–9, excluding Cys-2 and Cys-7. Experimental Approach: CGRP derivatives were substituted with either cysteine or alanine; further residues were introduced at position 6. Their affinity was measured by radioligand binding and their efficacy by measuring cAMP production in SK-N-MC cells and β-arrestin 2 translocation in CHO-K1 cells at the CGRP receptor. Key Results: Substitution of Ala-5 by cysteine reduced affinity 270-fold and reduced efficacy for production of cAMP in SK-N-MCs. Potency at β-arrestin translocation was reduced by ninefold. Substitution of Thr-6 by cysteine destroyed all measurable efficacy of both cAMP and β-arrestin responses; substitution with either alanine or serine impaired potency. Substitutions at positions 1, 4, 8 and 9 resulted in approximately 10-fold reductions in potency at both responses. Similar observations were made at a second CGRP-activated receptor, the AMY1(a) receptor. Conclusions and Implications: Ala-5 and Thr-6 are key determinants of agonist activity for CGRP. Ala-5 is also very important for receptor binding. Residues outside of the 1–7 ring also contribute to agonist activity. PMID:24125506

  5. Expression and function of calcitonin gene-related peptide (CGRP) receptors in trigeminal ganglia of R192Q Cacna1a knock-in mice.

    PubMed

    Vilotti, Sandra; Vana, Natascha; Van den Maagdenberg, Arn M J M; Nistri, Andrea

    2016-05-01

    Migraine is a neurovascular brain disorder suggested to be due to dysfunction of the trigeminovascular system with sensitization of trigeminal ganglion (TG) nociceptors. Since the neuropeptide calcitonin gene-related peptide (CGRP) has been established as a key player in the pathogenesis of migraine, CGRP receptor antagonists have been considered useful compounds to block headache originating from hyperactivation of such TG neurons. Whereas there is some information on the expression of CGRP receptors in postmortem human tissue, data are lacking for migraineurs suffering from common or genetic migraine. To help to clarify these issues it is very useful to study a transgenic knock-in (KI) mouse model of hemiplegic migraine expressing a R192Q missense mutation in the α1 subunit of CaV2.1 calcium channels previously found in patients with familial hemiplegic migraine type-1 (FHM-1). The aim of the present study, therefore, was to compare CGRP receptor expression and function in wildtype (WT) versus KI mouse TG. The principal components of the CGRP receptor, namely the CLR and RAMP-1 proteins, were similarly expressed in WT and KI TG neurons (in situ or in culture) and responded to exogenous CGRP with a strong rise in cAMP concentration. Hence, the previously reported phenotype of sensitization of KI TG neurons is not due to up-regulation of CGRP receptors but is likely caused by a constitutively larger release of CGRP. This observation implies that, in FHM-1 TG, normal TG sensory neuron signaling can be restored once the extracellular concentration of CGRP returns to control level with targeted treatment. PMID:27021026

  6. Calcitonin gene-related peptide cooperates with substance P to inhibit melanogenesis and induces apoptosis of B16F10 cells.

    PubMed

    Zhou, Jia; Feng, Jun-Yi; Wang, Qian; Shang, Jing

    2015-07-01

    Skin is the largest organ in human body and works as biologically active barrier to provide critical preservation of body homeostasis. The skin is highly innervated by a plenitude of nerve fiber subpopulations, each carrying one or more neuronal mediators. Melanocyte itself also intimately contact with nerve fibers to form 'synaptic-like structure' and its functions may be directly regulated by the mediators contained in terminals of intra-epidermal nerve fibers. Clinical and biochemical studies have suggested that calcitonin gene-related peptide (CGRP) is involved in vitiligo skin. The present study was designed to investigate the effect of CGRP on epidermal melanocytes. After treatment with CGRP ranging from 0 to 500 ng/mL for 48 h, tyrosinase activity and melanogenesis were with little changes compared to treatment with medium only in B16F10 cells. Treatment with 500 ng/mL of CGRP cooperates with substance P (SP) (0.1-10 nM) to decrease tyrosinase activity and decrease melanin biosynthesis in B16F10 cells in a concentration-dependent manner. Furthermore, CGRP (8-37) antagonizes the synergistic effect of CGRP. The effect of CGRP on the cell apoptosis was examined. Treatments with 0-500 ng/mL of CGRP for 24 h, the expression levels of cleaved caspase-3, total caspase-3, cleaved caspase-9 and total caspase-9 were increased in a concentration-dependent manner. And 500 ng/mL of CGRP induced B16F10 cell apoptosis showed by TUNEL assay. In addition, Bax expression was up-regulated and Bcl-2 down-regulated in response to CGRP treatment. Hence, the Bax/Bcl-2 ratio was significantly increased. These in vitro observations indicate the pro-apoptotic impact of CGRP on B16F10 cell. PMID:25982845

  7. Exogenous asymmetric dimethylarginine (ADMA) in pathogenesis of ischemia-reperfusion-induced gastric lesions: interaction with protective nitric oxide (NO) and calcitonin gene-related peptide (CGRP).

    PubMed

    Magierowski, Marcin; Jasnos, Katarzyna; Sliwowski, Zbigniew; Surmiak, Marcin; Krzysiek-Maczka, Gracjana; Ptak-Belowska, Agata; Kwiecien, Slawomir; Brzozowski, Tomasz

    2014-01-01

    Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) synthesis inhibitor and pro-inflammatory factor. We investigated the role of ADMA in rat gastric mucosa compromised through 30 min of gastric ischemia (I) and 3 h of reperfusion (R). These I/R animals were pretreated with ADMA with or without the combination of L-arginine, calcitonin gene-related peptide (CGRP) or a small dose of capsaicin, all of which are known to afford protection against gastric lesions, or with a farnesoid X receptor (FXR) agonist, GW 4064, to increase the metabolism of ADMA. In the second series, ADMA was administered to capsaicin-denervated rats. The area of gastric damage was measured with planimetry, gastric blood flow (GBF) was determined by H2-gas clearance, and plasma ADMA and CGRP levels were determined using ELISA and RIA. ADMA significantly increased I/R-induced gastric injury while significantly decreasing GBF, the luminal NO content, and the plasma level of CGRP. This effect of ADMA was significantly attenuated by pretreatment with CGRP, L-arginine, capsaicin, or a PGE2 analogue. In GW4064 pretreated animals, the I/R injury was significantly reduced and this effect was abolished by co-treatment with ADMA. I/R damage potentiated by ADMA was exacerbated in capsaicin-denervated animals with a further reduction of CGRP. Plasma levels of IL-10 were significantly decreased while malonylodialdehyde (MDA) and plasma TNF-α contents were significantly increased by ADMA. In conclusion, ADMA aggravates I/R-induced gastric lesions due to a decrease of GBF, which is mediated by a fall in NO and CGRP release, and the enhancement of lipid peroxidation and its pro-inflammatory properties. PMID:24658439

  8. Calcitonin Gene-Related Peptide-Exposed Endothelial Cells Bias Antigen Presentation to CD4+ T Cells toward a Th17 Response.

    PubMed

    Ding, Wanhong; Stohl, Lori L; Xu, Linghui; Zhou, Xi K; Manni, Michela; Wagner, John A; Granstein, Richard D

    2016-03-01

    Calcitonin gene-related peptide (CGRP) is a neuropeptide with well-established immunomodulatory functions. CGRP-containing nerves innervate dermal blood vessels and lymph nodes. We examined whether CGRP regulates the outcome of Ag presentation by Langerhans cells (LCs) to T cells through actions on microvascular endothelial cells (ECs). Exposure of primary murine dermal microvascular ECs (pDMECs) to CGRP followed by coculture with LCs, responsive CD4(+) T cells and Ag resulted in increased production of IL-6 and IL-17A accompanied by inhibition of IFN-γ, IL-4, and IL-22 compared with wells containing pDMECs treated with medium alone. Physical contact between ECs and LCs or T cells was not required for this effect and, except for IL-4, we demonstrated that IL-6 production by CGRP-treated pDMECs was involved in these effects. CD4(+) cells expressing cytoplasmic IL-17A were increased, whereas cells expressing cytoplasmic IFN-γ or IL-4 were decreased by the presence of CGRP-treated pDMECs. In addition, the level of retinoic acid receptor-related orphan receptor γt mRNA was significantly increased, whereas T-bet and GATA3 expression was inhibited. Immunization at the site of intradermally administered CGRP led to a similar bias in CD4(+) T cells from draining lymph node cells toward IL-17A and away from IFN-γ. Actions of nerve-derived CGRP on ECs may have important regulatory effects on the outcome of Ag presentation with consequences for the expression of inflammatory skin disorders involving Th17 cells. PMID:26829986

  9. Involvement of calcitonin gene-related peptide (CGRP) receptors in insulin-induced vasodilatation in mesenteric resistance blood vessels of rats

    PubMed Central

    Mimaki, Yuichi; Kawasaki, Hiromu; Okazaki, Masatoshi; Nakatsuma, Akira; Araki, Hiroaki; Gomita, Yutaka

    1998-01-01

    The vascular effect of insulin in the mesenteric resistance blood vessel and the role of calcitonin gene-related peptide (CGRP)-receptor in insulin-induced vascular responsiveness were investigated in rats.The mesenteric vascular beds isolated from Wistar rats were perfused with Krebs solution, and perfusion pressure was measured with a pressure transducer. In preparations contracted by perfusion with Krebs solution containing methoxamine in the presence of guanethidine, the perfusion of insulin (from 0.1 to 3000 nM) caused a concentration-dependent decrease in perfusion pressure due to vasodilatation. The pD2 value and maximum relaxation (%) were 6.94±0.22 and 43.9±5.2, respectively.This vasodilator response to insulin was unaffected by 100 nM propranolol (β-adrenoceptor antagonist) plus 100 nM atropine (muscarinic cholinoceptor antagonist), 100 μM L-NG-nitroarginine (nitric oxide synthase inhibitor), 1 μM ouabain (Na+-K+ ATPase inhibitor), or 1 μM glibenclamide (ATP sensitive K+-channel inhibitor).In preparations without endothelium, perfusion of insulin produced a marked vasodilatation. The pD2 value and maximum relaxation (%) were 7.62±0.21 and 81.0±4.6, respectively, significantly greater than in preparations with intact endothelium.The vasodilator responses to insulin in the preparations without endothelium were significantly inhibited by CGRP[8–37], a CGRP receptor antagonist, whereas pretreatment with capsaisin, a toxin for CGRP-containing nerves, did not affect insulin-induced vasodilatation.These results suggest that insulin induces non-adrenergic, non-cholinergic and endothelium-independent vasodilatation, which is partially mediated by CGRP receptors. PMID:9605576

  10. Similarity between class A and class B G-protein-coupled receptors exemplified through calcitonin gene-related peptide receptor modelling and mutagenesis studies

    PubMed Central

    Vohra, Shabana; Taddese, Bruck; Conner, Alex C.; Poyner, David R.; Hay, Debbie L.; Barwell, James; Reeves, Philip J.; Upton, Graham J. G.; Reynolds, Christopher A.

    2013-01-01

    Modelling class B G-protein-coupled receptors (GPCRs) using class A GPCR structural templates is difficult due to lack of homology. The plant GPCR, GCR1, has homology to both class A and class B GPCRs. We have used this to generate a class A–class B alignment, and by incorporating maximum lagged correlation of entropy and hydrophobicity into a consensus score, we have been able to align receptor transmembrane regions. We have applied this analysis to generate active and inactive homology models of the class B calcitonin gene-related peptide (CGRP) receptor, and have supported it with site-directed mutagenesis data using 122 CGRP receptor residues and 144 published mutagenesis results on other class B GPCRs. The variation of sequence variability with structure, the analysis of polarity violations, the alignment of group-conserved residues and the mutagenesis results at 27 key positions were particularly informative in distinguishing between the proposed and plausible alternative alignments. Furthermore, we have been able to associate the key molecular features of the class B GPCR signalling machinery with their class A counterparts for the first time. These include the [K/R]KLH motif in intracellular loop 1, [I/L]xxxL and KxxK at the intracellular end of TM5 and TM6, the NPXXY/VAVLY motif on TM7 and small group-conserved residues in TM1, TM2, TM3 and TM7. The equivalent of the class A DRY motif is proposed to involve Arg2.39, His2.43 and Glu3.46, which makes a polar lock with T6.37. These alignments and models provide useful tools for understanding class B GPCR function. PMID:23235263

  11. Calcitonin gene-related peptide protects rats from cerebral ischemia/reperfusion injury via a mechanism of action in the MAPK pathway

    PubMed Central

    YANG, SI; YUAN, YONGJIE; JIAO, SHAN; LUO, QI; YU, JINLU

    2016-01-01

    The aim of the present study was to investigate the protective function and underlying mechanism of calcitonin gene-related peptide (CGRP) on cerebral ischemia/reperfusion damage in rats. Adult male Wistar rats were selected for the establishment of an ischemia/reperfusion injury model through the application of a middle cerebral artery occlusion. Animals were randomly divided into 6 groups of 24 animals. Drugs were administered according to the design of each group; animals were administered CGRP, CGRP8–37, PD98059 and SB20358. The neurobehavioral scores of the rat cerebral ischemia model in each group were calculated. The infarction range of the rat brain tissues was observed by 2,3,5-triphenyltetrazolium chloride staining. The expression levels of three proteins, phosphorylated c-Jun N-terminal kinase (JNK)/JNK, phosphorylated extracellular signal-regulated protein kinase (ERK)/ERK and p-p38/p38, in the mitogen-activated protein kinase (MAPK) pathway in the brain tissues was detected by western blotting. The results showed that CGRP could improve the neurobehavioral function of the ischemic rats and reduce the infarction range. Western blotting results confirmed that the function of the CGRP was mediated mainly through the reduction of the JNK and p38 phosphorylation and the promotion of ERK phosphorylation. Therefore, the present study confirmed that an increase in the exogenous CRGP could effectively improve ischemia/reperfusion injury of the brain tissue. The mechanisms of action were achieved through a reduction in JNK and p38 phosphorylation and an increase in ERL phosphorylation in the MAPK pathway. These mechanisms were interdependent. PMID:27284409

  12. Decreased calcitonin gene-related peptide expression in the dorsal root ganglia of TNF-deficient mice in a monoiodoacetate-induced knee osteoarthritis model

    PubMed Central

    Taniguchi, Aya; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Sakuma, Yoshihiro; Oikawa, Yasuhiro; Kubota, Go; Inage, Kazuhide; Sainoh, Takeshi; Nakamura, Junichi; Aoki, Yasuchika; Toyone, Tomoaki; Inoue, Gen; Suzuki, Miyako; Yamauchi, Kazuyo; Suzuki, Takane; Takahashi, Kazuhisa; Ohtori, Seiji; Orita, Sumihisa

    2015-01-01

    Background: The detailed mechanisms of knee osteoarthritis (OA) pain have not been clarified, but involvement of inflammatory cytokines such as tumor necrosis factor-alpha (TNF) has been suggested. The present study aimed to investigate the more detailed neurological involvement of TNF in joint pain using a TNF-knockout mouse OA model. Methods: The right knees of twelve-week-old C57BL/6J wild and TNF-deficient knockout (TNF-ko) mice (n=15, each group) were given a single intra-articular injection of 10 µg monoiodoacetate in 10 mL sterile saline. The left knees were only punctured as the control. Evaluations were performed immediately after the injection (baseline) and at 7, 14, and 28 days after the injection with a subsequent intra-articular injection of neurotracer into both knees. The animals were evaluated for immunofluorescence of the lumbar dorsal root ganglia (DRG) innervating the knee joints. The injected knees were observed macroscopically and mouse pain-related behaviors were scored. Results: Macroscopic observation showed similar knee OA development in both wild and TNF-ko mice. Calcitonin gene-related peptide (CGRP, a neuropeptide identified as a inflammatory pain-related biomarker) was significantly increased in DRG neurons innervating OA-induced knee joints with significantly less CGRP expression in TNF-ko animals. Pain-related behavior scoring showed a significant increase in pain in OA-induced joints, but there was no significant difference in pain observed between the wild and TNF-ko mice. Conclusions: The result of the present study indicates the possible association of TNF-alpha in OA pain but not OA development. PMID:26722492

  13. Calcitonin gene-related peptide does not mediate the abnormal vascular reactivity observed in a rat model of acute Pseudomonas pneumonia.

    PubMed

    Fox, G A; Paterson, N A; McCormack, D G

    1996-06-01

    Abnormal systemic and pulmonary vascular reactivity has been demonstrated in numerous models of sepsis and pneumonia. Furthermore, the attenuated hypoxic pulmonary pressor response observed in these animals probably is responsible for the ventilation/perfusion (V/Q) mismatching and consequent arterial hypoxemia. We hypothesized that excess release of endogenous vasodilators such as calcitonin gene-related peptide (CGRP) in pneumonia was responsible for the diminished hypoxic pressor response. Using the CGRP receptor antagonist CGRP (8-37), we examined the role of CGRP in the attenuated hypoxic pulmonary response in a rat model of acute Pseudomonas pneumonia. Sixteen Sprague-Dawley rats were instrumented for chronic hemodynamic monitoring and subsequently randomized to either Pneumonia (n = 8), induced by the instillation of 0.2 ml broth containing 2 x 10(8) colony-forming units (CFU)/ml Pseudomonas aeruginosa into the right lower lobe, or Sham (n = 8) procedure. Hemodynamic measurements and the hypoxic (FiO2 = 0.08) pulmonary pressor response were recorded at baseline, 48 h after the pneumonia or sham procedure and after the administration of 250 micrograms CGRP (8-37) (post-CGRP(8-37)). The regional distribution of pulmonary blood flow was determined by the injection of radioactive microspheres. Forty-eight hours after the instillation of Pseudomonas, Pneumonia animals had significantly increased cardiac output (CO) as compared with Sham (193 +/- 7 vs. 154 +/- 7 ml/min, p < 0.05), slightly decreased mean arterial pressure (MAP 109 +/- 4 vs. 118 +/- 3 mm Hg, p = NS), and reduced total systemic vascular resistance (TSVR 0.57 +/- 0.03 vs. 0.78 +/- 0.05 mm Hg.min.ml-1, p < 0.05). Pneumonia animals were further characterized by increased mean pulmonary artery pressure (MPAP) as compared with Sham (24 +/- 2 vs. 20 +/- 1 mm Hg, p < 0.05) animals, and an increased alveolar-arterial (A-a) oxygen gradient (31 +/- 3 vs. 20 +/- 4 mm Hg, p < 0.05). The administration of CGRP

  14. The effect of 17β-estradiol on gene expression of calcitonin gene-related peptide and some pro-inflammatory mediators in peripheral blood mononuclear cells from patients with pure menstrual migraine

    PubMed Central

    Karkhaneh, Azam; Ansari, Mohammad; Emamgholipour, Solaleh; Rafiee, Mohammad Hessam

    2015-01-01

    Objective(s): The neuropeptide calcitonin gene-related peptide (CGRP) has long been postulated to play an integral role in the pathophysiology of migraine. Earlier studies showed that CGRP can stimulate the synthesis and release of nitric oxide (NO) and cytokines from trigeminal ganglion glial cells. The purpose of this study was to determine the effect of 17β-estradiol in regulation of CGRP expression, inducible nitric oxide synthase (iNOS) activity, and NO and interleukin-1beta (IL-1β) release in cultured peripheral blood mononuclear cells (PBMCs) from patients with pure menstrual migraine and healthy individuals. Materials and Methods: This study was performed on twelve patients with pure menstrual migraine and twelve age-and sex-matched healthy individuals. PBMCs treated with 17β-estradiol for 24 hr at physiological and pharmacological doses. Gene expression was evaluated by real time-PCR. CGRP and IL-1β proteins in culture supernatant were determined by ELISA method. Activity of iNOS in PBMCs and total nitrite in the culture supernatant were measured by colorimetric assays. Results: Treatment with 17β-estradiol had a biphasic effect on expression of CGRP. We found that 17β-estradiol treatment at pharmacological dose significantly increases mRNA expression of CGRP in both groups (P<0.001), whereas at physiological dose it could significantly decrease CGRP mRNA expression (P<0.001), CGRP protein levels, IL-1β release, NO production and iNOS activity only in patient groups (P<0.05). Conclusion: Collectively, it appears that 17β-estradiol can exert protective effect on decrease of inflammation in migraine via decrease in levels of CGRP, IL-1β and iNOS activity; however, more studies are necessary in this regard. PMID:26526225

  15. Comparison of the effects of salmon calcitonin (sCT) and calcitonin gene-related peptide (CGRP) in a number of in vivo and in vitro tests

    SciTech Connect

    Welch, S.P.; Brase, D.; Cooper, C.; Dewey, W.L.

    1986-03-05

    sCT and CGRP have been shown previously to have multiple activities in the central nervous system (CNS). Recent work has shown that CGRP (15 ..mu..g) intraventricularly (IVT) produces a naloxone reversible 37% inhibition in the p-phenylquinone test (PPQ) accompanied by severe diarrhea. The ED50 of sCT in the PPQ test is 362 ng and this effect is not reversed totally by naloxone. The onset of CGRP is more rapid than that of sCT. sCT and CGRP (10/sup -6/M) both produce naloxone reversible inhibition of the electrically stimulated guinea pig ileum (GPI) (25% and 50% respectively). Both sCT and CGRP (10/sup -6/ M) produce contracture (15% and 40% respectively) of the non-stimulated GPI that is not blocked by atropine. Both sCT and CGRP block the naloxone-induced contracture of the morphine (MS04) dependent ilea (29% and 68% respectively). Both sCT and CGRP produce biphasic shifts in the MS04 acetylcholine dose-effect curves in the stimulated and nonstimulated GPI, respectively. Neither sCT nor CGRP (10/sup -9/ to 10/sup -4/ M) displaces /sup 3/H-naloxone binding to mouse brain membranes. Both sCT and CGRP may produce their effects by modulation of CA/sup +2/ fluxes in the CNS and GPI.

  16. Involvement of calcitonin gene-related peptide (CGRP) receptors in insulin-induced vasodilatation in mesenteric resistance blood vessels of rats.

    PubMed

    Mimaki, Y; Kawasaki, H; Okazaki, M; Nakatsuma, A; Araki, H; Gomita, Y

    1998-04-01

    1. The vascular effect of insulin in the mesenteric resistance blood vessel and the role of calcitonin generelated peptide (CGRP)-receptor in insulin-induced vascular responsiveness were investigated in rats. 2. The mesenteric vascular beds isolated from Wistar rats were perfused with Krebs solution, and perfusion pressure was measured with a pressure transducer. In preparations contracted by perfusion with Krebs solution containing methoxamine in the presence of guanethidine, the perfusion of insulin (from 0.1 to 3000 nM) caused a concentration-dependent decrease in perfusion pressure due to vasodilatation. The pD2 value and maximum relaxation (%) were 6.94+/-0.22 and 43.9+/-5.2, respectively. 3. This vasodilator response to insulin was unaffected by 100 nM propranolol (beta-adrenoceptor antagonist) plus 100 nM atropine (muscarinic cholinoceptor antagonist), 100 microM L-NG-nitroarginine (nitric oxide synthase inhibitor), 1 microM ouabain (Na+-K+ ATPase inhibitor), or 1 microM glibenclamide (ATP sensitive K+-channel inhibitor). 4. In preparations without endothelium, perfusion of insulin produced a marked vasodilatation. The pD2 value and maximum relaxation (%) were 7.62+/-0.21 and 81.0+/-4.6, respectively, significantly greater than in preparations with intact endothelium. 5. The vasodilator responses to insulin in the preparations without endothelium were significantly inhibited by CGRP[8 37], a CGRP receptor antagonist, whereas pretreatment with capsaisin, a toxin for CGRP-containing nerves, did not affect insulin-induced vasodilatation. 6. These results suggest that insulin induces non-adrenergic, non-cholinergic and endothelium-independent vasodilatation, which is partially mediated by CGRP receptors. PMID:9605576

  17. Correlation between algogenic effects of calcitonin-gene-related peptide (CGRP) and activation of trigeminal vascular system, in an in vivo experimental model of nitroglycerin-induced sensitization.

    PubMed

    Capuano, Alessandro; Greco, Maria Cristina; Navarra, Pierluigi; Tringali, Giuseppe

    2014-10-01

    The neural mechanism(s) underlying migraine remain poorly defined at present; preclinical and clinical studies show an involvement of CGRP in this disorder. However current evidence pointed out that CGRP does not exert an algogenic action per se, but it is able to mediate migraine pain only if the trigeminal-vascular system is sensitized. The present study was addressed to investigate CGRP-evoked behavior in nitric oxide (NO) sensitized rats, using an experimental model of nitroglycerin induced sensitization of trigeminal system, looking at neuropeptide release from different cerebral areas after the intra-peritoneal (i.p.) administration of NO-donors. CGRP injected into the rat whisker pad did not induce significant changes in face rubbing behavior compared to controls. On the contrary, CGRP injected in animals pre-treated with 10mg/kg nitroglycerin significantly increased the time spent in face rubbing. Nitroglycerin pre-treated animals did not show any rubbing behavior after locally injected saline. Furthermore, the i.p. treatment with nitroglycerin produced an increase of CGRP levels in brainstem and trigeminal ganglia, but not in the hypothalamus and hippocampus. The absolute amounts of CGRP produced in the brainstem were lower compared to those in the trigeminal ganglion; however, after nitroglycerin stimulation the percentage increase was higher in the brainstem. In conclusion, findings presented in this study suggest that CGRP induces a painful behavior in rats only after sensitization of trigeminal system; thus supporting the concept that a genetic as well as acquired predisposition to trigemino- vascular activation represents the neurobiological basis of CGRP nociceptive effects in migraineurs. PMID:24998872

  18. Discovery of (5S,6S,9R)-5-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl 4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-1-yl)piperidine-1-carboxylate (BMS-927711): an oral calcitonin gene-related peptide (CGRP) antagonist in clinical trials for treating migraine.

    PubMed

    Luo, Guanglin; Chen, Ling; Conway, Charles M; Denton, Rex; Keavy, Deborah; Signor, Laura; Kostich, Walter; Lentz, Kimberley A; Santone, Kenneth S; Schartman, Richard; Browning, Marc; Tong, Gary; Houston, John G; Dubowchik, Gene M; Macor, John E

    2012-12-13

    Calcitonin gene-related peptide (CGRP) receptor antagonists have demonstrated clinical efficacy in the treatment of acute migraine. Herein, we describe the design, synthesis, and preclinical characterization of a highly potent, oral CGRP receptor antagonist BMS-927711 (8). Compound 8 has good oral bioavailability in rat and cynomolgus monkey, attractive overall preclinical properties, and shows dose-dependent activity in a primate model of CGRP-induced facial blood flow. Compound 8 is presently in phase II clinical trials. PMID:23153230

  19. Negative pressure wound therapy-associated tissue trauma and pain: a controlled in vivo study comparing foam and gauze dressing removal by immunohistochemistry for substance P and calcitonin gene-related peptide in the wound edge.

    PubMed

    Malmsjö, Malin; Gustafsson, Lotta; Lindstedt, Sandra; Ingemansson, Richard

    2011-12-01

    Pain upon negative pressure wound therapy (NPWT) dressing removal has been reported and is believed to be associated with the observation that granulation tissue grows into foam. Wound tissue damage upon removal of the foam may cause the reported pain. Calcitonin gene-related peptide (CGRP) and substance P are neuropeptides that cause inflammation and signal pain and are known to be released when tissue trauma occurs. The aim of this controlled in vivo study was to compare the expression of CGRP and substance P in the wound bed in control wounds and following NPWT and foam or gauze dressing removal. Eight pigs with two wounds each were treated with open-pore structure polyurethane foam or AMD gauze and NPWT of 0 (control) or -80 mm Hg for 72 hours. Following removal of the wound filler, the expression of CGRP and substance P was measured, using arbitrary units, in sections of biopsies from the wound bed using immunofluorescence techniques. Substance P and CGRP were more abundant in the wound edge following the removal of foam than of gauze dressings and least abundant in control wounds. The immunofluorescence staining of the wound edge for CGRP was 52 ± 3 au after the removal of gauze and 97 ± 5 au after the removal of foam (P <0.001). For substance P, the staining was 55 ± 3 au after gauze removal and 95 ± 4 au after foam removal (P <0.001). CGRP and substance P staining was primarily located to nerves and leukocytes. The increase in CGRP and substance P immunofluorescence was especially prominent in the dermis but also was seen in subcutaneous and muscle tissue. Using gauze may be one way of reducing NPWT dressing change-related pain. New wound fillers designed to optimize granulation tissue formation and minimize pain issues presumably will be developed in the near future. PMID:22156176

  20. The potential for prazosin and calcitonin gene-related peptide (CGRP) in causing hypoxia in tumours.

    PubMed Central

    Burney, I. A.; Maxwell, R. J.; Griffiths, J. R.; Field, S. B.

    1991-01-01

    Using 31P NMR spectroscopy, changes in tumour metabolic status were studied in a transplanted rat fibrosarcoma following the administration of vasodilators. Mean Arterial Blood Pressure (MABP) was monitored simultaneously. Two vasodilators were studied, prazosin and CGRP, which altered the NMR parameters Pi/sigma P, beta NTP,Pi, PCr/Pi and PME/Pi in a dose dependent manner. There was a good correlation between the various NMR parameters; for analysis, Pi/sigma P was used for convenience. With increasing doses of vasodilator, Pi/sigma P increased and the MABP decreased. Reduction in pHNMR showed a correlation with decreasing MABP following the administration of prazosin but not after CGRP. Both prazosin and CGRP produced changes in 31P NMR spectra consistent with a reduction in tumour blood flow. The results for prazosin and CGRP were comparable and showed a 15-20% increase in Pi/sigma P for a 20% reduction in MABP. These results were compared with those from hydralazine. With hydralazine an acceptable reduction in blood pressure (up to approximately 25%) has little effect and may even alter NMR parameters consistent with an increase in blood flow, a reduction of approximately 40% is required for a significant decrease in flow. Both prazosin and CGRP are shown to be far more effective than hydralazine in causing tumour hypoxia at a clinically acceptable reduction in blood pressure. CGRP may be the more suitable for clinical use because of its short half life, its capability to achieve controlled hypotension and the relatively few side effects associated with its use. PMID:1911217

  1. Structure of the mouse calcitonin/calcitonin gene-related peptide alpha and beta genes.

    PubMed

    Thomas, P M; Nasonkin, I; Zhang, H; Gagel, R F; Cote, G J

    2001-01-01

    We report the cloning, genomic organization and sequence of the mouse alpha-CALC and beta-CALC genes. The two genes share extensive sequence homology. The transcription units of both genes contain 6 exons. Transcripts of the alpha-CALC gene were found to alternatively include exon 4 or exons 5 and 6. For the beta-CALC gene exon 4 was not detected in transcripts derived from this gene. The predicted mouse alpha-CGRP was found to be identical to rat alpha-CGRP, however, beta-CGRP predicted amino acid sequences revealed three amino acid differences suggesting these residues are not critical to CGRP function. PMID:11761712

  2. Indole-3-carbinol protects against cisplatin-induced acute nephrotoxicity: role of calcitonin gene-related peptide and insulin-like growth factor-1.

    PubMed

    El-Naga, Reem N; Mahran, Yasmen F

    2016-01-01

    Nephrotoxicity associated with the clinical use of the anticancer drug cisplatin is a limiting problem. Thus, searching for new protective measures is required. Indole-3-carbinol is a powerful anti-oxidant, anti-inflammatory and anti-tumor agent. The present study aimed to investigate the potential protective effect of indole-3-carbinol against cisplatin-induced acute nephrotoxicity in rats. Rats were pre-treated with 20 mg/kg indole-3-carbinol orally before giving cisplatin (7 mg/kg). Cisplatin-induced acute nephrotoxicity was demonstrated where relative kidney weight, BUN and serum creatinine were significantly increased. Increased oxidative stress was evident in cisplatin group where GSH and SOD tissue levels were significantly depleted. Also, lipid peroxidation and NOX-1 were increased as compared to the control. Additionally, renal expression of pro-inflammatory mediators was induced by cisplatin. Cisplatin-induced cell death was shown by increased caspase-3 and decreased expression of EGF, IGF-1 and IGF-1 receptor. Nephrotoxicity, oxidative stress, inflammation and apoptotic effects induced by cisplatin were significantly ameliorated by indole-3-carbinol pre-treatment. Besides, the role of CGRP in cisplatin-induced nephrotoxicity was explored. Furthermore, cisplatin cytotoxic activity was significantly enhanced by indole-3-carbinol pre-treatment in vitro. In conclusion, indole-3-carbinol provides protection against cisplatin-induced nephrotoxicity. Also, reduced expression of CGRP may play a role in the pathogenesis of cisplatin-induced renal injury. PMID:27417335

  3. Protective role of ellagitannins from Eucalyptus citriodora against ethanol-induced gastric ulcer in rats: impact on oxidative stress, inflammation and calcitonin-gene related peptide.

    PubMed

    Al-Sayed, Eman; El-Naga, Reem N

    2015-01-15

    The gastroprotective activity of an ellagitannin-rich fraction obtained from Eucalyptus citriodora (ECF) was investigated against ethanol-induced gastric ulceration in rats. The rats were pretreated with ECF (25, 50 and 100mg/kg) 1h before the administration of absolute ethanol to induce acute gastric ulceration. The gastric lesions were significantly reduced by all doses of ECF. Notably, pre-treatment with ECF (100mg/kg) conferred 99.6% gastroprotection, which is significantly higher than that produced by omeprazole. Moreover, ECF administration markedly increased the mucin content in a dose-dependent manner. The potent gastroprotective effect of ECF could be partly mediated by attenuating ethanol-induced oxidative stress. ECF-pre-treatment markedly increased the depleted GSH and SOD levels in a dose-dependent manner. Moreover, ECF significantly decreased the elevated MDA tissue levels induced by ethanol administration. The results demonstrated that ECF administration exerted a powerful anti-inflammatory activity as evidenced by the reduction in the pro-inflammatory markers; IL-1β, TNF-α, 5-LO and COX-2. Additionally, the caspase-3 tissue levels were significantly reduced in the groups pre-treated with ECF. These results suggest that ECF could exert a beneficial gastroprotective effect through their antioxidant, anti-inflammatory and anti-apoptotic properties. Furthermore, ECF pre-treatment significantly attenuated the ethanol-induced decrease in CGRP expression, which has a protective role against gastric ulceration. Histopathological examination revealed intact mucosal layer, absence of hemorrhage and necrosis in groups treated with ECF. Ellagitannins were identified as the major active constituents responsible for the marked antioxidant and gastroprotective properties of ECF. The HPLC-PDA-ESI/MS/MS technique was employed to identify the ellagitannins of E. citriodora. PMID:25636864

  4. Indole-3-carbinol protects against cisplatin-induced acute nephrotoxicity: role of calcitonin gene-related peptide and insulin-like growth factor-1

    PubMed Central

    El-Naga, Reem N.; Mahran, Yasmen F.

    2016-01-01

    Nephrotoxicity associated with the clinical use of the anticancer drug cisplatin is a limiting problem. Thus, searching for new protective measures is required. Indole-3-carbinol is a powerful anti-oxidant, anti-inflammatory and anti-tumor agent. The present study aimed to investigate the potential protective effect of indole-3-carbinol against cisplatin-induced acute nephrotoxicity in rats. Rats were pre-treated with 20 mg/kg indole-3-carbinol orally before giving cisplatin (7 mg/kg). Cisplatin-induced acute nephrotoxicity was demonstrated where relative kidney weight, BUN and serum creatinine were significantly increased. Increased oxidative stress was evident in cisplatin group where GSH and SOD tissue levels were significantly depleted. Also, lipid peroxidation and NOX-1 were increased as compared to the control. Additionally, renal expression of pro-inflammatory mediators was induced by cisplatin. Cisplatin-induced cell death was shown by increased caspase-3 and decreased expression of EGF, IGF-1 and IGF-1 receptor. Nephrotoxicity, oxidative stress, inflammation and apoptotic effects induced by cisplatin were significantly ameliorated by indole-3-carbinol pre-treatment. Besides, the role of CGRP in cisplatin-induced nephrotoxicity was explored. Furthermore, cisplatin cytotoxic activity was significantly enhanced by indole-3-carbinol pre-treatment in vitro. In conclusion, indole-3-carbinol provides protection against cisplatin-induced nephrotoxicity. Also, reduced expression of CGRP may play a role in the pathogenesis of cisplatin-induced renal injury. PMID:27417335

  5. Transcutaneous Electrical Nerve Stimulation (TENS) Improves the Diabetic Cytopathy (DCP) via Up-Regulation of CGRP and cAMP

    PubMed Central

    Yi, Chaoran; Huang, Yi; Yu, Wen; Ling, Lin; Dai, Yutian; Wei, Zhongqing

    2013-01-01

    The objective of this study was to investigate the effects and mechanism of Transcutaneous Electrical Nerve Stimulation (TENS) on the diabetic cytopathy (DCP) in the diabetic bladder. A total of 45 rats were randomly divided into diabetes mellitus (DM)/TENS group (n = 15), DM group (n = 15) and control group (n = 15). The rats in the DM/TENS and TENS groups were electronically stimulated (stimulating parameters: intensity-31 V, frequency-31 Hz, and duration of stimulation of 15 min) for three weeks. Bladder histology, urodynamics and contractile responses to field stimulation and carbachol were determined. The expression of calcitonin gene-related peptide (CGRP) was analyzed by RT-PCR and Western blotting. The results showed that contractile responses of the DM rats were ameliorated after 3 weeks of TENS. Furthermore, TENS significantly increased bladder wet weight, volume threshold for micturition and reduced PVR, V% and cAMP content of the bladder. The mRNA and protein levels of CGRP in dorsal root ganglion (DRG) in the DM/TENS group were higher than those in the DM group. TENS also significantly up-regulated the cAMP content in the bladder body and base compared with diabetic rats. We conclude that TENS can significantly improve the urine contractility and ameliorate the feeling of bladder fullness in DM rats possibly via up-regulation of cAMP and CGRP in DRG. PMID:23468996

  6. Transcutaneous electrical nerve stimulation (TENS) improves the diabetic cytopathy (DCP) via up-regulation of CGRP and cAMP.

    PubMed

    Ding, Liucheng; Song, Tao; Yi, Chaoran; Huang, Yi; Yu, Wen; Ling, Lin; Dai, Yutian; Wei, Zhongqing

    2013-01-01

    The objective of this study was to investigate the effects and mechanism of Transcutaneous Electrical Nerve Stimulation (TENS) on the diabetic cytopathy (DCP) in the diabetic bladder. A total of 45 rats were randomly divided into diabetes mellitus (DM)/TENS group (n=15), DM group (n=15) and control group (n=15). The rats in the DM/TENS and TENS groups were electronically stimulated (stimulating parameters: intensity-31 V, frequency-31 Hz, and duration of stimulation of 15 min) for three weeks. Bladder histology, urodynamics and contractile responses to field stimulation and carbachol were determined. The expression of calcitonin gene-related peptide (CGRP) was analyzed by RT-PCR and Western blotting. The results showed that contractile responses of the DM rats were ameliorated after 3 weeks of TENS. Furthermore, TENS significantly increased bladder wet weight, volume threshold for micturition and reduced PVR, V% and cAMP content of the bladder. The mRNA and protein levels of CGRP in dorsal root ganglion (DRG) in the DM/TENS group were higher than those in the DM group. TENS also significantly up-regulated the cAMP content in the bladder body and base compared with diabetic rats. We conclude that TENS can significantly improve the urine contractility and ameliorate the feeling of bladder fullness in DM rats possibly via up-regulation of cAMP and CGRP in DRG. PMID:23468996

  7. Inclusion of Cocoa as a Dietary Supplement Represses Expression of Inflammatory Proteins in Spinal Trigeminal Nucleus in Response to Chronic Trigeminal Nerve Stimulation

    PubMed Central

    Cady, Ryan J.; Denson, Jennifer E.; Durham, Paul L.

    2013-01-01

    Scope Central sensitization is implicated in the pathology of temporomandibular joint disorder (TMD) and other types of orofacial pain. We investigated the effects of dietary cocoa on expression of proteins involved in the development of central sensitization in the spinal trigeminal nucleus (STN) in response to inflammatory stimulation of trigeminal nerves. Methods and results Male Sprague Dawley rats were fed either a control diet or an isocaloric diet consisting of 10% cocoa powder 14 days prior to bilateral injection of complete Freund’s adjuvant (CFA) into the temporomandibular joint to promote prolonged activation of trigeminal ganglion neurons and glia. While dietary cocoa stimulated basal expression of GLAST and MKP-1 when compared to animals on a normal diet, cocoa suppressed basal calcitonin gene-related peptide levels in the STN. CFA-stimulated levels of protein kinase A, P2X3, P-p38, GFAP, and OX-42, whose elevated levels in the STN are implicated in central sensitization, were repressed to near control levels in animals on a cocoa enriched diet. Similarly, dietary cocoa repressed CFA-stimulated inflammatory cytokine expression. Conclusion Based on our findings, we speculate that cocoa enriched diets could be beneficial as a natural therapeutic option for TMD and other chronic orofacial pain conditions. PMID:23576361

  8. Local cooling alters neural mechanisms producing changes in peripheral blood flow by spinal cord stimulation.

    PubMed

    Tanaka, Satoshi; Barron, Kirk W; Chandler, Margaret J; Linderoth, Bengt; Foreman, Robert D

    2003-03-28

    This study was performed to investigate the respective role of sensory afferent and sympathetic fibers in peripheral vasodilatation induced by spinal cord stimulation at different hindpaw skin temperatures. Cooling the skin was used as a strategy to enhance sympathetic activity [Am. J. Physiol.: Heart Circ. Physiol. 263 (1992) H1197]. Cutaneous blood flow in the footpad of anesthetized rats was recorded using laser Doppler flowmetry. Local cooling (<25 degrees C) or moderate local cooling (25-28 degrees C) of the hindpaw was produced with a cooling copper coil. Spinal cord stimulation delivered at clinically relevant parameters and with 30%, 60%, and 90% of motor threshold induced the early phase of vasodilatation in the cooled and the moderately cooled hindpaw. In addition, spinal cord stimulation at 90% of motor threshold produced the late phase of vasodilatation only in the cooled hindpaw, which was possible to block by the autonomic ganglion-blocking agent, hexamethonium. The early responses to spinal cord stimulation in the moderately cooled hindpaw were not affected by hexamethonium. In contrast, both the early and the late phase responses were eliminated by CGRP (8-37), an antagonist of the calcitonin gene-related peptide receptor. After dorsal rhizotomy, spinal cord stimulation at 90% of motor threshold elicited hexamethonium-sensitive vasodilatation in the cooled hindpaw (late phase). These results suggest that spinal cord stimulation-induced vasodilatation in the cooled hindpaw (<25 degrees C) is mediated via both the sensory afferent (early phase of vasodilatation) and via suppression of the sympathetic efferent activity (late phase) although the threshold for vasodilatation via the sympathetic efferent fibers is higher than that via sensory nerves. In contrast, vasodilatation via sensory afferent fibers may predominate with moderate temperatures (25-28 degrees C). Thus, two complementary mechanisms for spinal cord stimulation-induced vasodilatation may

  9. The adrenal contribution to the neuroendocrine responses to splanchnic nerve stimulation in conscious calves.

    PubMed Central

    Bloom, S R; Edwards, A V; Jones, C T

    1988-01-01

    1. The extent to which the adrenal gland contributes to neuroendocrine responses to electrical stimulation of the peripheral end of the splanchnic nerve has been investigated in conscious calves in which the right nerve was stimulated either at 4 Hz continuously for 10 min or at 40 Hz in 1 s bursts at 10 s intervals for the same period. 2. It was confirmed that the release of neuropeptide Y (NPY) and of gastrin-releasing peptide (GRP) is potentiated by stimulation in bursts at a relatively high frequency and shown that the adrenal gland made a negligible contribution to these responses. 3. There was no detectable change in the concentration of vasoactive intestinal peptide (VIP) in the arterial plasma but the existence of a very small but highly significant rise in the output of VIP from the adrenal provided evidence that it was released within the gland in response to splanchnic nerve stimulation. 4. The concentration of calcitonin gene-related peptide (CGRP) in the arterial and adrenal venous effluent plasma was consistently below the level of detection of the assay. 5. Splanchnic nerve stimulation resulted in an abrupt rise in the output of both free and total met5-enkephalin-like immunoreactivity from the adrenal gland which was substantially potentiated by stimulating in bursts. This pattern of stimulation also increased the proportion released in a high-molecular-weight form. 6. Stimulation in bursts significantly enhanced the output of both adrenaline and noradrenaline from the adrenal and resulted in the release of proportionately more noradrenaline. Small amounts of dopamine and DOPAC were also released during splanchnic nerve stimulation and the output of dopamine was significantly increased by stimulating in bursts. 7. Both patterns of stimulation elicited an abrupt rise in mean plasma adrenocorticotrophic hormone (ACTH) concentration, which was associated with an increase in mean adrenal cortisol output and the former effect was significantly enhanced

  10. Excitation-induced cell damage and beta2-adrenoceptor agonist stimulated force recovery in rat skeletal muscle.

    PubMed

    Mikkelsen, Ulla Ramer; Gissel, Hanne; Fredsted, Anne; Clausen, Torben

    2006-02-01

    Intensive exercise leads to a loss of force, which may be long lasting and associated with muscle cell damage. To simulate this impairment and to develop means of compensating the loss of force, extensor digitorum longus muscles from 4-wk-old rats were fatigued using intermittent 40-Hz stimulation (10 s on, 30 s off). After stimulation, force recovery, cell membrane leakage, and membrane potential were followed for 240 min. The 30-60 min of stimulation reduced tetanic force to approximately 10% of the prefatigue level, followed by a spontaneous recovery to approximately 20% in 120-240 min. Loss of force was associated with a decrease in K+ content, gain of Na+ and Ca2+ content, leakage of the intracellular enzyme lactic acid dehydrogenase (10-fold increase), and depolarization (13 mV). Stimulation of the Na+-K+ pump with either the beta2-adrenoceptor agonist salbutamol, epinephrine, rat calcitonin gene-related peptide (rCGRP), or dibutyryl cAMP improved force recovery by 40-90%. The beta-blocker propranolol abolished the effect of epinephrine on force recovery but not that of CGRP. Both spontaneous and salbutamol-induced force recovery were prevented by ouabain. The salbutamol-induced force recovery was associated with repolarization of the membrane potential (12 mV) to the level measured in unfatigued muscles. In conclusion, in muscles exposed to fatiguing stimulation leading to a considerable loss of force, cell leakage, and depolarization, stimulation of the Na+-K+ pump induces repolarization and improves force recovery, possibly due to the electrogenic action of the Na+-K+ pump. This mechanism may be important for the restoration of muscle function after intense exercise. PMID:16210418

  11. Inefficient constitutive inhibition of P2X3 receptors by brain natriuretic peptide system contributes to sensitization of trigeminal sensory neurons in a genetic mouse model of familial hemiplegic migraine

    PubMed Central

    Marchenkova, Anna; Vilotti, Sandra; Ntamati, Niels; van den Maagdenberg, Arn MJM

    2016-01-01

    Background On trigeminal ganglion neurons, pain-sensing P2X3 receptors are constitutively inhibited by brain natriuretic peptide via its natriuretic peptide receptor-A. This inhibition is associated with increased P2X3 serine phosphorylation and receptor redistribution to non-lipid raft membrane compartments. The natriuretic peptide receptor-A antagonist anantin reverses these effects. We studied whether P2X3 inhibition is dysfunctional in a genetic familial hemiplegic migraine type-1 model produced by introduction of the human pathogenic R192Q missense mutation into the mouse CACNA1A gene (knock-in phenotype). This model faithfully replicates several properties of familial hemiplegic migraine type-1, with gain-of-function of CaV2.1 Ca2+ channels, raised levels of the algogenic peptide calcitonin gene-related peptide, and enhanced activity of P2X3 receptors in trigeminal ganglia. Results In knock-in neurons, anantin did not affect P2X3 receptor activity, membrane distribution, or serine phosphorylation level, implying ineffective inhibition by the constitutive brain natriuretic peptide/natriuretic peptide receptor-A pathway. However, expression and functional properties of this pathway remained intact together with its ability to downregulate TRPV1 channels. Reversing the familial hemiplegic migraine type-1 phenotype with the CaV2.1-specific antagonist, ω-agatoxin IVA restored P2X3 activity to wild-type level and enabled the potentiating effects of anantin again. After blocking calcitonin gene-related peptide receptors, P2X3 receptors exhibited wild-type properties and were again potentiated by anantin. Conclusions P2X3 receptors on mouse trigeminal ganglion neurons are subjected to contrasting modulation by inhibitory brain natriuretic peptide and facilitatory calcitonin gene-related peptide that both operate via complex intracellular signaling. In the familial hemiplegic migraine type-1 migraine model, the action of calcitonin gene-related peptide appears to

  12. GLP-1 receptor stimulation of the lateral parabrachial nucleus reduces food intake: neuroanatomical, electrophysiological, and behavioral evidence.

    PubMed

    Richard, Jennifer E; Farkas, Imre; Anesten, Fredrik; Anderberg, Rozita H; Dickson, Suzanne L; Gribble, Fiona M; Reimann, Frank; Jansson, John-Olov; Liposits, Zsolt; Skibicka, Karolina P

    2014-11-01

    The parabrachial nucleus (PBN) is a key nucleus for the regulation of feeding behavior. Inhibitory inputs from the hypothalamus to the PBN play a crucial role in the normal maintenance of feeding behavior, because their loss leads to starvation. Viscerosensory stimuli result in neuronal activation of the PBN. However, the origin and neurochemical identity of the excitatory neuronal input to the PBN remain largely unexplored. Here, we hypothesize that hindbrain glucagon-like peptide 1 (GLP-1) neurons provide excitatory inputs to the PBN, activation of which may lead to a reduction in feeding behavior. Our data, obtained from mice expressing the yellow fluorescent protein in GLP-1-producing neurons, revealed that hindbrain GLP-1-producing neurons project to the lateral PBN (lPBN). Stimulation of lPBN GLP-1 receptors (GLP-1Rs) reduced the intake of chow and palatable food and decreased body weight in rats. It also activated lPBN neurons, reflected by an increase in the number of c-Fos-positive cells in this region. Further support for an excitatory role of GLP-1 in the PBN is provided by electrophysiological studies showing a remarkable increase in firing of lPBN neurons after Exendin-4 application. We show that within the PBN, GLP-1R activation increased gene expression of 2 energy balance regulating peptides, calcitonin gene-related peptide (CGRP) and IL-6. Moreover, nearly 70% of the lPBN GLP-1 fibers innervated lPBN CGRP neurons. Direct intra-lPBN CGRP application resulted in anorexia. Collectively, our molecular, anatomical, electrophysiological, pharmacological, and behavioral data provide evidence for a functional role of the GLP-1R for feeding control in the PBN. PMID:25116706

  13. Peptide portions may hold key to amplifying bone against porosis

    SciTech Connect

    Cotton, P.

    1990-02-02

    Pieces of peptides that are encoded in the calcitonin gene may explain enigmas in treatment of bone disease. Amplification of bone formation by two peptides with similar amino acid sequences was reported at the Third International Conference on the Fundamentals of Bone Growth at the University of California, Los Angeles (UCLA), schools of medicine and dentistry. One treatment enigma is that calcitonin regulates normal bone resorption but does not work as well when administered for the treatment of osteoporosis. While hormone therapy does work, it has wide-ranging effects like the potential for an increased risk of breast cancer. Bone-growth promotion by a better-known peptide, calcitonin gene-related peptide (CGRP), was described. The CGRP is usually processed in the nervous system and has a wide range of activity.

  14. Antimicrobial peptide scolopendrasin VII, derived from the centipede Scolopendra subspinipes mutilans, stimulates macrophage chemotaxis via formyl peptide receptor 1.

    PubMed

    Park, Yoo Jung; Lee, Ha Young; Jung, Young Su; Park, Joon Seong; Hwang, Jae Sam; Bae, Yoe-Sik

    2015-08-01

    In this study, we report that one of the antimicrobial peptides scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates actin polymerization and the subsequent chemotactic migration of macrophages through the activation of ERK and protein kinase B (Akt) activity. The scolopendrasin VII-induced chemotactic migration of macrophages is inhibited by the formyl peptide receptor 1 (FPR1) antagonist cyclosporine H. We also found that scolopendrasin VII stimulate the chemotactic migration of FPR1-transfected RBL-2H3 cells, but not that of vector-transfected cells; moreover, scolopendrasin VII directly binds to FPR1. Our findings therefore suggest that the antimicrobial peptide scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates macrophages, resulting in chemotactic migration via FPR1 signaling, and the peptide can be useful in the study of FPR1-related biological responses. PMID:26129676

  15. Helical synthetic peptides that stimulate cellular cholesterol efflux

    SciTech Connect

    Bielicki, John K.; Natarajan, Pradeep

    2010-04-06

    The present invention provides peptides comprising at least one amphipathic alpha helix and having an cholesterol mediating activity and a ABCA stabilization activity. The invention further provides methods of using such peptides.

  16. Starfish gonadotropic hormone: Relaxin-like gonad-stimulating peptides.

    PubMed

    Mita, Masatoshi

    2016-05-01

    Relaxin-like gonad-stimulating peptide (RGP) of starfish Patiria (= Asterina) pectinifera is the first identified invertebrate gonadotropin to trigger final gamete maturation. Recently, chemical structures of RGP were identified in several species of starfish. Three kinds of RGP molecules are found in the class Asteroidea. The chemical structure of P. pectinifera RGP (PpeRGP) is conserved among starfish of the order Valvatida beyond species. In contrast, the chemical structures of RGP identified in Asterias amurensis and Aphelasterias japonica of the order Forcipulatida are quite different from that of PpeRGP. The chemical structure of RGP in A. amurensis (AamRGP) is exactly the same as that in Asterias rubens (the order Forcipulatida), Astropecten scoparius (the order Paxillosida), Astropecten polyacanthus (the order Paxillosida), and Echinaster luzonicus (the order Spinulosida). The chemical structure of Coscinasterias acutispina RGP (the order Forcipulatida) is consistent with that of A. japonica RGP (AjaRGP). In cross-experiments using P. pectinifera, A. amurensis, and A. japonica ovaries, AamRGP and AjaRGP can induce each species of ovaries. Neither AamRGP nor AjaRGP induce oocyte maturation and ovulation in the ovary of P. pectinifera, although the PpeRGP is active in ovaries of A. amurensis and A. japonica. This suggests that the AamRGP and AjaRGP partly act species specificity. PMID:27102940

  17. Sensory nerves contribute to cutaneous vasodilator response to cathodal stimulation in healthy rats.

    PubMed

    Gohin, Stéphanie; Decorps, Johanna; Sigaudo-Roussel, Dominique; Fromy, Bérengère

    2015-09-01

    Cutaneous current-induced vasodilation (CIV) in response to galvanic current application is an integrative model of neurovascular interaction that relies on capsaicin-sensitive fiber activation. The upstream and downstream mechanisms related to the activation of the capsaicin-sensitive fibers involved in CIV are not elucidated. In particular, the activation of cutaneous transient receptor potential vanilloid type-1 (TRPV1) channels and/or acid-sensing ion channels (ASIC) (activators mechanisms) and the release of calcitonin gene-related peptide (CGRP) and substance P (SP) (effector mechanisms) have been tested. To assess cathodal CIV, we measured cutaneous blood flow using laser Doppler flowmetry for 20min following cathodal current application (240s, 100μA) on the skin of the thigh in anesthetized healthy rats for 20min. CIV was studied in rats treated with capsazepine and amiloride to inhibit TRPV1 and ASIC channels, respectively; CGRP8-37 and SR140333 to antagonize CGRP and neurokinin-1 (NK1) receptors, respectively; compared to their respective controls. Cathodal CIV was attenuated by capsazepine (12±2% vs 54±6%, P<0.001), amiloride (19±8% vs 61±6%, P<0.01), CGRP8-37 (15±6% vs 61±6%, P<0.001) and SR140333 (9±5% vs 54±6%, P<0.001) without changing local acidification. This is the first integrative study performed in healthy rats showing that cutaneous vasodilation in response to cathodal stimulation is initiated by activation of cutaneous TRPV1 and ASIC channels likely through local acidification. The involvement of CGRP and NK1 receptors suggests that cathodal CIV is the result of CGRP and SP released through activated capsaicin-sensitive fibers. Therefore cathodal CIV could be a valuable method to assess sensory neurovascular function in the skin, which would be particularly relevant to evaluate the presence of small nerve fiber disorders and the effectiveness of treatments. PMID:26205659

  18. CGRP may regulate bone metabolism through stimulating osteoblast differentiation and inhibiting osteoclast formation.

    PubMed

    He, Haitao; Chai, Jianshen; Zhang, Shengfu; Ding, Linlin; Yan, Peng; Du, Wenjun; Yang, Zhenzhou

    2016-05-01

    Calcitonin-gene-related peptide (CGRP) is a neuropeptide, which is widely distributed throughout the central and peripheral nervous systems. Numerous mechanisms underlying the action of CGRP in osteoblast-associated cells have been suggested for bone growth and metabolism. The present study was designed to closely investigate the osteoblast‑ and osteoclast-associated mechanisms of the effect of CGRP administration on bone metabolism in primary osteoblasts. Primary osteoblasts were obtained from newborn rabbit calvaria and incubated with different concentrations of human CGRP (hCGRP), hCGRP and hCGRP (8‑37), or without treatment as a control. Intracellular calcium (Ca2+) and cyclic adenosine monophosphate (cAMP) were detected following treatment, as well as the expression levels of osteoblast differentiation markers, including activating transcription factor‑4 (ATF4) and osteocalcin (OC), and receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG). The isolated primary osteoblasts were found to stain positively for ALP. hCGRP treatment had no significant effect on transient intracellular Ca2+ in the osteoblasts. Treatment of the osteoblasts with hCGRP led to elevations in the expression levels of cAMP, ATF4 and OPG, and downregulation in the expression of RANKL, in a dose‑dependent manner. These effects were markedly reversed by the addition of hCGRP (8‑37). The results of the present study demonstrated that CGRP administration not only stimulated osteoblast differentiation, as demonstrated by upregulated expression levels of ATF4 and OC in the hCGRP‑treated osteoblasts, but also inhibited OPG/RANKL‑regulated osteoclastogenesis. CGRP may act as a modulator of bone metabolism through osteoblast and osteoclast-associated mechanisms, which result in osteoblast formation with subsequent activation of bone formation. PMID:27035229

  19. SPARC is a source of copper-binding peptides that stimulate angiogenesis.

    PubMed

    Lane, T F; Iruela-Arispe, M L; Johnson, R S; Sage, E H

    1994-05-01

    SPARC is a transiently expressed extracellular matrix-binding protein that alters cell shape and regulates endothelial cell proliferation in vitro. In this study, we show that SPARC mRNA and protein are synthesized by endothelial cells during angiogenesis in vivo. SPARC and peptides derived from a cationic region of the protein (amino acids 113-130) stimulated the formation of endothelial cords in vitro; moreover, these peptides stimulated angiogenesis in vivo. Mapping of the active domain demonstrated that the sequence KGHK was responsible for most of the angiogenic activity; substitution of the His residue decreased the effect. We found that proteolysis of SPARC provided a source of KGHK, GHK, and longer peptides that contained these sequences. Although the Cu(2+)-GHK complex had been identified as a mitogen/morphogen in normal human plasma, we found KGHK and longer peptides to be potent stimulators of angiogenesis. SPARC113-130 and KGHK were shown to bind Cu2+ with high affinity; however, previous incubation with Cu2+ was not required for the stimulatory activity. Since a peptide from a second cationic region of SPARC (SPARC54-73) also bound Cu2+ but had no effect on angiogenesis, the angiogenic activity appeared to be sequence specific and independent of bound Cu2+. Thus, specific degradation of SPARC, a matrix-associated protein expressed by endothelial cells during vascular remodeling, releases a bioactive peptide or peptides, containing the sequence (K)GHK, that could regulate angiogenesis in vivo. PMID:7514608

  20. SPARC is a source of copper-binding peptides that stimulate angiogenesis

    PubMed Central

    1994-01-01

    SPARC is a transiently expressed extracellular matrix-binding protein that alters cell shape and regulates endothelial cell proliferation in vitro. In this study, we show that SPARC mRNA and protein are synthesized by endothelial cells during angiogenesis in vivo. SPARC and peptides derived from a cationic region of the protein (amino acids 113- 130) stimulated the formation of endothelial cords in vitro; moreover, these peptides stimulated angiogenesis in vivo. Mapping of the active domain demonstrated that the sequence KGHK was responsible for most of the angiogenic activity; substitution of the His residue decreased the effect. We found that proteolysis of SPARC provided a source of KGHK, GHK, and longer peptides that contained these sequences. Although the Cu(2+)-GHK complex had been identified as a mitogen/morphogen in normal human plasma, we found KGHK and longer peptides to be potent stimulators of angiogenesis. SPARC113-130 and KGHK were shown to bind Cu2+ with high affinity; however, previous incubation with Cu2+ was not required for the stimulatory activity. Since a peptide from a second cationic region of SPARC (SPARC54-73) also bound Cu2+ but had no effect on angiogenesis, the angiogenic activity appeared to be sequence specific and independent of bound Cu2+. Thus, specific degradation of SPARC, a matrix-associated protein expressed by endothelial cells during vascular remodeling, releases a bioactive peptide or peptides, containing the sequence (K)GHK, that could regulate angiogenesis in vivo. PMID:7514608

  1. TRPA1 receptor stimulation by hydrogen peroxide is critical to trigger hyperalgesia and inflammation in a model of acute gout.

    PubMed

    Trevisan, Gabriela; Hoffmeister, Carin; Rossato, Mateus Fortes; Oliveira, Sara Marchesan; Silva, Mariane Arnoldi; Silva, Cássia Regina; Fusi, Camilla; Tonello, Raquel; Minocci, Daiana; Guerra, Gustavo Petri; Materazzi, Serena; Nassini, Romina; Geppetti, Pierangelo; Ferreira, Juliano

    2014-07-01

    Acute gout attacks produce severe joint pain and inflammation associated with monosodium urate (MSU) crystals leading to oxidative stress production. The transient potential receptor ankyrin 1 (TRPA1) is expressed by a subpopulation of peptidergic nociceptors and, via its activation by endogenous reactive oxygen species, including hydrogen peroxide (H2O2), contributes to pain and neurogenic inflammation. The aim of this study was to investigate the role of TRPA1 in hyperalgesia and inflammation in a model of acute gout attack in rodents. Inflammatory parameters and mechanical hyperalgesia were measured in male Wistar rats and in wild-type (Trpa1(+/+)) or TRPA1-deficient (Trpa1(-/-)) male mice. Animals received intra-articular (ia, ankle) injection of MSU. The role of TRPA1 was assessed by receptor antagonism, gene deletion or expression, sensory fiber defunctionalization, and calcitonin gene-related peptide (CGRP) release. We found that nociceptor defunctionalization, TRPA1 antagonist treatment (via ia or oral administration), and Trpa1 gene ablation abated hyperalgesia and inflammatory responses (edema, H2O2 generation, interleukin-1β release, and neutrophil infiltration) induced by ia MSU injection. In addition, we showed that MSU evoked generation of H2O2 in synovial tissue, which stimulated TRPA1 producing CGRP release and plasma protein extravasation. The MSU-elicited responses were also reduced by the H2O2-detoxifying enzyme catalase and the reducing agent dithiothreitol. TRPA1 activation by MSU challenge-generated H2O2 mediates the entire inflammatory response in an acute gout attack rodent model, thus strengthening the role of the TRPA1 receptor and H2O2 production as potential targets for treatment of acute gout attacks. PMID:24780252

  2. Atrial natriuretic peptide stimulates salt secretion by shark rectal gland by releasing VIP

    SciTech Connect

    Silva, P.; Stoff, J.S.; Solomon, R.J.; Lear, S.; Kniaz, D.; Greger, R.; Epstein, F.H.

    1987-01-01

    Salt secretion by the isolated perfused rectal gland of the spiny dogfish shark, Squalus acanthias, is stimulated by synthetic rat atrial natriuretic peptide (ANP II) as well as extracts of shark heart, but not by 8-bromo-cyclic guanosine 5'-monophosphate. Cardiac peptides have no effect on isolated rectal gland cells or perfused tubules, suggesting that stimulation requires an intact gland. The stimulation of secretion by ANP II is eliminated by maneuvers that block neurotransmitter release. Cardiac peptides stimulate the release of vasoactive intestinal peptide (VIP), known to be present in rectal glands nerves, into the venous effluent of perfused glands in parallel with their stimulation of salt secretion, but the release of VIP induced by ANP II is prevented by perfusion with procaine. VIP was measured by radioimmunoassay. Cardiac peptides thus appear to regulate rectal gland secretion by releasing VIP from neural stores within the gland. It is possible that other physiological effects of these hormones might be explained by an action to enhanced local release of neurotransmitters.

  3. Purification and identification of lipolysis-stimulating peptides derived from enzymatic hydrolysis of soy protein.

    PubMed

    Tsou, May-June; Kao, Fuh-Juin; Lu, Hsi-Chi; Kao, Hao-Chun; Chiang, Wen-Dee

    2013-06-01

    The aim of this study was to purify and identify lipolysis-stimulating peptides derived from Flavourzyme®-soy protein isolate (SPI) hydrolysate (F-SPIH). Glycerol release was employed as a marker for lipolysis in 3T3-L1 adipocytes. A higher glycerol release represents a better lipolysis-stimulating activity. The peptide fraction with highest glycerol release obtained from F-SPIH fractionated by sequential ultrafiltration membranes was further purified using gel filtration chromatography and two steps of reverse-phase high-performance liquid chromatography. The peptides were identified using liquid chromatography-tandem mass spectrometry (LC/MS/MS). Three lipolysis-stimulating peptides were obtained, and the amino acid sequences were ILL, LLL and VHVV, respectively. The in vitro effect of gastrointestinal proteases on lipolysis-stimulating activity of synthetic ILL, LLL and VHVV, respectively, was also investigated. The result suggested that the gastrointestinal protease did not affect lipolysis-stimulating activity of the three novel peptides, which reveals their potential to act as anti-obesity ingredients. PMID:23411267

  4. Stimulation of Lysine Decarboxylase Production in Escherichia coli by Amino Acids and Peptides1

    PubMed Central

    Cascieri, T.; Mallette, M. F.

    1973-01-01

    A commercial hydrolysate of casein stimulated production of lysine decarboxylase (EC 4.1.1.18) by Escherichia coli B. Cellulose and gel chromatography of this hydrolysate yielded peptides which were variably effective in this stimulation. Replacement of individual, stimulatory peptides by equivalent amino acids duplicated the enzyme levels attained with those peptides. There was no indication of specific stimulation by any peptide. The peptides were probably taken up by the oligopeptide transport system of E. coli and hydrolyzed intracellularly by peptidases to their constituent amino acids for use in enzyme synthesis. Single omission of amino acids from mixtures was used to screen them for their relative lysine decarboxylase stimulating abilities. Over 100 different mixtures were evaluated in establishing the total amino acid requirements for maximal synthesis of lysine decarboxylase by E. coli B. A mixture containing all of the common amino acids except glutamic acid, aspartic acid, and alanine increased lysine decarboxylase threefold over an equivalent weight of casein hydrolysate. The nine most stimulatory amino acids were methionine, arginine, cystine, leucine, isoleucine, glutamine, threonine, tyrosine, and asparagine. Methionine and arginine quantitatively were the most important. A mixture of these nine was 87% as effective as the complete mixture. Several amino acids were inhibitory at moderate concentrations, and alanine (2.53 mM) was the most effective. Added pyridoxine increased lysine decarboxylase activity 30%, whereas other B vitamins and cyclic adenosine 5′-monophosphate had no effect. PMID:4588201

  5. Identification of peptide-specific TCR genes by in vitro peptide stimulation and CDR3 length polymorphism analysis.

    PubMed

    Shao, Hongwei; Lin, Yanmei; Wang, Teng; Ou, Yusheng; Shen, Han; Tao, Changli; Wu, Fenglin; Zhang, Wenfeng; Bo, Huaben; Wang, Hui; Huang, Shulin

    2015-07-10

    Identification of TCR genes specific for tumor-associated antigens (TAAs) is necessary for TCR gene modification of T cells, which is applied in anti-tumor adoptive T cell therapy (ACT). The usual identification methods are based on isolating single peptide-responding T cells and cloning the TCR gene by in vitro expansion or by single-cell RT-PCR. However, the long and exacting in vitro culture period and demanding operational requirements restrict the application of these methods. Immunoscope is an effective tool that profiles a repertoire of TCRs and identifies significantly expanded clones through CDR3 length analysis. In this study, a survivin-derived mutant peptide optimized for HLA-A2 binding was selected to load DCs and activate T cells. The monoclonal expansion of TCRA and TCRB genes was separately identified by Immunoscope analysis and following sequence identification, the properly paired TCR genes were transferred into T cells. Peptide recognition and cytotoxicity assays indicated that TCR-modified PBMCs could respond to both the mutant and wild type peptides and lyse target cells. These results show that combining Immunoscope with in vitro peptide stimulation provides an alternative and superior method for identifying specific TCR genes, which represents a significant advance for the application of TCR gene-modified T cells. PMID:25890221

  6. Preferred recycling pathway by internalized PGE2 EP4 receptor following agonist stimulation in cultured dorsal root ganglion neurons contributes to enhanced EP4 receptor sensitivity.

    PubMed

    St-Jacques, Bruno; Ma, Weiya

    2016-06-21

    Prostaglandin E2 (PGE2), a well-known pain mediator abundantly produced in injured tissues, sensitizes nociceptive dorsal root ganglion (DRG) neurons (nociceptors) through its four EP receptors (EP1-4). Our prior study showed that PGE2 or EP4 agonist stimulates EP4 externalization and this event was not only suppressed by the inhibitor of anterograde export, but also by the recycling inhibitor (St-Jacques and Ma, 2013). These data suggest that EP4 recycling also contributes to agonist-enhanced EP4 surface abundance. In the current study, we tested this hypothesis using antibody-feeding-based internalization assay, recycling assay and FITC-PGE2 binding assay. We observed that selective EP4 agonist 1-hydroxy-PGE1 (1-OH-PGE1) or CAY10850 time- and concentration-dependently increased EP4 internalization in cultured DRG neuron. Internalized EP4 was predominantly localized in the early endosomes and recycling endosomes, but rarely in the late endosomes and lysosomes. These observations were confirmed by FITC-PGE2 binding assay. We further revealed that 1-OH-PGE1 or CAY10850 time- and concentration-dependently increased EP4 recycling. Double exposures to 1-OH-PGE1 induced a greater increase in calcitonin gene-related peptide (CGRP) release than a single exposure or vehicle exposure, an event blocked by pre-treatment with the recycling inhibitor monensin. Our data suggest that EP4 recycling contributes to agonist-induced cell surface abundance and consequently enhanced receptor sensitivity. Facilitating EP4 externalization and recycling is a novel mechanism underlying PGE2-induced nociceptor sensitization. PMID:27060485

  7. Peptides having reduced toxicity that stimulate cholesterol efflux

    DOEpatents

    Bielicki, John K.; Johansson, Jan; Danho, Waleed

    2016-08-16

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABCA1 that parallels that of full-length apolipoproteins. Further, the peptides of the invention have little or no toxicity when administered at therapeutic and higher doses. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  8. Peptide YY antagonizes beta-adrenergic-stimulated release of insulin in dogs

    SciTech Connect

    Greeley, G.H. Jr.; Lluis, F.; Gomex, G.; Ishizuka, J.; Holland, B.; Thompson, J.C. )

    1988-04-01

    Peptide YY (PYY) and neuropeptide Y (NPY) are peptides of 36 amino acids that share structural homologies with pancreatic polypeptide (PP). PP is predominantly found in the endocrine pancreas. PYY is primarily found in mucosal endocrine cells of the distal ileum, colon, and rectum, whereas NPY is found in both the peripheral and central nervous system. Previous studies indicate that these peptides can interact with the autonomic nervous system. The objective of the present experiments was to study the effect of PYY on neurally stimulated insulin release in conscious dogs. Intravenous administration of PYY (100, 200, and 400 pmol{center dot}kg{sup {minus}1} {center dot}h{sup {minus}1}) reduced 2-DG-stimulated insulin release in a dose-dependent manner (P <0.05) without affecting plasma glucose levels. Administration of NPY, but not PP, reduced 2-DG-stimulated release of insulin. The inhibitory action of PYY on 2-DG-stimulated insulin release persisted in the presence of atropine or phentolamine treatment; however, hexamethonium alone or phentolamine plus propranolol treatment blocked the inhibitory action of PYY. Release of insulin stimulated by the {beta}-agonist isoproterenol was also inhibited by PYY. These results indicate that PYY can inhibit autonomic neurotransmission by a mechanism that may involve ganglionic or postganglionic inhibition of {beta}-adrenergic stimulation. The findings suggest a role for PYY and NPY in the autonomic regulation of insulin release.

  9. Vasoactive intestinal peptide stimulates protein phosphorylation in a colonic epithelial cell line

    SciTech Connect

    Cohn, J.A.

    1987-09-01

    The T/sub 84/ colonic epithelial cell line was used to examine protein phosphorylation during neurohumoral stimulation of ion transport. T/sub 84/ cell monolayers grown on collagen-coated filters were mounted in Ussing chambers to measure ion transport stimulated by vasoactive intestinal peptide. Maximal stimulation of active secretion occurred after 8-10 min of stimulation. Protein phosphorylation events accompanying stimulated secretion were detected using two-dimensional gel electrophoresis to resolve phosphoproteins from monolayers previously labeled using /sup 32/P/sub i/. Within 8 min of exposure to vasoactive intestinal peptide, several phosphorylation events were detected, including a two- to fivefold increase in /sup 32/P incorporation into four soluble proteins with apparent molecular weights of 17,000, 18,000, 23,000, and 37,000. The same phosphorylation response occurs in monolayers stimulated by dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP), suggesting that cAMP mediates these intracellular events. This study indicates that changes in protein phosphorylation accompany the secretory action of vasocactive intestinal peptide and suggests that T/sub 84/ cells offer a useful model for studying the possibility that such phosphorylation events regulate enterocyte ion transport.

  10. Transient expression of somatostatin messenger RNA and peptide in the hypoglossal nucleus of the neonatal rat.

    PubMed

    Seroogy, K B; Bayliss, D A; Szymeczek, C L; Hökfelt, T; Millhorn, D E

    1991-06-21

    The postnatal developmental expression of somatostatin mRNA and peptide in the rat hypoglossal nucleus was analyzed using immunocytochemical and in situ hybridization techniques. Both the neuropeptide and its cognate mRNA were found to be transiently present within a subpopulation of hypoglossal motoneurons during the neonatal period. At the day of birth, a large population of perikarya situated in caudal, ventral regions of the hypoglossal nucleus expressed somatostatin. By postnatal day 7, the number of hypoglossal somata which expressed somatostatin had diminished considerably, and by 2 weeks postnatal, only few such cell bodies were found. By 3-4 weeks postnatal, somatostatin peptide- and mRNA-containing hypoglossal motoneurons were rarely observed, and in the adult, they were never detected, despite the use of colchicine. A double-labeling co-localization technique was used to demonstrate that somatostatin, when present perinatally, always coexisted with calcitonin gene-related peptide in hypoglossal motoneurons. The latter peptide, in contrast to somatostatin, was expressed in large numbers of somata throughout the entire hypoglossal nucleus and persisted within the motoneurons throughout development into adulthood. These results demonstrate that somatostatin is transiently expressed in motoneurons of the caudal, ventral tier of the hypoglossal nucleus in the neonatal rat. The developmental disappearance of somatostatin is most likely not due to cell death; hypoglossal somata continue to express calcitonin gene-related peptide, with which somatostatin coexisted perinatally, a high levels throughout development. Thus, it appears that the regulation of somatostatin expression in hypoglossal neurons occurs at the level of gene transcription or mRNA stability/degradation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1680035

  11. Expression of messenger RNAs for peptides and tyrosine hydroxylase in primary sensory neurons that innervate arterial baroreceptors and chemoreceptors.

    PubMed

    Czyzyk-Krzeska, M F; Bayliss, D A; Lawson, E E; Millhorn, D E

    1991-08-01

    Retrograde fiber tracing and in situ hybridization were used to determine expression of mRNAs for preprotachykinin A (ppTA), calcitonin gene related peptide (CGRP), preproenkephalin A (ENK), neuropeptide tyrosine (NPY) and somatostatin (SOM) as well as tyrosine hydroxylase (TH) in the petrosal ganglia primary sensory neurons which innervate carotid sinus baroreceptors and carotid body chemoreceptors. Perfusion of the carotid sinus with the retrogradely transported dye (Fluoro-Gold) labeled primary sensory neurons in petrosal ganglion. Numerous somata in the petrosal ganglion labeled with dye contained mRNAs for all the above peptides, except SOM. Moreover, TH mRNA was found in a substantial number of retrogradely labeled cells in the petrosal ganglion. This study provides information concerning which of the numerous peptides identified in sensory neurons of petrosal ganglion may be involved in modulation of the arterial baroreceptor and chemoreceptor reflexes. PMID:1681484

  12. A new relaxin-like gonad-stimulating peptide identified in the starfish Asterias amurensis.

    PubMed

    Mita, Masatoshi; Daiya, Misaki; Haraguchi, Shogo; Tsutsui, Kazuyoshi; Nagahama, Yoshitaka

    2015-10-01

    Relaxin-like gonad-stimulating peptide (RGP) of starfish Asterina pectinifera was the first invertebrate gonadotropin to have its chemical structure identified. However, it is unclear whether gonadotropic hormones in other species starfish are relaxin-like peptides. Thus, this study tried to identify the molecular structure of gonadotropic hormone in Asterias amurensis. As a result, we identified A. amurensis gonadotropic hormone as the RGP (AamRGP). The DNA sequence encoding AamRGP consisted of 330 base pairs with an open reading frame encoding a peptide of 109 amino acids (aa), including a signal peptide (26 aa), B-chain (20 aa), C-peptide (38 aa) and A-chain (25 aa). Comparing with A. pectinifera RGP (ApeRGP), the amino acid identity levels between AmaRGP and ApeRGP were 58% for the A-chain and 73% for the B-chain. Furthermore, chemical synthetic AamRGP induced gamete spawning and oocyte maturation in ovarian fragments of A. amurensis. In contrast, the ovary of A. pectinifera failed to respond to the AamRGP. This suggested that AamRGP is a new relaxin-like peptide. PMID:26163025

  13. ZP-binding peptides identified via phage display stimulate production of sperm antibodies in dogs.

    PubMed

    Samoylova, Tatiana I; Cox, Nancy R; Cochran, Anna M; Samoylov, Alexandre M; Griffin, Brenda; Baker, Henry J

    2010-07-01

    Zona pellucida (ZP) glycoproteins play a central role in sperm-oocyte binding and fertilization. Sperm protein sequences that are involved in sperm-ZP recognition and have an important role in fertilization represent attractive targets for development of contraceptive vaccines, yet are currently unknown. To identify peptide sequences that recognize and bind to ZP proteins, we developed a novel selection procedure from phage display libraries that utilizes intact oocytes surrounded by ZP proteins. The major advantage of this procedure is that ZP proteins remain in their native conformation unlike a selection protocol previously published that utilized solubilized ZP on artificial solid support. Several peptides of 7 and 12 amino acids with binding specificity to canine ZP proteins were identified. Four of them (LNSFLRS, SSWYRGA, YLPIYTIPSMVY, and NNQSPILKLSIH) plus a control ZP-binding peptide (YLPVGGLRRIGG) from the literature were synthesized and tested for antigenic properties in dogs. NNQSPILKLSIH peptide stimulated production of anti-peptide antibodies. These antibodies bind to the acrosomal region of the canine sperm cell, demonstrating ability to act as sperm antibodies. The identified ZP-binding peptides (mimicking sperm cell surface antigens) may be useful in the design of immunocontraceptive agents for dogs. PMID:20434854

  14. β-casein-derived peptides, produced by bacteria, stimulate cancer cell invasion and motility

    PubMed Central

    Oliveira, Maria José; Van Damme, Jozef; Lauwaet, Tineke; De Corte, Veerle; De Bruyne, Georges; Verschraegen, Gerda; Vaneechoutte, Mario; Goethals, Marc; Ahmadian, Mohammad Reza; Müller, Oliver; Vandekerckhove, Joël; Mareel, Marc; Leroy, Ancy

    2003-01-01

    In colon cancer, enteric bacteria and dietary factors are major determinants of the microenvironment but their effect on cellular invasion is not known. We therefore incubated human HCT-8/E11 colon cancer cells with bacteria or bacterial conditioned medium on top of collagen type I gels. Listeria monocytogenes stimulate cellular invasion through the formation of a soluble motility-promoting factor, identified as a 13mer β-casein-derived peptide (HKEMPFPKYPVEP). The peptide is formed through the combined action of Mpl, a Listeria thermolysin-like metalloprotease, and a collagen-associated trypsin-like serine protease. The 13mer peptide was also formed by tumour biopsies isolated from colon cancer patients and incubated with a β-casein source. The pro- invasive 13mer peptide-signalling pathway implicates activation of Cdc42 and inactivation of RhoA, linked to each other through the serine/threonine p21- activated kinase 1. Since both changes are necessary but not sufficient, another pathway might branch upstream of Cdc42 at phosphatidylinositol 3-kinase. Delta opioid receptor (δOR) is a candidate receptor for the 13mer peptide since naloxone, an δOR antagonist, blocks both δOR serine phosphorylation and 13mer peptide-mediated invasion. PMID:14609961

  15. Alpha-Melanocyte Stimulating Hormone: An Emerging Anti-Inflammatory Antimicrobial Peptide

    PubMed Central

    Singh, Madhuri; Mukhopadhyay, Kasturi

    2014-01-01

    The alpha-melanocyte stimulating hormone (α-MSH) is a neuropeptide belonging to the melanocortin family. It is well known for its anti-inflammatory and antipyretic effects and shares several characteristics with antimicrobial peptides (AMPs). There have been some recent reports about the direct antimicrobial activity of α-MSH against various microbes belonging to both fungal and bacterial pathogens. Similar to α-MSH's anti-inflammatory properties, its C-terminal residues also exhibit antimicrobial activity parallel to that of the entire peptide. This review is focused on the current findings regarding the direct antimicrobial potential and immunomodulatory mechanism of α-MSH and its C-terminal fragments, with particular emphasis on the prospects of α-MSH based peptides as a strong anti-infective agent. PMID:25140322

  16. Replacement of the Disulfide Bridge in a KLK3-Stimulating Peptide Using Orthogonally Protected Building Blocks

    PubMed Central

    2013-01-01

    Peptide “B-2”, which is one of the most potent kallikrein-related peptidase 3 (KLK3)-stimulating compounds, consists of 12 amino acids and is cyclized by a disulfide bridge between the N- and C-terminal cysteines. Orthogonally protected building blocks were used in the peptide synthesis to introduce a disulfide bridge mimetic consisting of four carbon atoms. The resulting pseudopeptides with alkane and E-alkene linkers doubled the proteolytic activity of KLK3 at a concentration of 14 μM. They were almost as potent as the parent “B-2” peptide, which gives a 3.6-fold increase in the proteolytic activity of KLK3 at the same concentration. PMID:24900791

  17. A relaxin-like gonad-stimulating peptide from the starfish Aphelasterias japonica.

    PubMed

    Mita, Masatoshi; Katayama, Hidekazu

    2016-04-01

    Relaxin-like gonad-stimulating peptide (RGP) in starfish is the first identified invertebrate gonadotropin responsible for final gamete maturation. In this study, a new ortholog RGP was identified from Aphelasterias japonica. The DNA sequence encoding A. japonica RGP (AjaRGP) consists of 342 base pairs with an open reading frame encoding a peptide of 113 amino acids (aa), including a signal peptide (26aa), B-chain (20aa), C-peptide (42aa), and A-chain (25aa). AjaRGP is a heterodimeric peptide with disulfide cross-linkages. Comparing with Asterias amurensis RGP (AamRGP) and Patiria (=Asterina) pectinifera RGP (PpeRGP), the amino acid identity levels of AjaRGP with respect to AamRGP and PpeRGP are 84% and 58% for the A-chain and 90% and 68% for the B-chain, respectively. This suggests that AjaRGP is closer to AmaRGP rather than PpeRGP. Although chemical synthetic AjaRGP can induce gamete spawning and oocyte maturation in ovarian fragments of A. japonica, the ovary of P. pectinifera fails to respond to AjaRGP. This suggests that AjaRGP acts species-specifically. PMID:26944483

  18. Targeted Melanoma Imaging and Therapy with Radiolabeled Alpha-Melanocyte Stimulating Hormone Peptide Analogues

    PubMed Central

    Quinn, Thomas; Zhang, Xiuli; Miao, Yubin

    2010-01-01

    Radiolabeled alpha-melanocyte stimulating hormone (α-MSH) analogues have been used to define the expression, affinity and function of the melanocortin-1 receptor (MC1-R). The MC1-R is one of a family of five G-protein linker receptors, which is primarily involved in regulation of skin pigmentation. Over-expression of the MC1-R on melanoma tumor cells has made it an attractive target for the development of α-MSH peptide based imaging and therapeutic agents. Initially, the native α-MSH peptide was radiolabeled directly, but it suffered from low specific activity and poor stability. The addition of non-natural amino acids yielded α-MSH analogues with greater MC-1R affinity and stability. Furthermore, peptide cyclization via disulfide and lactam bond formation as well as site-specific metal coordination resulted in additional gains in receptor affinity and peptide stability in vitro and in vivo. Radiochemical stability of the α-MSH analogues was improved through the conjugation of metal chelators to the peptide’s N-terminus or lysine residues for radionuclide coordination. In vitro cell binding studies demonstrated that the radiolabeled α-MSH analogues had low to subnanomolar affinities for the MC1-R. Biodistribution and imaging studies in the B16 mouse melanoma modeled showed rapid tumor uptake of the radiolabeled peptides, with the cyclic peptides demonstrating prolonged tumor retention. Cyclic α-MSH analogues labeled with beta and alpha emitting radionuclides demonstrated melanoma therapeutic efficacy in the B16 melanoma mouse model. Strong pre-clinical imaging and therapy data highlight the clinical potential use of radiolabeled α-MSH peptides for melanoma imaging and treatment of disseminated disease. PMID:20467398

  19. Natriuretic peptides stimulate the cardiac sodium pump via NPR-C-coupled NOS activation.

    PubMed

    William, M; Hamilton, E J; Garcia, A; Bundgaard, H; Chia, K K M; Figtree, G A; Rasmussen, H H

    2008-04-01

    Natriuretic peptides (NPs) and their receptors (NPRs) are expressed in the heart, but their effects on myocyte function are poorly understood. Because NPRs are coupled to synthesis of cGMP, an activator of the sarcolemmal Na(+)-K(+) pump, we examined whether atrial natriuretic peptide (ANP) regulates the pump. We voltage clamped rabbit ventricular myocytes and identified electrogenic Na(+)-K(+) pump current (arising from the 3:2 Na(+):K(+) exchange and normalized for membrane capacitance) as the shift in membrane current induced by 100 micromol/l ouabain. Ten nanomoles per liter ANP stimulated the Na(+)-K(+) pump when the intracellular compartment was perfused with pipette solutions containing 10 mmol/l Na(+) but had no effect when the pump was at near maximal activation with 80 mmol/l Na(+) in the pipette solution. Stimulation was abolished by inhibition of cGMP-activated protein kinase with KT-5823, nitric oxide (NO)-activated guanylyl cyclase with 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ), or NO synthase with N(G)-nitro-L-arginine methyl ester (L-NAME). Since synthesis of cGMP by NPR-A and NPR-B is not NO dependent or ODQ sensitive, we exposed myocytes to AP-811, a highly selective ligand for the NPR-C "clearance" receptor. It abolished ANP-induced pump stimulation. Conversely, the selective NPR-C agonist ANP(4-23) reproduced stimulation. The stimulation was blocked by l-NAME. To examine NO production in response to ANP(4-23), we loaded myocytes with the NO-sensitive fluorescent dye diacetylated diaminofluorescein-2 and examined them by confocal microscopy. ANP(4-23) induced a significant increase in fluorescence, which was abolished by L-NAME. We conclude that NPs stimulate the Na(+)-K(+) pump via an NPR-C and NO-dependent pathway. PMID:18272821

  20. Antimicrobial peptides trigger a division block in Escherichia coli through stimulation of a signalling system.

    PubMed

    Yadavalli, Srujana S; Carey, Jeffrey N; Leibman, Rachel S; Chen, Annie I; Stern, Andrew M; Roggiani, Manuela; Lippa, Andrew M; Goulian, Mark

    2016-01-01

    Antimicrobial peptides are an important component of the molecular arsenal employed by hosts against bacteria. Many bacteria in turn possess pathways that provide protection against these compounds. In Escherichia coli and related bacteria, the PhoQ/PhoP signalling system is a key regulator of this antimicrobial peptide defence. Here we show that treating E. coli with sublethal concentrations of antimicrobial peptides causes cells to filament, and that this division block is controlled by the PhoQ/PhoP system. The filamentation results from increased expression of QueE, an enzyme that is part of a tRNA modification pathway but that, as we show here, also affects cell division. We also find that a functional YFP-QueE fusion localizes to the division septum in filamentous cells, suggesting QueE blocks septation through interaction with the divisome. Regulation of septation by PhoQ/PhoP may protect cells from antimicrobial peptide-induced stress or other conditions associated with high-level stimulation of this signalling system. PMID:27471053

  1. Antimicrobial peptides trigger a division block in Escherichia coli through stimulation of a signalling system

    PubMed Central

    Yadavalli, Srujana S.; Carey, Jeffrey N.; Leibman, Rachel S.; Chen, Annie I.; Stern, Andrew M.; Roggiani, Manuela; Lippa, Andrew M.; Goulian, Mark

    2016-01-01

    Antimicrobial peptides are an important component of the molecular arsenal employed by hosts against bacteria. Many bacteria in turn possess pathways that provide protection against these compounds. In Escherichia coli and related bacteria, the PhoQ/PhoP signalling system is a key regulator of this antimicrobial peptide defence. Here we show that treating E. coli with sublethal concentrations of antimicrobial peptides causes cells to filament, and that this division block is controlled by the PhoQ/PhoP system. The filamentation results from increased expression of QueE, an enzyme that is part of a tRNA modification pathway but that, as we show here, also affects cell division. We also find that a functional YFP–QueE fusion localizes to the division septum in filamentous cells, suggesting QueE blocks septation through interaction with the divisome. Regulation of septation by PhoQ/PhoP may protect cells from antimicrobial peptide-induced stress or other conditions associated with high-level stimulation of this signalling system. PMID:27471053

  2. Antibacterial Activity of a Competence-Stimulating Peptide in Experimental Sepsis Caused by Streptococcus pneumoniae

    PubMed Central

    Oggioni, Marco R.; Iannelli, Francesco; Ricci, Susanna; Chiavolini, Damiana; Parigi, Riccardo; Trappetti, Claudia; Claverys, Jean-Pierre; Pozzi, Gianni

    2004-01-01

    Streptococcus pneumoniae, a major cause of human disease, produces a 17-mer autoinducer peptide pheromone (competence-stimulating peptide [CSP]) for the control of competence for genetic transformation. Due to previous work linking CSP to stress phenotypes, we set up an in vivo sepsis model to assay its effect on virulence. Our data demonstrate a significant increase in the rates of survival of mice, reductions of blood S. pneumoniae counts, and prolonged times to death for mice treated with CSP. In vitro the dose of CSP used in the animal model produced a transitory inhibition of growth. When a mutant with a mutation in the CSP sensor histidine kinase was assayed, no bacteriostatic phenotype was detected in vitro and no change in disease outcome was observed in vivo. The data demonstrate that CSP, which induces in vitro a temporary growth arrest through stimulation of its cognate histidine kinase receptor, is able to block systemic disease in mice. This therapeutic effect is novel, in that the drug-like effect is obtained by stimulation, rather than inhibition, of a bacterial drug target. PMID:15561850

  3. Protective effect of atrial natriuretic peptide on electrical-field-stimulated rat ventricular strips during hypoxia.

    PubMed

    Ljusegren, M E; Andersson, R G

    1994-12-01

    We have previously shown that atrial natriuretic peptide reduces lactate accumulation in non-beating rat ventricular myocardium exposed to hypoxic conditions, and that hypoxia induces release of atrial natriuretic peptide from isolated rat atrial tissue. In these studies we suggested that atrial natriuretic peptide may be physiologically important for protection of the myocardium during periods of oxygen deficit. In the present study, we used isolated strips of rat right ventricle, contracted by electrical-field-stimulation, as a model of a beating myocardium. After contraction stabilization, hypoxic conditions were introduced through aeration with 20% O2, held for 20 or 30 min., and then interrupted by reoxygenation with 95% O2. The contractile force was recorded and the percentage regain of the contractions after reoxygenation was considered as an indication of the amount of cell damage induced during the period of hypoxia. The results show that after 30 min. of hypoxia and subsequent reoxygenation, ventricular strips treated with atrial natriuretic peptide (0.1 microM) recovered 67.9 +/- 2.8% of the prehypoxic force of contraction; control strips from the same ventricle regained 44.9 +/- 4.4% (P = 0.015) of their initial contractile activity. After 20 min. of hypoxia followed by reoxygenation, a ventricular strip incubated together with an atrium regained 78.6 +/- 2.4% of the prehypoxic force of contraction as compared to a 60.2 +/- 2.7% regain (P = 0.002) for the control strip. We conclude that atrial natriuretic peptide protects the working ventricular myocardium during hypoxia, which further supports our previously reported suggestion that the effect on myocardial metabolism is physiologically relevant during situations of oxygen deficit in heart muscle. PMID:7899254

  4. Histone H4-related osteogenic growth peptide (OGP): a novel circulating stimulator of osteoblastic activity.

    PubMed Central

    Bab, I; Gazit, D; Chorev, M; Muhlrad, A; Shteyer, A; Greenberg, Z; Namdar, M; Kahn, A

    1992-01-01

    It has been established that regenerating marrow induces an osteogenic response in distant skeletal sites and that this activity is mediated by factors released into the circulation by the healing tissue. In the present study we have characterized one of these factors, a 14 amino acid peptide named osteogenic growth peptide (OGP). Synthetic OGP, identical in structure to the native molecule, stimulates the proliferation and alkaline phosphatase activity of osteoblastic cells in vitro and increases bone mass in rats when injected in vivo. Immunoreactive OGP in high abundance is present physiologically in the serum, mainly in the form of an OGP-OGP binding protein complex. A marked increase in serum bound and unbound OGP accompanies the osteogenic phase of post-ablation marrow regeneration and associated systemic osteogenic response. Authentic OGP is identical to the C-terminus of histone H4 and shares a five residue motif with a T-cell receptor beta-chain V-region and the Bacillus subtilis outB locus. Since these latter proteins have not been implicated previously in the control of cell proliferation or differentiation, OGP may belong to a novel, heretofore unrecognized family of regulatory peptides. Perhaps more importantly, OGP appears to represent a new class of molecules involved in the systemic control of osteoblast proliferation and differentiation. Images PMID:1582415

  5. Activation of EP4 receptors contributes to prostaglandin E2-mediated stimulation of renal sensory nerves.

    PubMed

    Kopp, Ulla C; Cicha, Michael Z; Nakamura, Kazuhiro; Nüsing, Rolf M; Smith, Lori A; Hökfelt, Tomas

    2004-12-01

    Induction of cyclooxygenase-2 (COX-2) in the renal pelvic wall increases prostaglandin E(2) (PGE(2)) leading to stimulation of cAMP production, which results in substance P (SP) release and activation of renal mechanosensory nerves. The subtype of PGE receptors involved, EP2 and/or EP4, was studied by immunohistochemistry and renal pelvic administration of agonists and antagonists of EP2 and EP4 receptors. EP4 receptor-like immunoreactivity (LI) was colocalized with calcitonin gene-related peptide (CGRP)-LI in dorsal root ganglia (DRGs) at Th(9)-L(1) and in nerve terminals in the renal pelvic wall. Th(9)-L(1) DRG neurons also contained EP3 receptor-LI and COX-2-LI, each of which was colocalized with CGRP-LI in some neurons. No renal pelvic nerves contained EP3 receptor-LI and only very few nerves COX-2-LI. The EP1/EP2 receptor antagonist AH-6809 (20 microM) had no effect on SP release produced by PGE(2) (0.14 microM) from an isolated rat renal pelvic wall preparation. However, the EP4 receptor antagonist L-161,982 (10 microM) blocked the SP release produced by the EP2/EP4 receptor agonist butaprost (10 microM) 12 +/- 2 vs. 2 +/- 1 and PGE(2), 9 +/- 1 vs. 1 +/- 0 pg/min. The SP release by butaprost and PGE(2) was similarly blocked by the EP4 receptor antagonist AH-23848 (30 microM). In anesthetized rats, the afferent renal nerve activity (ARNA) responses to butaprost 700 +/- 100 and PGE(2).780 +/- 100%.s (area under the curve of ARNA vs. time) were unaffected by renal pelvic perfusion with AH-6809. However, 1 microM L-161,982 and 10 microM AH-23848 blocked the ARNA responses to butaprost by 94 +/- 5 and 78 +/- 10%, respectively, and to PGE(2) by 74 +/- 16 and 74 +/- 11%, respectively. L-161,982 also blocked the ARNA response to increasing renal pelvic pressure 10 mmHg, 85 +/- 5%. In conclusion, PGE(2) increases renal pelvic release of SP and ARNA by activating EP4 receptors on renal sensory nerve fibers. PMID:15292051

  6. Self-Assembly and Collagen-Stimulating Activity of a Peptide Amphiphile Incorporating a Peptide Sequence from Lumican.

    PubMed

    Hamley, Ian W; Dehsorkhi, Ashkan; Castelletto, Valeria; Walter, Merlin N M; Connon, Che J; Reza, Mehedi; Ruokolainen, Janne

    2015-04-21

    The self-assembly and bioactivity of a peptide amphiphile (PA) incorporating a 13-residue sequence derived from the last 13 amino acids of the C-terminus of lumican, C16-YEALRVANEVTLN, attached to a hexadecyl (C16) lipid chain have been examined. Lumican is a proteoglycan found in many types of tissue and is involved in collagen fibril organization. A critical aggregation concentration (cac) for the PA was determined through pyrene fluorescence measurements. The structure of the aggregates was imaged using electron microscopy, and twisted and curved nanotapes were observed. In situ small-angle X-ray scattering and fiber X-ray diffraction reveal that these tapes contain interdigitated bilayers of the PA molecules. FTIR and circular dichroism spectroscopy and fiber X-ray diffraction indicate that the lumican sequence in the PA adopts a β-sheet secondary structure. Cell assays using human dermal fibroblasts show that below the cac the PA displays good biocompatibility and also stimulates collagen production over a period of 3 weeks, exceeding a 2-fold enhancement for several concentrations. Thus, this PA has promise in future biological applications, in particular, in tissue engineering. PMID:25835126

  7. Stimulation of murine peritoneal macrophage functions by neuropeptide Y and peptide YY. Involvement of protein kinase C.

    PubMed Central

    De la Fuente, M; Bernaez, I; Del Rio, M; Hernanz, A

    1993-01-01

    The peptides neuropeptide Y (NPY) and peptide YY (PYY) at concentrations from 10(-12) M to 10(-8) M have been shown in this study to stimulate significantly, in vitro, several functions of resting peritoneal macrophages from BALB/c mice: adherence to substrate, chemotaxis, ingestion of inert particles (latex beads) and foreign cells (Candida albicans), and production of superoxide anion measured by nitroblue tetrazolium reduction. A dose-response relationship was observed, with a maximal stimulation of the macrophage functions studied at 10(-10) M. These effects seem to be produced by specific receptors for the neuropeptides studied in peritoneal macrophages. Whereas the two peptides induced no change of intracellular cyclic AMP, they caused a significant stimulation of protein kinase C (PKC) in murine macrophages. These results suggest that NPY and PYY produce their effects on macrophage function through PKC activation. PMID:8262554

  8. Flavonoids stimulate cholecystokinin peptide secretion from the enteroendocrine STC-1 cells.

    PubMed

    Al Shukor, Nadin; Ravallec, Rozenn; Van Camp, John; Raes, Katleen; Smagghe, Guy

    2016-09-01

    Animal experiments showed that flavonoids might have the potential for an anti-obesity effect by reducing weight and food intake. However, the exact mechanisms that could be involved in these proposed effects are still under investigation. The complex process of food intake is partially regulated by gastrointestinal hormones. Cholecystokinin (CCK) is the best known gastrointestinal hormone to induce satiety signal that plays a key role in food intake regulation. It is released from the endocrine cells (I cell) in response to the ingestion of nutrients into the small intestine. In this study, we investigated the possible effects of flavonoids (quercetin, kaempferol, apigenin, rutin and baicalein) on stimulation of CCK release in vitro using enteroendocrine STC-1 cells. In comparison with the control, quercetin, kaempferol and apigenin resulted in a significant increase in CCK secretion with quercetin showing the highest activity. On the other hand, no significant effect was seen by rutin and baicalein. To our knowledge, this is the first report to study the stimulation of CCK peptide hormone secretion from STC-1 cells by quercetin and kaempferol, rutin, apigenin and baicalein. Based on the cell-based results in this work, it can be suggested that the reported activity of flavonoids against food intake and weight could be mediated by stimulation of CCK signal which in turn is responsible for food intake reduction, but future animal and human studies are needed to confirm this conclusion at organism level. PMID:27496247

  9. Peptide 19-2.5 inhibits heparan sulfate-triggered inflammation in murine cardiomyocytes stimulated with human sepsis serum.

    PubMed

    Martin, Lukas; Schmitz, Susanne; De Santis, Rebecca; Doemming, Sabine; Haase, Hajo; Hoeger, Janine; Heinbockel, Lena; Brandenburg, Klaus; Marx, Gernot; Schuerholz, Tobias

    2015-01-01

    Myocardial dysfunction in sepsis has been linked to inflammation caused by pathogen-associated molecular patterns (PAMPs) as well as by host danger-associated molecular patterns (DAMPs). These include soluble heparan sulfate (HS), which triggers the devastating consequences of the pro-inflammatory cascades in severe sepsis and septic shock. Thus, there is increasing interest in the development of anti-infective agents, with effectiveness against both PAMPs and DAMPs. We hypothesized that a synthetic antimicrobial peptide (peptide 19-2.5) inhibits inflammatory response in murine cardiomyocytes (HL-1 cells) stimulated with PAMPs, DAMPs or serum from patients with septic shock by reduction and/or neutralization of soluble HS. In the current study, our data indicate that the treatment with peptide 19-2.5 decreases the inflammatory response in HL-1 cells stimulated with either PAMPs or DAMPs. Furthermore, our work shows that soluble HS in serum from patients with Gram-negative or Gram-positive septic shock induces a strong pro-inflammatory response in HL-1 cells, which can be effectively blocked by peptide 19-2.5. Based on these findings, peptide 19-2.5 is a novel anti-inflammatory agent interacting with both PAMPs and DAMPs, suggesting peptide 19-2.5 may have the potential for further development as a broad-spectrum anti-inflammatory agent in sepsis-induced myocardial inflammation and dysfunction. PMID:26024383

  10. Peptide drugs accelerate BMP-2-induced calvarial bone regeneration and stimulate osteoblast differentiation through mTORC1 signaling.

    PubMed

    Sugamori, Yasutaka; Mise-Omata, Setsuko; Maeda, Chizuko; Aoki, Shigeki; Tabata, Yasuhiko; Murali, Ramachandran; Yasuda, Hisataka; Udagawa, Nobuyuki; Suzuki, Hiroshi; Honma, Masashi; Aoki, Kazuhiro

    2016-08-01

    Both W9 and OP3-4 were known to bind the receptor activator of NF-κB ligand (RANKL), inhibiting osteoclastogenesis. Recently, both peptides were shown to stimulate osteoblast differentiation; however, the mechanism underlying the activity of these peptides remains to be clarified. A primary osteoblast culture showed that rapamycin, an mTORC1 inhibitor, which was recently demonstrated to be an important serine/threonine kinase for bone formation, inhibited the peptide-induced alkaline phosphatase activity. Furthermore, both peptides promoted the phosphorylation of Akt and S6K1, an upstream molecule of mTORC1 and the effector molecule of mTORC1, respectively. In the in vivo calvarial defect model, W9 and OP3-4 accelerated BMP-2-induced bone formation to a similar extent, which was confirmed by histomorphometric analyses using fluorescence images of undecalcified sections. Our data suggest that these RANKL-binding peptides could stimulate the mTORC1 activity, which might play a role in the acceleration of BMP-2-induced bone regeneration by the RANKL-binding peptides. PMID:27345003

  11. Rapid increase in enzyme and peptide mRNA in sympathetic ganglia after electrical stimulation in humans.

    PubMed Central

    Schalling, M; Stieg, P E; Lindquist, C; Goldstein, M; Hökfelt, T

    1989-01-01

    Thoracic ganglia in humans were studied after electrical, preganglionic stimulation using in situ hybridization with synthetic oligonucleotide probes against the catecholamine-synthesizing enzymes tyrosine hydroxylase (EC 1.14.16.2) and dopamine beta-hydroxylase (EC 1.14.17.1) and neuropeptide tyrosine. Immunohistochemical analysis was also performed. Following short peroperative stimulation a severalfold increase in all three mRNAs was found in principal ganglion cells, whereas no definite changes could be detected in enzyme or peptide levels with immunohistochemistry. The results suggest a very rapid and sensitive regulation of genes involved in signal transmission in the sympathetic nervous system of humans. Moreover, they indicate that electrical stimulation of neurons and/or pathways combined with in situ hybridization may be used as a method to define neuronal projections by visualizing increases in mRNAs for transmitter enzymes and/or peptide in target cells. Images PMID:2567003

  12. PD-L1 peptide co-stimulation increases immunogenicity of a dendritic cell-based cancer vaccine.

    PubMed

    Munir Ahmad, Shamaila; Martinenaite, Evelina; Hansen, Morten; Junker, Niels; Borch, Troels Holz; Met, Özcan; Donia, Marco; Svane, Inge Marie; Andersen, Mads Hald

    2016-08-01

    We recently described naturally occurring PD-L1-specific T cells that recognize PD-L1-expressing immune cells as well as malignant cells. In the present study, we investigated whether the immunogenicity of a dendritic cell (DC)-based vaccine could be influenced by co-stimulation with a known PD-L1-derived epitope. We incubated a PD-L1-derived peptide epitope (19 amino acids long) or a control peptide (an irrelevant HIV epitope) with peripheral blood mononuclear cells from patients with malignant melanoma who had received a DC-based vaccine. We observed a significantly higher number of T cells that reacted to the vaccine in cultures that had been co-stimulated with the PD-L1 peptide epitope compared to cultures incubated with control peptide. Next, we characterized a novel PD-L1-derived epitope (23 amino acids long) and found that co-stimulation with both PD-L1 epitopes boosted the immune response elicited by the DC vaccine even further. Consequently, we observed a significant increase in the number of vaccine-reacting T cells in vitro. In conclusion, activation of PD-L1-specific T cells may directly modulate immunogenicity of DC vaccines. Addition of PD-L1 epitopes may thus be an easily applicable and attractive option to augment the effectiveness of cancer vaccines and other immunotherapeutic agents. PMID:27622072

  13. Analysis of the proteolysis of bioactive peptides using a peptidomics approach

    PubMed Central

    Kim, Yun-Gon; Lone, Anna Mari; Saghatelian, Alan

    2014-01-01

    Identifying the peptidases that inactivate bioactive peptides (e.g. peptide hormones and neuropeptides) in mammals is an important unmet challenge. This protocol describes a recent approach that combines liquid chromatography-mass spectrometry peptidomics to identify endogenous cleavage sites of a bioactive peptide, the subsequent biochemical purification of a candidate peptidase based on these cleavage sites, and validation of the candidate peptidase’s role in the physiological regulation of the bioactive peptide by examining a peptidase knockout mouse. We highlight successful application of this protocol to discover that insulin-degrading enzyme (IDE) regulates physiological calcitonin gene-related peptide (CGRP) levels and detail the key stages and steps in this approach. This protocol requires 7 days of work; however, the total time for this protocol is highly variable because of its dependence on the availability of biological reagents, namely purified enzymes and knockout mice. The protocol is valuable because it expedites the characterization of mammalian peptidases, such as IDE, which in certain instances can be used to develop novel therapeutics. PMID:23949379

  14. Oral administration of osteocalcin improves glucose utilization by stimulating glucagon-like peptide-1 secretion.

    PubMed

    Mizokami, Akiko; Yasutake, Yu; Higashi, Sen; Kawakubo-Yasukochi, Tomoyo; Chishaki, Sakura; Takahashi, Ichiro; Takeuchi, Hiroshi; Hirata, Masato

    2014-12-01

    Uncarboxylated osteocalcin (GluOC), a bone-derived hormone, regulates energy metabolism by stimulating insulin secretion and pancreatic β-cell proliferation. We previously showed that the effect of GluOC on insulin secretion is mediated largely by glucagon-like peptide-1 (GLP-1) secreted from the intestine in response to GluOC exposure. We have now examined the effect of oral administration of GluOC on glucose utilization as well as the fate of such administered GluOC in mice. Long-term intermittent or daily oral administration of GluOC reduced the fasting blood glucose level and improved glucose tolerance in mice without affecting insulin sensitivity. It also increased the fasting serum insulin concentration as well as the β-cell area in the pancreas. A small proportion of orally administered GluOC reached the small intestine and remained there for at least 24h. GluOC also entered the general circulation, and the serum GLP-1 concentration was increased in association with the presence of GluOC in the intestine and systemic circulation. The putative GluOC receptor, GPRC6A was detected in intestinal cells, and was colocalized with GLP-1 in some of these cells. Our results suggest that orally administered GluOC improved glucose handling likely by acting from both the intestinal lumen and the general circulation, with this effect being mediated in part by stimulation of GLP-1 secretion. Oral administration of GluOC warrants further study as a safe and convenient option for the treatment or prevention of metabolic disorders. PMID:25230237

  15. Angiotensin II-stimulated secretion of arginine vasopressin is inhibited by atrial natriuretic peptide in humans.

    PubMed

    Matsukawa, Toshiyoshi; Miyamoto, Takenori

    2011-03-01

    We investigated the effect of the intravenous infusion of atrial natriuretic peptide (ANP) on the response of plasma arginine vasopressin (AVP) levels to intravenous infusion of angiotensin II (ANG II) in healthy individuals. Intravenous infusion of ANP (10 ng·kg(-1)·min(-1)) slightly but significantly decreased plasma AVP levels, while intravenous infusion of ANG II (10 ng·kg(-1)·min(-1)) resulted in slightly increased plasma AVP levels. ANG II infused significant elevations in arterial blood pressure and central venous pressure (CVP). Because the elevation in blood pressure could have potentially inhibited AVP secretion via baroreceptor reflexes, the effect of ANG II on blood pressure was attenuated by the simultaneous infusion of nitroprusside. ANG II alone produced a remarkable increase in plasma AVP levels when infused with nitroprusside, whereas the simultaneous ANP intravenous infusion (10 ng·kg(-1)·min(-1)) abolished the increase in plasma AVP levels induced by ANG II when blood pressure elevation was attenuated by nitroprusside. Thus, ANG II increased AVP secretion and ANP inhibited not only basal AVP secretion but also ANG II-stimulated AVP secretion in humans. These findings support the hypothesis that circulating ANP modulates AVP secretion, in part, by antagonizing the action of circulating ANG II. PMID:21123762

  16. 83-kilodalton heat shock proteins of trypanosomes are potent peptide-stimulated ATPases.

    PubMed Central

    Nadeau, K.; Sullivan, M. A.; Bradley, M.; Engman, D. M.; Walsh, C. T.

    1992-01-01

    A Crithidia fasciculata 83-kDa protein purified during a separate study of C. fasciculata trypanothione synthetase was shown to have ATPase activity and to belong to the hsp90 family of stress proteins. Because no ATPase activity has previously been reported for the hsp90 class, ATP utilization by C. fasciculata hsp83 was characterized: this hsp83 has an ATPase kcat of 150 min-1 and a Km of 60 microM, whereas the homologous mammalian hsp90 binds ATP but has no ATPase activity. Crithidia fasciculata hsp83 undergoes autophosphorylation on serine and threonine at a rate constant of 3.3 x 10(-3) min-1. Similar analysis was performed on recombinant Trypanosoma cruzi hsp83, and comparable ATPase parameters were obtained (kcat = 100 min-1, Km = 80 microM, kautophosphorylation = 6.3 x 10(-3) min-1). The phosphoenzyme is neither on the ATPase hydrolytic pathway nor does it affect ATPase catalytic efficiency. Both C. fasciculata and T. cruzi hsp83 show up to fivefold stimulation of ATPase activity by peptides of 6-24 amino acids. PMID:1304385

  17. Structural Basis for Receptor Activity-Modifying Protein-Dependent Selective Peptide Recognition by a G Protein-Coupled Receptor.

    PubMed

    Booe, Jason M; Walker, Christopher S; Barwell, James; Kuteyi, Gabriel; Simms, John; Jamaluddin, Muhammad A; Warner, Margaret L; Bill, Roslyn M; Harris, Paul W; Brimble, Margaret A; Poyner, David R; Hay, Debbie L; Pioszak, Augen A

    2015-06-18

    Association of receptor activity-modifying proteins (RAMP1-3) with the G protein-coupled receptor (GPCR) calcitonin receptor-like receptor (CLR) enables selective recognition of the peptides calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) that have diverse functions in the cardiovascular and lymphatic systems. How peptides selectively bind GPCR:RAMP complexes is unknown. We report crystal structures of CGRP analog-bound CLR:RAMP1 and AM-bound CLR:RAMP2 extracellular domain heterodimers at 2.5 and 1.8 Å resolutions, respectively. The peptides similarly occupy a shared binding site on CLR with conformations characterized by a β-turn structure near their C termini rather than the α-helical structure common to peptides that bind related GPCRs. The RAMPs augment the binding site with distinct contacts to the variable C-terminal peptide residues and elicit subtly different CLR conformations. The structures and accompanying pharmacology data reveal how a class of accessory membrane proteins modulate ligand binding of a GPCR and may inform drug development targeting CLR:RAMP complexes. PMID:25982113

  18. Structural Basis for Receptor Activity-Modifying Protein-Dependent Selective Peptide Recognition by a G Protein-Coupled Receptor

    PubMed Central

    Booe, Jason M.; Walker, Christopher S.; Barwell, James; Kuteyi, Gabriel; Simms, John; Jamaluddin, Muhammad A.; Warner, Margaret L.; Bill, Roslyn M.; Harris, Paul W.; Brimble, Margaret A.; Poyner, David R.; Hay, Debbie L.; Pioszak, Augen A.

    2015-01-01

    Summary Association of receptor activity-modifying proteins (RAMP1-3) with the G protein-coupled receptor (GPCR) calcitonin receptor-like receptor (CLR) enables selective recognition of the peptides calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) that have diverse functions in the cardiovascular and lymphatic systems. How peptides selectively bind GPCR:RAMP complexes is unknown. We report crystal structures of CGRP analog-bound CLR:RAMP1 and AM-bound CLR:RAMP2 extracellular domain heterodimers at 2.5 and 1.8 Å resolutions, respectively. The peptides similarly occupy a shared binding site on CLR with conformations characterized by a β-turn structure near their C termini rather than the α-helical structure common to peptides that bind related GPCRs. The RAMPs augment the binding site with distinct contacts to the variable C-terminal peptide residues and elicit subtly different CLR conformations. The structures and accompanying pharmacology data reveal how a class of accessory membrane proteins modulate ligand binding of a GPCR and may inform drug development targeting CLR:RAMP complexes. PMID:25982113

  19. Sumatriptan inhibits the release of CGRP and substance P from the rat spinal cord.

    PubMed

    Arvieu, L; Mauborgne, A; Bourgoin, S; Oliver, C; Feltz, P; Hamon, M; Cesselin, F

    1996-08-12

    The possible presynaptic action of the anti-migraine drug sumatriptan on primary afferent fibres containing substance P and/or calcitonin gene-related peptide was investigated on superfused rat horizontal spinal cord slices with attached dorsal roots. Electrical stimulation of dorsal roots triggered a significant overflow of both peptides; this could be reduced by sumatriptan in a concentration-dependent manner. As expected from the involvement of 5-HT1B/1.D beta receptors, methiothepin, (-)tertatolol and GR 127,935, but not WAY 100,635, prevented the inhibitors effect of sumatriptan. These data support the idea that the anti-migraine action of sumatriptan may involve, at least in part, a presynaptic inhibitory control of nociceptive (trigeminovascular) substance P- and/or calcitonin gene-related peptide-containing sensory fibres. PMID:8905706

  20. Participation of the ascending serotonergic system in the stimulation of atrial natriuretic peptide release.

    PubMed Central

    Reis, L C; Ramalho, M J; Favaretto, A L; Gutkowska, J; McCann, S M; Antunes-Rodrigues, J

    1994-01-01

    Results obtained in our laboratories have provided evidence for the participation of the hypothalamic atrial natriuretic peptide (ANP) neuronal system in the regulation of water and electrolyte homeostasis. The anterior ventral third ventricular (AV3V) region, a site of the perikarya of the ANP neurons, receives important afferent input from ascending serotoninergic axons. We hypothesized that the ascending serotoninergic tract might be involved in control of the liberation of ANP. Therefore, electrolytic lesions were produced in the mesencephalic dorsal raphé nucleus (DRN), the site of perikarya of serotonin (5-HT) neurons whose axons project to the AV3V region. Rats with sham lesions constituted the control group. In a second group of animals, the serotoninergic system was depleted of 5-HT by lateral ventricular administration of p-chlorophenylalanine (PCPA), an amino acid that causes depletion of 5-HT from the serotoninergic neurons. Control animals were injected with an equal amount of isotonic saline. The DRN lesions induced an increase of water intake and urine output beginning on the first day that lasted for 1 week after lesions were produced. There was a concomitant sodium retention that lasted for the same period of time. When water-loaded, DRN-lesioned and PCPA-injected animals showed diminished excretion of sodium, accompanied by a decrease in basal plasma ANP concentrations, and blockade of the increase in plasma ANP, which followed blood volume expansion by intraatrial injection of hypertonic saline. The results are interpreted to mean that ascending stimulatory serotoninergic input into the ANP neuronal system in the AV3V region produces a tonic stimulation of ANP release, which augments sodium excretion and inhibits water intake. Therefore, in the absence of this serotoninergic input following destruction of the serotoninergic neurons by DRN lesions or intraventricular injection of PCPA, an antinatriuretic effect is obtained that is associated with

  1. Molecular and functional characterization of amylin, a peptide associated with type 2 diabetes mellitus

    SciTech Connect

    Roberts, A.N.; Leighton, B.; Todd, J.A.; Schofield, P.N.; Sutton, R.; Day, A.J.; Foot, E.A.; Willis, A.C.; Reid, K.B.M.; Cooper, H.J.S. ); Holt, S.; Boyd, Y. Medical Research Council Radiobiology Unit, Chilton )

    1989-12-01

    The 37-amino acid peptide called amylin is a major component of the islet amyloid deposited in the pancreases of persons with type 2 diabetes mellitus. The authors report the isolation of a partial cDNA clone and a phage {lambda} genomic clone of the coding region of the amylin gene. The DNA sequence encodes a protein sequences identical to that of amylin isolated from the amyloid found in the diabetic pancreas and shows that amylin is likely to be synthesized as a precursor peptide, now named proamylin. They have demonstrated that the amylin gene is present on chromosome 12 and that it is probably transcribed in the islets of Langerhans. The sequences of the genes for amyli and the calcitonin gene-related peptides (CGRPs) show strong similarity, especially over their 5{prime} coding regions, where both peptides have a conserved intramolecular disulfide bridge, and also over their 3{prime} coding regions, where the presence of a glycine codon strongly suggests that the carboxylterminal residue of amylin, like that of CGRP, is amidated. To examine the functional relevance of these posttranslational modifications, the biological activity of amylin synthesized with or without the disulfide bridge and/or amidation was measured. It was found that both features are necessary for full biological activity, thereby confirming the functional importance of those regions of the molecule whose sequences are conserved at both protein and genetic levels.

  2. Comparison of the effects of pantethine and fursultiamine on plasma gastrointestinal peptide levels in healthy volunteers.

    PubMed

    Suzuki, Yosuke; Itoh, Hiroki; Abe, Tomohide; Nishimura, Fumihiro; Sato, Yuhki; Takeyama, Masaharu

    2011-01-01

    Pantethine and fursultiamine have been evaluated for their clinical usefulness in the treatment and prevention of uncomplicated postoperative adhesive intestinal obstruction. In recent years, the actions of drugs used to treat gastrointestinal diseases have been elucidated pharmacologically from the viewpoints of gastrointestinal peptide levels. We examined the effects of pantethine and fursultiamine on plasma levels of calcitonin gene-related peptide (CGRP)-, vasoactive intestinal polypeptide (VIP)-, motilin- and substance P (SP)-like immunoreactive substances (IS) in healthy subjects. An open-labeled study was conducted on five healthy volunteers. Each subject was administered a single oral dose of pantethine, fursultiamine and placebo at intervals of one month. Venous blood samples were collected before and at 20, 40, 60, 90, 120, 180 and 240 min after each administration. Plasma peptide levels were measured using a highly sensitive enzyme immunoassay. A single oral dose of pantethine resulted in significant increases of plasma CGRP- and VIP-IS levels compared to placebo. Furthermore, areas under the plasma concentration-time curves (AUC(0-240)) of CGRP- and VIP-IS were significantly higher after pantethine administration compared with placebo. On the other hand, fursultiamine had no effect on plasma levels and AUC(0-240) of CGRP-, VIP-, motilin- and SP-IS. This study demonstrated the different effects of pantethine and fursultiamine from the viewpoint of plasma gastrointestinal peptide changes. The pharmacological effects of pantethine may be closely related to the changes in plasma CGRP- and VIP-IS levels. PMID:21963510

  3. Targeting of follicle stimulating hormone peptide-conjugated dendrimers to ovarian cancer cells

    NASA Astrophysics Data System (ADS)

    Modi, Dimple A.; Sunoqrot, Suhair; Bugno, Jason; Lantvit, Daniel D.; Hong, Seungpyo; Burdette, Joanna E.

    2014-02-01

    Ovarian cancer is the most lethal gynecological malignancy. Current treatment modalities include a combination of surgery and chemotherapy, which often lead to loss of fertility in premenopausal women and a myriad of systemic side effects. To address these issues, we have designed poly(amidoamine) (PAMAM) dendrimers to selectively target the follicle stimulating hormone receptor (FSHR), which is overexpressed by tumorigenic ovarian cancer cells but not by immature primordial follicles and other non-tumorigenic cells. Fluorescein-labeled generation 5 (G5) PAMAM dendrimers were conjugated with the binding peptide domain of FSH (FSH33) that has a high affinity to FSHR. The targeted dendrimers exhibited high receptor selectivity to FSHR-expressing OVCAR-3 cells, resulting in significant uptake and downregulation of an anti-apoptotic protein survivin, while showing minimal interactions with SKOV-3 cells that do not express FSHR. The selectivity of the FSH33-targeted dendrimers was further validated in 3D organ cultures of normal mouse ovaries. Immunostaining of the conjugates revealed their selective binding and uptake by ovarian surface epithelium (OSE) cells that express FSHR, while sparing the immature primordial follicles. In addition, an in vivo study monitoring tissue accumulation following a single intraperitoneal (i.p.) injection of the conjugates showed significantly higher accumulation of FSH33-targeted dendrimers in the ovary and oviduct compared to the non-targeted conjugates. These proof-of-concept findings highlight the potential of these FSH33-targeted dendrimers to serve as a delivery platform for anti-ovarian cancer drugs, while reducing their systemic side effects by preventing nonspecific uptake by the primordial follicles.Ovarian cancer is the most lethal gynecological malignancy. Current treatment modalities include a combination of surgery and chemotherapy, which often lead to loss of fertility in premenopausal women and a myriad of systemic side

  4. Subpopulation-Specific Transcriptome Analysis of Competence-Stimulating-Peptide-Induced Streptococcus mutans▿†

    PubMed Central

    Lemme, André; Gröbe, Lothar; Reck, Michael; Tomasch, Jürgen; Wagner-Döbler, Irene

    2011-01-01

    Competence-stimulating-peptide (CSP)-mediated competence development in Streptococcus mutans is a transient and biphasic process, since only a subpopulation induces the expression of ComX in the presence of CSP, and the activation of the DNA uptake machinery in this fraction shuts down ∼3 to 4 h postinduction. Here, we combine for the first time, to our knowledge, the bacterial flow-cytometric sorting of cells and subpopulation-specific transcriptome analysis of both the competent and noncompetent fraction of CSP-treated S. mutans cells. Sorting was guided by a ComX-green fluorescent protein (ComX-GFP) reporter, and the transcriptome analysis demonstrated the successful combination of both methods, because a strong enrichment of transcripts for comX and its downstream genes was achieved. Three two-component systems were expressed in the competent fraction, and among them was ComDE. Moreover, the recently identified regulator system ComR/S was expressed exclusively in the competent fraction. In contrast, the expression of bacteriocin-related genes was at the same level in all cells. GFP reporter strains for ComE and CipB (mutacin V) confirmed this expression pattern on the single-cell level. Fluorescence microscopy revealed that some ComX-expressing cells committed autolysis in an early stage of competence initiation. In viable ComX-expressing cells, the uptake of DNA could be shown on the single-cell level. This study demonstrates that all cells in the population respond to CSP through the activation of bacteriocin-related genes. Some of these cells start to activate ComX expression but then segregate into two subpopulations, one becoming competent and another one that lyses, resulting in intrapopulation diversity. PMID:21317319

  5. Molecular mechanisms underlying bile acid-stimulated glucagon-like peptide-1 secretion

    PubMed Central

    Parker, HE; Wallis, K; le Roux, CW; Wong, KY; Reimann, F; Gribble, FM

    2012-01-01

    BACKGROUND AND PURPOSE The glucagon-like peptides GLP-1 and GLP-2 are secreted from enteroendocrine L-cells following nutrient ingestion. Drugs that increase activity of the GLP-1 axis are highly successful therapies for type 2 diabetes, and boosting L-cell secretion is a potential strategy for future diabetes treatment. The aim of the present study was to further our understanding of the bile acid receptor GPBA (TGR5), an L-cell target currently under therapeutic exploration. EXPERIMENTAL APPROACH GLUTag cells and mixed primary murine intestinal cultures were exposed to bile acids and a specific agonist, GPBAR-A. Secretion was measured using hormone assays and intracellular calcium and cAMP responses were monitored using real-time imaging techniques. KEY RESULTS Bile acid-triggered GLP-1 secretion from GLUTag cells was GPBA-dependent, as demonstrated by its abolition following tgr5 siRNA transfection. Bile acids and GPBAR-A increased GLP-1 secretion from intestinal cultures, with evidence for synergy between the effects of glucose and GPBA activation. Elevation of cAMP was observed following GPBA activation in individual GLUTag cells. Direct calcium responses to GPBAR-A were small, but in the presence of the agonist, a subpopulation of cells that was previously poorly glucose-responsive exhibited robust glucose responses. In vivo, increased delivery of bile to more distal regions of the ileum augmented L-cell stimulation. CONCLUSIONS AND IMPLICATIONS GPBA signalling in L-cells involves rapid elevation of cAMP, and enhanced calcium and secretory responses to glucose. Modulation of this receptor therapeutically may be an attractive strategy to enhance GLP-1 secretion and achieve better glycaemic control in diabetic patients. PMID:21718300

  6. Characterization of desmoglein-3 epitope region peptides as synthetic antigens: analysis of their in vitro T cell stimulating efficacy, cytotoxicity, stability, and their conformational features.

    PubMed

    Szabados, Hajnalka; Uray, Katalin; Majer, Zsuzsa; Silló, Pálma; Kárpáti, Sarolta; Hudecz, Ferenc; Bősze, Szilvia

    2015-09-01

    Desmoglein-3 (Dsg3) adhesion protein is the main target of autoantibodies and autoreactive T cells in Pemphigus vulgaris (PV) autoimmune skin disorder. Several mapping studies of Dsg3 T cell epitope regions were performed, and based on those data, we designed and synthesized four peptide series corresponding to Dsg3 T cell epitope regions. Each peptide series consists of a 17mer full-length peptide (Dsg3/189-205, Dsg3/206-222, Dsg3/342-358, and Dsg3/761-777) and its N-terminally truncated derivatives, resulting in 15 peptides altogether. The peptides were prepared on solid phase and were chemically characterized. In order to establish a structure-activity relationship, the solution conformation of the synthetic peptides has been investigated using electronic circular dichroism spectroscopy. The in vitro T cell stimulating efficacy of the peptides has been determined on peripheral blood mononuclear cells isolated from whole blood of PV patients and also from healthy donors. After 20 h of stimulation, the interferon (IFN)-γ content of the supernatants was measured by enzyme-linked immunosorbent assay. In the in vitro conditions, peptides were stable and non-cytotoxic. The in vitro IFN-γ production profile of healthy donors and PV patients, induced by peptides as synthetic antigens, was markedly different. The most unambiguous differences were observed after stimulation with 17mer peptide Dsg3/342-358, and three truncated derivatives from two other peptide series, namely, peptides Dsg3/192-205, Dsg3/763-777, and Dsg3/764-777. Comparative analysis of in vitro activity and the capability of oligopeptides to form ordered or unordered secondary structure showed that peptides bearing high solvent sensibility and backbone flexibility were the most capable to distinguish between healthy and PV donors. PMID:26250896

  7. An Arg-Gly-Asp peptide stimulates Ca2+ efflux from osteoclast precursors through a novel mechanism

    NASA Technical Reports Server (NTRS)

    Yamakawa, K.; Duncan, R.; Hruska, K. A.

    1994-01-01

    We examined the effect of a peptide containing the Arg-Gly-Asp (RGD) sequence on 45Ca2+ efflux from osteoclast precursors. 45Ca(2+)-loaded osteoclast precursors were treated with GRGDSP (170 microM) for 10 min after 30 min of basal perfusion with a bicarbonate-containing buffer. GRGDSP significantly increased fractional efflux of Ca2+ from treated cells compared with vehicle-treated cells (P < 0.01) or cells treated with up to 200 micrograms/ml of a control peptide containing GRGESP. The effect of RGD was sustained for 15 min after the peptide was removed from the perfusate, but control levels of Ca2+ efflux returned by 1 h. The Ca2+ efflux effect of GRGDSP was most likely due to activation of the plasma membrane Ca(2+)-adenosinetriphosphatase (Ca(2+)-ATPase) pump, as indicated by its inhibition with vanadate and a calmodulin antagonist, N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide, and the absence of an effect of Na+/Ca2+ exchange inhibition. An inhibitor of cyclic nucleotide-dependent protein kinases, N-[2-(methylamino)ethyl]-5-isoquinoline-sulfonamide (0.1 mM), failed to inhibit GRGDSP-stimulated Ca2+ efflux. However, genistein and herbimycin A, inhibitors of protein-tyrosine kinases, blocked Ca2+ efflux stimulated by GRGDSP. The results indicate that RGD sequences of matrix proteins may stimulate Ca2+ efflux from osteoclasts through activation of protein-tyrosine kinases and suggest that GRGDSP-stimulated Ca2+ efflux is mediated via the plasma membrane Ca(2+)-ATPase.

  8. Fine-tuning the stimulation of MLL1 methyltransferase activity by a histone H3-based peptide mimetic

    SciTech Connect

    Avdic, Vanja; Zhang, Pamela; Lanouette, Sylvain; Voronova, Anastassia; Skerjanc, Ilona; Couture, Jean-Francois

    2011-08-24

    The SET1 family of methyltransferases carries out the bulk of histone H3 Lys-4 methylation in vivo. One of the common features of this family is the regulation of their methyltransferase activity by a tripartite complex composed of WDR5, RbBP5, and Ash2L. To selectively probe the role of the SET1 family of methyltransferases, we have developed a library of histone H3 peptide mimetics and report herein the characterization of an N{alpha} acetylated form of histone H3 peptide (N{alpha}H3). Binding and inhibition studies reveal that the addition of an acetyl moiety to the N terminus of histone H3 significantly enhances its binding to WDR5 and prevents the stimulation of MLL1 methyltransferase activity by the WDR5-RbBP5-Ash2L complex. The crystal structure of N{alpha}H3 in complex with WDR5 reveals that a high-affinity hydrophobic pocket accommodates the binding of the acetyl moiety. These results provide the structural basis to control WDR5-RbBP5-Ash2L-MLL1 activity and a tool to manipulate stem cell differentiation programs.-Avdic, V., Zhang, P., Lanouette, S., Voronova, A., Skerjanc, I., Couture, J.-F. Fine-tuning the stimulation of MLL1 methyltransferase activity by a histone H3-based peptide mimetic.

  9. Helodermin-like peptides in thyroid C cells: stimulation of thyroid hormone secretion and suppression of calcium incorporation into bone.

    PubMed Central

    Grunditz, T; Persson, P; Håkanson, R; Absood, A; Böttcher, G; Rerup, C; Sundler, F

    1989-01-01

    Helodermin is a vasoactive intestinal peptide-like peptide in the salivary gland venom of the lizard Heloderma suspectum. Helodermin-like immunofluorescence was observed in the parafollicular (C) cells in several mammals and in the C cell homologues of the chicken ultimobranchial gland. Thus, helodermin-like peptides coexist with calcitonin. The results of radioimmunoassay agreed with the immunocytochemical findings. HPLC of rat thyroid extracts revealed one major peak of helodermin-like immunoreactivity, which eluted in a position close to that of lizard helodermin. Helodermin stimulated basal thyroid hormone secretion and colloid droplet formation in conscious mice. The effect of large doses of helodermin was quite long-lasting and the maximal response occurred after 2-6 hr. In addition, helodermin suppressed the incorporation of calcium into bone in conscious rats. The findings suggest that helodermin-like peptides in C cells may be involved in the local regulation of thyroid hormone secretion and in the maintenance of calcium homeostasis. Images PMID:2645580

  10. Melanoma Therapy with Rhenium-Cyclized Alpha Melanocyte Stimulating Hormone Peptide Analogs

    SciTech Connect

    Thomas P Quinn

    2005-11-22

    Malignant melanoma is the 6th most commonly diagnosed cancer with increasing incidence in the United States. It is estimated that 54,200 cases of malignant melanoma will be newly diagnosed and 7,600 cases of death will occur in the United States in the year 2003 (1). At the present time, more than 1.3% of Americans will develop malignant melanoma during their lifetime (2). The average survival for patients with metastatic melanoma is about 6-9 months (3). Moreover, metastatic melanoma deposits are resistant to conventional chemotherapy and external beam radiation therapy (3). Systematic chemotherapy is the primary therapeutic approach to treat patients with metastatic melanoma. Dacarbazine is the only single chemotherapy agent approved by FDA for metastatic melanoma treatment (5). However, the response rate to Dacarbazine is only approximately 20% (6). Therefore, there is a great need to develop novel treatment approaches for metastatic melanoma. The global goal of this research program is the rational design, characterization and validation of melanoma imaging and therapeutic radiopharmaceuticals. Significant progress has been made in the design and characterization of metal-cyclized radiolabeled alpha-melanocyte stimulating hormone peptides. Therapy studies with {sup 188}Re-CCMSH demonstrated the therapeutic efficacy of the receptor-targeted treatment in murine and human melanoma bearing mice (previous progress report). Dosimetry calculations, based on biodistribution data, indicated that a significant dose was delivered to the tumor. However, {sup 188}Re is a very energetic beta-particle emitter. The longer-range beta-particles theoretically would be better for larger tumors. In the treatment of melanoma, the larger primary tumor is usually surgically removed leaving metastatic disease as the focus of targeted radiotherapy. Isotopes with lower beta-energies and/or shorter particle lengths should be better suited for targeting metastases. The {sup 177}Lu

  11. Elastin peptides prepared from piscine and mammalian elastic tissues inhibit collagen-induced platelet aggregation and stimulate migration and proliferation of human skin fibroblasts.

    PubMed

    Shiratsuchi, Eri; Ura, Megumi; Nakaba, Misako; Maeda, Iori; Okamoto, Kouji

    2010-11-01

    We obtained pure elastin peptides from bovine ligamentum nuchae, porcine aorta, and bonito bulbus arteriosus. The inhibitory activity of these elastin peptides on platelet aggregation induced by collagen and the migratory and proliferative responsivenesses of human skin fibroblasts to these elastin peptides were examined. All of bonito, bovine, and porcine elastin peptides found to inhibit platelet aggregation, but bonito elastin peptides showed a higher inhibitory activity than bovine and porcine elastin peptides did. All elastin peptides enhanced the proliferation of fibroblasts 3.5- to 4.5-fold at a concentration of 10 µg/ml. Bovine and porcine elastin peptides stimulated the migration of fibroblasts, with the optimal response occurring at 10(-1) µg/ml, while maximal response was at 10(2) µg/ml for bonito elastin peptides. Furthermore, pretreatment of fibroblasts by lactose depressed their ability to migrate in response to all elastin peptides, suggesting the involvement of elastin receptor in cell response. These results suggest that both mammalian and piscine elastin peptides can be applied as useful biomaterials in which elasticity, antithrombotic property, and the enhancement of cell migration and proliferation are required. PMID:20853312

  12. Nucleobindin-1 encodes a nesfatin-1-like peptide that stimulates insulin secretion.

    PubMed

    Ramesh, Naresh; Mohan, Haneesha; Unniappan, Suraj

    2015-05-15

    Nesfatin-1 (82 amino acid) is an anorexigenic and insulinotropic peptide encoded in a secreted precursor, nucleobindin-2 (NUCB2). Nucleobindin-1 (NUCB1) is a protein with very high sequence similarity to NUCB2. We hypothesized that a nesfatin-1 like peptide (NLP) is encoded in NUCB1, and this peptide is biologically active. In silico analysis found a signal peptide cleavage site at position 25 (Arginine) and 26 (Valine) preceding the NLP region in NUCB1 sequence, and potential proprotein convertase cleavage sites at Lys-Arg (KR), forming a 77 amino acid NLP. RT-PCR studies found NUCB1 mRNA in both pancreas and MIN6 cells. NUCB1-like immunoreactivity was detected in mouse insulinoma (MIN6) cells, and pancreatic islet beta cells of mice. In order to determine the biological activity of NLP, MIN6 cells were incubated with synthetic rat NLP. NLP (10nM and 100nM) upregulated preproinsulin mRNA expression and insulin secretion at 1h post-incubation. In identical experiments using MIN6 cells, a scrambled peptide based on the NLP sequence did not elicit any effects on preproinsulin mRNA expression or insulin secretion. From this result, it is clear that an intact NLP sequence is required for its biological activity. NLP appears as another endogenous insulinotropic peptide encoded in NUCB1. PMID:25907657

  13. Ingramon, a Peptide Inhibitor of MCP-1 Chemokine, Reduces Migration of Blood Monocytes Stimulated by Glioma-Conditioned Medium.

    PubMed

    Krasnikova, T L; Arefieva, T I; Pylaeva, E A; Sidorova, M V

    2016-02-01

    Malignant gliomas are most common and fatal primary brain tumors. In addition to neoplastic cells, the tumor tissue contains microglial cells and monocyte-derived macrophages. It is an established fact that monocyte recruiting promotes the tumor growth and dissemination. Monocyte chemotactic protein-1 (MCP-1) is the major attractant for monocytes. We have previously synthesized an MCP-1 antagonist ingramon, a synthetic peptide fragment (65-76) of this chemokine. In the present study, we demonstrated that glioma-conditioned medium contains MCP-1 and stimulates migration of blood monocytes. Ingramon inhibited the effect of glioma-conditioned medium on monocyte migration. PMID:26906197

  14. Proteolytic degradation and deactivation of amphibian skin peptides obtained by electrical stimulation of their dorsal glands.

    PubMed

    Samgina, Tatiana Yu; Tolpina, Miriam I; Hakalehto, Elias; Artemenko, Konstantin A; Bergquist, Jonas; Lebedev, Albert T

    2016-05-01

    Amphibians are among the oldest creatures on our planet. Their only defensive weapon efficient against microorganisms and predators involves their skin secretion. The wide range of biological activities of the peptides in the skin secretion of amphibians makes these compounds rather interesting for generation of prospective pharmaceuticals. The first step in studying these molecules requires their structures to be established. Mass spectrometry is the most powerful tool for this purpose. The sampling and sample preparation stages preceding mass spectrometry experiments appear to be rather crucial. The results obtained here demonstrate that these preparation procedures might lead to partial or complete loss of the bioactive peptides in the secretion. Five minutes in water was enough to completely destroy all of the bioactive peptides in the skin secretion of the marsh frog (Rana ridibunda); even immediate addition of methanol to the water solution of the peptides did not prevent partial destruction. Concerted effort should be directed towards development of the most efficient procedure to keep the secreted peptides intact. Graphical Abstract ᅟ. PMID:26975184

  15. Brain Natriuretic Peptide Stimulates Lipid Metabolism through Its Receptor NPR1 and the Glycerolipid Metabolism Pathway in Chicken Adipocytes.

    PubMed

    Huang, H Y; Zhao, G P; Liu, R R; Li, Q H; Zheng, M Q; Li, S F; Liang, Z; Zhao, Z H; Wen, J

    2015-11-01

    Brain natriuretic peptide (BNP) is related to lipid metabolism in mammals, but its effect and the molecular mechanisms underlying it in chickens are incompletely understood. We found that the level of natriuretic peptide precursor B (NPPB, which encodes BNP) mRNA expression in high-abdominal-fat chicken groups was significantly higher than that of low-abdominal-fat groups. Partial correlations indicated that changes in the weight of abdominal fat were positively correlated with NPPB mRNA expression level. In vitro, compared with the control group, preadipocytes with NPPB interference showed reduced levels of proliferation, differentiation, and glycerin in media. Treatments of cells with BNP led to enhanced proliferation and differentiation of cells and glycerin concentration, and mRNA expression of its receptor natriuretic peptide receptor 1 (NPR1) was upregulated significantly. In cells exposed to BNP, 482 differentially expressed genes were identified compared with controls without BNP. Four genes known to be related to lipid metabolism (diacylglycerol kinase; lipase, endothelial; 1-acylglycerol-3-phosphate O-acyltransferase 1; and 1-acylglycerol-3-phosphate O-acyltransferase 2) were enriched in the glycerolipid metabolism pathway and expressed differentially. In conclusion, BNP stimulates the proliferation, differentiation, and lipolysis of preadipocytes through upregulation of the levels of expression of its receptor NPR1 and key genes enriched in the glycerolipid metabolic pathway. PMID:26463554

  16. Stimulation of transit-peptide release and ATP hydrolysis by a cochaperone during protein import into chloroplasts

    PubMed Central

    Chou, Ming-Lun; Chu, Chiung-Chih; Chen, Lih-Jen; Akita, Mitsuru; Li, Hsou-min

    2006-01-01

    Three components of the chloroplast protein translocon, Tic110, Hsp93 (ClpC), and Tic40, have been shown to be important for protein translocation across the inner envelope membrane into the stroma. We show the molecular interactions among these three components that facilitate processing and translocation of precursor proteins. Transit-peptide binding by Tic110 recruits Tic40 binding to Tic110, which in turn causes the release of transit peptides from Tic110, freeing the transit peptides for processing. The Tic40 C-terminal domain, which is homologous to the C terminus of cochaperones Sti1p/Hop and Hip but with no known function, stimulates adenosine triphosphate hydrolysis by Hsp93. Hsp93 dissociates from Tic40 in the presence of adenosine diphosphate, suggesting that Tic40 functions as an adenosine triphosphatase activation protein for Hsp93. Our data suggest that chloroplasts have evolved the Tic40 cochaperone to increase the efficiency of precursor processing and translocation. PMID:17158958

  17. Blood feeding and insulin-like peptide 3 stimulate proliferation of hemocytes in the mosquito Aedes aegypti.

    PubMed

    Castillo, Julio; Brown, Mark R; Strand, Michael R

    2011-10-01

    All vector mosquito species must feed on the blood of a vertebrate host to produce eggs. Multiple cycles of blood feeding also promote frequent contacts with hosts, which enhance the risk of exposure to infectious agents and disease transmission. Blood feeding triggers the release of insulin-like peptides (ILPs) from the brain of the mosquito Aedes aegypti, which regulate blood meal digestion and egg formation. In turn, hemocytes serve as the most important constitutive defense in mosquitoes against pathogens that enter the hemocoel. Prior studies indicated that blood feeding stimulates hemocytes to increase in abundance, but how this increase in abundance is regulated is unknown. Here, we determined that phagocytic granulocytes and oenocytoids express the A. aegypti insulin receptor (AaMIR). We then showed that: 1) decapitation of mosquitoes after blood feeding inhibited hemocyte proliferation, 2) a single dose of insulin-like peptide 3 (ILP3) sufficient to stimulate egg production rescued proliferation, and 3) knockdown of the AaMIR inhibited ILP3 rescue activity. Infection studies indicated that increased hemocyte abundance enhanced clearance of the bacterium Escherichia coli at lower levels of infection. Surprisingly, however, non-blood fed females better survived intermediate and high levels of E. coli infection than blood fed females. Taken together, our results reveal a previously unrecognized role for the insulin signaling pathway in regulating hemocyte proliferation. Our results also indicate that blood feeding enhances resistance to E. coli at lower levels of infection but reduces tolerance at higher levels of infection. PMID:21998579

  18. Activation of TRPM3 by a potent synthetic ligand reveals a role in peptide release

    PubMed Central

    Held, Katharina; Kichko, Tatjana; De Clercq, Katrien; Klaassen, Hugo; Van Bree, Rieta; Vanherck, Jean-Christophe; Marchand, Arnaud; Reeh, Peter W.; Chaltin, Patrick; Voets, Thomas; Vriens, Joris

    2015-01-01

    Transient receptor potential (TRP) cation channel subfamily M member 3 (TRPM3), a member of the TRP channel superfamily, was recently identified as a nociceptor channel in the somatosensory system, where it is involved in the detection of noxious heat; however, owing to the lack of potent and selective agonists, little is known about other potential physiological consequences of the opening of TRPM3. Here we identify and characterize a synthetic TRPM3 activator, CIM0216, whose potency and apparent affinity greatly exceeds that of the canonical TRPM3 agonist, pregnenolone sulfate (PS). In particular, a single application of CIM0216 causes opening of both the central calcium-conducting pore and the alternative cation permeation pathway in a membrane-delimited manner. CIM0216 evoked robust calcium influx in TRPM3-expressing somatosensory neurons, and intradermal injection of the compound induced a TRPM3-dependent nocifensive behavior. Moreover, CIM0216 elicited the release of the peptides calcitonin gene-related peptide (CGRP) from sensory nerve terminals and insulin from isolated pancreatic islets in a TRPM3-dependent manner. These experiments identify CIM0216 as a powerful tool for use in investigating the physiological roles of TRPM3, and indicate that TRPM3 activation in sensory nerve endings can contribute to neurogenic inflammation. PMID:25733887

  19. Structure and function of a peptide pheromone family that stimulate the vomeronasal sensory system in mice.

    PubMed

    Abe, Takayuki; Touhara, Kazushige

    2014-08-01

    Mammals use pheromones to communicate with other animals of the same species. In mice, the VNO (vomeronasal organ) has a pivotal role in pheromone detection. We discovered a 7 kDa peptide, ESP1 (exocrine-gland-secreting peptide 1), in tear fluids from male mice that enhances the sexual behaviour of female mice via the VNO. NMR studies demonstrate that ESP1 adopts a compact structure with a helical fold stabilized by an intramolecular disulfide bridge. Functional analysis in combination with docking simulation indicates that ESP1 is recognized by a specific G-protein-coupled vomeronasal receptor, V2Rp5, via charge-charge interactions in the large extracellular region of the receptor. ESP1 is a member of the ESP family, which comprises 38 homologous genes in mice, and some of these genes are expressed in a sex- or age-dependent manner. Most recently, ESP22 was found to be released specifically in juvenile tear fluids and to inhibit the sexual behaviour of adult male mice. These studies demonstrate that peptide pheromones are used for chemical communication in mice, and they indicate a structural basis for the narrowly tuned perception of mammalian peptide pheromones by vomeronasal receptors. PMID:25109971

  20. Hypergravity differentially modulates cGMP efflux in human melanocytic cells stimulated by nitric oxide and natriuretic peptides

    NASA Astrophysics Data System (ADS)

    Ivanova, K.; Stieber, C.; Lambers, B.; Block, I.; Krieg, R.; Wellmann, A.; Gerzer, R.

    Nitric oxide NO plays a key role in many patho physiologic processes including inflammation and skin cancer The diverse cellular effects of NO are mainly mediated by activation of the soluble guanylyl cyclase sGC isoform that leads to increases in intracellular cGMP levels whereas the membrane-bound isoforms serve as receptors for natriuretic peptides e g ANP In human skin epidermal melanocytes represent the principal cells for skin pigmentation by synthesizing the pigment melanin Melanin acts as a scavenger for free radicals that may arise during metabolic stress as a result of potentially harmful effects of the environment In previous studies we found that long-term exposure to hypergravity stimulated cGMP efflux in normal human melanocytes NHMs and non-metastatic melanoma cells at least partly by an enhanced expression of the multidrug resistance proteins MRP and cGMP transporters MRP4 5 The present study investigated whether hypergravity generated by centrifugal acceleration may modulate the cGMP efflux in NO-stimulated NHMs and melanoma cells MCs with different metastatic potential The NONOates PAPA-NO and DETA-NO were used as direct NO donors for cell stimulation In the presence of 0 1 mM DETA-NO t 1 2 sim 20 h long-term application of hypergravity up to 5 g for 24 h reduced intracellular cGMP levels by stimulating cGMP efflux in NHMs and non-metastatic MCs in comparison to 1 g whereas exposure to 5 g for 6 h in the presence of 0 1 mM PAPA-NO t 1 2 sim 30 min was not effective The hypergravity-stimulated

  1. Peptides in the gastrointestinal tract in human immunodeficiency virus infection. The GI/HIV Study Group of the University of Calgary.

    PubMed

    Sharkey, K A; Sutherland, L R; Davison, J S; Zwiers, H; Gill, M J; Church, D L

    1992-07-01

    The presence of immunoreactivity to the neuronal phosphoprotein B-50 and the peptides bombesin, calcitonin gene-related peptide, galanin, neurotensin, neuropeptide Y, somatostatin, substance P, and vasoactive intestinal polypeptide was examined in biopsy specimens from the duodenum and rectum of human immunodeficiency virus (HIV)-seropositive and HIV-seronegative male homosexual patients. The distribution of B-50 and the peptides was correlated with HIV serology, number of CD4+ lymphocytes, and the presence of HIV in biopsy culture. There was a very low incidence of enteric pathogens in both groups of patients. It was found that HIV-seropositive patients had a greater incidence of abnormal patterns of immunoreactivity (reduced intensity and/or density of innervation) in enteric nerves and enteroendocrine cells than HIV-seronegative patients. A reduction of substance P immunoreactivity was significantly correlated with reduced CD4+ lymphocyte count and HIV status; a similar trend was also seen for somatostatin and vasoactive intestinal polypeptide. Using B-50 as a marker, it was found that both groups of patients had altered patterns of immunoreactivity in rectal nerves. The findings of this study suggest that some of the clinical symptoms associated with HIV infection may be caused by a specific HIV enteropathy that influences enteric nerve and/or enteroendocrine cell function by altering the density of peptide immunoreactivity. PMID:1535325

  2. Extracellular Life Cycle of ComS, the Competence-Stimulating Peptide of Streptococcus thermophilus

    PubMed Central

    Besset, Colette; Gitton, Christophe; Guillot, Alain; Fontaine, Laetitia; Hols, Pascal; Monnet, Véronique

    2013-01-01

    In streptococci, ComX is the alternative sigma factor controlling the transcription of the genes encoding the genetic transformation machinery. In Streptococcus thermophilus, comX transcription is controlled by a complex consisting of a transcriptional regulator of the Rgg family, ComR, and a signaling peptide, ComS, which controls ComR activity. Following its initial production, ComS is processed, secreted, and imported back into the cell by the Ami oligopeptide transporter. We characterized these steps and the partners interacting with ComS during its extracellular circuit in more detail. We identified the mature form of ComS and demonstrated the involvement of the membrane protease Eep in ComS processing. We found that ComS was secreted but probably not released into the extracellular medium. Natural competence was first discovered in a chemically defined medium without peptides. We show here that the presence of a high concentration of nutritional peptides in the medium prevents the triggering of competence. In milk, the ecological niche of S. thermophilus, competence was found to be functional, suggesting that the concentration of nutritional peptides was too low to interfere with ComR activation. The kinetics of expression of the comS, comR, and comX genes and of a late competence gene, dprA, in cultures inoculated at different initial densities revealed that the activation mechanism of ComR by ComS is more a timing device than a quorum-sensing mechanism sensu stricto. We concluded that the ComS extracellular circuit facilitates tight control over the triggering of competence in S. thermophilus. PMID:23396911

  3. A dimeric peptide with erythropoiesis-stimulating activity uniquely affects erythropoietin receptor ligation and cell surface expression.

    PubMed

    Verma, Rakesh; Green, Jennifer M; Schatz, Peter J; Wojchowski, Don M

    2016-08-01

    Erythropoiesis-stimulating agents (ESAs) that exert long-acting antianemia effects have been developed recently, but their mechanisms are poorly understood. Analyses reveal unique erythropoietin receptor (EPOR)-binding properties for one such ESA, the synthetic EPOR agonist peginesatide. Compared with recombinant human EPO and darbepoietin, peginesatide exhibited a slow on rate, but sustained EPOR residency and resistant displacement. In EPO-dependent human erythroid progenitor UT7epo cells, culture in peginesatide unexpectedly upmodulated endogenous cell surface EPOR levels with parallel increases in full-length EPOR-68K levels. These unique properties are suggested to contribute to the durable activity of this (and perhaps additional) dimeric peptide hematopoietic growth factor receptor agonist. PMID:27174804

  4. Nesfatin-1 stimulates cholecystokinin and suppresses peptide YY expression and secretion in mice.

    PubMed

    Ramesh, Naresh; Mortazavi, Sima; Unniappan, Suraj

    2016-03-25

    Nesfatin-1 is an 82 amino acid secreted peptide encoded in the precursor, nucleobindin-2 (NUCB2). It is an insulinotropic anorexigen abundantly expressed in the stomach and hypothalamus. Post-prandial insulin secretion is predominantly regulated by incretins glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Nesfatin-1 was previously reported to modulate GLP-1 and GIP secretion in vitro in an enteroendocrine (STC-1) cell line. Intestine is a source of additional hormones including cholecystokinin (CCK) and peptide YY (PYY) that regulate metabolism. We hypothesized that nesfatin-1 modulates CCK and PYY secretion. Immunofluorescence histochemistry showed NUCB2/nesfatin-1 co-localizing CCK and PYY in the intestinal mucosa of mice. Static incubation of STC-1 cells with nesfatin-1 upregulated both CCK mRNA expression (1 and 10 nM) and secretion (0.1, 1 and 10 nM) at 1 h post-incubation. In contrast, nesfatin-1 treatment for 1 h downregulated PYY mRNA expression (all doses tested) and secretion (0.01 and 0.1 nM) in STC-1 cells. Continuous infusion of nesfatin-1 using osmotic mini-pumps for 12 h upregulated CCK mRNA expression in large intestine, and downregulated PYY mRNA expression in both large and small intestines of male C57BL/6J mice. In these tissues, Western blot analysis found a corresponding increase in CCK and a decrease in PYY content. Collectively, we provide new information on the cell specific localization of NUCB2/nesfatin-1 in the intestinal mucosa, and a novel function for nesfatin-1 in modulating intestinal CCK and PYY expression and secretion in mice. PMID:26920055

  5. Reducing renal uptake of 90Y- and 177Lu-labeled alpha-melanocyte stimulating hormone peptide analogues

    SciTech Connect

    Miao, Yubin; Fisher, Darrell R.; Quinn, Thomas P.

    2006-06-15

    The purpose of this study was to improve the tumor-to-kidney uptake ratios of 90Y- and 177Lu-[1,2,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-Re-Cys,D-Phe,Arg]alpha-melanocyte stimulating hormone (DOTA-RE(Arg)CCMSH), through coupling a negatively charged glutamic acid (Glu) to the peptide sequence. A new peptide of DOTA-Re(Glu,Arg)CCMSH was designed, synthesized and labeled with 90Y and 177Lu. Pharmacokinetics of 90Y- and 177Lu-DOTA-RE(Glu,Arg)CCNSH were determined in B16/F1 murine melanoma-bearing C57 mice. Both exhibited significantly less renal uptake than 90Y- and 177Lu-DOTA-Re(Arg)CCMSH at 30 min and at 2, 3, and 24 h after dose administration. The renal uptake values of 90Y- and 177Lu-DOTA-Re(Glu,Arg)CCMSH were 28.16% and 28.81% of those of 90Y- and 177Lu-DOTA-RE(Arg)CCMSH, respectively, at 4 hr post-injection. We also showed higher tumor-to-kidney uptake ratios 2.28 and 1.69 times that of 90Y- and 177Lu-DOTA-Re(Arg)CCMSH, respectively, at 4 h post-injection. The90Y- and 177Lu-DOTA-Re(Glu,Arg)CCMSH activity accumulation was low in normal organs except for kidneys. Coupling a negatively charged amino acid (Glu) to the CCMSH peptide sequence dramatically reduced the renal uptake values and increased the tumor-to-kidney uptake ratios of 90Y- and 177Lu-DOTA-Re(Glu,Arg)CCMSH, facilitating their potential applications as radiopharmaceuticals for targeted radionuclide therapy of melanoma.

  6. Endothelin-stimulated secretion of natriuretic peptides by rat atrial myocytes is mediated by endothelin A receptors.

    PubMed

    Thibault, G; Doubell, A F; Garcia, R; Larivière, R; Schiffrin, E L

    1994-03-01

    Endothelin (ET), a potent vasoconstrictor peptide, is known to enhance the secretion of atrial natriuretic factor (ANF) by the heart. In the present study, we investigated the potency of ET isopeptides to stimulate ANF and brain natriuretic peptide (BNP) secretion in primary cultures of neonatal atrial myocytes, and we characterized the receptor mediating these effects. All ET isopeptides caused a twofold increase of ANF and BNP secretion with the following order of potency: ET-1 approximately ET-2 > sarafotoxin 6b > ET-3. Secretion of the natriuretic peptides was blocked by BQ-123, an ETA-receptor antagonist, but was not affected by either IRL-1620 or [Ala1,3,11,15]ET-1, two ETB-receptor agonists. ET receptors were localized by autoradiography on the surface of atrial myocytes, indicating that contaminating cells were not responsible for 125I-ET-1 binding. Competition binding analyses were then used to assess the ET-receptor subtype on atrial myocyte membrane preparations. A high-affinity (100 pmol/L) binding site with high density (approximately 1500 fmol/mg) was found to preferentially bind the ET isopeptides in the following order: ET-1 > or = ET-2 > or = sarafotoxin 6b > ET-3. Binding was totally displaced by BQ-123 but not by IRL-1620. The ET binding site therefore had the characteristics of an ETA-like receptor. Analysis by cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that it possessed a molecular mass of approximately 50 kD. Northern blot analysis of both ETA- and ETB-receptor mRNAs allowed only the detection of the former, indicating that the ETB receptor may be expressed in very small amounts. These results demonstrate that ANF and BNP secretion by atrial myocytes is enhanced by ET via binding to an ETA-like receptor. PMID:8118954

  7. GH-releasing peptide-2 does not stimulate arginine vasopressin secretion in healthy men.

    PubMed

    Kamoi, Kyuzi; Minagawa, Shinichi; Kimura, Keita; Ishizawa, Masahiro; Ohara, Nobumasa; Uemura, Yasuyuki; Tsuchiya, Junpei

    2010-01-01

    Ghrelin has a stimulating effect on arginine vasopressin (AVP). However, it is not known whether GHRP-2, a synthetic ghrelin receptor agonist, also has a stimulating effect on AVP release in men. To determine whether the GHRP-2 test is useful for assessing AVP secretion, blood ACTH, GH, FSH, LH, PRL, TSH and AVP levels, as well as glucose, osmolality, sodium and hematocrit, were measured before and 15, 30, 45 and 60 min after an intravenous bolus of 100 microg GHRP-2 in 10 healthy men with and without fasting. Blood pressure was measured at 15-min intervals. AVP secretion was not stimulated by the GHRP-2 test with and without fasting. There were no significant differences in hematocrit, blood pressure and plasma osmolality before and after GFRP-2 injection, although significant (p<0.001) peak blood GH, and ACTH and PRL levels were observed 30 and 15 min after GHRP-2 injection with and without fasting, respectively, and the maximal peaks were significantly (p<0.05) higher with fasting than without fasting. These results suggest that AVP secretion is not stimulated by the GHRP-2 test both with and without fasting, though GH, ACTH and PRL levels were higher with than without fasting. PMID:19907099

  8. The selective non-peptidic delta opioid agonist SNC80 does not facilitate intracranial self-stimulation in rats

    PubMed Central

    Carmo, Gail Pereira Do; Folk, John E.; Rice, Kenner C.; Chartoff, Elena; Carlezon, William A.; Negus, S. Stevens

    2009-01-01

    Delta opioid receptor agonists are under development for a variety of clinical applications, and some findings in rats raise the possibility that agents with this mechanism have abuse liability. The present study assessed the effects of the non-peptidic delta opioid agonist SNC80 in an assay of intracranial self-stimulation (ICSS) in rats. ICSS was examined at multiple stimulation frequencies to permit generation of frequency-response rate curves and evaluation of curve shifts produced by experimental manipulations. Drug-induced leftward shifts in ICSS frequency-rate curves are often interpreted as evidence of abuse liability. However, SNC80 (1.0-10 mg/kg s.c.; 10-56 mg/kg i.p.) failed to alter ICSS frequency-rate curves at doses up to those that produced convulsions in the present study or other effects (e.g. antidepressant effects) in previous studies. For comparison, the monoamine releaser d-amphetamine (0.1-1.0 mg/kg, i.p.) and the kappa agonist U69,593 (0.1-0.56 mg/kg, i.p.) produced dose-dependent leftward and rightward shifts, respectively, in ICSS frequency-rate curves, confirming the sensitivity of the procedure to drug effects. ICSS frequency-rate curves were also shifted by two non-pharmacological manipulations (reductions in stimulus intensity and increases in response requirement). Thus, SNC80 failed to facilitate or attenuate ICSS-maintained responding under conditions in which other pharmacological and non-pharmacological manipulations were effective. These results suggest that non-peptidic delta opioid receptor agonists have negligible abuse-related effects in rats. PMID:19133255

  9. A Nascent Peptide Signal Responsive to Endogenous Levels of Polyamines Acts to Stimulate Regulatory Frameshifting on Antizyme mRNA*

    PubMed Central

    Yordanova, Martina M.; Wu, Cheng; Andreev, Dmitry E.; Sachs, Matthew S.; Atkins, John F.

    2015-01-01

    The protein antizyme is a negative regulator of cellular polyamine concentrations from yeast to mammals. Synthesis of functional antizyme requires programmed +1 ribosomal frameshifting at the 3′ end of the first of two partially overlapping ORFs. The frameshift is the sensor and effector in an autoregulatory circuit. Except for Saccharomyces cerevisiae antizyme mRNA, the frameshift site alone only supports low levels of frameshifting. The high levels usually observed depend on the presence of cis-acting stimulatory elements located 5′ and 3′ of the frameshift site. Antizyme genes from different evolutionary branches have evolved different stimulatory elements. Prior and new multiple alignments of fungal antizyme mRNA sequences from the Agaricomycetes class of Basidiomycota show a distinct pattern of conservation 5′ of the frameshift site consistent with a function at the amino acid level. As shown here when tested in Schizosaccharomyces pombe and mammalian HEK293T cells, the 5′ part of this conserved sequence acts at the nascent peptide level to stimulate the frameshifting, without involving stalling detectable by toe-printing. However, the peptide is only part of the signal. The 3′ part of the stimulator functions largely independently and acts at least mostly at the nucleotide level. When polyamine levels were varied, the stimulatory effect was seen to be especially responsive in the endogenous polyamine concentration range, and this effect may be more general. A conserved RNA secondary structure 3′ of the frameshift site has weaker stimulatory and polyamine sensitizing effects on frameshifting. PMID:25998126

  10. Fully Synthetic Granulocyte Colony-Stimulating Factor Enabled by Isonitrile-Mediated Coupling of Large, Side-Chain-Unprotected Peptides.

    PubMed

    Roberts, Andrew G; Johnston, Eric V; Shieh, Jae-Hung; Sondey, Joseph P; Hendrickson, Ronald C; Moore, Malcolm A S; Danishefsky, Samuel J

    2015-10-14

    Human granulocyte colony-stimulating factor (G-CSF) is an endogenous glycoprotein involved in hematopoiesis. Natively glycosylated and nonglycosylated recombinant forms, lenograstim and filgrastim, respectively, are used clinically to manage neutropenia in patients undergoing chemotherapeutic treatment. Despite their comparable therapeutic potential, the purpose of O-linked glycosylation at Thr133 remains a subject of controversy. In light of this, we have developed a synthetic platform to prepare G-CSF aglycone with the goal of enabling access to native and designed glycoforms with site-selectivity and glycan homogeneity. To address the synthesis of a relatively large, aggregation-prone sequence, we advanced an isonitrile-mediated ligation method. The chemoselective activation and coupling of C-terminal peptidyl Gly thioacids with the N-terminus of an unprotected peptide provide ligated peptides directly in a manner complementary to that with conventional native chemical ligation-desulfurization strategies. Herein, we describe the details and application of this method as it enabled the convergent total synthesis of G-CSF aglycone. PMID:26401918

  11. Short-term glucagon stimulation test of C-peptide effect on glucose utilization in patients with type 1 diabetes mellitus.

    PubMed

    Mojto, Viliam; Rausova, Zuzana; Chrenova, Jana; Dedik, Ladislav

    2015-12-01

    This work aimed to evaluate the use of a four-point glucagon stimulation test of C-peptide effect on glucose utilization in type 1 diabetic patients using a new mathematical model. A group of 32 type 1 diabetic patients and a group of 10 healthy control subjects underwent a four-point glucagon stimulation test with blood sampling at 0, 6, 15 and 30 min after 1 mg glucagon bolus intravenous administration. Pharmacokinetic and pharmacokinetic/pharmacodynamic models of C-peptide effect on glucose utilization versus area under curve (AUC) were used. A two-sample t test and ANOVA with Bonferroni correction were used to test the significance of differences between parameters. A significant difference between control and patient groups regarding the coefficient of whole-body glucose utilization and AUC C-peptide/AUC glucose ratio (p ≪ 0.001 and p = 0.002, respectively) was observed. The high correlation (r = 0.97) between modeled coefficient of whole-body glucose utilization and numerically calculated AUC C-peptide/AUC glucose ratio related to entire cohort indicated the stability of used method. The short-term four-point glucagon stimulation test allows the numerically calculated AUC C-peptide/AUC glucose ratio and/or the coefficient of whole-body glucose utilization calculated from model to be used to diagnostically identify type 1 diabetic patients. PMID:26607818

  12. Human Host Defense Peptide LL-37 Stimulates Virulence Factor Production and Adaptive Resistance in Pseudomonas aeruginosa

    PubMed Central

    Strempel, Nikola; Neidig, Anke; Nusser, Michael; Geffers, Robert; Vieillard, Julien; Lesouhaitier, Olivier; Brenner-Weiss, Gerald; Overhage, Joerg

    2013-01-01

    A multitude of different virulence factors as well as the ability to rapidly adapt to adverse environmental conditions are important features for the high pathogenicity of Pseudomonas aeruginosa. Both virulence and adaptive resistance are tightly controlled by a complex regulatory network and respond to external stimuli, such as host signals or antibiotic stress, in a highly specific manner. Here, we demonstrate that physiological concentrations of the human host defense peptide LL-37 promote virulence factor production as well as an adaptive resistance against fluoroquinolone and aminoglycoside antibiotics in P. aeruginosa PAO1. Microarray analyses of P. aeruginosa cells exposed to LL-37 revealed an upregulation of gene clusters involved in the production of quorum sensing molecules and secreted virulence factors (PQS, phenazine, hydrogen cyanide (HCN), elastase and rhamnolipids) and in lipopolysaccharide (LPS) modification as well as an induction of genes encoding multidrug efflux pumps MexCD-OprJ and MexGHI-OpmD. Accordingly, we detected significantly elevated levels of toxic metabolites and proteases in bacterial supernatants after LL-37 treatment. Pre-incubation of bacteria with LL-37 for 2 h led to a decreased susceptibility towards gentamicin and ciprofloxacin. Quantitative Realtime PCR results using a PAO1-pqsE mutant strain present evidence that the quinolone response protein and virulence regulator PqsE may be implicated in the regulation of the observed phenotype in response to LL-37. Further experiments with synthetic cationic antimicrobial peptides IDR-1018, 1037 and HHC-36 showed no induction of pqsE expression, suggesting a new role of PqsE as highly specific host stress sensor. PMID:24349231

  13. Biphasic Peptide Amphiphile Nanomatrix Embedded with Hydroxyapatite Nanoparticles for Stimulated Osteoinductive Response

    PubMed Central

    Anderson, Joel M.; Patterson, Jessica L.; Vines, Jeremy B.; Javed, Amjad; Gilbert, Shawn R.; Jun, Ho-Wook

    2013-01-01

    Formation of the native bone extracellular matrix (ECM) provides an attractive template for bone tissue engineering. The structural support and biological complexity of bone ECM are provided within a composite microenvironment that consists of an organic fibrous network reinforced by inorganic hydroxyapatite (HA) nanoparticles. Recreating this biphasic assembly, a bone ECM analogous scaffold comprised of self-assembling peptide amphiphile (PA) nanofibers and interspersed HA nanoparticles was investigated. PAs were endowed with biomolecular ligand signaling using a synthetically inscribed peptide sequence (i.e. RGDS) and integrated with HA nanoparticles to form a biphasic nanomatrix hydrogel. It was hypothesized the biphasic hydrogel would induce osteogenic differentiation of human mesenchymal stem cells (hMSCs) and improve bone healing as mediated by RGDS ligand signaling within PA nanofibers and embedded HA mineralization source. Viscoelastic stability of the biphasic PA hydrogels was evaluated with different weight concentrations of HA for improved gelation. After demonstrating initial viability, long-term cellularity and osteoinduction of encapsulated hMSCs in different PA hydrogels were studied in vitro. Temporal progression of osteogenic maturation was assessed by gene expression of key markers. A preliminary animal study demonstrated bone healing capacity of the biphasic PA nanomatrix under physiological conditions using a critical size femoral defect rat model. The combination of RGDS ligand signaling and HA nanoparticles within the biphasic PA nanomatrix hydrogel demonstrated the most effective osteoinduction and comparative bone healing response. Therefore, the biphasic PA nanomatrix establishes a well-organized scaffold with increased similarity to natural bone ECM with the prospect for improved bone tissue regeneration. PMID:22077993

  14. Human host defense peptide LL-37 stimulates virulence factor production and adaptive resistance in Pseudomonas aeruginosa.

    PubMed

    Strempel, Nikola; Neidig, Anke; Nusser, Michael; Geffers, Robert; Vieillard, Julien; Lesouhaitier, Olivier; Brenner-Weiss, Gerald; Overhage, Joerg

    2013-01-01

    A multitude of different virulence factors as well as the ability to rapidly adapt to adverse environmental conditions are important features for the high pathogenicity of Pseudomonas aeruginosa. Both virulence and adaptive resistance are tightly controlled by a complex regulatory network and respond to external stimuli, such as host signals or antibiotic stress, in a highly specific manner. Here, we demonstrate that physiological concentrations of the human host defense peptide LL-37 promote virulence factor production as well as an adaptive resistance against fluoroquinolone and aminoglycoside antibiotics in P. aeruginosa PAO1. Microarray analyses of P. aeruginosa cells exposed to LL-37 revealed an upregulation of gene clusters involved in the production of quorum sensing molecules and secreted virulence factors (PQS, phenazine, hydrogen cyanide (HCN), elastase and rhamnolipids) and in lipopolysaccharide (LPS) modification as well as an induction of genes encoding multidrug efflux pumps MexCD-OprJ and MexGHI-OpmD. Accordingly, we detected significantly elevated levels of toxic metabolites and proteases in bacterial supernatants after LL-37 treatment. Pre-incubation of bacteria with LL-37 for 2 h led to a decreased susceptibility towards gentamicin and ciprofloxacin. Quantitative Realtime PCR results using a PAO1-pqsE mutant strain present evidence that the quinolone response protein and virulence regulator PqsE may be implicated in the regulation of the observed phenotype in response to LL-37. Further experiments with synthetic cationic antimicrobial peptides IDR-1018, 1037 and HHC-36 showed no induction of pqsE expression, suggesting a new role of PqsE as highly specific host stress sensor. PMID:24349231

  15. Gene expression for peptides in neurons of the petrosal and nodose ganglia in rat.

    PubMed

    Czyzyk-Krzeska, M F; Bayliss, D A; Seroogy, K B; Millhorn, D E

    1991-01-01

    In situ hybridization was used to determine whether genes for neuropeptides [substance P/neurokinin A (SP/NKA), calcitonin gene-related peptide (CGRP), somatostatin (SOM), neuropeptide tyrosine (NPY) and cholecystokinin (CCK)] are expressed in inferior ganglia of the vagus (nodose) and glossopharyngeal (petrosal) nerves. Synthetic oligodeoxyribonucleotides, complementary to the cognate, mRNAs were labeled with [32P] or [35S], and hybridized to 10 microns thick sections of unperfused tissue which were then processed for film and emulsion autoradiography. We found numerous, clustered neuronal perikarya throughout the nodose and petrosal ganglia that expressed preprotachykinin A (SP/NKA) and CGRP mRNAs to varying degrees. Neurons expressing preproSOM mRNA were less abundant and more scattered throughout both ganglia. Notably, we found mRNA for NPY in cells (usually 5-10 per section) in both ganglia. To our knowledge, this is first evidence for NPY in these sensory ganglia. In contrast to previous immunohistochemical findings, we found no evidence for expression of preproCCK in either the nodose or petrosal ganglia. The present findings demonstrate that cells of the nodose and petrosal ganglia express the genes for a number of neuropeptides that are presumably involved with transmission of visceral sensory afferent information to higher order neurons of the central nervous system. PMID:1708726

  16. alpha-Lactalbumin hydrolysate stimulates glucagon-like peptide-2 secretion and small intestinal growth in suckling rats.

    PubMed

    Izumi, Hirohisa; Ishizuka, Satoshi; Inafune, Ayako; Hira, Tohru; Ozawa, Kazuhiro; Shimizu, Takashi; Takase, Mitsunori; Hara, Hiroshi

    2009-07-01

    We investigated whether bovine milk constituents influenced glucagon-like peptide (GLP)-2 secretion and intestinal growth in suckling rats. Male Sprague-Dawley rats (14 d old) received i.g. infusions of a milk protein fraction, a lactose solution, or the cream fraction of milk. The serum concentration of GLP-2, but not GLP-1, markedly increased in rats administered milk protein compared with those given the lactose solution or the cream fraction from 60 to 120 min after administration. In another experiment, both casein (CN) and whey protein isolate stimulated GLP-2 secretion at 120 min after administration, but soy protein and ovalbumin did not. Stimulation of GLP-2 secretion by several milk proteins was similar, including alpha-CN, alpha-lactalbumin (alpha-La), and beta-lactoglobulin, in a separate experiment. A hydrolysate of alpha-La obtained by incubation with protease A extracted from Aspergillus oryzae (LaHPA) caused almost twice the GLP-2 release due to intact alpha-La and other alpha-La hydrolysates. Free amino acid concentrations and molecular size distributions did not differ among alpha-La hydrolysates, including LaHPA. In rat pups reared with milk formulae containing alpha-La or LaHPA, LaHPA significantly promoted small intestinal elongation and increased the number of crypt epithelial cells compared with a formula containing intact alpha-La. LaHPA administration also increased the maltase:lactase activity ratio, a marker of maturation of the intestinal mucosa. In conclusion, milk proteins stimulate GLP-2 secretion and contribute to growth and maturation of the small intestine in suckling rats. PMID:19494023

  17. Acute effects of morphine and opioid peptides on the motility and responses of rat colon to electrical stimulation.

    PubMed Central

    Gillan, M. G.; Pollock, D.

    1980-01-01

    1 Morphine and leucine- and methionine-enkephalins inhibited the contractile response of the pithed rat colon to electrical stimulation of the spinal motor outflows and inhibited motor responses of the isolated colon to field stimulation. 2 Morphine and the opioid peptides also had an excitatory action in the colon. In the pithed rat, opiates caused regular fluctuations in intracolonic pressure and in the isolated colon, caused regular waves of contraction. This excitatory response was produced by low concentrations of the enkephalins (2 X 10(-8) M, 2 X 10(-9) M), was stereospecific and was antagonized by naloxone. 3 Opiate-induced contractions in the isolated colon were inhibited by catecholamines, adenine nucleotides and by phosphodiesterase inhibitors. These contractions were unaffected by ergotamine and tolazoline, or by propranolol. 4 The excitatory action of opiates in the isolated colon was not antagonized and usually was potentiated by atropine, (+)-tubocurarine and hexamethonium. In the absence of opiates, these drugs also produced similar waves of contraction, which were unaffected by naloxone. 5 Opiate-induced contractions occurred in colon rendered unresponsive to 5-hydroxytryptamine (5-HT) and these contractions were potentiated by the 5-HT antagonist, lysergic acid diethylamide, which, when administered alone, caused similar contractions. The 5-HT antagonist, cyproheptadine, inhibited opiate-induced contractions but was non-specific, since it also inhibited responses of the colon to carbachol and KC1. 6 Opiate-induced contractions were unaffected by procaine and were potentiated by tetrodotoxin. Both of these drugs, when administered alone, produced waves of contractions, which were similar to those produced by opiates but were unaffected by naloxone. 7 Contractions produced in the isolated colon either by opiates, atropine or (+)-tubocurarine, or any combination of these drugs, were inhibited by field stimulation applied at the peak of a wave of

  18. Vasoactive intestinal peptide synergistically stimulates DNA synthesis in mouse 3T3 cells: Role of cAMP, Ca sup 2+ , and protein kinase C

    SciTech Connect

    Zurier, B.B.; Kozma, M.; Sinnett-Smith, J.; Rozengurt, E. )

    1988-05-01

    Vasoactive intestinal peptide synergistically stimulated initiation of DNA synthesis in Swiss 3T3 cells. The peptide stimulated ({sup 3}H)thymidine incorporation in the presence of insulin and either forskolin or an inhibitor of cAMP phosphodiesterase in a concentration-dependent manner. Half-maximal effect was obtained at 1 nM. At mitogenic concentrations, VIP stimulated a marked accumulation (eightfold) of cAMP. In contrast to other growth-promoting neuropeptides, VIP did not induce an increase in cytosolic free Ca{sup 2+} or the activation of protein kinase C. The authors conclude that neuropeptides can modulate long-term cell proliferation through multiple signaling pathways.

  19. Speract, a sea urchin egg peptide that regulates sperm motility, also stimulates sperm mitochondrial metabolism.

    PubMed

    García-Rincón, Juan; Darszon, Alberto; Beltrán, Carmen

    2016-04-01

    Sea urchin sperm have only one mitochondrion, that in addition to being the main source of energy, may modulate intracellular Ca(2+) concentration ([Ca(2+)]i) to regulate their motility and possibly the acrosome reaction. Speract is a decapeptide from the outer jelly layer of the Strongylocentrotus purpuratus egg that upon binding to its receptor in the sperm, stimulates sperm motility, respiration and ion fluxes, among other physiological events. Altering the sea urchin sperm mitochondrial function with specific inhibitors of this organelle, increases [Ca(2+)]i in an external Ca(2+) concentration ([Ca(2+)]ext)-dependent manner (Ardón, et al., 2009. BBActa 1787: 15), suggesting that the mitochondrion is involved in sperm [Ca(2+)]i homeostasis. To further understand the interrelationship between the mitochondrion and the speract responses, we measured mitochondrial membrane potential (ΔΨ) and NADH levels. We found that the stimulation of sperm with speract depolarizes the mitochondrion and increases the levels of NADH. Surprisingly, these responses are independent of external Ca(2+) and are due to the increase in intracellular pH (pHi) induced by speract. Our findings indicate that speract, by regulating pHi, in addition to [Ca(2+)]i, may finely modulate mitochondrial metabolism to control motility and ensure that sperm reach the egg and fertilize it. PMID:26772728

  20. Tc-99m-labeled RGD-conjugated alpha-melanocyte stimulating hormone hybrid peptides with reduced renal uptake

    PubMed Central

    Yang, Jianquan; Hu, Chien-An

    2015-01-01

    The purpose of this study was to examine whether the replacement of the positively-charged Lys or Arg linker with a neutral linker could reduce the renal uptake of Arg-Gly-Asp (RGD)-conjugated alpha-melanocyte stimulating hormone (α-MSH) hybrid peptide. The RGD motif {cyclic(Arg-Gly-Asp-dTyr-Asp)} was coupled to [Cys3,4,10, d-Phe7, Arg11]α-MSH3–13 {(Arg11)CCMSH} through the neutral βAla or Ahx {aminohexanoic acid} linker (replacing the Lys or Arg linker) to generate novel RGD-βAla-(Arg11)CCMSH and RGD-Ahx-(Arg11)CCMSH hybrid peptides. The receptor binding affinity and cytotoxicity of RGD-βAla-(Arg11)CCMSH and RGD-Ahx-(Arg11)CCMSH were determined in B16/F1 melanoma cells. The melanoma targeting and imaging properties of 99mTc-RGD-βAla-(Arg11)CCMSH and 99mTc-RGD-Ahx-(Arg11)CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The replacement of the Lys or Arg linker with the βAla or Ahx linker retained nanomolar receptor binding affinities and remarkable cytotoxicity of RGD-βAla-(Arg11)CCMSH and RGD-Ahx-(Arg11)CCMSH. The receptor binding affinities of RGD-βAla-(Arg11)CCMSH and RGD-Ahx-(Arg11)CCMSH were 0.8 and 1.3 nM. Three-hour incubation with 0.1 µM of RGD-βAla-(Arg11)CCMSH and RGD-Ahx-(Arg11)CCMSH decreased the survival percentages of B16/F1 cells by 71 and 67% as compared to the untreated control cells five days post the treatment. The replacement of the Arg linker with the βAla or Ahx linker reduced the non-specific renal uptake of 99mTc-RGD-βAla-(Arg11)CCMSH and 99mTc-RGD-Ahx-(Arg11)CCMSH by 62% and 61% at 2 h post-injection. 99mTc-RGD-βAla-(Arg11)CCMSH displayed higher melanoma uptake than 99mTc-RGD-Ahx-(Arg11)CCMSH at 0.5, 2, 4 and 24 h post-injection. Enhanced tumor to kidney uptake ratio of 99mTc-RGD-βAla-(Arg11)CCMSH warranted the further evaluation of 188Re-labeled RGD-βAla-(Arg11)CCMSH as a novel MC1 receptor-targeting therapeutic peptide for melanoma treatment in the future. PMID:25557051

  1. Amyloid β peptide stimulates platelet activation through RhoA-dependent modulation of actomyosin organization.

    PubMed

    Sonkar, Vijay K; Kulkarni, Paresh P; Dash, Debabrata

    2014-04-01

    Platelets contribute to 95% of circulating amyloid precursor protein in the body and have widely been employed as a "peripheral" model of neurons in Alzheimer's disease. We sought to analyze the effects of amyloid β (Aβ) on platelets and to understand the underlying molecular mechanism. The Aβ active fragment containing amino acid sequence 25-35 (Aβ(25-35); 10-20 μM) was found to induce strong aggregation of human platelets, granule release, and integrin activation, similar to that elicited by physiological agonists. Platelets exposed to Aβ(25-35) retracted fibrin clot and displayed augmented adhesion to collagen under arterial shear, reflective of a switch to prothrombotic phenotype. Exposure of platelets to Aβ peptide (20 μM) resulted in a 4.2- and 2.3-fold increase in phosphorylation of myosin light chain (MLC) and MLC phosphatase, respectively, which was reversed by Y27632, an inhibitor of Rho-associated coiled-coil protein kinase (ROCK). Aβ(25-35)-induced platelet aggregation and clot retraction were also significantly attenuated by Y27632. Consistent with these findings, Aβ(25-35) elicited a significant rise in the level of RhoA-GTP in platelets. Platelets pretreated with reverse-sequenced Aβ fragment (Aβ(35-25)) and untreated resting platelets served as controls. We conclude that Aβ induces cellular activation through RhoA-dependent modulation of actomyosin, and hence, RhoA could be a potential therapeutic target in Alzheimer's disease and cerebral amyloid angiopathy. PMID:24421399

  2. Glucose-dependent insulinotropic peptide stimulates thymidine incorporation in endothelial cells: role of endothelin-1

    NASA Technical Reports Server (NTRS)

    Ding, Ke-Hong; Zhong, Qing; Isales, Carlos M.; Iscules, C. M. (Principal Investigator)

    2003-01-01

    We have previously characterized the receptor for glucose-dependent insulinotropic polypeptide (GIPR) in vascular endothelial cells (EC). Different EC types were found to contain distinct GIPR splice variants. To determine whether activation of the GIPR splice variants resulted in different cellular responses, we examined GIP effects on human umbilical vein endothelial cells (HUVEC), which contain two GIPR splice variants, and compared them with a spontaneously transformed human umbilical vein EC line, ECV 304, which contains four GIPR splice variants. GIP dose-dependently stimulated HUVEC and ECV 304 proliferation as measured by [3H]thymidine incorporation. GIP increased endothelin-1 (ET-1) secretion from HUVEC but not from ECV 304. Use of the endothelin B receptor blocker BQ-788 resulted in an inhibition of [3H]thymidine incorporation in HUVEC but not in ECV 304. These findings suggest that, although GIP increases [3H]thymidine incorporation in both HUVEC and ECV 304, this proliferative response is mediated by ET-1 only in HUVEC. These differences in cellular response to GIP may be related to differences in activation of GIPR splice variants.

  3. Conformations of peptide fragments comprising the complete sequence of component III of Chi t I and their relationship to T-cell stimulation.

    PubMed

    Czisch, M; Liebers, V; Bernstein, R; Chen, Z; Baur, X; Holak, T A

    1994-08-16

    Conformational preferences of synthetic peptides that span the complete sequence of Chironomus thummi hemoglobin (Chi t I) component III were studied by nuclear magnetic resonance (NMR) and CD spectroscopies. The peptides, 19-21 amino acids in length, were studied in water, except for the C-terminal peptide, which was investigated in DMSO-d6. NMR showed that all investigated peptides lacked uniquely folded conformations in water at 4 degrees C and pH 3.0 or at 10 degrees C and pD 6.6 in DMSO. However, some preferential helix-like conformations for the peptides corresponding to the helices of the folded protein could be seen in solution. These peptides showed characteristic interactions for conformations in both the beta- and alpha-regions of phi-psi space, based on strong C alpha H(i)-NH(i + 1) interactions, and on NH-NH, C alpha H(i)-NH-(i + 2), C alpha H(i)-NH(i + 3), and C alpha H(i)-C beta H(i + 3) interactions, respectively. Helical motifs seem not to be the most important factors in determining MHC-binding and/or T-cell recognition. However, there is a tendency that more stabilized secondary structures show higher T-cell stimulation. PMID:8068617

  4. The vasorelaxant effect of adrenomedullin, proadrenomedullin N-terminal 20 peptide and amylin in human skin.

    PubMed

    Hasbak, Philip; Eskesen, Karen; Lind, Henrik; Holst, Jan; Edvinsson, Lars

    2006-08-01

    In this study we aimed to assess in vivo, the vasodilator effects of adrenomedullin, proadrenomedullin N-terminal 20 peptide (PAMP) and amylin in human skin vasculature and compare the responses to the effects mediated by the endogenous neuropeptides calcitonin gene-related peptide (CGRP) and substance P and to examine the mRNA expression of calcitonin receptor-like receptor (CL-R) and receptor-activity modifying proteins, RAMP1, RAMP 2 and RAMP3 in human subcutaneous arteries. Changes in skin blood flow of the forearm were measured using a Laser Doppler Imager after intradermal injection of the peptides. The mRNA expression was assessed by real-time reverse transcriptase-polymerase chain reaction (real-time PCR). CGRP, adrenomedullin and amylin induced concentration-dependent, long-lasting increases in skin blood flow. The response to PAMP was shorter in duration appearing similar to the transient response induced by substance P. PAMP (10(-6)-10(-5) M) caused distinct itch sensation and local erythema. This effect could be abolished when combining the histamine H1-receptor antagonist mepyramin and PAMP. Real-time PCR data showed a higher level of mRNA for RAMP2 than CL-R, RAMP1 and RAMP3 in the tissue. Though the PCR data demonstrated the presence of mRNA for both CGRP1 and adrenomedullin receptors the rank order of potency (CGRP>adrenomedullin>amylin) for the blood flow increase indicated vasodilatation for these peptides was induced by activation of CGRP1 receptors. Intradermal injection of CGRP, adrenomedullin and amylin induces long lasting dilatation of human skin vasculature by activation of CGRP1 receptors. PAMP induces transient vasodilatation. PAMP but not CGRP, adrenomedullin and amylin causes itch sensation and local erythema. The transient effect on vasodilatation as response to PAMP is discussed. PMID:16918718

  5. Comparative Effects of Prolonged and Intermittent Stimulation of the Glucagon-Like Peptide 1 Receptor on Gastric Emptying and Glycemia

    PubMed Central

    Umapathysivam, Mahesh M.; Lee, Michael Y.; Jones, Karen L.; Annink, Christopher E.; Cousins, Caroline E.; Trahair, Laurence G.; Rayner, Chris K.; Chapman, Marianne J.; Nauck, Michael A.; Horowitz, Michael; Deane, Adam M.

    2014-01-01

    Acute administration of glucagon-like peptide 1 (GLP-1) and its agonists slows gastric emptying, which represents the major mechanism underlying their attenuation of postprandial glycemic excursions. However, this effect may diminish during prolonged use. We compared the effects of prolonged and intermittent stimulation of the GLP-1 receptor on gastric emptying and glycemia. Ten healthy men received intravenous saline (placebo) or GLP-1 (0.8 pmol/kg ⋅ min), as a continuous 24-h infusion (“prolonged”), two 4.5-h infusions separated by 20 h (“intermittent”), and a 4.5-h infusion (“acute”) in a randomized, double-blind, crossover fashion. Gastric emptying of a radiolabeled mashed potato meal was measured using scintigraphy. Acute GLP-1 markedly slowed gastric emptying. The magnitude of the slowing was attenuated with prolonged but maintained with intermittent infusions. GLP-1 potently diminished postprandial glycemia during acute and intermittent regimens. These observations suggest that short-acting GLP-1 agonists may be superior to long-acting agonists when aiming specifically to reduce postprandial glycemic excursions in the treatment of type 2 diabetes. PMID:24089511

  6. Vasoactive intestinal peptide enhanced aromatase activity in the neonatal rat ovary before development of primary follicles or responsiveness to follicle-stimulating hormone

    SciTech Connect

    George, F.W.; Ojeda, S.R.

    1987-08-01

    The authors have investigated the factors that regulate aromatase activity in fetal-neonatal rat ovaries. Ovarian aromatase activity (assessed by measuring the amount of /sup 3/H/sub 2/O formed from (1..beta..-/sup 3/H)testosterone) is low prior to birth and increases to values greater than 30 pmol/hr per mg of protein between days 8 and 12 after birth. The appearance of ovarian aromatase coincides with the development of primordial follicles. Fetal-neonatal ovaries maintained in serum-free organ culture do not develop aromatase activity at the expected time. Ovine follicle-stimulating hormone, ovine luteinizing hormone, or their combination failed to induce the enzyme activity in cultured fetal ovaries, whereas follicle-stimulating hormone is effective in preventing the decline in aromatase activity when postnatal day 8 ovaries are placed in culture. In contrast to follicle-stimulating hormone, dibutyryl-cAMP markedly enhances ovarian aromatase in cultured fetal ovaries. Likewise, enhancement of endogenouse cAMP formation with forskolin or cholera toxin caused an increase in enzyme activity within 24 hr. Vasoactive intestinal peptide, a peptide known to occur in ovarian nerves, caused a dose-dependent increase in aromatase activity in fetal ovaries prior to folliculogenesis. Of related peptides tested, only the peptide having N-terminal histidine and C-terminal isoleucine amide was capable of inducing aromatase activity in fetal ovaries. The fact that VIP can induce aromatase activity in fetal rat ovaries prior to follicle formation and prior to responsiveness to follicle-stimulating hormone suggests that this neuropeptide may play a critical role in ovarian differentiation.

  7. Selective CGRP and adrenomedullin peptide binding by tethered RAMP-calcitonin receptor-like receptor extracellular domain fusion proteins

    PubMed Central

    Moad, Heather E; Pioszak, Augen A

    2013-01-01

    Calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) are related peptides that are potent vasodilators. The CGRP and AM receptors are heteromeric protein complexes comprised of a shared calcitonin receptor-like receptor (CLR) subunit and a variable receptor activity modifying protein (RAMP) subunit. RAMP1 enables CGRP binding whereas RAMP2 confers AM specificity. How RAMPs determine peptide selectivity is unclear and the receptor stoichiometries are a topic of debate with evidence for 1:1, 2:2, and 2:1 CLR:RAMP stoichiometries. Here, we describe bacterial production of recombinant tethered RAMP-CLR extracellular domain (ECD) fusion proteins and biochemical characterization of their peptide binding properties. Tethering the two ECDs ensures complex stability and enforces defined stoichiometry. The RAMP1-CLR ECD fusion purified as a monomer, whereas the RAMP2-CLR ECD fusion purified as a dimer. Both proteins selectively bound their respective peptides with affinities in the low micromolar range. Truncated CGRP(27-37) and AM(37-52) fragments were identified as the minimal ECD complex binding regions. The CGRP C-terminal amide group contributed to, but was not required for, ECD binding, whereas the AM C-terminal amide group was essential for ECD binding. Alanine-scan experiments identified CGRP residues T30, V32, and F37 and AM residues P43, K46, I47, and Y52 as critical for ECD binding. Our results identify CGRP and AM determinants for receptor ECD complex binding and suggest that the CGRP receptor functions as a 1:1 heterodimer. In contrast, the AM receptor may function as a 2:2 dimer of heterodimers, although our results cannot rule out 2:1 or 1:1 stoichiometries. PMID:24115156

  8. Asthma as an axon reflex.

    PubMed

    Barnes, P J

    1986-02-01

    In asthma, damage to airway epithelium, possibly caused by eosinophil products, exposes C-fibre afferent nerve endings. Stimulation of these endings by inflammatory mediators such as bradykinin may result in an axon (local) reflex with antidromic conduction down afferent nerve collaterals and release of sensory neuropeptides such as substance P, neurokinin A, and calcitonin gene-related peptide. These peptides are potent inducers of airway smooth muscle contraction, bronchial oedema, extravasation of plasma, mucus hypersecretion, and possibly inflammatory cell infiltration and secretion. Thus, axon reflexes could account for at least some of the pathophysiology of asthma and this concept might lead to new strategies for treatment. PMID:2418322

  9. Atrial Natriuretic Peptide Stimulates Dopamine Tubular Transport by Organic Cation Transporters: A Novel Mechanism to Enhance Renal Sodium Excretion

    PubMed Central

    Kouyoumdzian, Nicolás M.; Rukavina Mikusic, Natalia L.; Kravetz, María C.; Lee, Brenda M.; Carranza, Andrea; Del Mauro, Julieta S.; Pandolfo, Marcela; Gironacci, Mariela M.; Gorzalczany, Susana; Toblli, Jorge E.; Fernández, Belisario E.

    2016-01-01

    The aim of this study was to demonstrate the effects of atrial natriuretic peptide (ANP) on organic cation transporters (OCTs) expression and activity, and its consequences on dopamine urinary levels, Na+, K+-ATPase activity and renal function. Male Sprague Dawley rats were infused with isotonic saline solution during 120 minutes and randomized in nine different groups: control, pargyline plus tolcapone (P+T), ANP, dopamine (DA), D-22, DA+D-22, ANP+D-22, ANP+DA and ANP+DA+D-22. Renal functional parameters were determined and urinary dopamine concentration was quantified by HPLC. Expression of OCTs and D1-receptor in membrane preparations from renal cortex tissues were determined by western blot and Na+, K+-ATPase activity was determined using in vitro enzyme assay. 3H-DA renal uptake was determined in vitro. Compared to P+T group, ANP and dopamine infusion increased diuresis, urinary sodium and dopamine excretion significantly. These effects were more pronounced in ANP+DA group and reversed by OCTs blockade by D-22, demonstrating that OCTs are implied in ANP stimulated-DA uptake and transport in renal tissues. The activity of Na+, K+-ATPase exhibited a similar fashion when it was measured in the same experimental groups. Although OCTs and D1-receptor protein expression were not modified by ANP, OCTs-dependent-dopamine tubular uptake was increased by ANP through activation of NPR-A receptor and protein kinase G as signaling pathway. This effect was reflected by an increase in urinary dopamine excretion, natriuresis, diuresis and decreased Na+, K+-ATPase activity. OCTs represent a novel target that links the activity of ANP and dopamine together in a common mechanism to enhance their natriuretic and diuretic effects. PMID:27392042

  10. Increased Litter Size and Suckling Intensity Stimulate mRNA of RFamide-related Peptide in Rats

    PubMed Central

    Noroozi, Atefeh; Jafarzadeh Shirazi, Mohammad Reza; Tamadon, Amin; Moghadam, Ali; Niazi, Ali

    2015-01-01

    Background RFamide-related peptide-3 (RFRP-3) inhibits gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) secretion in rats. This study evaluates the effects of litter size and suckling intensity on RFRP mRNA expression in the dorsomedial hypothalamic nucleus (DMH) of rats. Materials and Methods A total of 32 pregnant and 4 non-lactating ovariectomized (control group) Sprague-Dawley rats were used in this experimental study. Lactating rats were allotted to 8 equal groups. In 3 groups, the litter size was adjusted to 5, 10, or 15 pups upon parturition. Dams were allowed to suckle their pups continuously until 8 days postpartum. In the other 3 groups, the litter size was adjusted to 5 pups following birth. These pups were separated from the dams for 6 hours on day 8 postpartum, after which the pups were allowed to suckle for 2.5, 5, or 7.5 minutes prior to killing the dams. In 2 groups, lactating rats with 10 and 15 pups were separated from their pups for 6 hours on day 8 postpartum. In these groups, the pups were allowed to suckle their dams for 5 minutes before the dams were killed. All rats were killed on day 8 postpartum and the DMH was removed from each rat. We evaluated RFRP mRNA expression using realtime polymerase chain reaction (PCR). Results The expression of RFRP mRNA in the DMH increased with increased litter size and suckling intensity compared to the controls. The effect of suckling intensity on the expression of RFRP mRNA was more pronounced compared to the litter size. Conclusion Increased litter size and suckling intensity stimulated RFRP mRNA expression in the DMH which might contribute to lactation anestrus in rats. PMID:26644862

  11. The novel anti-migraine agent rizatriptan inhibits neurogenic dural vasodilation and extravasation.

    PubMed

    Williamson, D J; Shepheard, S L; Hill, R G; Hargreaves, R J

    1997-06-01

    These studies in anaesthetised rats showed, using intravital microscopy, that the novel anti-migraine agent, rizatriptan, significantly reduced electrically stimulated dural vasodilation but had no effect on increases in dural vessel diameter produced by exogenous substance P or calcitonin gene-related peptide (CGRP). Rizatriptan also significantly inhibited dural plasma protein extravasation produced by high intensity electrical stimulation of the trigeminal ganglion. We suggest that rizatriptan inhibits the release of sensory neuropeptides from perivascular trigeminal nerves to prevent neurogenic vasodilation and extravasation in the dura mater. These prejunctional inhibitory effects may be involved in the anti-migraine action of rizatriptan. PMID:9203569

  12. Vasoactive intestinal peptide: A potent stimulator of adenosine 3′:5′-cyclic monophosphate accumulation in gut carcinoma cell lines in culture*

    PubMed Central

    Laburthe, M.; Rousset, M.; Boissard, C.; Chevalier, G.; Zweibaum, A.; Rosselin, G.

    1978-01-01

    Vasoactive intestinal peptide (VIP) is a potent and efficient stimulator of adenosine 3′:5′-cyclic monophosphate (cAMP) accumulation in a human colon carcinoma cell line, HT 29. cAMP accumulation is sensitive to a concentration of VIP as low as 3×10-12 M. Maximum VIP-induced cAMP levels were observed with 10-9 M VIP and are about 200 times above the basal levels. Half-maximum cAMP production was obtained at 3×10-10 M VIP. 125I-Labeled VIP was found to bind to HT 29 cells; this binding was competitively inhibited by concentrations of unlabeled VIP between 10-10 and 10-7 M. Half-maximum inhibition of binding was observed with 2×10-9 M VIP. Secretin also stimulated cAMP accumulation in HT 29 cells, but its effectiveness was 1/1000 that of VIP. The other peptides tested at 10-7 M, such as insulin, glucagon, bovine pancreatic polypeptide, somatostatin, octapeptide of cholecystokinin, neurotensin, and substance P, did not stimulate cAMP accumulation. Prostaglandin E1 and catecholamines stimulated cAMP production but were 1/2.3 and 1/5.5 as efficient as VIP, respectively. Another malignant cell line from the gut, the human rectal tumor cell line HRT 18, is also sensitive to VIP. In HRT 18 cells, VIP stimulated cAMP accumulation with a maximal effect at 10-8 M; half-maximum stimulation was observed at about 10-9 M. These results demonstrate the presence of VIP receptors in two malignant human intestinal cell lines (HT 29 and HRT 18) in culture and provide a model for studying the action of VIP on cell proliferation. PMID:208077

  13. Melanoma-targeting properties of (99m)technetium-labeled cyclic alpha-melanocyte-stimulating hormone peptide analogues.

    PubMed

    Chen, J; Cheng, Z; Hoffman, T J; Jurisson, S S; Quinn, T P

    2000-10-15

    Preliminary reports have demonstrated that (99m)technetium (Tc)-labeled cyclic [Cys(3,4,10), D-Phe7]alpha-MSH(3-13) (CCMSH) exhibits high tumor uptake and retention values in a murine melanoma mouse model. In this report, the tumor targeting mechanism of 99mTc-CCMSH was studied and compared with four other radiolabeled alpha-melanocyte stimulating hormone (alpha-MSH) peptide analogues: 125I-(Tyr2)-[Nle4, D-Phe7]alpha-MSH [125I-(Tyr2)-NDP]; 99mTc-CGCG-NDP; 99mTc-Gly11-CCMSH; and 99mTc-Nle11-CCMSH. In vitro receptor binding, internalization, and cellular retention of radiolabeled alpha-MSH analogues in B16/F1 murine cell line demonstrated that >70% of the receptor-bound radiolabeled analogues were internalized together with the receptor. Ninety % of the internalized 125I-(Tyr2)-NDP, whereas only 36% of internalized 99mTc-CCMSH, was released from the cells into the medium during a 4-h incubation at 37 degrees C. Two mouse models, C57 mice and severe combined immunodeficient (Scid) mice, inoculated s.c. with B16/F1 murine and TXM-13 human melanoma cells were used for the in vivo studies. Tumor uptake values of 11.32 and 2.39 [% injected dose (ID)/g] for 99mTc-CCMSH at 4 h after injection, resulted in an uptake ratio of tumor:blood of 39.0 and 11.5 in murine melanoma-C57 and human melanoma-Scid mouse models, respectively. Two strategies for decreasing the nonspecific kidney uptake of 99mTc-CCMSH, substitution of Lys11 in CCMSH with Gly11 or Nle11, and lysine coinjection, were evaluated. The biodistribution data for the modified peptides showed that Lys11 replacement dramatically decreased the kidney uptake, whereas the tumor uptakes of 99mTc-Nle11- and 99mTc-Gly11-CCMSH were significantly lower than that of 99mTc-CCMSH. Lysine coinjection significantly decreased the kidney uptake (e.g., from 14.6% ID/g to 4.5% ID/g at 4 h after injection in murine melanoma-C57 mice) without significantly changing the value of tumor uptake of 99mTc-CCMSH. In conclusion, the compact

  14. 203Pb-Labeled Alpha-Melanocyte-Stimulating Hormone Peptide as an Imaging Probe for Melanoma Detection

    SciTech Connect

    Yubin, Miao; Figueroa, Said D.; Fisher, Darrell R.; Moore, Herbert A.; Testa, Richard F.; Hoffman, Timothy J.; Quinn, Thomas P.

    2008-05-01

    Abbreviations: a-MSH; alpha melanocyte stimulating hormone, DOTA; 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, Re(Arg11)CCMSH; DOTA-[Cys3,4,10, D-Phe7, Arg11]a-MSH3-13, NDP; [Nle4,d-Phe7] a-MSH3-13. Abstract Peptide-targeted alpha therapy with 200 mCi of 212Pb-DOTA-Re(Arg11)CCMSH cured 45% of B16/F1 murine melanoma-bearing C57 mice in a 120-day study, highlighting its melanoma treatment potential. However, there is a need to develop an imaging surrogate for patient specific dosimetry and to monitor the tumor response to 212Pb-DOTA-Re(Arg11)CCMSH therapy. The purpose of this study was to evaluate the potential of 203Pb-DOTA-Re(Arg11)CCMSH as a matched-pair SPECT imaging agent for 212Pb-DOTA-Re(Arg11)CCMSH. Method: DOTA-Re(Arg11)CCMSH was labeled with 203Pb in 0.5 M NH4OAc buffer at pH 5.4. The internalization and efflux of 203Pb-DOTA-Re(Arg11)CCMSH were determined in B16/F1 melanoma cells. The pharmacokinetics of 203Pb-DOTA-Re(Arg11)CCMSH were examined in B16/F1 melanoma-bearing C57 mice. A micro-SPECT/CT imaging study was performed with 203Pb-DOTA-Re(Arg11)CCMSH in a B16/F1 melanoma-bearing C57 mouse at 2 h post-injection. Results: 203Pb-DOTA-Re(Arg11)CCMSH was easily prepared in NH4OAc buffer and completely separated from the excess non-radiolabeled peptide by RP-HPLC. 203Pb-DOTA-Re(Arg11)CCMSH displayed fast internalization and extended retention in B16/F1 cells. Approximately 73% of 203Pb-DOTA-Re(Arg11)CCMSH activity internalized after a 20-min incubation at 25C. After incubating the cells in culture media for 20 min, 78% of internalized activity remained in the cells. 203Pb-DOTA-Re(Arg11)CCMSH exhibited similar biodistribution pattern with 212Pb-DOTA-Re(Arg11)CCMSH in B16/F1 melanoma-bearing mice. 203Pb-DOTA-Re(Arg11)CCMSH exhibited the peak tumor uptake of 12.00 +/- 3.20 %ID/g at 1 h post-injection. The tumor uptake gradually decreased to 3.43 +/- 1.12 %ID/g at 48 h post-injection. 203Pb-DOTA-Re(Arg11)CCMSH exhibited the peak tumor to kidney

  15. Synthetic peptides based upon a three-dimensional model for the receptor recognition site of follicle-stimulating hormone exhibit antagonistic or agonistic activity at low concentrations.

    PubMed Central

    Hage-van Noort, M; Puijk, W C; Plasman, H H; Kuperus, D; Schaaper, W M; Beekman, N J; Grootegoed, J A; Meloen, R H

    1992-01-01

    Follicle-stimulating hormone (follitropin, FSH) belongs to a group of closely related glycoprotein hormones that contain two noncovalently linked dissimilar subunits designated alpha and beta. By using synthetic peptides, several receptor interaction sites in these hormones have been identified; however, the peptides have a reduced potency (lowest effective concentration of 10(-4) to 10(-5) M) relative to the hormone itself (10(-8) to 10(-11) M). This suggests that the peptides represent only a portion of a larger recognition site in the intact hormone that comprises parts of both the beta and the alpha chains. To develop peptides that exhibit FSH-antagonistic activity at low concentrations, we have constructed a three-dimensional model for FSH, which is based on an alignment of both the beta and the alpha chains of glycoprotein hormones with thioredoxin, for which x-ray diffraction data are available. This model resulted in the prediction of a conformational receptor-binding site in FSH, in which (parts of) three earlier proposed binding regions on the FSH molecule [namely, the regions FSH alpha-(34-37), with the amino acid sequence SRAY; FSH beta-(40-43), with the amino acid sequence TRDL; and FSH beta-(87-94), the "determinant loop" with the amino acid sequence CDSDSTDC] are located within 10 A of one another. On the basis of this model, peptides have been synthesized in which two of these binding regions are linked by a synthetic amino acid whose length was derived from the model, Ac-TDSDS-NH-(CH2)5-CO-SRAY-NH2 and Ac-SRAY-NH-(CH2)4-CO-TRDL-NH2. Both peptides inhibited FSH-induced cAMP production in Sertoli cells at 1000-fold lower concentrations (10(-7) M) than the peptides Ac-TRDL-NH2, Ac-SRAY-NH2, or Ac-TDSDS-NH2. In another peptide, Ac-TDSDS-NH-(CH2)5-CO-SRAY-NH-(CH2)4-CO-TRDL-NH2, all three binding regions have been linked. This peptide appeared to be a strong agonist of FSH action, as measured by the ability to stimulate cAMP production, at concentrations

  16. Calcitonin and Amylin Receptor Peptide Interaction Mechanisms: INSIGHTS INTO PEPTIDE-BINDING MODES AND ALLOSTERIC MODULATION OF THE CALCITONIN RECEPTOR BY RECEPTOR ACTIVITY-MODIFYING PROTEINS.

    PubMed

    Lee, Sang-Min; Hay, Debbie L; Pioszak, Augen A

    2016-04-15

    Receptor activity-modifying proteins (RAMP1-3) determine the selectivity of the class B G protein-coupled calcitonin receptor (CTR) and the CTR-like receptor (CLR) for calcitonin (CT), amylin (Amy), calcitonin gene-related peptide (CGRP), and adrenomedullin (AM) peptides. RAMP1/2 alter CLR selectivity for CGRP/AM in part by RAMP1 Trp-84 or RAMP2 Glu-101 contacting the distinct CGRP/AM C-terminal residues. It is unclear whether RAMPs use a similar mechanism to modulate CTR affinity for CT and Amy, analogs of which are therapeutics for bone disorders and diabetes, respectively. Here, we reproduced the peptide selectivity of intact CTR, AMY1 (CTR·RAMP1), and AMY2 (CTR·RAMP2) receptors using purified CTR extracellular domain (ECD) and tethered RAMP1- and RAMP2-CTR ECD fusion proteins and antagonist peptides. All three proteins bound salmon calcitonin (sCT). Tethering RAMPs to CTR enhanced binding of rAmy, CGRP, and the AMY antagonist AC413. Peptide alanine-scanning mutagenesis and modeling of receptor-bound sCT and AC413 supported a shared non-helical CGRP-like conformation for their TN(T/V)G motif prior to the C terminus. After this motif, the peptides diverged; the sCT C-terminal Pro was crucial for receptor binding, whereas the AC413/rAmy C-terminal Tyr had little or no influence on binding. Accordingly, mutant RAMP1 W84A- and RAMP2 E101A-CTR ECD retained AC413/rAmy binding. ECD binding and cell-based signaling assays with antagonist sCT/AC413/rAmy variants with C-terminal residue swaps indicated that the C-terminal sCT/rAmy residue identity affects affinity more than selectivity. rAmy(8-37) Y37P exhibited enhanced antagonism of AMY1 while retaining selectivity. These results reveal unexpected differences in how RAMPs determine CTR and CLR peptide selectivity and support the hypothesis that RAMPs allosterically modulate CTR peptide affinity. PMID:26895962

  17. Regeneration of putative sensory and sympathetic cutaneous nerve endings in the rat foot after sciatic nerve injury.

    PubMed

    Stankovic, N; Johansson, O; Hildebrand, C

    1996-01-01

    The present study examines the occurrence of calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profiles in glabrous and hairy foot skin from normal and nerve-injured rats. After neurotomy/suture, glabrous skin samples contain few calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profies. The number of calcitonin gene-related peptide- and substance P-like immunoreacive profiles in the epidermis is significantly subnormal. Hairy skin from these rats does also contain few calcitonin gene-related peptide-, substance P- and tyrosine hydroxylase-like immunoreactive profiles. In addition, the presence of epidermal calcitonin gene-related peptide-like imunoreactive profiles in glabrous skin is subnormal on the contralateral side. After nerve crush injury, the occurrence of calcitonin gene-related peptide-like, but not substance P-like, immunoreactive profiles in th epidermis of the glabrous skin is significantly subnormal. The occurrence of tyrosine hylase-like immnunoreactive fibres in relation to the digital artery is also subnormal. The occurrence in hairy skin of calcitonin gene-related peptide-like immunoreactive, substance P-like immunoreactive and tyrosine hydroxylase-like immunoreactive profiles is subnormal. In both skin types, the contralateral occurrence of such profiles is subjectively normal. These results show that the occurrence of calcitonin gene-related peptide-, substance P-, and tyrosine hydroxylase-like immunoreactive profiles in glabrous and hairy foot skin is clearly subnormal after neurotomy and suture and less abnormal after nerve crush. After neurotomy and suture the contralateral side is also affected. PMID:10970110

  18. Pregnancy Increases Relaxation in Human Omental Arteries to the CGRP Family of Peptides.

    PubMed

    Dong, Yuanlin; Betancourt, Ancizar; Chauhan, Madhu; Balakrishnan, Meena; Lugo, Fernando; Anderson, Matthew L; Espinoza, Jimmy; Fox, Karin; Belfort, Michael; Yallampalli, Chandrasekhar

    2015-12-01

    Calcitonin gene-related peptide (CALCB) and its family members adrenomedullin (ADM) and intermedin (ADM2) play important roles in maintaining vascular adaptations during pregnancy in animal models. The present study was designed to evaluate the responses of omental arteries to CALCB, ADM, and ADM2 in pregnant and nonpregnant women, and to determine the mechanisms involved. By using resistance omental arteries collected from nonpregnant women (n = 15) during laparotomy and from term pregnant women (n = 15) at cesarean delivery, this study shows that the receptor components--calcitonin receptor-like receptor (CALCRL) and receptor activity-modifying proteins (RAMPs) 1, 2 and 3--are localized to endothelial and smooth muscle cells in omental arteries, with increased expressions of both mRNA and protein in pregnant compared with nonpregnant women. The myography study demonstrated that CALCB, ADM, and ADM2 (0.1-100 nM) dose dependently relax U46619 (1 muM) precontracted omental artery segments, and the maximum possible effects to CALCB and ADM2, but not to ADM, are significantly enhanced in pregnant compared with nonpregnant women. Further, the vasodilatory responses to CALCB, ADM, and ADM2 are reduced by inhibitors of nitric oxide (NO) synthase (L-NAME), adenylyl cyclase (SQ22536), voltage-activated potassium channels (4-aminopyrodin and tetrabutylammonium), Ca(2+)-activated potassium channel (charybdotoxin), and cyclooxygenase (indomethacin). In conclusion, the CALCB family of peptides, CALCB and ADM2, increase human omental artery relaxation during pregnancy through diverse mechanisms, including NO, endothelium-derived hyperpolarizing factors (EDHFs) and prostaglandins, and thus could contribute to the vascular adaptations during pregnancy in the human. PMID:26510864

  19. LPXRFamide peptide stimulates growth hormone and prolactin gene expression during the spawning period in the grass puffer, a semi-lunar synchronized spawner.

    PubMed

    Shahjahan, Md; Doi, Hiroyuki; Ando, Hironori

    2016-02-01

    Gonadotropin-inhibitory hormone (GnIH) plays as a multifunctional neurohormone that controls reproduction in birds and mammals. LPXRFamide (LPXRFa) peptide, the fish ortholog of GnIH, has been shown to regulate the secretion of not only gonadotropin (GTH) but also growth hormone (GH) and prolactin (PRL), which are potentially important for gonadal function. To investigate the role of LPXRFa peptide on reproduction of the grass puffer, which spawns in semilunar cycles, we examined changes in the levels of gh and prl expression over the several months during the reproductive cycle, and the effects of goldfish LPXRFa peptide-1 (gfLPXRFa-1) on their expression were examined using primary pituitary cultures. The expression levels of both gh and prl showed significant changes during the reproductive cycle in both sexes with one peak in the spawning and pre-spawning periods for gh and prl, respectively. Particularly, gh showed substantial increase in expression in the spawning and post-spawning periods, indicative of its essentiality in the advanced stage of reproduction. gfLPXRFa-1 stimulated the expression of both gh and prl but there was a marked difference in response between them: gfLPXRFa-1 stimulated gh expression at a relatively low dose but little effect was observed on prl. Combined with the previous results of daily and circadian oscillations of lpxrfa expression, the present results suggest that LPXRFa peptide is important in the control of the cyclic reproduction by serving as a multifunctional hypophysiotropic factor that regulates the expression of gh and prl as well as GTH subunit genes. PMID:26385315

  20. Leucine leucine-37 uses formyl peptide receptor-like 1 to activate signal transduction pathways, stimulate oncogenic gene expression, and enhance the invasiveness of ovarian cancer cells.

    PubMed

    Coffelt, Seth B; Tomchuck, Suzanne L; Zwezdaryk, Kevin J; Danka, Elizabeth S; Scandurro, Aline B

    2009-06-01

    Emerging evidence suggests that the antimicrobial peptide, leucine leucine-37 (LL-37), could play a role in the progression of solid tumors. LL-37 is expressed as the COOH terminus of human cationic antimicrobial protein-18 (hCAP-18) in ovarian, breast, and lung cancers. Previous studies have shown that the addition of LL-37 to various cancer cell lines in vitro stimulates proliferation, migration, and invasion. Similarly, overexpression of hCAP-18/LL-37 in vivo accelerates tumor growth. However, the receptor or receptors through which these processes are mediated have not been thoroughly examined. In the present study, expression of formyl peptide receptor-like 1 (FPRL1) was confirmed on ovarian cancer cells. Proliferation assays indicated that LL-37 does not signal through a G protein-coupled receptor, such as FPRL1, to promote cancer cell growth. By contrast, FPRL1 was required for LL-37-induced invasion through Matrigel. The peptide stimulated mitogen-activated protein kinase and Janus-activated kinase/signal transducers and activators of transcription signaling cascades and led to the significant activation of several transcription factors, through both FPRL1-dependent and FPRL1-independent pathways. Likewise, expression of some LL-37-stimulated genes was attenuated by the inhibition of FPRL1. Increased expression of CXCL10, EGF, and PDGF-BB as well as other soluble factors was confirmed from conditioned medium of LL-37-treated cells. Taken together, these data suggest that LL-37 potentiates a more aggressive behavior from ovarian cancer cells through its interaction with FPRL1. PMID:19491199

  1. Leucine Leucine-37 Uses Formyl Peptide Receptor–Like 1 to Activate Signal Transduction Pathways, Stimulate Oncogenic Gene Expression, and Enhance the Invasiveness of Ovarian Cancer Cells

    PubMed Central

    Coffelt, Seth B.; Tomchuck, Suzanne L.; Zwezdaryk, Kevin J.; Danka, Elizabeth S.; Scandurro, Aline B.

    2009-01-01

    Emerging evidence suggests that the antimicrobial peptide, leucine leucine-37 (LL-37), could play a role in the progression of solid tumors. LL-37 is expressed as the COOH terminus of human cationic antimicrobial protein-18 (hCAP-18) in ovarian, breast, and lung cancers. Previous studies have shown that the addition of LL-37 to various cancer cell lines in vitro stimulates proliferation, migration, and invasion. Similarly, overexpression of hCAP-18/LL-37 in vivo accelerates tumor growth. However, the receptor or receptors through which these processes are mediated have not been thoroughly examined. In the present study, expression of formyl peptide receptor–like 1 (FPRL1) was confirmed on ovarian cancer cells. Proliferation assays indicated that LL-37 does not signal through a G protein–coupled receptor, such as FPRL1, to promote cancer cell growth. By contrast, FPRL1 was required for LL-37–induced invasion through Matrigel. The peptide stimulated mitogen-activated protein kinase and Janus-activated kinase/signal transducers and activators of transcription signaling cascades and led to the significant activation of several transcription factors, through both FPRL1-dependent and FPRL1-independent pathways. Likewise, expression of some LL-37–stimulated genes was attenuated by the inhibition of FPRL1. Increased expression of CXCL10, EGF, and PDGF-BB as well as other soluble factors was confirmed from conditioned medium of LL-37–treated cells. Taken together, these data suggest that LL-37 potentiates a more aggressive behavior from ovarian cancer cells through its interaction with FPRL1. PMID:19491199

  2. Graphene oxide-stimulated myogenic differentiation of C2C12 cells on PLGA/RGD peptide nanofiber matrices

    NASA Astrophysics Data System (ADS)

    Shin, Y. C.; Lee, J. H.; Kim, M. J.; Hong, S. W.; Oh, J.-W.; Kim, C.-S.; Kim, B.; Hyun, J. K.; Kim, Y.-J.; Han, D.-W.

    2015-07-01

    During the last decade, much attention has been paid to graphene-based nanomaterials because they are considered as potential candidates for biomedical applications such as scaffolds for tissue engineering and substrates for the differentiation of stem cells. Until now, electrospun matrices composed of various biodegradable copolymers have been extensively developed for tissue engineering and regeneration; however, their use in combination with graphene oxide (GO) is novel and challenging. In this study, nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and M13 phage with RGD peptide displayed on its surface (RGD peptide-M13 phage) were prepared as extracellular matrix (ECM)-mimicking substrates. RGD peptide is a tripeptide (Arg-Gly-Asp) found on ECM proteins that promotes various cellular behaviors. The physicochemical properties of PLGA and RGD peptide-M13 phage (PLGA/RGD peptide) nanofiber matrices were characterized by atomic force microscopy, Fourier-transform infrared spectroscopy and thermogravimetric analysis. In addition, the growth of C2C12 mouse myoblasts on the PLGA/RGD peptide matrices was examined by measuring the metabolic activity. Moreover, the differentiation of C2C12 mouse myoblasts on the matrices when treated with GO was evaluated. The cellular behaviors, including growth and differentiation of C2C12 mouse myoblasts, were substantially enhanced on the PLGA/RGD peptide nanofiber matrices when treated with GO. Overall, these findings suggest that the PLGA/RGD peptide nanofiber matrices can be used in combination with GO as a novel strategy for skeletal tissue regeneration.

  3. The 'headache tree' via umbellulone and TRPA1 activates the trigeminovascular system.

    PubMed

    Nassini, Romina; Materazzi, Serena; Vriens, Joris; Prenen, Jean; Benemei, Silvia; De Siena, Gaetano; la Marca, Giancarlo; Andrè, Eunice; Preti, Delia; Avonto, Cristina; Sadofsky, Laura; Di Marzo, Vincenzo; De Petrocellis, Luciano; Dussor, Greg; Porreca, Frank; Taglialatela-Scafati, Orazio; Appendino, Giovanni; Nilius, Bernd; Geppetti, Pierangelo

    2012-02-01

    The California bay laurel or Umbellularia californica (Hook. & Arn.) Nutt., is known as the 'headache tree' because the inhalation of its vapours can cause severe headache crises. However, the underlying mechanism of the headache precipitating properties of Umbellularia californica is unknown. The monoterpene ketone umbellulone, the major volatile constituent of the leaves of Umbellularia californica, has irritating properties, and is a reactive molecule that rapidly binds thiols. Thus, we hypothesized that umbellulone stimulates the transient receptor potential ankyrin 1 channel in a subset of peptidergic, nocioceptive neurons, activating the trigeminovascular system via this mechanism. Umbellulone, from µM to sub-mM concentrations, selectively stimulated transient receptor potential ankyrin 1-expressing HEK293 cells and rat trigeminal ganglion neurons, but not untransfected cells or neurons in the presence of the selective transient receptor potential ankyrin 1 antagonist, HC-030031. Umbellulone evoked a calcium-dependent release of calcitonin gene-related peptide from rodent trigeminal nerve terminals in the dura mater. In wild-type mice, umbellulone elicited excitation of trigeminal neurons and released calcitonin gene-related peptide from sensory nerve terminals. These two responses were absent in transient receptor potential ankyrin 1 deficient mice. Umbellulone caused nocioceptive behaviour after stimulation of trigeminal nerve terminals in wild-type, but not transient receptor potential ankyrin 1 deficient mice. Intranasal application or intravenous injection of umbellulone increased rat meningeal blood flow in a dose-dependent manner; a response selectively inhibited by systemic administration of transient receptor potential ankyrin 1 or calcitonin gene-related peptide receptor antagonists. These data indicate that umbellulone activates, through a transient receptor potential ankyrin 1-dependent mechanism, the trigeminovascular system, thereby causing

  4. Selective cleavage of SNAREs in sensory neurons unveils protein complexes mediating peptide exocytosis triggered by different stimuli.

    PubMed

    Meng, Jianghui; Dolly, J Oliver; Wang, Jiafu

    2014-10-01

    Oligomerisation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes is required for synaptic vesicle fusion and neurotransmitter release. How these regulate the release of pain peptides elicited by different stimuli from sensory neurons has not been established. Herein, K(+) depolarization was found to induce multiple sodium dodecyl sulfate (SDS)-resistant SNARE complexes in sensory neurons exposed to botulinum neurotoxins (BoNTs), with molecular weights ranging from 104-288 k (large) to 38-104 k (small). Isoform 1 of vesicle-associated membrane protein 1 (VAMP 1) assembled into stable complexes upon depolarisation and was required for the participation of intact synaptosome-associated protein of relative molecular mass 25 k (SNAP-25) or BoNT/A-truncated form (SNAP-25A) in the large functional and small inactive SDS-resistant SNARE complexes. Cleaving VAMP 1 decreased SNAP-25A in the functional complexes to a much greater extent than the remaining intact SNAP-25. Syntaxin 1 proved essential for the incorporation of intact and SNAP-25A into the large complexes. Truncation of syntaxin 1 by BoNT/C1 caused /A- and/or /C1-truncated SNAP-25 to appear in non-functional complexes and blocked the release of calcitonin gene-related peptide (CGRP) elicited by capsaicin, ionomycin, thapsigargin or K(+) depolarization. Only the latter two were susceptible to /A. Inhibition of CGRP release by BoNT/A was reversed by capsaicin and/or ionomycin, an effect overcome by BoNT/C1. Unlike BoNT/B, BoNT/D cleaved VAMP 1 in addition to 2 and 3 in rat sensory neurons and blocked both CGRP and substance P release. Thus, unlike SNAP-25, syntaxin 1 and VAMP 1 are more suitable targets to abolish functional SNARE complexes and pain peptide release evoked by any stimuli. PMID:24604356

  5. Statins Promote the Degradation of Extracellular Amyloid β-Peptide by Microglia via Stimulation of Exosome-associated Insulin-degrading Enzyme (IDE) Secretion*

    PubMed Central

    Tamboli, Irfan Y.; Barth, Esther; Christian, Leonie; Siepmann, Martin; Kumar, Sathish; Singh, Sandesh; Tolksdorf, Karen; Heneka, Michael T.; Lütjohann, Dieter; Wunderlich, Patrick; Walter, Jochen

    2010-01-01

    Epidemiological studies indicate that intake of statins decrease the risk of developing Alzheimer disease. Cellular and in vivo studies suggested that statins might decrease the generation of the amyloid β-peptide (Aβ) from the β-amyloid precursor protein. Here, we show that statins potently stimulate the degradation of extracellular Aβ by microglia. The statin-dependent clearance of extracellular Aβ is mainly exerted by insulin-degrading enzyme (IDE) that is secreted in a nonconventional pathway in association with exosomes. Stimulated IDE secretion and Aβ degradation were also observed in blood of mice upon peripheral treatment with lovastatin. Importantly, increased IDE secretion upon lovastatin treatment was dependent on protein isoprenylation and up-regulation of exosome secretion by fusion of multivesicular bodies with the plasma membrane. These data demonstrate a novel pathway for the nonconventional secretion of IDE via exosomes. The modulation of this pathway could provide a new strategy to enhance the extracellular clearance of Aβ. PMID:20876579

  6. The Anorexigenic Peptide Neuromedin U (NMU) Attenuates Amphetamine-Induced Locomotor Stimulation, Accumbal Dopamine Release and Expression of Conditioned Place Preference in Mice.

    PubMed

    Vallöf, Daniel; Vestlund, Jesper; Engel, Jörgen A; Jerlhag, Elisabet

    2016-01-01

    Amphetamine dependence, besides its substantial economical consequence, is a serious cause of mortality and morbidity. By investigations of the neurochemical correlates through which addictive drugs, such as amphetamine, activate the mesoaccumbal dopamine system unique targets for treatment of drug addiction can be identified. This reward link consists of a dopamine projection from the ventral tegmental area to the nucleus accumbens (NAc) suggesting that these brain areas are important for reward. The physiological function of gut-brain peptides has expanded beyond food intake modulation and involves regulation of drug reinforcement. A novel candidate for reward regulation is the anorexigenic peptide neuromedin U (NMU). We therefore investigated the effects of intracerebroventricular (icv) administration of NMU on amphetamine's well-documented effects on the mesoaccumbal dopamine system, i.e. locomotor stimulation and accumbal dopamine release in mice. In addition, the effect of accumbal NMU administration on locomotor activity was examined. The effect of NMU, icv or intra-NAc, on the expression of conditioned place preference (CPP) was elucidated. Firstly, we showed that icv administration of NMU attenuate the amphetamine-induced locomotor stimulation, accumbal dopamine release and expression of CPP in mice. Secondly, we found that a lower dose of NMU (icv) reduce the amphetamine-induced locomotor stimulation in mice. Thirdly, we demonstrated that NMU administration into the NAc block the ability of amphetamine to cause a locomotor stimulation in mice. However, accumbal NMU administration did not attenuate the amphetamine-induced expression of CPP in mice. Our novel data suggest that central NMU signalling is involved in development of amphetamine dependence. PMID:27139195

  7. The Anorexigenic Peptide Neuromedin U (NMU) Attenuates Amphetamine-Induced Locomotor Stimulation, Accumbal Dopamine Release and Expression of Conditioned Place Preference in Mice

    PubMed Central

    Vallöf, Daniel; Vestlund, Jesper; Engel, Jörgen A.; Jerlhag, Elisabet

    2016-01-01

    Amphetamine dependence, besides its substantial economical consequence, is a serious cause of mortality and morbidity. By investigations of the neurochemical correlates through which addictive drugs, such as amphetamine, activate the mesoaccumbal dopamine system unique targets for treatment of drug addiction can be identified. This reward link consists of a dopamine projection from the ventral tegmental area to the nucleus accumbens (NAc) suggesting that these brain areas are important for reward. The physiological function of gut-brain peptides has expanded beyond food intake modulation and involves regulation of drug reinforcement. A novel candidate for reward regulation is the anorexigenic peptide neuromedin U (NMU). We therefore investigated the effects of intracerebroventricular (icv) administration of NMU on amphetamine’s well-documented effects on the mesoaccumbal dopamine system, i.e. locomotor stimulation and accumbal dopamine release in mice. In addition, the effect of accumbal NMU administration on locomotor activity was examined. The effect of NMU, icv or intra-NAc, on the expression of conditioned place preference (CPP) was elucidated. Firstly, we showed that icv administration of NMU attenuate the amphetamine-induced locomotor stimulation, accumbal dopamine release and expression of CPP in mice. Secondly, we found that a lower dose of NMU (icv) reduce the amphetamine-induced locomotor stimulation in mice. Thirdly, we demonstrated that NMU administration into the NAc block the ability of amphetamine to cause a locomotor stimulation in mice. However, accumbal NMU administration did not attenuate the amphetamine-induced expression of CPP in mice. Our novel data suggest that central NMU signalling is involved in development of amphetamine dependence. PMID:27139195

  8. Electrophysiological and neurochemical techniques to investigate sensory neurons in analgesia research.

    PubMed

    Babes, Alexandru; Fischer, Michael J M; Reid, Gordon; Sauer, Susanne K; Zimmermann, Katharina; Reeh, Peter W

    2010-01-01

    The primary afferent nociceptive neuron has recently attracted major research interest because of the cloning of very selectively expressed and well-conserved ion channel genes. All parts of the neuron, sensory terminals, axon and cell body, are accessible to validated research techniques in vitro using various isolated tissues or cells taken from laboratory animals. Single-unit recording and measuring stimulated calcitonin gene-related peptide (CGRP) release as well as patch-clamping and calcium imaging of cultured sensory neurons provide different kinds of information, and no model alone answers all questions. In combination, however, consistent results and complementary evidence form a solid basis for translational research to follow. PMID:20336427

  9. The Anthocyanin Delphinidin 3-Rutinoside Stimulates Glucagon-Like Peptide-1 Secretion in Murine GLUTag Cell Line via the Ca2+/Calmodulin-Dependent Kinase II Pathway

    PubMed Central

    Kato, Masaki; Tani, Tsubasa; Terahara, Norihiko; Tsuda, Takanori

    2015-01-01

    Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted from enteroendocrine L-cells. Although several nutrients induce GLP-1 secretion, there is little evidence to suggest that non-nutritive compounds directly increase GLP-1 secretion. Here, we hypothesized that anthocyanins induce GLP-1 secretion and thereby significantly contribute to the prevention and treatment of diabetes. Delphinidin 3-rutinoside (D3R) was shown to increase GLP-1 secretion in GLUTag L cells. The results suggested that three hydroxyl or two methoxyl moieties on the aromatic ring are essential for the stimulation of GLP-1 secretion. Notably, the rutinose moiety was shown to be a potent enhancer of GLP-1 secretion, but only in conjunction with three hydroxyl moieties on the aromatic ring (D3R). Receptor antagonist studies revealed that D3R-stimulates GLP-1 secretion involving inositol 1,4,5-trisphosphate receptor-mediated intracellular Ca2+ mobilization. Treatment of GLUTag cells with a Ca2+/calmodulin-dependent kinaseII (CaMKII) inhibitor (KN-93) abolished D3R-stimulated GLP-1 secretion. In addition, treatment of GLUTag cells with D3R resulted in activation of CaMKII. Pre-treatment of cells with a G protein-coupled receptor (GPR) 40/120 antagonist (GW1100) also significantly decreased D3R-stimulated GLP-1 secretion. These observations suggest that D3R stimulates GLP-1 secretion in GLUTag cells, and that stimulation of GLP-1 secretion by D3R is mediated via Ca2+-CaMKII pathway, which may possibly be mediated by GPR40/120. These findings provide a possible molecular mechanism of GLP-1 secretion in intestinal L-cells mediated by foods or drugs and demonstrate a novel biological function of anthocyanins in regards to GLP-1 secretion. PMID:25962102

  10. Nesfatin-1 stimulates glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide secretion from STC-1 cells in vitro.

    PubMed

    Ramesh, Naresh; Mortazavi, Sima; Unniappan, Suraj

    2015-06-26

    Nesfatin-1 is an 82 amino acid peptide encoded in a secreted precursor, nucleobindin 2. It is an anorexigenic and insulinotropic peptide found abundantly in the hypothalamus, pancreas and gastric oxyntic mucosa. NUCB2 mRNA expression is 10 fold higher in the gastric mucosa than in brain, suggesting gastrointestinal tract as a main source of nesfatin-1. Meal responsive insulin secretion is regulated by incretins glucagon-like peptide-1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP). Since both nesfatin-1 and incretins modulate insulin secretion, we hypothesized that nesfatin-1 is present in the enteroendocrine cells, and that it regulates incretin secretion. RT-PCR analysis found NUCB2 mRNA expression, and immunofluorescence microscopy determined nesfatin-1 immunoreactivity in STC-1, an enteroendocrine cell line. NUCB2/nesfatin-1 is co-localized with GLP-1 and GIP in mouse small intestinal cells. Static incubation of STC-1 cells with nesfatin-1 upregulated preproglucagon (GLP-1 precursor) mRNA (0.01, 0.1, 1 and 10 nM) and GLP-1 secretion (0.1, 1 and 10 nM). Nesfatin-1 also enhanced GIP mRNA (0.1, 1 and 10 nM) and GIP secretion (1 and 10 nM). Together, our data support the hypothesis that nesfatin-1 is present in enteroendocrine cells and that it stimulates incretin secretion. Future studies should aim for nesfatin-1 and incretin interactions in vivo. PMID:25930999

  11. Regulatory peptides modulate adhesion of polymorphonuclear leukocytes to bronchial epithelial cells through regulation of interleukins, ICAM-1 and NF-kappaB/IkappaB.

    PubMed

    Zhang, Jian-Song; Tan, Yu-Rong; Xiang, Yang; Luo, Zi-Qiang; Qin, Xiao-Qun

    2006-02-01

    A complex network of regulatory neuropeptides controls airway inflammation reaction, in which airway epithelial cells adhering to and activating leukocytes is a critical step. To study the effect of intrapulmonary regulatory peptides on adhesion of polymorphonuclear leukocytes (PMNs) to bronchial epithelial cells (BECs) and its mechanism, several regulatory peptides including vasoactive intestinal peptide (VIP), epidermal growth factor (EGF), endothelin-1 (ET-1) and calcitonin gene-related peptide (CGRP), were investigated. The results demonstrated that VIP and EGF showed inhibitory effects both on the secretion of IL-1, IL-8 and the adhesion of PMNs to BECs, whereas ET-1 and CGRP had the opposite effect. Anti-intercellular adhesion molecule-1 (ICAM-1) antibody could block the adhesion of PMNs to ozone-stressed BECs. Using immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR), it was shown that VIP and EGF down-regulated the expression of ICAM-1 in BECs, while ET-1 and CGRP up-regulated ICAM-1 expression. NF-kappaB inhibitor MG132 blocked ICAM-1 expression induced by ET-1 and CGRP. Furthermore, in electric mobility shift assay (EMSA), VIP and EGF restrained the binding activity of NF-kappaB to the NF-kappaB binding site within the ICAM-1 promoter in ozone-stressed BECs, while CGRP and ET-1 promoted this binding activity. IkappaB degradation was consistent with NF-kappaB activation. These observations indicate that VIP and EGF inhibit inflammation, while ET-1 and CGRP enhance the inflammation reaction. PMID:16474903

  12. A TLR4-interacting peptide inhibits lipopolysaccharide-stimulated inflammatory responses, migration and invasion of colon cancer SW480 cells

    PubMed Central

    Rakhesh, Madhusoodhanan; Cate, Moriasi; Vijay, Ramani; Shrikant, Anant; Shanjana, Awasthi

    2012-01-01

    Inflammation is a major risk factor for carcinogenesis in patients affected by chronic colitis, yet the molecular mechanisms underlying the progression from chronic inflammation to cancer are not completely understood. Activation of the Toll-like receptor 4 (TLR4)-NFκB signaling axis is associated with inflammation. Thus, we hypothesized that inhibition of TLR4-NFκB signaling might help in limiting inflammatory responses and inflammation-induced oncogenesis. In this work, we studied the effects of a TLR4-interacting surfactant protein A-derived (SPA4) peptide on lipopolysaccharide (LPS)-induced TLR4-NFκB signaling and cancer progression. We first characterized this peptide for its ability to bind the TLR4 ligand-LPS and for physico-chemical characteristics. Inflammation was induced by challenging the colon cancer SW480 cells with Escherichia coli LPS. Cells were then treated with varying amounts of the SPA4 peptide. Changes in the expression of TLR4, interleukin (IL)-1β and IL-6, in intracellular NFκB-related signal transducers (IKBα, p65, phosphorylated IKBα, phosphorylated p65, RelB, COX-2) as well as in the transcriptional activity of NFκB were studied by immunocytochemistry, immunoblotting and NFκB reporter assay, respectively. Simultaneously, the effects on LPS-induced cell migration and invasion were determined. We found that the SPA4 peptide does not bind to LPS. Rather, its binding to TLR4 inhibits the LPS-induced phosphorylation of p65, production of IL-1β and IL-6, activity of NFκB, migration and invasion of SW480 cells. In conclusion, our results suggest that the inhibition of TLR4-NFκB signaling by a TLR4-binding peptide may help for the treatment of chronic inflammation and prevention of inflammation-induced cancer in patients with colitis. PMID:23264896

  13. Hsp90-peptide complexes stimulate antigen presentation through the class II pathway after binding scavenger receptor SREC-I

    PubMed Central

    Murshid, Ayesha; Gong, Jianlin; Calderwood, Stuart K

    2016-01-01

    Molecular chaperones such as heat shock protein 90 (Hsp90) have been shown to form complexes with tumor antigens and can be used to prepare anticancer vaccines largely due to this property. Earlier studies had suggested that, mice immunized with a molecular chaperone based vaccine derived from tumors became immune to further vaccination and that both CD8+ and CD4+ T cells were activated by the chaperone vaccine in a manner dependent on scavenger receptor SREC-I. Here we have investigated mechanisms whereby SREC-I might facilitate uptake of Hsp90 conjugated peptides by APC into the MHC class II pathway for presentation to CD4+ T cells. Our studies showed that antigenic peptides associated with Hsp90 were taken up into the Class II pathway by a mechanism dependent on SREC-I binding and internalization and presented to CD4+ T cells. In addition our studies showed that SREC-I could associate with MHC class II molecules on the cell surface and in intracellular endosomes, suggesting a mechanism involving facilitated uptake of peptides into the MHC class II pathway. These studies in addition to our earlier findings showed SREC-I to play a primary role in chaperone-associated antigen uptake both through cross priming of MHC class I molecules and entry into the class II pathway. PMID:25155057

  14. Effects of membrane polyunsaturated fatty acids on opiate peptide inhibition of basal and prostaglandin E1-stimulated cyclic AMP formation in intact N1E-115 neuroblastoma cells.

    PubMed

    Murphy, M G; Moak, C M; Rao, B G

    1987-12-01

    The effects of membrane polyunsaturated fatty acids (PUFA) on opiate peptide-mediated inhibition of basal and prostaglandin E1-stimulated cyclic AMP formation were examined in intact N1E-115 neuroblastoma cells. Addition of opiate peptides such as methionine 5-enkephalin (metEnk) to control cultures and to cultures that had been supplemented for 48 hr with 50 microM linoleic acid resulted in dose-dependent decreases in cAMP formation; these decreases were blocked by naloxone. Maximum inhibition of basal cyclase activity was 50-55% in both control and PUFA-enriched cells; however, half-maximal inhibition required ten times more metEnk in supplemented cultures than in controls. This is consistent with our observation that the affinity of binding of [tyrosyl-3',5'-3H(N)](2-D-alanine-5-D-leucine)enkephalin ([3H]DADLE) to intact PUFA-enriched cells was lower than that to control cells. Receptor density was not modified as a result of supplementation. Addition of prostaglandin E1 (PGE1) to the cells produced rapid dose-dependent increases in cAMP formation. Maximum responses were higher in PUFA-enriched than in control cells (1924 and 972 pmol cAMP formed/mg protein respectively). Also, the apparent value for EC50 for PGE1 was consistently lower in supplemented cultures. MetEnk reduced PGE1-stimulated cAMP formation by 45-55% in both control and supplemented cells, and values for IC50 were similar (approximately 30 nM) in both. In the presence of the opiate peptide, values for EC50 for PGE1 were similar in control and PUFA-enriched cultures (0.07 and 0.09 microM respectively). The data from these studies suggest that membrane PUFA increase the efficiency of coupling of receptors that stimulate cAMP formation and decrease the efficiency of those that mediate inhibition. PMID:2825714

  15. Surface-associated material from the bacterium Actinobacillus actinomycetemcomitans contains a peptide which, in contrast to lipopolysaccharide, directly stimulates fibroblast interleukin-6 gene transcription.

    PubMed

    Reddi, K; Nair, S P; White, P A; Hodges, S; Tabona, P; Meghji, S; Poole, S; Wilson, M; Henderson, B

    1996-03-15

    The oral commensal Gram-negative bacterium Actinobacillus actinomycetemcomitans is believed to be the causative organism of localized juvenile periodontitis, a disease in which there is rapid loss of alveolar bone supporting the teeth. Previously, we have reported that gentle saline extraction of this bacterium removed a loosely adherent proteinaceous fraction from the cell surface of the bacterium, which we have termed surface-associated material. This material contained potent bone-resorbing activity. We now report that surface-associated material is also a potent stimulator of cytokines, and in particular, interleukin-6 (IL-6) synthesis, while the lipopolysaccharide from this bacterium is only a weak stimulator of IL-6 synthesis by fibroblasts and monocytes. In contrast to enteric lipopolysaccharide (LPS), which induces fibroblast IL-1, IL-6 and tumour necrosis factor (TNF) alpha synthesis, surface-associated material stimulated gingival fibroblasts to synthesize only IL-6, with no induction of IL-1 or TNF (the normal inducers of IL-6 synthesis). Reverse transcriptase PCR also failed to detect mRNA for IL-1 or TNF in surface-associated-material-stimulated fibroblasts, although both mRNAs were present in Escherichia coli LPS-stimulated cells. Neutralizing antibodies to IL-1 and/or TNF or the natural IL-1 receptor antagonist (IL-1ra) inhibited enteric LPS-induced IL-6 synthesis, but did not inhibit surface-associated-material-induced synthesis. In addition, dexamethasone, which completely suppressed LPS-induced IL-6 synthesis, only inhibited surface-associated-material-induced IL-6 synthesis by 50%. This suggests that the active constituent in the surface-associated material stimulates IL-6 gene transcription by a transcriptional control mechanism distinct to that of E. coli LPS. The IL-6 stimulating activity of the surface-associated material is inhibited by both heat and trypsin, suggesting that it is proteinaceous. The activity has been isolated using anion

  16. Prenatal exposure to ethanol stimulates hypothalamic CCR2 chemokine receptor system: Possible relation to increased density of orexigenic peptide neurons and ethanol drinking in adolescent offspring.

    PubMed

    Chang, G-Q; Karatayev, O; Leibowitz, S F

    2015-12-01

    Clinical and animal studies indicate that maternal consumption of ethanol during pregnancy increases alcohol drinking in the offspring. Possible underlying mechanisms may involve orexigenic peptides, which are stimulated by prenatal ethanol exposure and themselves promote drinking. Building on evidence that ethanol stimulates neuroimmune factors such as the chemokine CCL2 that in adult rats is shown to colocalize with the orexigenic peptide, melanin-concentrating hormone (MCH) in the lateral hypothalamus (LH), the present study sought to investigate the possibility that CCL2 or its receptor CCR2 in LH is stimulated by prenatal ethanol exposure, perhaps specifically within MCH neurons. Our paradigm of intraoral administration of ethanol to pregnant rats, at low-to-moderate doses (1 or 3g/kg/day) during peak hypothalamic neurogenesis, caused in adolescent male offspring twofold increase in drinking of and preference for ethanol and reinstatement of ethanol drinking in a two-bottle choice paradigm under an intermittent access schedule. This effect of prenatal ethanol exposure was associated with an increased expression of MCH and density of MCH(+) neurons in LH of preadolescent offspring. Whereas CCL2(+) cells at this age were low in density and unaffected by ethanol, CCR2(+) cells were dense in LH and increased by prenatal ethanol, with a large percentage (83-87%) identified as neurons and found to colocalize MCH. Prenatal ethanol also stimulated the genesis of CCR2(+) and MCH(+) neurons in the embryo, which co-labeled the proliferation marker, BrdU. Ethanol also increased the genesis and density of neurons that co-expressed CCR2 and MCH in LH, with triple-labeled CCR2(+)/MCH(+)/BrdU(+) neurons that were absent in control rats accounting for 35% of newly generated neurons in ethanol-exposed rats. With both the chemokine and MCH systems believed to promote ethanol consumption, this greater density of CCR2(+)/MCH(+) neurons in the LH of preadolescent rats suggests that

  17. Subcomponent Vaccine Based on CTA1-DD Adjuvant with Incorporated UreB Class II Peptides Stimulates Protective Helicobacter pylori Immunity

    PubMed Central

    Nedrud, John G.; Bagheri, Nayer; Schön, Karin; Xin, Wei; Bergroth, Hilda; Eliasson, Dubravka Grdic; Lycke, Nils Y.

    2013-01-01

    A mucosal vaccine against Helicobacter pylori infection could help prevent gastric cancers and peptic ulcers. While previous attempts to develop such a vaccine have largely failed because of the requirement for safe and effective adjuvants or large amounts of well defined antigens, we have taken a unique approach to combining our strong mucosal CTA1-DD adjuvant with selected peptides from urease B (UreB). The protective efficacy of the selected peptides together with cholera toxin (CT) was first confirmed. However, CT is a strong adjuvant that unfortunately is precluded from clinical use because of its toxicity. To circumvent this problem we have developed a derivative of CT, the CTA1-DD adjuvant, that has been found safe in non-human primates and equally effective compared to CT when used intranasally. We genetically fused the selected peptides into the CTA1-DD plasmid and found after intranasal immunizations of Balb/c mice using purified CTA1-DD with 3 copies of an H. pylori urease T cell epitope (CTA1-UreB3T-DD) that significant protection was stimulated against a live challenge infection. Protection was, however, weaker than with the gold standard, bacterial lysate+CT, but considering that we only used a single epitope in nanomolar amounts the results convey optimism. Protection was associated with enhanced Th1 and Th17 immunity, but immunizations in IL-17A-deficient mice revealed that IL-17 may not be essential for protection. Taken together, we have provided evidence for the rational design of an effective mucosal subcomponent vaccine against H. pylori infection based on well selected protective epitopes from relevant antigens incorporated into the CTA1-DD adjuvant platform. PMID:24391754

  18. Subcomponent vaccine based on CTA1-DD adjuvant with incorporated UreB class II peptides stimulates protective Helicobacter pylori immunity.

    PubMed

    Nedrud, John G; Bagheri, Nayer; Schön, Karin; Xin, Wei; Bergroth, Hilda; Eliasson, Dubravka Grdic; Lycke, Nils Y

    2013-01-01

    A mucosal vaccine against Helicobacter pylori infection could help prevent gastric cancers and peptic ulcers. While previous attempts to develop such a vaccine have largely failed because of the requirement for safe and effective adjuvants or large amounts of well defined antigens, we have taken a unique approach to combining our strong mucosal CTA1-DD adjuvant with selected peptides from urease B (UreB). The protective efficacy of the selected peptides together with cholera toxin (CT) was first confirmed. However, CT is a strong adjuvant that unfortunately is precluded from clinical use because of its toxicity. To circumvent this problem we have developed a derivative of CT, the CTA1-DD adjuvant, that has been found safe in non-human primates and equally effective compared to CT when used intranasally. We genetically fused the selected peptides into the CTA1-DD plasmid and found after intranasal immunizations of Balb/c mice using purified CTA1-DD with 3 copies of an H. pylori urease T cell epitope (CTA1-UreB3T-DD) that significant protection was stimulated against a live challenge infection. Protection was, however, weaker than with the gold standard, bacterial lysate+CT, but considering that we only used a single epitope in nanomolar amounts the results convey optimism. Protection was associated with enhanced Th1 and Th17 immunity, but immunizations in IL-17A-deficient mice revealed that IL-17 may not be essential for protection. Taken together, we have provided evidence for the rational design of an effective mucosal subcomponent vaccine against H. pylori infection based on well selected protective epitopes from relevant antigens incorporated into the CTA1-DD adjuvant platform. PMID:24391754

  19. The non-peptide GLP-1 receptor agonist WB4-24 blocks inflammatory nociception by stimulating β-endorphin release from spinal microglia

    PubMed Central

    Fan, Hui; Gong, Nian; Li, Teng-Fei; Ma, Ai-Niu; Wu, Xiao-Yan; Wang, Ming-Wei; Wang, Yong-Xiang

    2015-01-01

    BACKGROUND AND PURPOSE Two peptide agonists of the glucagon-like peptide-1 (GLP-1) receptor, exenatide and GLP-1 itself, exert anti-hypersensitive effects in neuropathic, cancer and diabetic pain. In this study, we have assessed the anti-allodynic and anti-hyperalgesic effects of the non-peptide agonist WB4-24 in inflammatory nociception and the possible involvement of microglial β-endorphin and pro-inflammatory cytokines. EXPERIMENTAL APPROACH We used rat models of inflammatory nociception induced by formalin, carrageenan or complete Freund's adjuvant (CFA), to test mechanical allodynia and thermal hyperalgesia. Expression of β-endorphin and pro-inflammatory cytokines was measured using real-time quantitative PCR and fluorescent immunoassays. KEY RESULTS WB4-24 displaced the specific binding of exendin (9–39) in microglia. Single intrathecal injection of WB4-24 (0.3, 1, 3, 10, 30 and 100 μg) exerted dose-dependent, specific, anti-hypersensitive effects in acute and chronic inflammatory nociception induced by formalin, carrageenan and CFA, with a maximal inhibition of 60–80%. Spinal WB4-24 was not effective in altering nociceptive pain. Subcutaneous injection of WB4-24 was also antinociceptive in CFA-treated rats. WB4-24 evoked β-endorphin release but did not inhibit expression of pro-inflammatory cytokines in either the spinal cord of CFA-treated rats or cultured microglia stimulated by LPS. WB4-24 anti-allodynia was prevented by a microglial inhibitor, β-endorphin antiserum and a μ-opioid receptor antagonist. CONCLUSIONS AND IMPLICATIONS Our results suggest that WB4-24 inhibits inflammatory nociception by releasing analgesic β-endorphin rather than inhibiting the expression of proalgesic pro-inflammatory cytokines in spinal microglia, and that the spinal GLP-1 receptor is a potential target molecule for the treatment of pain hypersensitivity including inflammatory nociception. PMID:25176008

  20. Supra-molecular assembly of a lumican-derived peptide amphiphile enhances its collagen-stimulating activity.

    PubMed

    Walter, Merlin N M; Dehsorkhi, Ashkan; Hamley, Ian W; Connon, Che J

    2016-02-01

    C16-YEALRVANEVTLN, a peptide amphiphile (PA) incorporating a biologically active amino acid sequence found in lumican, has been examined for its influence upon collagen synthesis by human corneal fibroblasts in vitro, and the roles of supra-molecular assembly and activin receptor-like kinase ALK receptor signaling in this effect were assessed. Cell viability was monitored using the Alamar blue assay, and collagen synthesis was assessed using Sirius red. The role of ALK signaling was studied by receptor inhibition. Cultured human corneal fibroblasts synthesized significantly greater amounts of collagen in the presence of the PA over both 7-day and 21-day periods. The aggregation of the PA to form nanotapes resulted in a notable enhancement in this activity, with an approximately two-fold increase in collagen production per cell. This increase was reduced by the addition of an ALK inhibitor. The data presented reveal a stimulatory effect upon collagen synthesis by the primary cells of the corneal stroma, and demonstrate a direct influence of supra-molecular assembly of the PA upon the cellular response observed. The effects of PA upon fibroblasts were dependent upon ALK receptor function. These findings elucidate the role of self-assembled nanostructures in the biological activity of peptide amphiphiles, and support the potential use of a self-assembling lumican derived PA as a novel biomaterial, intended to promote collagen deposition for wound repair and tissue engineering purposes. PMID:26626506

  1. Correction of a splice-site mutation in the beta-globin gene stimulated by triplex-forming peptide nucleic acids.

    PubMed

    Chin, Joanna Y; Kuan, Jean Y; Lonkar, Pallavi S; Krause, Diane S; Seidman, Michael M; Peterson, Kenneth R; Nielsen, Peter E; Kole, Ryszard; Glazer, Peter M

    2008-09-01

    Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin, causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian cells via site-specific binding and creation of altered helical structures that provoke DNA repair. We have designed a series of triplex-forming PNAs that can specifically bind to sequences in the human beta-globin gene. We demonstrate here that these PNAs, when cotransfected with recombinatory donor DNA fragments, can promote single base-pair modification at the start of the second intron of the beta-globin gene, the site of a common thalassemia-associated mutation. This single base pair change was detected by the restoration of proper splicing of transcripts produced from a green fluorescent protein-beta-globin fusion gene. The ability of these PNAs to induce recombination was dependent on dose, sequence, cell-cycle stage, and the presence of a homologous donor DNA molecule. Enhanced recombination, with frequencies up to 0.4%, was observed with use of the lysomotropic agent chloroquine. Finally, we demonstrate that these PNAs were effective in stimulating the modification of the endogenous beta-globin locus in human cells, including primary hematopoietic progenitor cells. This work suggests that PNAs can be effective tools to induce heritable, site-specific modification of disease-related genes in human cells. PMID:18757759

  2. Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I

    PubMed Central

    Lim, Chae Jin; Jeon, Jung Eun; Jeong, Se Kyoo; Yoon, Seok Jeong; Kwon, Seon Deok; Lim, Jina; Park, Keedon; Kim, Dae Yong; Ahn, Jeong Keun; Kim, Bong-Woo

    2015-01-01

    Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. [BMB Reports 2015; 48(9): 501-506] PMID:25644636

  3. ER stress stimulates production of the key antimicrobial peptide, cathelicidin, by forming a previously unidentified intracellular S1P signaling complex

    PubMed Central

    Park, Kyungho; Ikushiro, Hiroko; Shin, Kyong-Oh; Kim, Young il; Kim, Jong Youl; Lee, Yong-Moon; Yano, Takato; Holleran, Walter M.; Elias, Peter; Uchida, Yoshikazu

    2016-01-01

    We recently identified a previously unidentified sphingosine-1-phosphate (S1P) signaling mechanism that stimulates production of a key innate immune element, cathelicidin antimicrobial peptide (CAMP), in mammalian cells exposed to external perturbations, such as UVB irradiation and other oxidative stressors that provoke subapoptotic levels of endoplasmic reticulum (ER) stress, independent of the well-known vitamin D receptor-dependent mechanism. ER stress increases cellular ceramide and one of its distal metabolites, S1P, which activates NF-κB followed by C/EBPα activation, leading to CAMP production, but in a S1P receptor-independent fashion. We now show that S1P activates NF-κB through formation of a previously unidentified signaling complex, consisting of S1P, TRAF2, and RIP1 that further associates with three stress-responsive proteins; i.e., heat shock proteins (GRP94 and HSP90α) and IRE1α. S1P specifically interacts with the N-terminal domain of heat shock proteins. Because this ER stress-initiated mechanism is operative in both epithelial cells and macrophages, it appears to be a universal, highly conserved response, broadly protective against diverse external perturbations that lead to increased ER stress. Finally, these studies further illuminate how ER stress and S1P orchestrate critical stress-specific signals that regulate production of one protective response by stimulating production of the key innate immune element, CAMP. PMID:26903652

  4. Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I.

    PubMed

    Lim, Chae Jin; Jeon, Jung Eun; Jeong, Se Kyoo; Yoon, Seok Jeong; Kwon, Seon Deok; Lim, Jina; Park, Keedon; Kim, Dae Yong; Ahn, Jeong Keun; Kim, Bong-Woo

    2015-09-01

    Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. PMID:25644636

  5. CRMP-2 peptide mediated decrease of high and low voltage-activated calcium channels, attenuation of nociceptor excitability, and anti-nociception in a model of AIDS therapy-induced painful peripheral neuropathy

    PubMed Central

    2012-01-01

    Background The ubiquity of protein-protein interactions in biological signaling offers ample opportunities for therapeutic intervention. We previously identified a peptide, designated CBD3, that suppressed inflammatory and neuropathic behavioral hypersensitivity in rodents by inhibiting the ability of collapsin response mediator protein 2 (CRMP-2) to bind to N-type voltage-activated calcium channels (CaV2.2) [Brittain et al. Nature Medicine 17:822–829 (2011)]. Results and discussion Here, we utilized SPOTScan analysis to identify an optimized variation of the CBD3 peptide (CBD3A6K) that bound with greater affinity to Ca2+ channels. Molecular dynamics simulations demonstrated that the CBD3A6K peptide was more stable and less prone to the unfolding observed with the parent CBD3 peptide. This mutant peptide, conjugated to the cell penetrating motif of the HIV transduction domain protein TAT, exhibited greater anti-nociception in a rodent model of AIDS therapy-induced peripheral neuropathy when compared to the parent TAT-CBD3 peptide. Remarkably, intraperitoneal administration of TAT-CBD3A6K produced none of the minor side effects (i.e. tail kinking, body contortion) observed with the parent peptide. Interestingly, excitability of dissociated small diameter sensory neurons isolated from rats was also reduced by TAT-CBD3A6K peptide suggesting that suppression of excitability may be due to inhibition of T- and R-type Ca2+ channels. TAT-CBD3A6K had no effect on depolarization-evoked calcitonin gene related peptide (CGRP) release compared to vehicle control. Conclusions Collectively, these results establish TAT-CBD3A6K as a peptide therapeutic with greater efficacy in an AIDS therapy-induced model of peripheral neuropathy than its parent peptide, TAT-CBD3. Structural modifications of the CBD3 scaffold peptide may result in peptides with selectivity against a particular subset of voltage-gated calcium channels resulting in a multipharmacology of action on the target. PMID

  6. Solid-Phase Peptide Head-to-Side Chain Cyclodimerization: Discovery of C2-Symmetric Cyclic Lactam Hybrid α-Melanocyte-Stimulating Hormone (MSH)/Agouti-Signaling Protein (ASIP) Analogues with Potent Activities at the Human Melanocortin Receptors

    PubMed Central

    Mayorov, Alexander V.; Cai, Minying; Palmer, Erin S.; Liu, Zhihua; Cain, James P.; Vagner, Josef; Trivedi, Dev; Hruby, Victor J.

    2011-01-01

    A novel hybrid melanocortin pharmacophore was designed based on the pharmacophores of the Agouti signaling protein (ASIP), an endogenous melanocortin antagonist, and α-melanocyte-stimulating hormone (α-MSH), an endogenous melanocortin agonist. The designed hybrid ASIP/MSH pharmacophore was explored in monomeric cyclic, and cyclodimeric templates. The monomeric cyclic disulfide series yielded peptides with hMC3R-selective non-competitive binding affinities. The direct on-resin peptide lactam cyclodimerization yielded nanomolar range (25-120 nM) hMC1R-selective full and partial agonists in the cyclodimeric lactam series which demonstrates an improvement over the previous attempts at hybridization of MSH and agouti protein sequences. The secondary structure-oriented pharmacophore hybridization strategy will prove useful in development of unique allosteric and orthosteric melanocortin receptor modulators. This report also illustrates the utility of peptide cyclodimerization for the development of novel GPCR peptide ligands. PMID:20688117

  7. Vasoactive intestinal peptide (VIP) differentially affects inflammatory immune responses in human monocytes infected with viable Salmonella or stimulated with LPS.

    PubMed

    Askar, Basim; Ibrahim, Hiba; Barrow, Paul; Foster, Neil

    2015-09-01

    We compared the effect of VIP on human blood monocytes infected with Salmonella typhimurium 4/74 or stimulated with LPS. VIP (10(-7)M) increased monocyte viability by 24% and 9% when cultured for 24h with 4/74 or Salmonella LPS (100ng/ml), respectively. Significantly increased (P<0.05) numbers of 4/74 were also recovered from monocytes co-cultured with VIP after 6h post-infection (pi) and this remained high after 24h pi. Both 4/74 and LPS increased (P<0.05) the concentration of TNF-α, IL-1β and IL-6 measured in monocyte supernatants. However, LPS induced this effect more rapidly while, with the exception of IL-6, 4/74 induced higher concentrations (P<0.05). VIP significantly decreased (P<0.05) TNF-α and IL-1β production by 4/74-infected monocytes after 6 pi, but only after 24h in LPS-cultured monocytes. This trend was reversed for IL-6 production. However, TNF-α and IL-1β production by 4/74-infected monocytes, cultured with VIP, still remained higher (P<0.05) than concentrations measured in supernatants cultured only with LPS. VIP also increased (P<0.05) production of anti-inflammatory IL-10 in both 4/74 and LPS cultures after 24h. We also show a differential effect of VIP on the expression of TNFα and IL-6 receptors, since VIP was only able to decreased expression in LPS-stimulated monocytes but not in 4/74-infected monocytes. In conclusion, we show a differential effect of VIP on human monocytes infected with virulent Salmonella or stimulated with LPS. Our study suggests that the use of VIP in bacteraemia and/or sepsis may be limited to an adjunctive therapy to antibiotic treatment. PMID:26206287

  8. Stimulation of glucagon-like peptide-1 secretion downstream of the ligand-gated ion channel TRPA1

    PubMed Central

    Emery, Edward C.; Diakogiannaki, Eleftheria; Gentry, Clive; Psichas, Arianna; Habib, Abdella M.; Bevan, Stuart; Fischer, Michael J. M.; Reimann, Frank; Gribble, Fiona M.

    2015-01-01

    Stimulus-coupled incretin secretion from enteroendocrine cells plays a fundamental role in glucose homeostasis, and could be targeted for the treatment of type-2 diabetes. Here, we investigated the expression and function of transient receptor potential (TRP) ion channels in enteroendocrine L-cells producing glucagon-like peptide-1 (GLP-1). By microarray and qPCR analysis we identified trpa1 as an L-cell enriched transcript in the small intestine. Calcium imaging of primary L-cells and the model cell line GLUTag revealed responses triggered by the TRPA1 agonists allyl-isothiocyanate (AITC, mustard oil), carvacrol and polyunsaturated fatty acids, that were blocked by TRPA1 antagonists. Electrophysiology in GLUTag cells showed that carvacrol induced a current with characteristics typical of TRPA1 and triggered the firing of action potentials. TRPA1 activation caused an increase in GLP-1 secretion from primary murine intestinal cultures and GLUTag cells; an effect that was abolished in cultures from trpa1−/− mice or by pharmacological TRPA1 inhibition. These findings present TRPA1 as a novel sensory mechanism in enteroendocrine L-cells, coupled to the facilitation of GLP-1 release, which may be exploitable as a target for treating diabetes. PMID:25325736

  9. Metabolic Syndrome Abolishes Glucagon-Like Peptide 1 Receptor Agonist Stimulation of SERCA in Coronary Smooth Muscle.

    PubMed

    Dineen, Stacey L; McKenney, Mikaela L; Bell, Lauren N; Fullenkamp, Allison M; Schultz, Kyle A; Alloosh, Mouhamad; Chalasani, Naga; Sturek, Michael

    2015-09-01

    Metabolic syndrome (MetS) doubles the risk of adverse cardiovascular events. Glucagon-like peptide 1 (GLP-1) receptor agonists induce weight loss, increase insulin secretion, and improve glucose tolerance. Studies in healthy animals suggest cardioprotective properties of GLP-1 receptor agonists, perhaps partially mediated by improved sarco-endoplasmic reticulum Ca(2+) ATPase (SERCA) activity. We examined the acute effect of GLP-1 receptor agonists on coronary smooth muscle cells (CSM) enzymatically isolated from lean, healthy Ossabaw miniature swine. Intracellular Ca(2+) handling was interrogated with fura-2. The GLP-1 receptor agonist exenatide activated SERCA but did not alter other Ca(2+) transporters. Further, we tested the hypothesis that chronic, in vivo treatment with GLP-1 receptor agonist AC3174 would attenuate coronary artery disease (CAD) in swine with MetS. MetS was induced in 20 swine by 6 months' feeding of a hypercaloric, atherogenic diet. Swine were then randomized (n = 10/group) into placebo or AC3174 treatment groups and continued the diet for an additional 6 months. AC3174 treatment attenuated weight gain, increased insulin secretion, and improved glucose tolerance. Intravascular ultrasound and histology showed no effect of AC3174 on CAD. MetS abolished SERCA activation by GLP-1 receptor agonists. We conclude that MetS confers vascular resistance to GLP-1 receptor agonists, partially through impaired cellular signaling steps involving SERCA. PMID:25845661

  10. Targeted disruption of the CCR5 gene in human hematopoietic stem cells stimulated by peptide nucleic acids

    PubMed Central

    Schleifman, Erica B.; Bindra, Ranjit; Leif, Jean; Campo, Jacob del; Rogers, Faye A.; Uchil, Pradeep; Kutsch, Olaf; Shultz, Leonard D.; Kumar, Priti; Greiner, Dale L.; Glazer, Peter M.

    2011-01-01

    SUMMARY Peptide nucleic acids (PNAs) bind duplex DNA in a sequence-specific manner, creating triplex structures that can provoke DNA repair and produce genome modification. CCR5 encodes a chemokine receptor required for HIV-1 entry into human cells and individuals carrying mutations in this gene are resistant to HIV-1 infection. Transfection of human cells with PNAs targeted to the CCR5 gene, plus donor DNAs designed to introduce stop codons mimicking the naturally occurring CCR5-delta32 mutation, produced 2.46% targeted gene modification. CCR5 modification was confirmed at the DNA, RNA and protein levels and was shown to confer resistance to infection with HIV-1. Targeting of CCR5 was achieved in human CD34+ hematopoietic stem cells (HSCs) with subsequent engraftment into mice and persistence of the gene modification more than four months post-transplantation. This work suggests a therapeutic strategy for CCR5 knockout in HSCs from HIV-1-infected individuals, rendering cells resistant to HIV-1 and preserving immune system function. PMID:21944757

  11. Vasoactive intestinal peptide stimulates melanogenesis in B16F10 mouse melanoma cells via CREB/MITF/tyrosinase signaling.

    PubMed

    Yuan, Xing-Hua; Yao, Cheng; Oh, Jang-Hee; Park, Chi-Hyun; Tian, Yu-Dan; Han, Mira; Kim, Ji Eun; Chung, Jin Ho; Jin, Zhe-Hu; Lee, Dong Hun

    2016-08-26

    Vasoactive intestinal peptide (VIP), one of the major skin neuropeptides, has been suggested to have active roles in the pathogenesis of inflammatory skin disorders such as atopic dermatitis and psoriasis, which can commonly cause post-inflammatory hyperpigmentation. However, the effect of VIP on melanogenesis remains unknown. In this study, we showed that the melanin contents, tyrosinase activity, and gene expression of tyrosinase and microphthalmia-associated transcription factor (MITF) were significantly increased by treatment with VIP in B16F10 mouse melanoma cells and the stimulatory melanogenic effect was further examined in human epidermal melanocytes (HEMns). In addition, phosphorylated levels of CRE-binding protein (CREB) and protein kinase A (PKA) were markedly increased after VIP treatment, but not p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), or Akt, indicating the possible PKA-CREB signaling pathway involved in VIP-induced melanogenesis. This result was further verified by the fact that VIP induced increased melanin synthesis, and protein levels of phosphorylated CREB, MITF, tyrosinase were significantly attenuated by H89 (a specific PKA inhibitor). These data suggest that VIP-induced upregulation of tyrosinase through the CREB-MITF signaling pathway plays an important role in finding new treatment strategy for skin inflammatory diseases related pigmentation disorders. PMID:27343558

  12. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons

    PubMed Central

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1ARH) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1ARH neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1ARH neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1ARH neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1ARH neurons. We propose that Kiss1ARH neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. DOI: http://dx.doi.org/10.7554/eLife.16246.001 PMID:27549338

  13. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons.

    PubMed

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D; Kelly, Martin J; Rønnekleiv, Oline K

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1(ARH)) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1(ARH) neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1(ARH) neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1(ARH) neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1(ARH) neurons. We propose that Kiss1(ARH) neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. PMID:27549338

  14. Na+ transport across rumen epithelium of hay-fed sheep is acutely stimulated by the peptide IGF-1 in vitro.

    PubMed

    Shen, Zanming; Martens, Holger; Schweigel-Röntgen, Monika

    2012-04-01

    An energy-rich diet leads to enhanced ruminal Na(+) absorption, which is associated with elevated plasma insulin-like growth factor 1 (IGF-1) levels and an increased number of IGF-1 receptors in rumen papillae. This study examined the in vitro effect of IGF-1 on Na(+) transport across the rumen epithelium of hay-fed sheep, in which the IGF-1 concentration in plasma is lower than in concentrate-fed animals. At concentrations ranging from 20 to 100 μg l(-1), serosal LR3-IGF-1, a recombinant analogue of IGF-1, rapidly (within 30 min) stimulated the mucosal-to-serosal Na(+) flux (J(ms)Na) and consequently the net Na(+) flux (J(net)Na). Compared with controls, J(net)Na increased by about 60% (P < 0.05) following the serosal application of LR3-IGF-1 (20 μg l(-1)). The IGF-1-induced increment of J(ms)Na and J(net)Na was inhibited by mucosal amiloride (1 mmol l(-1)). Neither IGF-1 nor amiloride altered tissue conductance or the short-circuit current of the isolated rumen epithelium. These data support the assumption that the stimulating effect of serosally applied IGF-1 on Na(+) transport across the rumen epithelium is mediated by Na(+)-H(+) exchange (NHE). A further study was performed with cultured rumen epithelial cells and a fluorescent probe (BCECF) to estimate the rate of pH(i) recovery after acid loading. The pH(i) of isolated rumen epithelial cells was 6.43 ± 0.15 after butyrate loading and recovered by 0.26 ± 0.02 pH units (15 min)(-1). Application of LR3-IGF-1 (20 μg l(-1)) significantly increased the rate of pH(i) recovery to 0.33 ± 0.02 pH units (15 min)(-1). Amiloride administration reduced the recovery rate in both control and IGF-1-stimulated cells. These results show, for the first time, that an acute effect of IGF-1 on Na(+) absorption across rumen epithelium results from increased NHE activity. Insulin-like growth factor 1 is thus important for the fast functional adaptation of ruminal Na(+) transport via NHE. PMID:22227200

  15. Effect of different intestinal conditions on the intermolecular interaction between insulin and cell-penetrating peptide penetratin and on its contribution to stimulation of permeation through intestinal epithelium.

    PubMed

    Kamei, Noriyasu; Aoyama, Yukina; Khafagy, El-Sayed; Henmi, Mao; Takeda-Morishita, Mariko

    2015-08-01

    Our recent studies have shown that the coadministration of cell-penetrating peptides (CPPs) is a potential strategy for oral delivery of peptide- and protein-based biopharmaceuticals. The intermolecular interaction between drug and CPP is an essential factor in the effective delivery of these drugs, but the characteristics of the interaction under the conditions of the intestinal lumen remain unknown. In this study, therefore, we examined the characteristics of binding of the amphipathic CPP penetratin to insulin and the efficiency of its enhancement of epithelial insulin transport at different pH and in simulated intestinal fluids (SIFs). The binding between insulin and penetratin was pH dependent and particularly decreased at pH 5.0. In addition, we clarified that the sodium taurocholate (NaTC) present in two types of SIF (fasted-state SIF [FaSSIF] and fed-state SIF [FeSSIF]) affected binding efficiency. However, the permeation of insulin through a Caco-2 cell monolayer was significantly facilitated by coincubation with l- or d-penetratin at various pH values. Moreover, the permeation-stimulating effect of l-penetratin was observed in FaSSIF containing NaTC and lecithin, but not in 3mM NaTC solution, suggesting that the presence of lecithin was the key factor in maintaining the ability of penetratin to enhance the intestinal absorption of biopharmaceuticals. This report describes the essential considerations for in vivo use and clinical application of a CPP-based oral delivery strategy. PMID:25960330

  16. Interaction of myenteric neurons and extrinsic nerves in the intestinal inhibitory response induced by mesenteric nerve stimulation.

    PubMed

    Yamasato, T; Nakayama, S

    1991-04-01

    Effects of the mesenteric nerve stimulation (MNS) on the twitch contraction induced by field stimulation were investigated regarding the relationship between myenteric neurons and extrinsic cholinergic nerves in the guinea-pig mesenteric nerve-ileal preparation. The twitch contraction was inhibited after MNS. The inhibition of the twitch contraction after MNS was induced twice, just after MNS (1st inhibition) and 2-3 min later (2nd inhibition) (type I), or once, just after MNS (1st inhibition) (type II), in recovery course of twitch contraction for 6-8 min. The 1st inhibition was slightly decreased by guanethidine and hexamethonium. The inhibitory response (1st inhibition) in both types I and II was recovered to the control level by pretreatment with naloxone (recovered twitch contraction), but the late inhibitory response (2nd inhibition) was markedly observed after 2-3 min in types I and II. Either the 1st or the 2nd inhibition was not altered by capsaicin, desensitization to calcitonin gene-related polypeptide (CGRP), vasoactive intestinal polypeptide (VIP), somatostatin, or galanin. The recovered twitch contraction in types I and II was decreased by CGRP-desensitization, or capsaicin. These results suggest that the first inhibitory response was induced by enteric opioid neurons connected with extrinsic cholinergic nerves, but the 2nd inhibition was induced by unknown substances other than CGRP, VIP, somatostatin, and galanin. The twitch contraction may partly be induced by endogenous neurokinin-like substances. And, some CGRP containing neurons, which connect with extrinsic cholinergic nerves, probably activate the intrinsic excitatory neurons. PMID:1678243

  17. Sensitive detection of human papillomavirus type 16 E7-specific T cells by ELISPOT after multiple in vitro stimulations of CD8+ T cells with peptide-pulsed autologous dendritic cells

    PubMed Central

    Cools, Nathalie; Ponsaerts, Peter; Lenjou, Marc; Nijs, Griet; Van Bockstaele, Dirk R; Van Tendeloo, Viggo FI; Berneman, Zwi N

    2006-01-01

    Background Cervical cancer is the second most common gynecological cancer amongst women world-wide. Despite optimized protocols, standard treatments still face several disadvantages. Therefore, research aims at the development of immune-based strategies using tumor antigen-loaded dendritic cells for the induction of cellular anti-tumor immunity. Results In this study, we used dendritic cells loaded with the HLA-A2-restricted HPV type 16 E711–20 peptide in order to induce an in vitro CD8+ T cell response. For this purpose, peptide-pulsed dendritic cells were co-cultured with autologous CD8+ T cells. After 5 weekly stimulations with peptide-pulsed mature dendritic cells, cultured T cells were analyzed for antigen specificity by an IFN-γ ELISPOT assay. Using this ELISPOT assay, we were able to detect E7-specific IFN-γ-secreting CD8+ T cells in 5/5 healthy donors. Conclusion We show that peptide-pulsed mature dendritic cells are able to stimulate a HPV type 16 E7 peptide-specific immune response in vitro. These experiments describe an efficient culture protocol for antigen-specific T cells for use in pre-clinical vaccination research and confirm the need for sensitive T cell assays for detection of tumor-specific immune responses in vitro. PMID:17067378

  18. Differential gene expression of RAW 264.7 macrophages in response to the RGD peptide lunasin with and without lipopolysaccharide stimulation.

    PubMed

    Dia, Vermont P; de Mejia, Elvira Gonzalez

    2011-10-01

    Lunasin is a novel peptide from soybean with demonstrated chemopreventive property. We compared the effect of lunasin on gene expression of RAW 264.7 macrophages with and without lipopolysaccharide (LPS)-stimulation. Our hypothesis was that lunasin will have a differential effect in RAW 264.7 gene expression in a normal and challenged state. Analysis of the microarray data using False Discovery Rate (FDR) method resulted in the identification of 340 up-regulated and 162 down-regulated genes (FDR p-value <0.05) associated with simultaneous treatment of lunasin and LPS for 24h. Treatment of lunasin with no LPS for 24h resulted in the up-regulation of 855 genes and down-regulation of 397 genes. Pre-treatment of lunasin for 24h resulted in the up-regulation of 35 genes and down-regulation of 65 genes in LPS-stimulated RAW 264.7 macrophages. GeneVenn analysis of these three sets of genes showed that there are 66 genes common among the three groups which are mostly associated with regulation of cell death, ion binding and transcription as datamined by DAVID. Analysis of the 838 genes unique to lunasin alone by functional annotation clustering tool showed that lunasin mostly affected genes associated with RNA processing, apoptosis and protein kinase activity. Further datamining of these genes by ingenuity pathway analysis (IPA) showed that lunasin affected genes involved in cellular growth and proliferation, cellular function and maintenance, and cell to cell signaling and interaction. These findings support the potential chemopreventive and chemotherapeutic use of lunasin against cancer. PMID:21964376

  19. Cytokine production by mononuclear cells following stimulation with a peptide-containing, endotoxin-free Escherichia coli extract.

    PubMed

    Thomsen, A; Loppnow, H

    1995-05-01

    The beneficial effects of the E. coli extract Colibiogen inj. N (Cb) observed in therapy of inflammatory bowel diseases, allergies, or gastrointestinal tumors are possibly mediated by the induction of cytokines in human leukocytes or vascular cells. Thus, the induction of the cytokines interleukin 1 (IL1), IL6 and tumor necrosis factor (TNF) in human mononuclear cells (MNC) and vascular cells was investigated in vitro. Various administration forms of the extract (including Cb-inj. N, Cb-oral, and Cb-infantibus N) induced the release of IL1 and IL6 from MNC. The compounds stimulated TNF production less potently, possibly due to a lower sensitivity of the TNF assay system, as compared to the IL1 and IL6 detection system. The MNC produced the cytokines with a kinetics similar to that observed with other stimuli. Monospecific antibodies abolished the respective cytokine activity in the biological assays. Addition of submaximal amounts of endotoxin potently enhanced the IL1- and IL6-inducing activity of the bacterial extract, indicating synergism of the extract and endotoxin. These results provide evidence that cytokines produced by MNC following administration of the tested bacterial extract may contribute to the regulation of the immune response during therapy of gastrointestinal tumors. At present the in vivo production of cytokines following treatment with the bacterial extract tested is under investigation in a phase III study. PMID:7612070

  20. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    SciTech Connect

    Han, Hui; Peng, Ji-Run; Chen, Peng-Cheng; Gong, Lei; Qiao, Shi-Shi; Wang, Wen-Zhen; Cui, Zhu-Qingqing; Yu, Xin; Wei, Yu-Hua; Leng, Xi-Sheng

    2011-08-05

    Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  1. Serotonin and CGRP in migraine.

    PubMed

    Aggarwal, Milan; Puri, Veena; Puri, Sanjeev

    2012-04-01

    Migraine is defined as recurrent attack of headache that are commonly unilateral and accompanied by gastrointestinal and visual disorders. Migraine is more prevalent in females than males with a ratio of 3:1. It is primarily a complex neurovascular disorder involving local vasodilation of intracranial, extracerebral blood vessels and simultaneous stimulation of surrounding trigeminal sensory nervous pain pathway that results in headache. The activation of 'trigeminovascular system' causes release of various vasodilators, especially calcitonin gene-related peptide (CGRP) that induces pain response. At the same time, decreased levels of neurotransmitter, serotonin have been observed in migraineurs. Serotonin receptors have been found on the trigeminal nerve and cranial vessels and their agonists especially triptans prove effective in migraine treatment. It has been found that triptans act on trigeminovascular system and bring the elevated serum levels of key molecules like calcitonin gene related peptide (CGRP) to normal. Currently CGRP receptor antagonists, olcegepant and telcagepant are under consideration for antimigraine therapeutics. It has been observed that varying levels of ovarian hormones especially estrogen influence serotonin neurotransmission system and CGRP levels making women more predisposed to migraine attacks. This review provides comprehensive information about the role of serotonin and CGRP in migraine, specifically the menstrual migraine. PMID:25205974

  2. Bacteriocin Inducer Peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel peptides produced by bacteriocin-producing bacteria stimulate the production of bacteriocins in vitro. The producer bacteria are cultured in the presence of a novel inducer bacteria and a peptide having a carboxy terminal sequence of VKGLT in order to achieve an increase in bacteriocin produc...

  3. Possible involvement of integrin-mediated signalling in oocyte activation: evidence that a cyclic RGD-containing peptide can stimulate protein kinase C and cortical granule exocytosis in mouse oocytes

    PubMed Central

    Tatone, Carla; Carbone, Maria Cristina

    2006-01-01

    Background Mammalian sperm-oocyte interaction at fertilization involves several combined interactions between integrins on the oocyte and integrin ligands (disintegrins) on the sperm. Recent research has indicated the ability of peptides containing the RGD sequence that characterized several sperm disintegrins, to induce intracellular Ca2+ transients and to initiate parthenogenetic development in amphibian and bovine oocytes. In the present study, we investigate the hypothesis that an integrin-associated signalling may participate in oocyte activation signalling by determining the ability of a cyclic RGD-containing peptide to stimulate the activation of protein kinase C (PKC) and the exocytosis of cortical granules in mouse oocytes. Methods An In-Vitro-Fertilization assay (IVF) was carried in order to test the condition under which a peptide containing the RGD sequence, cyclo(Arg-Gly-Asp-D-Phe-Val), was able to inhibit sperm fusion with zona-free mouse oocytes at metaphase II stage. PKC activity was determined by means of an assay based on the ability of cell lysates to phosphorylate MARKS peptide, a specific PKC substrate. Loss of cortical granules was evaluated by measuring density in the oocyte cortex of cortical granules stained with LCA-biotin/Texas red-streptavidin. In all the experiments, effects of a control peptide containing a non RGD sequence, cyclo(Arg-Ala-Asp-D-Phe-Val), were evaluated. Results The IVF assay revealed that the fusion rate declined significantly when insemination was carried out in the presence of cyclic RGD peptide at concentrations > or = 250 microM (P < 0.05, Student-Newman-Keuls Method). When the peptide was applied to the oocytes at these concentrations, a dose-dependent increase of PKC activity was observed, in association with a loss of cortical granules ranging from 38+/-2.5 % to 52+/-5.4 %. Evaluation of meiotic status revealed that cyclic RGD peptide was ineffective in inducing meiosis resumption under conditions used in the

  4. Administration of insulin-like growth factor-I (IGF-I) peptides for three days stimulates proliferation of the small intestinal epithelium in rats.

    PubMed Central

    Steeb, C B; Trahair, J F; Read, L C

    1995-01-01

    It has previously been shown that longterm administration of insulin-like growth factor-I (IGF-I) or the analogue Long R3 IGF-I (LR3IGF-I) selectively stimulate growth of the gastrointestinal tract in gut resected, dexamethasone treated, and normal rats. In this study, the short-term effects of IGF-I administration on intestinal proliferation have been investigated. Female rats (110 g, five-six/group) were infused for three days with 2.5 mg/kg/day of either IGF-I or LR3IGF-I and compared with vehicle treated or untreated control rats. LR3IGF-I but not IGF-I increased body weight and wet tissue weight of the small and large intestine (+20%), compared with controls. Tissue weight responses were independent of food intake and were reflected in the histology of the tissue. In LR3IGF-I treated animals, duodenal and ileal crypts length were increased by 13 and 22%, respectively, associated with an increase in crypt cell number. No such histological changes were seen in IGF-I treated rats. Tritiated thymidine labelling indices were significantly increased after administration of either IGF-I or LR3IGF-I (up to 14%) in both the duodenum and ileum. In IGF-I treated rats, increased nuclear labelling was not associated with an increase in the crypt compartment. In contrast, LR3IGF-I induced proportional increments in thymidine labelling and crypt size, suggesting that LR3IGF-I is not only more potent than the native peptide but also induced proliferative events more rapidly. In the colon, the thymidine labelling index was low, however, a non-significant increase in the number of cells labelled with thymidine was seen. These results suggest that within a three day treatment period intestinal mitogenesis is more advanced in animals treated with LR3IGF-I. The differences in proliferative response between the two peptides may be accounted for by variations in pharmacokinetics, clearance rates, and interactions with circulating and tissue specific binding proteins. PMID:8549937

  5. Administration of insulin-like growth factor-I (IGF-I) peptides for three days stimulates proliferation of the small intestinal epithelium in rats.

    PubMed

    Steeb, C B; Trahair, J F; Read, L C

    1995-11-01

    It has previously been shown that longterm administration of insulin-like growth factor-I (IGF-I) or the analogue Long R3 IGF-I (LR3IGF-I) selectively stimulate growth of the gastrointestinal tract in gut resected, dexamethasone treated, and normal rats. In this study, the short-term effects of IGF-I administration on intestinal proliferation have been investigated. Female rats (110 g, five-six/group) were infused for three days with 2.5 mg/kg/day of either IGF-I or LR3IGF-I and compared with vehicle treated or untreated control rats. LR3IGF-I but not IGF-I increased body weight and wet tissue weight of the small and large intestine (+20%), compared with controls. Tissue weight responses were independent of food intake and were reflected in the histology of the tissue. In LR3IGF-I treated animals, duodenal and ileal crypts length were increased by 13 and 22%, respectively, associated with an increase in crypt cell number. No such histological changes were seen in IGF-I treated rats. Tritiated thymidine labelling indices were significantly increased after administration of either IGF-I or LR3IGF-I (up to 14%) in both the duodenum and ileum. In IGF-I treated rats, increased nuclear labelling was not associated with an increase in the crypt compartment. In contrast, LR3IGF-I induced proportional increments in thymidine labelling and crypt size, suggesting that LR3IGF-I is not only more potent than the native peptide but also induced proliferative events more rapidly. In the colon, the thymidine labelling index was low, however, a non-significant increase in the number of cells labelled with thymidine was seen. These results suggest that within a three day treatment period intestinal mitogenesis is more advanced in animals treated with LR3IGF-I. The differences in proliferative response between the two peptides may be accounted for by variations in pharmacokinetics, clearance rates, and interactions with circulating and tissue specific binding proteins. PMID:8549937

  6. Dual Receptor-Targeting Tc-99m-Labeled Arg-Gly-Asp-Conjugated Alpha-Melanocyte Stimulating Hormone Hybrid Peptides for Human Melanoma Imaging

    PubMed Central

    Xu, Jingli; Yang, Jianquan; Miao, Yubin

    2014-01-01

    Introduction The aim of this study was to examine whether the substitution of the Lys linker with the aminooctanoic acid (Aoc) and polyethylene glycol (PEG) linker could substantially decrease the non-specific renal uptake of 99mTc-labeled Arg-Gly-Asp-conjugated α-melanocyte stimulating hormone (α-MSH) hybrid peptides. Methods The RGD motif {Arg-Gly-Asp-DTyr-Asp} was coupled to [Cys3,4,10, D-Phe7, Arg11]α-MSH3–13 via the Aoc or PEG2 linker to generate RGD-Aoc-(Arg11)CCMSH and RGD-PEG-(Arg11)CCMSH. The biodistribution results of 99mTc-RGD-Aoc-(Arg11)CCMSH and 99mTc-RGD-PEG2-(Arg11)CCMSH were examined in M21 human melanoma-xenografted nude mice. Results The substitution of Lys linker with Aoc and PEG2 linker significantly reduced the renal uptake of 99mTc-RGD-Aoc-(Arg11)CCMSH and 99mTc-RGD-PEG2-(Arg11)CCMSH by 58% and 63% at 2 h post-injection. The renal uptake of 99mTc-RGD-Aoc-(Arg11)CCMSH and 99mTc-RGD-PEG2-(Arg11)CCMSH was 27.93 ± 3.98 and 22.01 ± 9.89% ID/g at 2 h post-injection. 99mTc-RGD-Aoc-(Arg11)CCMSH displayed higher tumor uptake than 99mTc-RGD-PEG2-(Arg11)CCMSH (2.35 ± 0.12 vs. 1.71 ± 0.25% ID/g at 2 h post-injection). The M21 human melanoma lesions could be clearly visualized by SPECT/CT using 99mTc-RGD-Aoc-(Arg11)CCMSH as an imaging probe. Conclusions The favorable effect of Aoc and PEG2 linker in reducing the renal uptake provided a new insight into the design of novel dual receptor-targeting radiolabeled peptides. PMID:25577037

  7. Anti-Inflammatory Action of an Antimicrobial Model Peptide That Suppresses the TRIF-Dependent Signaling Pathway via Inhibition of Toll-Like Receptor 4 Endocytosis in Lipopolysaccharide-Stimulated Macrophages

    PubMed Central

    Shim, Do-Wan; Heo, Kang-Hyuck; Kim, Young-Kyu; Sim, Eun-Jeong; Kang, Tae-Bong; Choi, Jae-Wan; Sim, Dae-Won; Cheong, Sun-Hee; Lee, Seung-Hong; Bang, Jeong-Kyu; Won, Hyung-Sik; Lee, Kwang-Ho

    2015-01-01

    Antimicrobial peptides (AMPs), also called host defense peptides, particularly those with amphipathic helical structures, are emerging as target molecules for therapeutic development due to their immunomodulatory properties. Although the antimicrobial activity of AMPs is known to be exerted primarily by permeation of the bacterial membrane, the mechanism underlying its anti-inflammatory activity remains to be elucidated. We report potent anti-inflammatory activity of WALK11.3, an antimicrobial model peptide with an amphipathic helical conformation, in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. This peptide inhibited the expression of inflammatory mediators, including nitric oxide, COX-2, IL-1β, IL-6, INF-β, and TNF-α. Although WALK11.3 did not exert a major effect on all downstream signaling in the MyD88-dependent pathway, toll-like receptor 4 (TLR4)- mediated pro-inflammatory signals were markedly attenuated in the TRIF-dependent pathway due to inhibition of the phosphorylation of STAT1 by attenuation of IRF3 phosphorylation. WALK11.3 specifically inhibited the endocytosis of TLR4, which is essential for triggering TRIF-mediated signaling in macrophage cells. Hence, we suggest that specific interference with TLR4 endocytosis could be one of the major modes of the anti-inflammatory action of AMPs. Our designed WALK11 peptides, which possess both antimicrobial and anti-inflammatory activities, may be promising molecules for the development of therapies for infectious inflammation. PMID:26017270

  8. Novel non-peptide small molecules preventing IKKβ/NEMO association inhibit NF-κB activation in LPS-stimulated J774 macrophages.

    PubMed

    De Falco, Francesca; Di Giovanni, Carmen; Cerchia, Carmen; De Stefano, Daniela; Capuozzo, Antonella; Irace, Carlo; Iuvone, Teresa; Santamaria, Rita; Carnuccio, Rosa; Lavecchia, Antonio

    2016-03-15

    Nuclear Factor-κB (NF-κB) is a transcription factor regulating several genes involved in important physiological and pathological processes. NF-κB has been found constitutively activated in many inflammatory/immune diseases. In addition, a positive correlation between persistent activation of NF-κB and tumor promotion has been demonstrated. Since the IKK (IκB kinase) activation is an indispensable component of all pro-inflammatory signaling pathways leading to NF-κB activation, considerable efforts have been done in order to develop novel anti-inflammatory therapeutics targeting IKK. Association of the IKK complex relies on critical interactions between the C-terminus NBD (NEMO binding domain) of the catalytic subunits IKKα and IKKβ, and the regulatory subunit NEMO (NF-κB Essential Modulator). Thus, this IKK/NEMO interacting region provides an attractive target to prevent the IKK complex formation and NF-κB activation. In this regard, we have identified non-peptide small molecule disruptors of IKKβ/NEMO complex through a structure-based virtual screening (SBVS) of the NCI chemical library. Phenothiazine 22 and its close analogues (22.2, 22.4 and 22.10) were able to reduce nitrite production and iNOS mRNA expression in J774 murine macrophages stimulated with LPS for 24h. These effects were associated with a reduced NF-κB/DNA binding activity as well as a decreased expression of phosphorylated IKKβ, IκBα and NF-κB/p65 in these cells. These observations suggest that compound 22 and its three structural analogues by inhibiting IKKβ/NEMO association mediate the blockage of NF-κB signaling pathway and may prove effective in treatment of diseases in which the IKK/NF-κB pathway is dysregulated. PMID:26776306

  9. Chromanol 293B, an inhibitor of KCNQ1 channels, enhances glucose-stimulated insulin secretion and increases glucagon-like peptide-1 level in mice.

    PubMed

    Liu, Lijie; Wang, Fanfan; Lu, Haiying; Ren, Xiaomei; Zou, Jihong

    2014-01-01

    Glucose-stimulated insulin secretion (GSIS) is a highly regulated process involving complex interaction of multiple factors. Potassium voltage-gated channel subfamily KQT member 1 (KCNQ1) is a susceptibility gene for type 2 diabetes (T2D) and the risk alleles of the KCNQ1 gene appear to be associated with impaired insulin secretion. The role of KCNQ1 channel in insulin secretion has been explored by previous work in clonal pancreatic β-cells but has yet to be investigated in the context of primary islets as well as intact animals. Genetic studies suggest that altered incretin glucagon-like peptide-1 (GLP-1) secretion might be a potential link between KCNQ1 variants and impaired insulin secretion, but this hypothesis has not been verified so far. In the current study, we examined KCNQ1 expression in pancreas and intestine from normal mice and then investigated the effects of chromanol 293B, a KCNQ1 channel inhibitor, on insulin secretion in vitro and in vivo. By double-immunofluorescence staining, KCNQ1 was detected in insulin-positive β-cells and GLP-1-positive L-cells. Administration of chromanol 293B enhanced GSIS in cultured islets and intact animals. Along with the potentiated insulin secretion during oral glucose tolerance tests (OGTT), plasma GLP-1 level after gastric glucose load was increased in 293B treated mice. These data not only provided new evidence for the participation of KCNQ1 in GSIS at the level of pancreatic islet and intact animal but also indicated the potential linking role of GLP-1 between KCNQ1 and insulin secretion. PMID:25437377

  10. Sensory and autonomic innervation of the rat eyelid: neuronal origins and peptide phenotypes.

    PubMed

    Simons, E; Smith, P G

    1994-07-01

    Neuronal origins, peptide phenotypes and target distributions were determined for sensory and autonomic nerves projecting to the eyelid. The retrograde tracer, Fluoro-Ruby, was injected into the superior tarsal muscle and meibomian gland of Sprague-Dawley rats. Labelled neurons were observed within the pterygopalatine (31 +/- 6 of a total of 8238 +/- 1610 ganglion neurons), trigeminal (173 +/- 43 of 62,082 +/- 5869) and superior cervical ganglia (184 +/- 35 of 21,900 +/- 1741). Immunostaining revealed vasoactive intestinal polypeptide immunoreactivity (VIP-ir) in nearly all Fluoro-Ruby-labelled pterygopalatine ganglion neurons (86 +/- 5%) but only rarely in trigeminal (0.3 +/- 0.3%) or superior cervical (1.4 +/- 1.4%) ganglion neurons. Calcitonin gene-related peptide (CGRP)-ir was not observed in pterygopalatine or superior cervical ganglion somata, but was present in 24 +/- 4% of trigeminal neurons. Bright dopamine beta-hydroxylase (DBH) immunofluorescence was observed in the majority of eyelid-projecting neurons within the superior cervical ganglia (65 +/- 5%) and lighter staining was detected in pterygopalatine neurons (63 +/- 3%), but no DBH-ir was observed in trigeminal neurons. Examination of eyelid sections revealed dense VIP-ir innervation of meibomian gland acini and vasculature and modest distribution within tarsal muscle. CGRP-ir fibers surrounded ductal and vascular elements of the meibomian gland and the perimeter of tarsal muscle. DBH-ir fibers were associated with meibomian gland blood vessels and acini, and were more densely distributed within tarsal muscle. This study provides evidence for prominent meibomian gland innervation by parasympathetic pterygopalatine ganglion VIP-ir neurons, with more restricted innervation by sensory trigeminal CGRP-ir and sympathetic neurons. Tarsal muscle receives abundant sympathetic innervation, as well as moderate parasympathetic and sensory CGRP-ir projections. The eyelid contains substantial non-CGRP-ir sensory

  11. A rhesus monkey model to characterize the role of gastrin-releasing peptide (GRP) in lung development. Evidence for stimulation of airway growth.

    PubMed Central

    Li, K; Nagalla, S R; Spindel, E R

    1994-01-01

    Gastrin-releasing peptide (GRP) is developmentally expressed in human fetal lung and is a growth factor for normal and neoplastic lung but its role in normal lung development has yet to be clearly defined. In this study we have characterized the expression of GRP and its receptor in fetal rhesus monkey lung and determined the effects of bombesin on fetal lung development in vitro. By RNA blot analysis, GRP mRNA was first detectable in fetal monkey lung at 63 days gestation, reached highest levels at 80 days gestation, and then declined to near adult levels by 120 days gestation; a pattern closely paralleling GRP expression in human fetal lung. As in human lung, in situ hybridization localized GRP mRNA to neuroendocrine cells though during the canalicular phase of development (between 63-80 days gestation) GRP mRNA was present not only in classic pulmonary neuroendocrine cells, but also in cells of budding airways. Immunohistochemistry showed that bombesin-like immunoreactivity was present in neuroendocrine cells, but not in budding airways, suggesting that in budding airways either the GRP mRNA is not translated, is rapidly secreted, or a related, but different RNA is present. RNase protection analysis using a probe to the monkey GRP receptor demonstrated that the time course of receptor RNA expression closely paralleled the time course of GRP RNA expression. In situ hybridization showed that GRP receptors were primarily expressed in epithelial cells of the developing airways. Thus GRP would appear to be secreted from neuroendocrine cells to act on target cells in developing airways. This hypothesis was confirmed by organ culture of fetal monkey lung in the presence of bombesin and bombesin antagonists. Bombesin treatment at 1 and 10 nM significantly increased DNA synthesis in airway epithelial cells and significantly increased the number and size of airways in cultured fetal lung. In fact, culturing 60 d fetal lung for 5 d with 10 nM bombesin increased airway size

  12. Guanylyl cyclase/natriuretic peptide receptor-A signaling antagonizes the vascular endothelial growth factor-stimulated MAPKs and downstream effectors AP-1 and CREB in mouse mesangial cells

    PubMed Central

    Tripathi, Satyabha; Pandey, Kailash N.

    2012-01-01

    Along with its natriuretic, diuretic, and vasodilatory properties, atrial natriuretic peptide (ANP) and its guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) exhibit an inhibitory effect on cell growth and proliferation. However, the signaling pathways mediating this inhibition are not well understood. The objective of this study was to determine the effect of ANP-NPRA system on mitogen-activated protein kinases (MAPKs) and the downstream proliferative transcription factors involving activating protein-1 (AP-1) and cAMP-response element binding protein (CREB) in agonist-stimulated mouse mesangial cells (MMCs). We found that ANP inhibited vascular endothelial growth factor (VEGF)-stimulated phosphorylation of MAPKs (Erk1, Erk2, JNK, and p38), to a greater extent in NPRA-transfected cells (50–60%) relative to vector-transfected cells (25–30%). The analyses of the phosphorylated transcription factors revealed that ANP inhibited VEGF-stimulated activation of CREB, and the AP-1 subunits (c-jun and c-fos). Gel shift assays demonstrated that ANP inhibited VEGF-stimulated AP-1 and CREB DNA-binding ability by 67 % and 62 %, respectively. The addition of the protein kinase G (PKG) inhibitor, KT-5823, restored the VEGF-stimulated activation of MAPKs, AP-1, and CREB, demonstrating the integral role of cGMP/PKG signaling in NPRA-mediated effects. Our results delineate the under lying mechanisms through which ANP-NPRA system exerts an inhibitory effect on MAPKs and down-stream effector molecules, AP-1 and CREB, critical for cell growth and proliferation. PMID:22610792

  13. Antisecretory Factor Peptide AF-16 Inhibits the Secreted Autotransporter Toxin-Stimulated Transcellular and Paracellular Passages of Fluid in Cultured Human Enterocyte-Like Cells

    PubMed Central

    Nicolas, Valérie

    2014-01-01

    Both the endogenous antisecretory factor (AF) protein and peptide AF-16, which has a sequence that matches that of the active N-terminal region of AF, inhibit the increase in the epithelial transport of fluid and electrolytes induced by bacterial toxins in animal and ex vivo models. We conducted a study to investigate the inhibitory effect of peptide AF-16 against the increase of transcellular passage and paracellular permeability promoted by the secreted autotransporter toxin (Sat) in a cultured cellular model of the human intestinal epithelial barrier. Peptide AF-16 produced a concentration-dependent inhibition of the Sat-induced increase in the formation of fluid domes, in the mucosal-to-serosal passage of d-[1-14C]mannitol, and in the rearrangements in the distribution and protein expression of the tight junction (TJ)-associated proteins ZO-1 and occludin in cultured human enterocyte-like Caco-2/TC7 cell monolayers. In addition, we show that peptide AF-16 also inhibits the cholera toxin-induced increase of transcellular passage and the Clostridium difficile toxin-induced effects on paracellular permeability and TJ protein organization in Caco-2/TC7 cell monolayers. Treatment of cell monolayers by the lipid raft disorganizer methyl-β-cyclodextrin abolished the inhibitory activity of peptide AF-16 at the transcellular passage level and did not modify the effect of the peptide at the paracellular level. PMID:25534938

  14. Antisecretory factor peptide AF-16 inhibits the secreted autotransporter toxin-stimulated transcellular and paracellular passages of fluid in cultured human enterocyte-like cells.

    PubMed

    Nicolas, Valérie; Liévin-Le Moal, Vanessa

    2015-03-01

    Both the endogenous antisecretory factor (AF) protein and peptide AF-16, which has a sequence that matches that of the active N-terminal region of AF, inhibit the increase in the epithelial transport of fluid and electrolytes induced by bacterial toxins in animal and ex vivo models. We conducted a study to investigate the inhibitory effect of peptide AF-16 against the increase of transcellular passage and paracellular permeability promoted by the secreted autotransporter toxin (Sat) in a cultured cellular model of the human intestinal epithelial barrier. Peptide AF-16 produced a concentration-dependent inhibition of the Sat-induced increase in the formation of fluid domes, in the mucosal-to-serosal passage of D-[1-(14)C]mannitol, and in the rearrangements in the distribution and protein expression of the tight junction (TJ)-associated proteins ZO-1 and occludin in cultured human enterocyte-like Caco-2/TC7 cell monolayers. In addition, we show that peptide AF-16 also inhibits the cholera toxin-induced increase of transcellular passage and the Clostridium difficile toxin-induced effects on paracellular permeability and TJ protein organization in Caco-2/TC7 cell monolayers. Treatment of cell monolayers by the lipid raft disorganizer methyl-β-cyclodextrin abolished the inhibitory activity of peptide AF-16 at the transcellular passage level and did not modify the effect of the peptide at the paracellular level. PMID:25534938

  15. Effects of granulocyte-macrophage colony-stimulating factor and foreign helper protein as immunologic adjuvants on the T-cell response to vaccination with tyrosinase peptides.

    PubMed

    Scheibenbogen, Carmen; Schadendorf, Dirk; Bechrakis, Nikolaos E; Nagorsen, Dirk; Hofmann, Udo; Servetopoulou, Fotini; Letsch, Anne; Philipp, Armin; Foerster, Michael H; Schmittel, Alexander; Thiel, Eckhard; Keilholz, Ulrich

    2003-03-20

    Immunologic adjuvants are used to augment the immunogenicity of MHC class I-restricted peptide vaccines, but this effect has rarely been systematically evaluated in a clinical trial. We have investigated, in a phase I study, whether addition of the 2 adjuvants GM-CSF and KLH can enhance the T-cell response to MHC class I peptide vaccines. Forty-three high-risk melanoma patients who were clinically free of disease received 6 vaccinations with MHC class I-restricted tyrosinase peptides alone, with either GM-CSF or KLH or with a combination of both adjuvants. The primary end point was induction of tyrosinase-specific T cells, and serial T-cell monitoring was performed in unstimulated peripheral blood samples before and after the second, fourth and sixth vaccinations by ELISPOT assay. Tyrosinase-specific IFN-gamma-producing T cells were detected as early as 2 weeks after the second vaccination in 5 of 9 patients vaccinated with tyrosinase peptides in combination with GM-CSF and KLH but not in any patient vaccinated with tyrosinase peptides without adjuvants or in combination with either adjuvant alone. After 6 vaccinations, tyrosinase-specific T cells were found in patients immunized with peptides either without adjuvants (3 of 9 patients) or in combination with the single adjuvant GM-CSF (4 of 9 patients) but not with KLH (0 of 10 patients). Our results suggest that addition of either GM-CSF or KLH as a single adjuvant has little impact on the immunogenicity of tyrosinase peptides. The combined application of GM-CSF and KLH was associated with early induction of T-cell responses. PMID:12569574

  16. The Glucagon-Like Peptide 1 Analogue Exendin-4 Attenuates the Nicotine-Induced Locomotor Stimulation, Accumbal Dopamine Release, Conditioned Place Preference as well as the Expression of Locomotor Sensitization in Mice

    PubMed Central

    Egecioglu, Emil; Engel, Jörgen A.; Jerlhag, Elisabet

    2013-01-01

    The gastrointestinal peptide glucagon-like peptide 1 (GLP-1) is known to regulate consummatory behavior and is released in response to nutrient ingestion. Analogues of this peptide recently emerged as novel pharmacotherapies for treatment of type II diabetes since they reduce gastric emptying, glucagon secretion as well as enhance glucose-dependent insulin secretion. The findings that GLP-1 targets reward related areas including mesolimbic dopamine areas indicate that the physiological role of GLP-1 extends beyond food intake and glucose homeostasis control to include reward regulation. The present series of experiments was therefore designed to investigate the effects of the GLP-1 receptor agonist, Exendin-4 (Ex4), on established nicotine-induced effects on the mesolimbic dopamine system in mice. Specifically, we show that treatment with Ex4, at a dose with no effect per se, attenuate nicotine-induced locomotor stimulation, accumbal dopamine release as well as the expression of conditioned place preference in mice. In accordance, Ex4 also blocks nicotine-induced expression of locomotor sensitization in mice. Given that development of nicotine addiction largely depends on the effects of nicotine on the mesolimbic dopamine system these findings indicate that the GLP-1 receptor may be a potential target for the development of novel treatment strategies for nicotine cessations in humans. PMID:24204788

  17. T-cell mitogenesis stimulates the synthesis of a mRNA species coding for a 43-kDa peptide reactive with CM-H-9, a monoclonal antibody specific for placental isoferritin.

    PubMed Central

    Moroz, C; Shterman, N; Kupfer, B; Ginzburg, I

    1989-01-01

    In studying the changes that occur in concanavalin A-activated T lymphocytes, an mRNA species was discovered by hybridization of poly(A)+ mRNA with a human ferritin heavy chain cDNA probe. This ferritin mRNA, termed superheavy chain mRNA, differed from the known human ferritin heavy chain mRNAs by its larger size and degree of homology. The superheavy chain mRNA was isolated by sucrose-gradient centrifugation and translated in vitro in a cell-free system. The products obtained included two peptides (superheavy) of 43kDa that reacted with CM-H-9, a monoclonal antibody specific for placental isoferritin. De novo synthesis in intact transformed T cells revealed the synthesis of the superheavy chain peptides that were immunoprecipitated by anti-ferritin monoclonal antibody CM-G-8 and by placental isoferritin specific monoclonal antibody CM-H-9. The above results indicated that blast transformation of human T cells stimulated the appearance of a unique mRNA species that coded for a superheavy chain peptide associated with placental isoferritin, which was not detected in resting T cells. Images PMID:2654941

  18. Antimicrobial Peptides from Fish

    PubMed Central

    Masso-Silva, Jorge A.; Diamond, Gill

    2014-01-01

    Antimicrobial peptides (AMPs) are found widely distributed through Nature, and participate in the innate host defense of each species. Fish are a great source of these peptides, as they express all of the major classes of AMPs, including defensins, cathelicidins, hepcidins, histone-derived peptides, and a fish-specific class of the cecropin family, called piscidins. As with other species, the fish peptides exhibit broad-spectrum antimicrobial activity, killing both fish and human pathogens. They are also immunomodulatory, and their genes are highly responsive to microbes and innate immuno-stimulatory molecules. Recent research has demonstrated that some of the unique properties of fish peptides, including their ability to act even in very high salt concentrations, make them good potential targets for development as therapeutic antimicrobials. Further, the stimulation of their gene expression by exogenous factors could be useful in preventing pathogenic microbes in aquaculture. PMID:24594555

  19. CGRP receptors mediating CGRP-, adrenomedullin- and amylin-induced relaxation in porcine coronary arteries. Characterization with ‘Compound 1' (WO98/11128), a non-peptide antagonist

    PubMed Central

    Hasbak, Philip; Sams, Anette; Schifter, Søren; Longmore, Jenny; Edvinsson, Lars

    2001-01-01

    Calcitonin gene-related peptide (CGRP), amylin and adrenomedullin (AM) belong to the same family of peptides. Accumulating evidence indicate that the calcitonin (CT) receptor, the CT receptor-like receptor (CRLR) and receptor-activity-modifying proteins (RAMPs) form the basis of all the receptors in this family of peptides. Using reverse transcriptase–polymerase chain reaction the presence of mRNA sequences encoding the CRLR, RAMP1 and RAMP2 were demonstrated in porcine left anterior descending (LAD) coronary arteries, whereas porcine calcitonin (CT) receptor mRNA was not present. The partial porcine mRNA sequences shared 82–92% nucleotide identity with human sequences. The human peptides αCGRP, βCGRP, AM and amylin induced relaxation with pEC50 values of 8.1, 8.1, 6.7 and 6.1 M respectively. The antagonistic properties of a novel non-peptide CGRP antagonist ‘Compound 1' (WO98/11128), βCGRP8–37 and the proposed AM receptor antagonist AM22–52 were compared to the well-known CGRP1 receptor antagonist αCGRP8–37. The αCGRP8–37 and βCGRP8–37 induced concentration-dependent (10−7–10−5 M) rightward shift of both the αCGRP and βCGRP concentration-response curves. βCGRP8–37 (10−6 M) had the same effect as αCGRP8–37 (10−6 M), but with less potent rightward shift of the concentration-response curves for αCGRP, AM and amylin. Preincubation with ‘Compound 1' (10−7–10−5 M) and AM22–52 (10−6 M) had no significant antagonistic effect. In conclusion, the building blocks forming CGRP and AM receptors were present in the porcine LAD, whereas those of the amylin receptor were not. αCGRP, βCGRP, AM and amylin mediated vasorelaxation via the CGRP receptors. No functional response was detected to adrenomedullin via the adrenomedullin receptor. PMID:11498528

  20. Glucagon-like peptide-2 intracellularly stimulates eNOS phosphorylation and specifically induces submucosal arteriole vasodilation via a sheer stress-independent, local neural mechanism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive neuropeptide that exerts diverse actions in the gastrointestinal tract, including enhancing mucosal cell survival and proliferation, mucosal blood flow, luminal nutrient uptake, and suppressing gastric motility and secretion. We have shown th...

  1. Substitution of the Lys Linker with the β-Ala Linker Dramatically Decreased the Renal Uptake of 99mTc-Labeled Arg-X-Asp-Conjugated and X-Ala-Asp-Conjugated α-Melanocyte Stimulating Hormone Peptides

    PubMed Central

    2015-01-01

    The purpose of this study was to examine whether the substitution of the Lys linker with the β-Ala could reduce the renal uptake of 99mTc-labeled Arg-X-Asp-conjugated and X-Ala-Asp-conjugated α-melanocyte stimulating hormone (α-MSH) peptides. RSD-β-Ala-(Arg11)CCMSH (1) {c[Arg-Ser-Asp-dTyr-Asp]-β-Ala-Cys-Cys-Glu-His-dPhe-Arg-Trp-Cys-Arg-Pro-Val-NH2}, RTD-β-Ala-(Arg11)CCMSH (2), RVD-β-Ala-(Arg11)CCMSH (3), RAD-β-Ala-(Arg11)CCMSH (4), NAD-β-Ala-(Arg11)CCMSH (5), and EAD-β-Ala-(Arg11)CCMSH (6) peptides were synthesized and evaluated for their melanocortin 1 (MC1) receptor binding affinities in B16/F1 melanoma cells. The biodistribution of their 99mTc-conjugates were determined in B16/F1 melanoma-bearing C57 mice. The substitution of the Lys linker with β-Ala linker dramatically reduced the renal uptake of all six 99mTc-peptides. 99mTc-4 exhibited the highest melanoma uptake (15.66 ± 6.19% ID/g) and the lowest kidney uptake (20.18 ± 3.86% ID/g) among these 99mTc-peptides at 2 h postinjection. The B16/F1 melanoma lesions could be clearly visualized by single photon emission computed tomography (SPECT)/CT using 99mTc-4 as an imaging probe. PMID:25290883

  2. Interactions between opioid-peptides-containing pathways and GABA(A)-receptors-mediated systems modulate panic-like-induced behaviors elicited by electric and chemical stimulation of the inferior colliculus.

    PubMed

    Calvo, Fabrício; Coimbra, Norberto Cysne

    2006-08-01

    Aiming to clarify the effect of interactive interconnections between the endogenous opioid peptides-neural links and GABAergic pathways on panic-like responses, in the present work, the effect of the peripheral and central administration of morphine or the non-specific opioid receptors antagonist naloxone was evaluated on the fear-induced responses (defensive attention, defensive immobility and escape behavior) elicited by electric and chemical stimulation of the inferior colliculus. Central microinjections of opioid drugs in the inferior colliculus were also performed followed by local administration of the GABA(A)-receptor antagonist bicuculline. The defensive behavior elicited by the blockade of GABAergic receptors in the inferior colliculus had been quantitatively analyzed, recording the number of crossing, jump, rotation and rearing, in each minute, during 30 min, in the open-field test. The opioid receptors stimulation with morphine decreased the defensive attention, the defensive immobility and escape behavior thresholds, and the non-specific opioid receptors blockade caused opposite effects, enhancing the defensive behavior thresholds. These effects were corroborated by either the stimulation or the inhibition of opioid receptors followed by the GABA(A) receptor blockade with bicuculline, microinjected into the inferior colliculus. There was a significant increase in the diverse fear-induced responses caused by bicuculline with the pretreatment of the inferior colliculus with morphine, and the opposite effect was recorded after the pretreatment of the inferior colliculus nuclei with naloxone followed by bicuculline local administration. These findings suggest an interaction between endogenous opioid-peptides-containing connections and GABA(A)-receptor-mediated system with direct influence on the organization of the panic-like or fear-induced responses elaborated in the inferior colliculus during critical emotional states. PMID:16797498

  3. Insect peptide CopA3-induced protein degradation of p27Kip1 stimulates proliferation and protects neuronal cells from apoptosis

    SciTech Connect

    Nam, Seung Taek; Kim, Dae Hong; Lee, Min Bum; Nam, Hyo Jung; Kang, Jin Ku; Park, Mi Jung; Lee, Ik Hwan; Seok, Heon; Lee, Dong Gun; Hwang, Jae Sam; Kim, Ho

    2013-07-19

    Highlights: •CopA3 peptide isolated from the Korean dung beetle has antimicrobial activity. •Our study reported that CopA3 has anticancer and immunosuppressive effects. •We here demonstrated that CopA3 has neurotropic and neuroprotective effects. •CopA3 degrades p27Kip1 protein and this mediates effects of CopA3 on neuronal cells. -- Abstract: We recently demonstrated that the antibacterial peptide, CopA3 (a D-type disulfide dimer peptide, LLCIALRKK), inhibits LPS-induced macrophage activation and also has anticancer activity in leukemia cells. Here, we examined whether CopA3 could affect neuronal cell proliferation. We found that CopA3 time-dependently increased cell proliferation by up to 31 ± 2% in human neuroblastoma SH-SY5Y cells, and up to 29 ± 2% in neural stem cells isolated from neonatal mouse brains. In both cell types, CopA3 also significantly inhibited the apoptosis and viability losses caused by 6-hydroxy dopamine (a Parkinson disease-mimicking agent) and okadaic acid (an Alzheimer’s disease-mimicking agent). Immunoblotting revealed that the p27Kip1 protein (a negative regulator of cell cycle progression) was markedly degraded in CopA3-treated SH-SY5Y cells. Conversely, an adenovirus expressing p27Kip1 significantly inhibited the antiapoptotic effects of CopA3 against 6-hydroxy dopamine- and okadaic acid-induced apoptosis, and decreased the neurotropic effects of CopA3. These results collectively suggest that CopA3-mediated protein degradation of p27Kip1 may be the main mechanism through which CopA3 exerts neuroprotective and neurotropic effects.

  4. Anti-inflammatory and anti-infectious effects of Evodia rutaecarpa (Wuzhuyu) and its major bioactive components

    PubMed Central

    2011-01-01

    This article reviews the anti-inflammatory relative and anti-infectious effects of Evodia rutaecarpa and its major bioactive components and the involvement of the nitric oxide synthases, cyclooxygenase, NADPH oxidase, nuclear factor kappa B, hypoxia-inducible factor 1 alpha, reactive oxygen species, prostaglandins, tumor necrosis factor, LIGHT, amyloid protein and orexigenic neuropeptides. Their potential applications for the treatment of endotoxaemia, obesity, diabetes, Alzheimer's disease and their uses as cardiovascular and gastrointestinal protective agents, analgesics, anti-oxidant, anti-atherosclerosis agents, dermatological agents and anti-infectious agents are highlighted. Stimulation of calcitonin gene-related peptide release may partially explain the analgesic, cardiovascular and gastrointestinal protective, anti-obese activities of Evodia rutaecarpa and its major bioactive components. PMID:21320305

  5. [News in neurology 2014].

    PubMed

    Tsetsou, Spyridoula; Rossetti, Andrea O; Michel, Patrick; Hirt, Lorenz; Wider, Christian; Benninger, David; Kuntzer, Thierry; Nater, Bernard; Démonet, Jean-François; Schluep, Myriam; Du Pasquier, Renaud A; Vingerhoets, François

    2015-01-14

    In 2014, breastfeeding during maternal antiepileptic therapy seems to be safe for the children and can be recommended. Intravenous thrombolysis by Alteplase improves the outcome after a stroke if administered within 4.5 hours and it is also recommended in elderly population over 80 years. ProSavin genic therapy for Parkinson disease is under investigation. The Transcranial Magnetic Stimulation (TMS) has an analgesic effect in neuropathic pain as well as an antidepressant effect. Antagonists of calcitonin gene-related peptide can have a beneficial role in migraine prevention. Diagnostic biomarker panels for Alzheimer disease are under investigation. Oral teriflunomide and dimethyl fumarate (BG-12) for relapsing multiple sclerosis treatment are now available in Switzerland. PMID:25799659

  6. A flow cytometric approach for studying alterations in the cytoplasmic concentration of calcium ions in immune cells following stimulation with thymic peptides.

    PubMed

    Papaioannou, Nikos E; Voutsas, Ioannis F; Samara, Pinelopi; Tsitsilonis, Ourania E

    2016-04-01

    [Ca(2+)]i alterations are vital in signaling pathways of cell activation. We tried to detect such changes, in intracellular signaling pathways downstream TLR4 in immune cells, following stimulation with prothymosin alpha (proTα) and its decapeptide proTα(100-109). Human leukocytes were activated with LPS, proTα or proTα(100-109), directly or after 24h stimulation, while neutrophils were directly challenged. Cells were loaded with Fluo-4 and cytoplasmic Ca(2+) alterations were recorded by flow cytometry. Direct challenge with 20 μg/mL LPS induced a measurable [Ca(2+)]i increase in macrophages and neutrophils. Monocytes and macrophages incubated for 24h with LPS, proTα or proTα(100-109) and challenged with LPS, displayed a robust response. Lymphocytes and iDCs exhibited no alterations. Conclusively, we assessed a flow cytometry-based method for monitoring Ca(2+) ion influx changes in immune cells. Their stimulation with proTα or proTα(100-109) generates an activating background, similar to LPS, allowing for the detection of [Ca(2+)]i alterations induced upon subsequent challenge. PMID:26790897

  7. A neuroligin-1-derived peptide stimulates phosphorylation of the NMDA receptor NR1 subunit and rescues MK-801-induced decrease in long-term potentiation and memory impairment.

    PubMed

    Korshunova, Irina; Gjørlund, Michelle D; Owczarek, Sylwia; Petersen, Anders V; Perrier, Jean-François; Gøtzsche, Casper René; Berezin, Vladimir

    2015-03-01

    Neuroligins (NLs) are postsynaptic adhesion molecules, interacting with presynaptic neurexins (NXs), which determine the differential formation of excitatory (glutamatergic, NL1) and inhibitory (GABAergic, NL2) synapses. We have previously demonstrated that treatment with a NL2-derived peptide, neurolide-2, reduces sociability and increase animal aggression. We hypothesized that interfering with NL1 function at the excitatory synapses might regulate synaptic plasticity and learning, and counteract memory deficits induced by N-methyl-d-aspartate (NMDA) receptor inhibition. First, neuronal NMDA receptor phosphorylation after treatment with NL1 or a mimetic peptide, neurolide-1, was quantified by immunoblotting. Subsequently, we investigated effects of neurolide-1 on long-term potentiation (LTP) induction in hippocampal slices compromised by NMDA receptor inhibitor MK-801. Finally, we investigated neurolide-1 effects on short- and long-term social and spatial memory in social recognition, Morris water-maze, and Y-maze tests. We found that subcutaneous neurolide-1 administration, restored hippocampal LTP compromised by NMDA receptor inhibitor MK-801. It counteracted MK-801-induced memory deficit in the water-maze and Y-maze tests after long-term treatment (24 h and 1-2 h before the test), but not after short-term exposure (1-2 h). Long-term exposure to neurolide-1 also facilitated social recognition memory. In addition, neurolide-1-induced phosphorylation of the NMDA receptor NR1 subunit on a site important for synaptic trafficking, potentially favoring synaptic receptor retention. Our findings emphasize the role of NL1-NMDA receptor interaction in cognition, and identify neurolide-1, as a valuable pharmacological tool to examine the in vivo role of postsynaptic NL1 in cognitive behavior in physiological and pathological conditions. PMID:26038702

  8. Reflex splanchnic nerve stimulation increases levels of proenkephalin A mRNA and proenkephalin A-related peptides in the rat adrenal medulla.

    PubMed Central

    Kanamatsu, T; Unsworth, C D; Diliberto, E J; Viveros, O H; Hong, J S

    1986-01-01

    The effect of reflex splanchnic nerve stimulation on proenkephalin A biosynthesis was investigated in the rat adrenal medulla. Tissue levels of native [Met5]enkephalin-like immunoreactivity (IR) (measured by direct RIA of tissue extracts), cryptic [Met5]enkephalin-like IR (calculated as the increase in [Met5]enkephalin-like IR detected in tissue extracts after sequential digestion with trypsin and carboxypeptidase B), and proenkephalin A mRNA were determined in adrenal medulla from rats sacrificed at various times after a period of insulin-induced hypoglycemia. Two hours of insulin hypoglycemia, which produced intense reflex stimulation of the splanchnic nerves as evidenced by a 55% decrease in the adrenal medulla catecholamine levels, resulted in a 3-fold increase in proenkephalin A mRNA levels in this tissue. The proenkephalin A mRNA levels reached a maximum 15-fold increase over control values 24 hr after this period of hypoglycemic stress and then gradually declined with an approximate half-life of 4 days. Native and cryptic [Met5]enkephalin-like IR had increased 9-fold and 12-fold, respectively, 24 hr after this period of hypoglycemia, and both demonstrated maximum increases of 130-fold and 50-fold, respectively, after 96 hr. Combined pretreatment (i.p. administration) with the ganglionic and muscarinic blocking agents chlorisondamine (5 mg/kg of body weight) and atropine (1 mg/kg) blocked the increase in levels of proenkephalin A mRNA seen in the rat adrenal medulla following insulin hypoglycemia. These data indicate that reflex splanchnic nerve discharge stimulates proenkephalin biosynthesis, probably at the level of gene expression. Images PMID:3538020

  9. CGRP Antagonist Infused into the Bed Nucleus of the Stria Terminalis Impairs the Acquisition and Expression of Context but Not Discretely Cued Fear

    ERIC Educational Resources Information Center

    Sink, Kelly S.; Davis, Michael; Walker, David L.

    2013-01-01

    Calcitonin gene-related peptide (CGRP) infusions into the bed nucleus of the stria terminalis (BNST) evoke increases in startle amplitude and increases in anxiety-like behavior in the plus maze. Conversely, intra-BNST infusions of the CGRP antagonist CGRP[subscript 8-37] block unconditioned startle increases produced by fox odor. Here we evaluate…

  10. ACS Chemical Neuroscience Molecule Spotlight on Telcagepant (MK-0974)

    PubMed Central

    2011-01-01

    Telcagepant (MK-0974) is a novel calcitonin gene-related peptide (CGRP) receptor antagonist currently undergoing clinical trials for migraine (http://www.merck.com/research/pipeline/home.html). MK-0974 is currently being studied in phase III clinical trials. PMID:22816019

  11. Identification of potent CNS-penetrant thiazolidinones as novel CGRP receptor antagonists.

    PubMed

    Joshi, Pramod; Anderson, Corey; Binch, Hayley; Hadida, Sabine; Yoo, Sanghee; Bergeron, Danielle; Decker, Caroline; terHaar, Ernst; Moore, Jonathan; Garcia-Guzman, Miguel; Termin, Andreas

    2014-02-01

    Calcitonin gene-related peptide (CGRP) has been implicated in acute migraine pathogenesis. In an effort to identify novel CGRP receptor antagonists for the treatment of migraine, we have discovered thiazolidinone 49, a potent (Ki=30 pM, IC50=1 nM), orally bioavailable, CNS-penetrant CGRP antagonist with good pharmacokinetic properties. PMID:24405707

  12. Antimicrobial peptides

    PubMed Central

    2014-01-01

    With increasing antibiotics resistance, there is an urgent need for novel infection therapeutics. Since antimicrobial peptides provide opportunities for this, identification and optimization of such peptides have attracted much interest during recent years. Here, a brief overview of antimicrobial peptides is provided, with focus placed on how selected hydrophobic modifications of antimicrobial peptides can be employed to combat also more demanding pathogens, including multi-resistant strains, without conferring unacceptable toxicity. PMID:24758244

  13. Comparison of Follicle-Stimulating Hormone Glycosylation Microheterogenity by Quantitative Negative Mode Nano-Electrospray Mass Spectrometry of Peptide-N Glycanase-Released Oligosaccharides

    PubMed Central

    Bousfield, George R.; Butnev, Vladimir Y.; White, William K.; Hall, Aaron Smalter; Harvey, David J.

    2015-01-01

    Glycans from six highly purified hFSH preparations were released by peptide-N-glycanase digestion and analyzed by negative mode nano-ESI mass spectrometry before and after neuraminidase digestion. Pituitary glycan structures were mainly high-mannose, di-, tri-, and tetra-antennary, and their abundance largely paralleled that reported by other investigators using different approaches. For most of the FSH preparations, the differences in glycosylation appeared to be restricted to relative abundances of the major glycan families, as defined by their neutral core oligosaccharide structures. Qualitative differences between glycan populations were largely relegated to those species that were lowest in abundance. Significant qualitative differences were noted in two cases. Recombinant GH3-hFSH triantennary glycans appeared to have the third antenna exclusively on the mannose6-branch, in contrast to all pituitary and urinary hFSH triantennary glycans, in which this antenna was exclusively attached to the mannose3-branch. The hypo-glycosylated hFSH preparation isolated from purified hLH was decorated with high mannose glycans that accounted for over 40% of the total in this population. As this preparation was found to be consistently 20-fold more active than hFSH24 in FSH receptor-binding assays, it appears that both macroheterogeneity and microheterogeneity in FSH preparations need to be taken into account. PMID:25960929

  14. Stimulation of glucagon-like peptide-1 receptor through exendin-4 preserves myocardial performance and prevents cardiac remodeling in infarcted myocardium

    PubMed Central

    DeNicola, Megan; Du, Jianfeng; Wang, Zhengke; Yano, Naohiro; Zhang, Ling; Wang, Yigang; Qin, Gangjian; Zhuang, Shougang

    2014-01-01

    We have demonstrated that GLP-1 improved myocardial functional recovery in acute myocardial ischemic injury. However, whether stimulation of the GLP-1 receptor (GLP-1R) with exendin-4, a selective GLP-1R agonist, could initiate a protective effect in the heart remains to be determined. Mouse myocardial infarction (MI) was created by ligation of the left descending artery. After 48 h of MI, animals were divided into the following groups (n = 5–7/group): 1) sham (animals that underwent thoracotomy without ligation), 2) MI [animals that underwent MI and received a daily dose of intraperitoneal injection (ip) of saline]; and 3) MI + exendin-4 [infarcted mice that received injections of exendin-4 (0.1 mg/kg ip)]. Two weeks later, cardiac function was assessed by echocardiography and an isovolumetrically perfused heart. Compared with control MI hearts, stimulation of GLP-1R improved cardiac function, which was associated with attenuation of myocardial hypertrophy, the mitigation of interstitial fibrosis, and an increase in survival rate in post-MI hearts. Furthermore, H9c2 cardiomyoblasts were preconditioned with exendin-4 at a dose of 100 nmol/l and then subjected to hydrogen peroxide exposure at concentrations of 50 and 100 μmol/l. The exendin-4 treatment decreased lactate dehydrogenase leakage and increased cell survival. Notably, this event was also associated with the reduction of cleaved caspase-3 and caspase-9 and attenuation of reactive oxygen species production. Exendin-4 treatments improved mitochondrial respiration and suppressed the opening of mitochondrial permeability transition pore and protected mitochondria function. Our results indicate that GLP-1R serves as a novel approach to eliciting cardioprotection and mitigating oxidative stress-induced injury. PMID:25117407

  15. Replacement of Lys Linker with Arg Linker Resulting in Improved Melanoma Uptake and Reduced Renal Uptake of Tc-99m-Labeled Arg-Gly-Asp-Conjugated Alpha-Melanocyte Stimulating Hormone Hybrid Peptide

    PubMed Central

    Yang, Jianquan; Guo, Haixun; Padilla, R. Steve; Berwick, Marianne; Miao, Yubin

    2010-01-01

    The purpose of this study was to reduce the non-specific renal uptake of Arg-Gly-Asp (RGD)-conjugated alpha-melanocyte stimulating hormone (α-MSH) hybrid peptide through structural modification or L-lysine co-injection. The RGD motif {cyclic(Arg-Gly-Asp-dTyr-Asp)} was coupled to [Cys3,4,10, d-Phe7, Arg11]α-MSH3-13 {(Arg11)CCMSH} through the Arg linker (substituting the Lys linker) to generate a novel RGD-Arg-(Arg11)CCMSH hybrid peptide. The melanoma targeting and pharmacokinetic properties of 99mTc-RGD-Arg-(Arg11)CCMSH were determined in B16/F1 melanoma-bearing C57 mice. The effect of L-lysine co-injection on the renal uptake was determined through the co-injection of L-lysine with 99mTc-RGD-Arg-(Arg11)CCMSH or 99mTc-RGD-Lys-(Arg11)CCMSH. Replacement of the Lys linker with an Arg linker exhibited a profound effect in reducing the non-specific renal uptake of 99mTc-RGD-Arg-(Arg11)CCMSH, as well as increasing the tumor uptake of 99mTc-RGD-Arg-(Arg11)CCMSH compared to 99mTc-RGD-Lys-(Arg11)CCMSH. 99mTc-RGD-Arg-(Arg11)CCMSH exhibited high tumor uptake (21.41 ± 3.74% ID/g at 2 h post-injection) and prolonged tumor retention (6.81 ± 3.71% ID/g at 24 h post-injection) in B16/F1 melanoma-bearing mice. The renal uptake values of 99mTc-RGD-Arg-(Arg11)CCMSH were 40.14-64.08% of those of 99mTc-RGD-Lys-(Arg11)CCMSH (p<0.05) at 0.5, 2, 4 and 24 h post-injection. Co-injection of L-lysine was effective in decreasing the renal uptakes of 99mTc-RGD-Arg-(Arg11)CCMSH by 27.7% and 99mTc-RGD-Lys-(Arg11)CCMSH by 52.1% at 2 h post-injection. Substitution of the Lys linker with an Arg linker dramatically improved the melanoma uptake and reduced the renal uptake of 99mTc-RGD-Arg-(Arg11)CCMSH, warranting the further evaluation of 188Re-labeled RGD-Arg-(Arg11)CCMSH as a novel MC1 receptor-targeting therapeutic peptide for melanoma treatment in the future. PMID:20728365

  16. All-trans retinoic acid stimulates gene expression of the cardioprotective natriuretic peptide system and prevents fibrosis and apoptosis in cardiomyocytes of obese ob/ob mice.

    PubMed

    Manolescu, Daniel-Constantin; Jankowski, Marek; Danalache, Bogdan A; Wang, Donghao; Broderick, Tom L; Chiasson, Jean-Louis; Gutkowska, Jolanta

    2014-10-01

    In hypertensive rodents, retinoic acid (RA) prevents adverse cardiac remodelling and improves myocardial infarction outcome, but its role in obesity-related changes of cardiac tissue are unclear. We hypothesized that all-trans RA (ATRA) treatment will improve the cardioprotective oxytocin-natriuretic peptides (OT-NP) system, preventing apoptosis and collagen accumulation in hearts of ob/ob mice, a mouse model of obesity and insulin resistance. Female 9-week-old B6.V-Lep/J ob/ob mice (n = 16) were divided into 2 groups: 1 group (n = 8) treated with 100 μg of ATRA dissolved in 100 μL of corn oil (vehicle) delivered daily (∼2 μg·g body weight(-1)·day(-1)) by stomach intubation for 16 days, and 1 group (n = 8) that received the vehicle alone. A group of nonobese littermate mice (n = 9) served as controls. Ob/ob mice exhibited obesity, hyperglycaemia, and downregulation of the cardiac OT-NP system, including the mRNA for the transcription factor GATA4, OT receptor and brain NP, and the protein expression for endothelial nitric oxide synthase. Hearts from ob/ob mice also demonstrated increased apoptosis and collagen accumulation. ATRA treatment induced weight loss and decreased adipocytes diameter in the visceral fat, thus reducing visceral obesity, which is associated with a high risk for cardiovascular disease. RA treatment was associated with a reduction in hyperglycemia and a normalization of the OT-NP system's expression in the hearts of ob/ob mice. Furthermore, ATRA treatment prevented apoptosis and collagen accumulation in hearts of ob/ob mice. The present study indicates that ATRA treatment was effective in restoring the cardioprotective OT-NP system and in preventing abnormal cardiac remodelling in the ob/ob mice. PMID:25017112

  17. Therapeutic Efficacy of a {sup 188}Re-Labeled {alpha}-Melanocyte-Stimulating Hormone Peptide Analog in Murine and Human Melanoma-Bearing Mouse Models

    SciTech Connect

    Miao, Yubin; Owen, Nellie K.; Fisher, Darrell R.; Hoffman, Timothy J.; Quinn, Thomas P.

    2005-01-01

    The purpose of this study was to examine the therapeutic efficacy of {sup 188}Re-(Arg{sup 11})CCMSH in the B16/F1 murine melanoma and TXM13 human melanoma bearing mouse models. Method: (Arg11)CCMSH was synthesized and labeled with {sup 188}Re to form {sup 188}Re-(Agr{sup 11})CCMSH. B16/F1 melanoma tumor bearing mice were administrated with 200 Ci, 600 Ci and 2x400 Ci of {sup 188}Re-(Arg{sup 11})CCMSH via the tail vein, respectively. TXM13 melanoma tumor hearing mice were separately injected with 600 Ci, 2x400 Ci and 1000 Ci of 100Re-(Arg{sup 11})CCMSH through the tail vein. Two groups of 10 mice bearing either B16/F1 or TXM13 tumors were injected with saline as untreated controls. Results: In contrast to the untreated control group, {sup 188}Re(Arg11)CCMSH yielded rapid and lasting therapeutic effects in the treatment groups with either B16/F1 or TXM13 tumors. The tumor growth rate was reduced and the survival rate was prolonged in the treatment groups. Treatment with 2x400 Ci of {sup 188}Re-Arg{sup 11}CCMSH significantly extended the mean life of B16/F1 tumor mice (p<0.05), while the mean life of TXm13 tumor mice was significantly prolonged after treatment with 600 Ci and 1000 Ci doses of {sup 188}Re-(Arg{sup 11})CCMSH (p<0.05 High-dose {sup 188}Re-(Arg{sup 11}))CCMSH produced no observed normal-tissue toxicity. Conclusions: The therapy study results revealed that {sup 188}Re-Arg11 CCMSH yielded significant therapeutic effects in both B16/F1 murine melanoma and TXM13 human melanoma bearing mouse models. {sup 188}Re-(Arg{sup 11})CCMSH appears to be a promising radiolabeled peptide for targeted radionuclide therapy of melanoma.

  18. GLP-1 Receptor Stimulation Reduces Amyloid-β Peptide Accumulation and Cytotoxicity in Cellular and Animal Models of Alzheimer’s Disease

    PubMed Central

    Li, Yazhou; Duffy, Kara B.; Ottinger, Mary Ann; Ray, Balmiki; Bailey, Jason A.; Holloway, Harold W.; Tweedie, David; Perry, TracyAnn; Mattson, Mark P.; Kapogiannis, Dimitrios; Sambamurti, Kumar; Lahiri, Debomoy K.; Greiga, Nigel H.

    2010-01-01

    Type 2 (T2) diabetes mellitus (DM) has been associated with an increased incidence of neurodegenerative disorders, including Alzheimer’s disease (AD). Several pathological features are shared between diabetes and AD, including dysfunctional insulin signaling and a dysregulation of glucose metabolism. It has therefore been suggested that not only may the two conditions share specific molecular mechanisms but also that agents with proven efficacy in one may be useful against the other. Hence, the present study characterized the effects of a clinically approved long-acting analogue, exendin-4 (Ex-4), of the endogenous insulin releasing incretin, glucagon-like peptide-1 (GLP-1), on stress-induced toxicity in neuronal cultures and on amyloid-β protein (Aβ) and tau levels in triple transgenic AD (3xTg-AD) mice with and without streptozocin (STZ)-induced diabetes. Ex-4 ameliorated the toxicity of Aβ and oxidative challenge in primary neuronal cultures and human SH-SY5Y cells in a concentration-dependent manner. When 11 to 12.5 month old female 3xTg AD mice were challenged with STZ or saline, and thereafter treated with a continuous subcutaneous infusion of Ex-4 or vehicle, Ex-4 ameliorated the diabetic effects of STZ in 3xTg-AD mice, elevating plasma insulin and lowering both plasma glucose and hemoglobin A1c (HbA1c) levels. Furthermore, brain levels of Aβ protein precursor and Aβ, which were elevated in STZ 3xTg-AD mice, were significantly reduced in Ex-4 treated mice. Brain tau levels were unaffected following STZ challenge, but showed a trend toward elevation that was absent following Ex-4 treatment. Together, these results suggest a potential value of Ex-4 in AD, particularly when associated with T2DM or glucose intolerance. PMID:20308787

  19. Identification of multifunctional peptides from human milk.

    PubMed

    Mandal, Santi M; Bharti, Rashmi; Porto, William F; Gauri, Samiran S; Mandal, Mahitosh; Franco, Octavio L; Ghosh, Ananta K

    2014-06-01

    Pharmaceutical industries have renewed interest in screening multifunctional bioactive peptides as a marketable product in health care applications. In this context, several animal and plant peptides with potential bioactivity have been reported. Milk proteins and peptides have received much attention as a source of health-enhancing components to be incorporated into nutraceuticals and functional foods. By using this source, 24 peptides have been fractionated and purified from human milk using RP-HPLC. Multifunctional roles including antimicrobial, antioxidant and growth stimulating activity have been evaluated in all 24 fractions. Nevertheless, only four fractions show multiple combined activities among them. Using a proteomic approach, two of these four peptides have been identified as lactoferrin derived peptide and kappa casein short chain peptide. Lactoferrin derived peptide (f8) is arginine-rich and kappa casein derived (f12) peptide is proline-rich. Both peptides (f8 and f12) showed antimicrobial activities against both Gram-positive and Gram-negative bacteria. Fraction 8 (f8) exhibits growth stimulating activity in 3T3 cell line and f12 shows higher free radical scavenging activity in comparison to other fractions. Finally, both peptides were in silico evaluated and some insights into their mechanism of action were provided. Thus, results indicate that these identified peptides have multiple biological activities which are valuable for the quick development of the neonate and may be considered as potential biotechnological products for nutraceutical industry. PMID:24703967

  20. A synthetic peptide corresponding to human FSH. beta. -subunit 33-53 binds to FSH receptor, stimulates basal estradiol biosynthesis, and is a partial antagonist of FSH

    SciTech Connect

    Santa Coloma, T.A.; Dattatreyamurty, B.; Reichert, L.E. Jr. )

    1990-02-06

    The authors have previously shown that hFSH-{beta} 34-37 (KTCT) and 49-52 (TRDL) inhibit binding of {sup 125}I-hFSH to FSH receptor in calf testis membranes and that hFSH-{beta} 33-53, which encompasses these tetrapeptides, inhibits binding with increased potency. hFSH-{beta} 33-53 rapidly dimerizes under conditions utilized in the receptor binding assay (pH 7.5) so that the binding inhibition reported earlier was due to the hFSH-{beta} 33-53 dimer rather than the monomer. At pH 6.5, conversion to dimer does not occur, and binding inhibition could be unequivocally attributed to the monomer. Radioiodinated and alkylated hFSH-{beta} 33-53 binds to the FSH receptor. The biological activity of hFSH-{beta} 33-53 was assessed by its ability to affect the conversion of androstenedione to estradiol in rat Sertoli cells cultures. This result demonstrates that the free R-SH group at Cys51 is not responsible for the inhibition. FSH-{beta} 33-53 also significantly stimulated basal levels of estradiol synthesis, but not to maximal levels observed with FSH (partial agonist). Neither the carbohydrate content of hFSH-{beta} nor the {alpha} subunit of FSH appears to be essential for signal transduction and expression of the hormone effect of FSH-{beta} 33-53.

  1. Lipolysis stimulating peptides of potato protein hydrolysate effectively suppresses high-fat-diet-induced hepatocyte apoptosis and fibrosis in aging rats

    PubMed Central

    Chiang, Wen-Dee; Huang, Chih Yang; Paul, Catherine Reena; Lee, Zong-Yan; Lin, Wan-Teng

    2016-01-01

    Background Non-alcoholic fatty liver disease (NAFLD) is one of the most common outcomes of obesity and is characterized by the accumulation of triglycerides, increased tissue apoptosis, and fibrosis. NAFLD is more common among elderly than in younger age groups, and it causes serious hepatic complications. Objective In this study, alcalase treatment derived potato protein hydrolysate (APPH) with lipolysis-stimulating property has been evaluated for its efficiency to provide hepato-protection in a high-fat-diet (HFD)-fed aging rats. Design Twenty-four-month-old SD rats were randomly divided into six groups (n=8): aged rats fed with standard chow, HFD-induced aged obese rats, HFD with low-dose (15 mg/kg/day) APPH treatment, HFD with moderate (45 mg/kg/day) APPH treatment, HFD with high (75 mg/kg/day) APPH treatment, and HFD with probucol. Results APPH was found to reduce the NAFLD-related effects in rat livers induced by HFD and all of the HFD-fed rats exhibited heavier body weight than those with control chow diet. However, the HFD-induced hepatic fat accumulation was effectively attenuated in rats administered with low (15 mg/kg/day), moderate (45 mg/kg/day), and high (75 mg/kg/day) doses of APPH. APPH oral administration also suppressed the hepatic apoptosis- and fibrosis-related proteins induced by HFD. Conclusions Our results thus indicate that APPH potentially attenuates hepatic lipid accumulation and anti-apoptosis and fibrosis effects in HFD-induced rats. APPH may have therapeutic potential in the amelioration of NAFLD liver damage. PMID:27415158

  2. Peptide Seems to Boost Human Memory.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1981

    1981-01-01

    This article discusses recent studies which have shown that the peptide hormone vasopressin apparently can stimulate memory and learning in healthy human volunteers and in certain mentally disturbed patients. (ECO)

  3. Amyloid β-peptide oligomers stimulate RyR-mediated Ca2+ release inducing mitochondrial fragmentation in hippocampal neurons and prevent RyR-mediated dendritic spine remodeling produced by BDNF.

    PubMed

    Paula-Lima, Andrea C; Adasme, Tatiana; SanMartín, Carol; Sebollela, Adriano; Hetz, Claudio; Carrasco, M Angélica; Ferreira, Sergio T; Hidalgo, Cecilia

    2011-04-01

    Soluble amyloid β-peptide oligomers (AβOs), increasingly recognized as causative agents of Alzheimer's disease (AD), disrupt neuronal Ca(2+) homeostasis and synaptic function. Here, we report that AβOs at sublethal concentrations generate prolonged Ca(2+) signals in primary hippocampal neurons; incubation in Ca(2+)-free solutions, inhibition of ryanodine receptors (RyRs) or N-methyl-d-aspartate receptors (NMDARs), or preincubation with N-acetyl-l-cysteine abolished these signals. AβOs decreased (6 h) RyR2 and RyR3 mRNA and RyR2 protein, and promoted mitochondrial fragmentation after 24 h. NMDAR inhibition abolished the RyR2 decrease, whereas RyR inhibition prevented significantly the RyR2 protein decrease and mitochondrial fragmentation induced by AβOs. Incubation with AβOs (6 h) eliminated the RyR2 increase induced by brain-derived nerve factor (BDNF) and the dendritic spine remodeling induced within minutes by BDNF or the RyR agonist caffeine. Addition of BDNF to neurons incubated with AβOs for 24 h, which had RyR2 similar to and slightly higher RyR3 protein content than those of controls, induced dendritic spine growth but at slower rates than in controls. These combined effects of sublethal AβOs concentrations (which include redox-sensitive stimulation of RyR-mediated Ca(2+) release, decreased RyR2 protein expression, mitochondrial fragmentation, and prevention of RyR-mediated spine remodeling) may contribute to impairing the synaptic plasticity in AD. PMID:20712397

  4. Ultrashort Antimicrobial Peptides with Antiendotoxin Properties

    PubMed Central

    Chih, Ya-Han; Lin, Yen-Shan; Yip, Bak-Sau; Wei, Hsiu-Ju; Chu, Hung-Lun; Yu, Hui-Yuan; Cheng, Hsi-Tsung

    2015-01-01

    Release of lipopolysaccharide (LPS) (endotoxin) from bacteria into the bloodstream may cause serious unwanted stimulation of the host immune system. Some but not all antimicrobial peptides can neutralize LPS-stimulated proinflammatory responses. Salt resistance and serum stability of short antimicrobial peptides can be boosted by adding β-naphthylalanine to their termini. Herein, significant antiendotoxin effects were observed in vitro and in vivo with the β-naphthylalanine end-tagged variants of the short antimicrobial peptides S1 and KWWK. PMID:26033727

  5. Peptide identification

    DOEpatents

    Jarman, Kristin H [Richland, WA; Cannon, William R [Richland, WA; Jarman, Kenneth D [Richland, WA; Heredia-Langner, Alejandro [Richland, WA

    2011-07-12

    Peptides are identified from a list of candidates using collision-induced dissociation tandem mass spectrometry data. A probabilistic model for the occurrence of spectral peaks corresponding to frequently observed partial peptide fragment ions is applied. As part of the identification procedure, a probability score is produced that indicates the likelihood of any given candidate being the correct match. The statistical significance of the score is known without necessarily having reference to the actual identity of the peptide. In one form of the invention, a genetic algorithm is applied to candidate peptides using an objective function that takes into account the number of shifted peaks appearing in the candidate spectrum relative to the test spectrum.

  6. [Brain natriuretic peptide].

    PubMed

    La Villa, G; Lazzeri, C; Fronzaroli, C; Franchi, F; Gentilini, P

    1995-01-01

    Brain natriuretic peptide (BNP) is a cardiac hormone with a spectrum of activities quite similar to those of atrial natriuretic peptide (ANP), including diuretic, natriuretic, hypotensive and smooth muscle relaxant activities. These effects are due to the stimulation of guanylate cyclase-linked natriuretic peptide receptors, leading to an increase in cyclic GMP concentration in target cells. BNP has a lower affinity than ANP for C (clearance) receptors, and is less susceptible to degradation by neutral endopeptidase-24.11, resulting in a longer half-life. In the kidney, BNP increases the glomerular filtration rate and inhibits sodium reabsorption in the distal tubule. It also inhibits the release of renin and aldosterone. Unlike ANP, produced by the atria, BNP is mainly synthesized and released into circulation by the left ventricle and is therefore influenced by stimuli involving this cardiac chamber, such as an increase in arterial pressure, left ventricular hypertrophy and dilation. Plasma BNP levels are very low in healthy subjects, and respond modestly, although significantly to physiological stimuli such as changes in posture or sodium intake. In contrast, plasma BNP concentrations increase in disease states such as cirrhosis with ascites, hypertension, chronic renal failure, acute myocardial infarction and congestive heart failure. In the latter condition, plasma BNP concentration is a reliable prognostic index. Evidence obtained by administering BNP to healthy subjects and hypertensive patients suggests that BNP, at physiological and pathophysiological plasma concentrations, markedly influences cardiovascular homeostasis, mainly due to its effects on sodium excretion and the renin-aldosterone axis. PMID:8718658

  7. Peptides and food intake.

    PubMed

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  8. Peptides and Food Intake

    PubMed Central

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  9. Peptide agonists of the thrombopoietin receptor.

    PubMed

    Dower, W J; Cwirla, S E; Balasubramanian, P; Schatz, P J; Baccanari, D P; Barrett, R W

    1998-01-01

    We have screened a variety of L-amino acid peptide libraries against the extracellular domain of the human thrombopoietin (HuTPO) receptor, c-Mpl. A large number of peptide ligands were recovered and categorized into two families. Peptides from each family compete with the binding of HuTPO and with the binding of peptides from the other familiy. Representative peptides were synthesized and found to activate the full-length HuTPO receptor expressed in Ba/F3 cells to promote proliferation. These peptide families show no apparent homology to the primary sequence of TPO. We have focused our optimization efforts on one of the peptides, a linear 14-mer (IEGPTLRQWLAARA) with an IC50 of 2 nM in a competition binding assay and an EC50 of 400 nM in the proliferation assay. In order to enhance the potency of the compound, we constructed dimeric peptides by linking the carboxy-termini of the 14-mers to a lysine branch. These molecules exhibited slightly higher affinity (0.5 nM) and greatly increased potency (0.1 nM). The EC50 of the dimeric peptide was equivalent to that of the 332 aa form of baculovirus-expressed recombinant HuTPO. As previously shown for the erythropoietin-mimetic peptides, the TPO-mimetic peptides probably activate the TPO receptor by binding and inducing receptor dimerization. This supposition is supported by the observation that covalent dimerization of the peptide enhances its potency by 4,000-fold over that of the monomer. The peptide dimer is also active in stimulating in vitro proliferation of progenitors and maturation of megakaryocytes from human bone marrow, and in promoting an increase in platelet count when administered to normal mice. PMID:11012174

  10. Antimicrobial peptides.

    PubMed

    Zhang, Ling-Juan; Gallo, Richard L

    2016-01-11

    Antimicrobial peptides and proteins (AMPs) are a diverse class of naturally occurring molecules that are produced as a first line of defense by all multicellular organisms. These proteins can have broad activity to directly kill bacteria, yeasts, fungi, viruses and even cancer cells. Insects and plants primarily deploy AMPs as an antibiotic to protect against potential pathogenic microbes, but microbes also produce AMPs to defend their environmental niche. In higher eukaryotic organisms, AMPs can also be referred to as 'host defense peptides', emphasizing their additional immunomodulatory activities. These activities are diverse, specific to the type of AMP, and include a variety of cytokine and growth factor-like effects that are relevant to normal immune homeostasis. In some instances, the inappropriate expression of AMPs can also induce autoimmune diseases, thus further highlighting the importance of understanding these molecules and their complex activities. This Primer will provide an update of our current understanding of AMPs. PMID:26766224

  11. Peptide arrays for screening cancer specific peptides.

    PubMed

    Ahmed, Sahar; Mathews, Anu Stella; Byeon, Nara; Lavasanifar, Afsaneh; Kaur, Kamaljit

    2010-09-15

    In this paper, we describe a novel method to screen peptides for specific recognition by cancer cells. Seventy peptides were synthesized on a cellulose membrane in an array format, and a direct method to study the peptide-whole cell interaction was developed. The relative binding affinity of the cells for different peptides with respect to a lead 12-mer p160 peptide, identified by phage display, was evaluated using the CyQUANT fluorescence of the bound cells. Screening allowed identification of at least five new peptides that displayed higher affinity (up to 3-fold) for MDA-MB-435 and MCF-7 human cancer cells compared to the p160 peptide. These peptides showed very little binding to the control (noncancerous) human umbilical vein endothelial cells (HUVECs). Three of these peptides were synthesized separately and labeled with fluorescein isothiocyanate (FITC) to study their uptake and interaction with the cancer and control cells using confocal laser scanning microscopy and flow cytometry. The results confirmed the high and specific affinity of an 11-mer peptide 11 (RGDPAYQGRFL) and a 10-mer peptide 18 (WXEAAYQRFL) for the cancer cells versus HUVECs. Peptide 11 binds different receptors on target cancer cells as its sequence contains multiple recognition motifs, whereas peptide 18 binds mainly to the putative p160 receptor. The peptide array-whole cell binding assay reported here is a complementary method to phage display for further screening and optimization of cancer targeting peptides for cancer therapy and diagnosis. PMID:20799711

  12. Intracellular signalling by C-peptide.

    PubMed

    Hills, Claire E; Brunskill, Nigel J

    2008-01-01

    C-peptide, a cleavage product of the proinsulin molecule, has long been regarded as biologically inert, serving merely as a surrogate marker for insulin release. Recent findings demonstrate both a physiological and protective role of C-peptide when administered to individuals with type I diabetes. Data indicate that C-peptide appears to bind in nanomolar concentrations to a cell surface receptor which is most likely to be G-protein coupled. Binding of C-peptide initiates multiple cellular effects, evoking a rise in intracellular calcium, increased PI-3-kinase activity, stimulation of the Na(+)/K(+) ATPase, increased eNOS transcription, and activation of the MAPK signalling pathway. These cell signalling effects have been studied in multiple cell types from multiple tissues. Overall these observations raise the possibility that C-peptide may serve as a potential therapeutic agent for the treatment or prevention of long-term complications associated with diabetes. PMID:18382618

  13. Immunoreactive opioid peptides in human breast cancer.

    PubMed Central

    Scopsi, L.; Balslev, E.; Brünner, N.; Poulsen, H. S.; Andersen, J.; Rank, F.; Larsson, L. I.

    1989-01-01

    Opioid peptides have a variety of actions on inter alia pituitary hormone secretion and the immune system. Release of endogenous opioids has been found to stimulate growth of experimental breast cancers and opiate receptor blockers have reduced the growth of chemically induced rat breast tumors. Opioid peptides may therefore play a role in human breast cancer. Invasive ductal carcinomas from 61 premenopausal women were immunocytochemically analyzed for the presence of opioid peptide immunoreactivity. Positive staining was unambiguously identified in 34 of the tumors (56%). In addition, a medullary carcinoma was positive. In a smaller series of tumors, opioid peptide immunoreactive cells were detected in both primary tumors and metastases. Positive tumor cells were usually few and scattered. Therefore, underestimates of their true frequency of occurrence are likely to have occurred, making accurate correlations with clinical behavior and estrogen receptor status difficult. No correlations with estrogen receptors were established for the unambiguously opioid peptide-positive tumors. Many of the positive tumors also stained with antibodies to gamma-endorphin and alpha-melanocyte-stimulating hormone, suggesting the presence of proopiomelanocortin-derived peptides in them. However, peptides derived from other opioid precursors also may be present in breast cancer. Images Figure 1 PMID:2464945

  14. Immunogenicity of GX301 cancer vaccine: Four (telomerase peptides) are better than one

    PubMed Central

    Fenoglio, Daniela; Parodi, Alessia; Lavieri, Rosa; Kalli, Francesca; Ferrera, Francesca; Tagliamacco, Augusto; Guastalla, Andrea; Lamperti, Maria Giuseppina; Giacomini, Mauro; Filaci, Gilberto

    2015-01-01

    Peptide540–548, peptide611–626, peptide672–686 and peptide766–780, which are derived from human telomerase, constitute the immunogenic component of the GX301 cancer vaccine. The relative immunogenicity of these peptides is unknown, thus it is unsure whether their combined use offers real advantages over single peptide stimulation. Hence, this study compared the number of specific immune responses and responders to each peptide, as well as to their mixture (meaning the co-presence of the 4 peptides in the same culture well), achieved after ex vivo stimulation of PBMC from 21, HLA-A2+ (n.11) or HLA-A2- (n.10), healthy donors. The study was performed on freshly collected PBMC (T0) and on PBMC stimulated for 10 d with single peptides or their mixture (T1). Peptide-specific immune responses were analyzed by Elispot and cytokine intracellular staining by flow cytometry. The results showed that each peptide induced specific immune responses in some subjects, with different panels of responders among the peptides. Moreover, the numbers of responses and responders to the single peptides or their mixture were comparable. Importantly, the overall number of responders to the 4 peptides was higher than to each single peptide, or to their mixture, both at T0 and T1. These data demonstrate the immunogenicity of each of the 4 GX301 telomerase peptides. Moreover, they show the advantage of multi-peptide over single peptide stimulation, providing a clear support to their combined administration in vaccination protocols. However, the data pose a warning against peptide administration as a mixture due to possible interference phenomena during antigen presentation processes. PMID:25714118

  15. The role of histamine in neurogenic inflammation

    PubMed Central

    Rosa, A C; Fantozzi, R

    2013-01-01

    The term ‘neurogenic inflammation’ has been adopted to describe the local release of inflammatory mediators, such as substance P and calcitonin gene-related peptide, from neurons. Once released, these neuropeptides induce the release of histamine from adjacent mast cells. In turn, histamine evokes the release of substance P and calcitonin gene-related peptide; thus, a bidirectional link between histamine and neuropeptides in neurogenic inflammation is established. The aim of this review is to summarize the most recent findings on the role of histamine in neurogenic inflammation, with particular regard to nociceptive pain, as well as neurogenic inflammation in the skin, airways and bladder. Linked Articles This article is part of a themed issue on Histamine Pharmacology Update. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2013.170.issue-1 PMID:23734637

  16. C-Peptide Test

    MedlinePlus

    ... C-peptide is a useful marker of insulin production. The following are some purposes of C-peptide ... it nearly impossible to directly evaluate endogenous insulin production. In these cases, C-peptide measurement is a ...

  17. Hydrophobic peptide auxotrophy in Salmonella typhimurium.

    PubMed Central

    Brãnes, L V; Somers, J M; Kay, W W

    1981-01-01

    The growth of a pleiotropic membrane mutant of Salmonella typhimurium with modified lipopolysaccharide composition was found to be strictly dependent on the peptone component of complex media. Nutritional Shiftdown into minimal media allowed growth for three to four generations. Of 20 commercial peptones, only enzymatic digests supported growth to varying degrees. Neither trace cations, amino acids, vitamins, carbohydrates, lipids, glutathione, polyamines, carbodimides, nor synthetic peptides stimulated growth; however, cells still metabolized carbohydrates, and amino acid transport systems were shown to be functional. A tryptic digest of casein was fractionated into four electrophoretically different peptide fractions of 1,000 to 1,200 molecular weight which supported growth to varying degrees. The best of these was further fractionated to two highly hydrophopic peptides. N-terminal modifications eliminated biological activity. Fluorescein-conjugated goat antibody to rabbit immunoglobulin G was used as a probe to detect antipeptide antibody-peptide complexes on membrane preparations. Cells grown on peptone distributed the peptide into both inner and outer membranes. The peptide could be removed with chaotropic agents, and cells had to be pregrown in peptone-containing media to bind the hydrophobic peptide. The gene (hyp) responsible for peptide auxotrophy was mapped at 44 to 45 units by conjugation. Images PMID:7024254

  18. Electrically evoked neuropeptide release and neurogenic inflammation differ between rat and human skin.

    PubMed

    Sauerstein, K; Klede, M; Hilliges, M; Schmelz, M

    2000-12-15

    Protein extravasation and vasodilatation can be induced by neuropeptides released from nociceptive afferents (neurogenic inflammation). We measured electrically evoked neuropeptide release and concomitant protein extravasation in human and rat skin using intradermal microdialysis. Plasmapheresis capillaries were inserted intradermally at a length of 1.5 cm in the volar forearm of human subjects or abdominal skin of rats. Capillaries were perfused with Ringer solution at a flow rate of 2.5 or 1.6 microl min(-1). After a baseline period of 60 min capillaries were stimulated electrically (1 Hz, 80 mA, 0.5 ms or 4 Hz, 30 mA, 0.5 ms) for 30 min using a surface electrode directly above the capillaries and a stainless-steel wire inserted in the capillaries. Total protein concentration was assessed photometrically and calcitonin gene-related peptide (CGRP) and substance P (SP) concentrations were measured by enzyme-linked immunosorbent assay (ELISA). In rat skin, electrical stimulation increased CGRP and total protein concentration in the dialysate. SP measurements showed a larger variance but only for the 1 Hz stimulation was the increased release significant. In human skin, electrical stimulation provoked a large flare reaction and at a frequency of 4 Hz both CGRP and SP concentrations increased significantly. In spite of the large flare reactions no protein extravasation was induced, which suggests major species differences. It will be of interest to investigate whether the lack of neurogenic protein extravasation is also valid under pathophysiological conditions. PMID:11118507

  19. Electrically evoked neuropeptide release and neurogenic inflammation differ between rat and human skin

    PubMed Central

    Sauerstein, Katja; Klede, Monika; Hilliges, Marita; Schmelz, Martin

    2000-01-01

    Protein extravasation and vasodilatation can be induced by neuropeptides released from nociceptive afferents (neurogenic inflammation). We measured electrically evoked neuropeptide release and concomitant protein extravasation in human and rat skin using intradermal microdialysis. Plasmapheresis capillaries were inserted intradermally at a length of 1.5 cm in the volar forearm of human subjects or abdominal skin of rats. Capillaries were perfused with Ringer solution at a flow rate of 2.5 or 1.6 μl min−1. After a baseline period of 60 min capillaries were stimulated electrically (1 Hz, 80 mA, 0.5 ms or 4 Hz, 30 mA, 0.5 ms) for 30 min using a surface electrode directly above the capillaries and a stainless-steel wire inserted in the capillaries. Total protein concentration was assessed photometrically and calcitonin gene-related peptide (CGRP) and substance P (SP) concentrations were measured by enzyme-linked immunosorbent assay (ELISA). In rat skin, electrical stimulation increased CGRP and total protein concentration in the dialysate. SP measurements showed a larger variance but only for the 1 Hz stimulation was the increased release significant. In human skin, electrical stimulation provoked a large flare reaction and at a frequency of 4 Hz both CGRP and SP concentrations increased significantly. In spite of the large flare reactions no protein extravasation was induced, which suggests major species differences. It will be of interest to investigate whether the lack of neurogenic protein extravasation is also valid under pathophysiological conditions. PMID:11118507

  20. Effects of Hange-koboku-to (Banxia-houpo-tang) on neuropeptide levels in human plasma and saliva.

    PubMed

    Naito, Takafumi; Itoh, Hiroki; Takeyama, Masaharu

    2003-11-01

    Hange-koboku-to (Banxia-houpo-tang), a Chinese herbal (Kampo) medicine, has been used for improvement of hoarse voice, something foreign body sensation in the throat and/or esophagus, and swallowing reflex, among other conditions. One of the mechanisms of the empirical effects is assumed to be due to local changes in neuropeptide levels locally. We investigated the effects of Hange-koboku-to on neuropeptides, calcitonin gene-related peptide (CGRP), substance P, somatostatin, and vasoactive intestinal peptide (VIP) in plasma and saliva, as well as on salivary secretion in healthy subjects. A single oral administration of Hange-koboku-to caused significant increases in substance P-immunoreactive substance (IS) (40 min) in plasma, and slightly increased in CGRP-IS and somatostatin-IS in plasma compared with placebo. In saliva neuropeptides, Hange-koboku-to caused significant increases in substance P-IS (20 min) and somatostatin-IS (40, 60 min), and a slight increase in VIP-IS. However, a single Hange-koboku-to stimulation did not have a significant effect of sialosis volume. These results seem to suggest that Hange-koboku-to improves hoarse voice, something foreign body sensation in the throat and esophagus, and swallowing reflex disorder, by stimulation of neuropeptidergic nerves locally. PMID:14600411

  1. Dendroaspis natriuretic peptide binds to the natriuretic peptide clearance receptor

    SciTech Connect

    Johns, Douglas G. . E-mail: Douglas.G.Johns@gsk.com; Ao, Zhaohui; Heidrich, Bradley J.; Hunsberger, Gerald E.; Graham, Taylor; Payne, Lisa; Elshourbagy, Nabil; Lu, Quinn; Aiyar, Nambi; Douglas, Stephen A.

    2007-06-22

    Dendroaspis natriuretic peptide (DNP) is a newly-described natriuretic peptide which lowers blood pressure via vasodilation. The natriuretic peptide clearance receptor (NPR-C) removes natriuretic peptides from the circulation, but whether DNP interacts with human NPR-C directly is unknown. The purpose of this study was to test the hypothesis that DNP binds to NPR-C. ANP, BNP, CNP, and the NPR-C ligands AP-811 and cANP(4-23) displaced [{sup 125}I]-ANP from NPR-C with pM-to-nM K {sub i} values. DNP displaced [{sup 125}I]-ANP from NPR-C with nM potency, which represents the first direct demonstration of binding of DNP to human NPR-C. DNP showed high pM affinity for the GC-A receptor and no affinity for GC-B (K {sub i} > 1000 nM). DNP was nearly 10-fold more potent than ANP at stimulating cGMP production in GC-A expressing cells. Blockade of NPR-C might represent a novel therapeutic approach in augmenting the known beneficial actions of DNP in cardiovascular diseases such as hypertension and heart failure.

  2. [Immune stimulative potency of milk proteins].

    PubMed

    Ambroziak, Adam; Cichosz, Grazyna

    2014-02-01

    Milk proteins are characterized by the highest immune stimulative potency from among all the proteins present in human diet. Whey proteins and numerous growth factors that regulate insulin secretion, differentiation of intestine epithelium cells, and also tissue restoration, are priceless in stimulation the immune system. Lactoferrin shows the most comprehensive pro-health properties: antioxidative, anticancer, immune stimulative and even chemopreventive. Also peptides and amino acids formed from casein and whey proteins possess immune stimulative activity. The most valuable proteins, i.e. lactoferrin, immune globulins, lactoperoxidase and lisozyme, together with bioactive peptides, are resistant to pepsin and trypsin activity. This is why they maintain their exceptional biological activity within human organism. Properly high consumption of milk proteins conditions correct function of immune system, especially at children and elderly persons. PMID:24720113

  3. Parthenolide inhibits nociception and neurogenic vasodilatation in the trigeminovascular system by targeting TRPA1 channel

    PubMed Central

    Materazzi, Serena; Benemei, Silvia; Fusi, Camilla; Gualdani, Roberta; De Siena, Gaetano; Vastani, Nisha; Andersson, David A.; Trevisan, Gabriela; Moncelli, Maria Rosa; Wei, Xiaomei; Dussor, Gregory; Pollastro, Federica; Patacchini, Riccardo; Appendino, Giovanni; Geppetti, Pierangelo; Nassini, Romina

    2013-01-01

    While feverfew has been used for centuries to treat pain and headaches and is recommended for migraine treatment, the mechanism for its protective action remains unknown. Migraine is triggered by calcitonin gene-related peptide (CGRP) release from trigeminal neurons. Peptidergic sensory neurons, express a series of transient receptor potential (TRP) channels, including the ankyrin 1 (TRPA1) channel. Recent findings have identified agents either inhaled from the environment or produced endogenously, which are known to trigger migraine or cluster headache attacks, as TRPA1 simulants. A major constituent of feverfew, parthenolide, may interact with TRPA1 nucleophilic sites, suggesting that feverfew antimigraine effect derives from its ability to target TRPA1. We found that parthenolide stimulates recombinant (transfected cells) or natively expressed (rat/mouse trigeminal neurons) TRPA1, where it, however, behaves as a partial agonist. Furthermore, in rodents, after initial stimulation, parthenolide desensitizes the TRPA1 channel, and renders peptidergic, TRPA1-expressing nerve terminals unresponsive to any stimulus. This effect of parthenolide abrogates nociceptive responses evoked by stimulation of peripheral trigeminal endings. TRPA1 targeting and neuronal desensitization by parthenolide inhibits CGRP release from trigeminal neurons and CGRP-mediated meningeal vasodilatation, evoked by either TRPA1 agonists or other unspecific stimuli. TRPA1 partial agonism, together with desensitization and nociceptor defunctionalization, ultimately resulting in inhibition of CGRP release within the trigeminovascular system, may contribute to the antimigraine effect of parthenolide. PMID:23933184

  4. Antimicrobial peptides in human skin disease

    PubMed Central

    Kenshi, Yamasaki; Richard, L. Gallo

    2009-01-01

    The skin continuously encounters microbial pathogens. To defend against this, cells of the epidermis and dermis have evolved several innate strategies to prevent infection. Antimicrobial peptides are one of the primary mechanisms used by the skin in the early stages of immune defense. In general, antimicrobial peptides have broad antibacterial activity against gram-positive and negative bacteria and also show antifungal and antiviral activity. The antimicrobial activity of most peptides occurs as a result of unique structural characteristics that enable them to disrupt the microbial membrane while leaving human cell membranes intact. However, antimicrobial peptides also act on host cells to stimulate cytokine production, cell migration, proliferation, maturation, and extracellular matrix synthesis. The production by human skin of antimicrobial peptides such as defensins and cathelicidins occurs constitutively but also greatly increases after infection, inflammation or injury. Some skin diseases show altered expression of antimicrobial peptides, partially explaining the pathophysiology of these diseases. Thus, current research suggests that understanding how antimicrobial peptides modify susceptibility to microbes, influence skin inflammation, and modify wound healing, provides greater insight into the pathophysiology of skin disorders and offers new therapeutic opportunities. PMID:18086583

  5. C-Peptide and its intracellular signaling.

    PubMed

    Hills, Claire E; Brunskill, Nigel J

    2009-01-01

    Although long believed to be inert, C-peptide has now been shown to have definite biological effects both in vitro and in vivo in diabetic animals and in patients with type 1 diabetes. These effects point to a protective action of C-peptide against the development of diabetic microvascular complications. Underpinning these observations is undisputed evidence of C-peptide binding to a variety of cell types at physiologically relevant concentrations, and the downstream stimulation of multiple cell signaling pathways and gene transcription via the activation of numerous transcription factors. These pathways affect such fundamental cellular processes as re-absorptive and/or secretory phenotype, migration, growth, and survival. Whilst the receptor remains to be identified, experimental data points strongly to the existence of a specific G-protein-coupled receptor for C-peptide. Of the cell types studied so far, kidney tubular cells express the highest number of C-peptide binding sites. Accordingly, C-peptide exerts major effects on the function of these cells, and in the context of diabetic nephropathy appears to antagonise the pathophysiological effects of major disease mediators such as TGFbeta1 and TNFalpha. Therefore, based on its cellular activity profile C-peptide appears well positioned for development as a therapeutic tool to treat microvascular complications in type 1 diabetes. PMID:20039003

  6. A Novel Retro-Inverso Peptide Inhibitor Reduces Amyloid Deposition, Oxidation and Inflammation and Stimulates Neurogenesis in the APPswe/PS1ΔE9 Mouse Model of Alzheimer’s Disease

    PubMed Central

    Parthsarathy, Vadivel; McClean, Paula L.; Hölscher, Christian; Taylor, Mark; Tinker, Claire; Jones, Glynn; Kolosov, Oleg; Salvati, Elisa; Gregori, Maria; Masserini, Massimo; Allsop, David

    2013-01-01

    Previously, we have developed a retro-inverso peptide inhibitor (RI-OR2, rGffvlkGr) that blocks the in vitro formation and toxicity of the Aβ oligomers which are thought to be a cause of neurodegeneration and memory loss in Alzheimer’s disease. We have now attached a retro-inverted version of the HIV protein transduction domain ‘TAT’ to RI-OR2 to target this new inhibitor (RI-OR2-TAT, Ac-rGffvlkGrrrrqrrkkrGy-NH2) into the brain. Following its peripheral injection, a fluorescein-labelled version of RI-OR2-TAT was found to cross the blood brain barrier and bind to the amyloid plaques and activated microglial cells present in the cerebral cortex of 17-months-old APPswe/PS1ΔE9 transgenic mice. Daily intraperitoneal injection of RI-OR2-TAT (at 100 nmol/kg) for 21 days into 10-months-old APPswe/PS1ΔE9 mice resulted in a 25% reduction (p<0.01) in the cerebral cortex of Aβ oligomer levels, a 32% reduction (p<0.0001) of β-amyloid plaque count, a 44% reduction (p<0.0001) in the numbers of activated microglial cells, and a 25% reduction (p<0.0001) in oxidative damage, while the number of young neurons in the dentate gyrus was increased by 210% (p<0.0001), all compared to control APPswe/PS1ΔE9 mice injected with vehicle (saline) alone. Our data suggest that oxidative damage, inflammation, and inhibition of neurogenesis are all a downstream consequence of Aβ aggregation, and identify a novel brain-penetrant retro-inverso peptide inhibitor of Aβ oligomer formation for further testing in humans as a potential disease-modifying treatment for Alzheimer’s disease. PMID:23382963

  7. Infant Stimulation.

    ERIC Educational Resources Information Center

    International Children's Centre, Paris (France).

    This set of documents consists of English, French, and Spanish translations of four pamphlets on infant stimulation. The pamphlets provide information designed for lay persons, educators and primary care personnel, academics and professionals, and for health administrators and family-planning organizations. The contents cover infant needs; infant…

  8. The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats

    PubMed Central

    Kim, Youngkyung; Kim, Eun-hye; Lee, Kyu Sang; Lee, Koeun; Park, Sung Ho; Na, Sook Hyun; Ko, Cheolwoong; Yooon, Young Wook

    2016-01-01

    This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, 8 mg/50 µl) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord. PMID:26807032

  9. Sensory neuropeptides and airway function.

    PubMed

    Solway, J; Leff, A R

    1991-12-01

    Sensory nerves synthesize tachykinins and calcitonin-gene related peptide and package these neuropeptides together in synaptic vesicles. Stimulation of these C-fibers by a range of chemical and physical factors results in afferent neuronal conduction that elicits central parasympathetic reflexes and in antidromic conduction that results in local release of neuropeptides through the axon reflex. In the airways, sensory neuropeptides act on bronchial smooth muscle, the mucosal vasculature, and submucosal glands to promote airflow obstruction, hyperemia, microvascular hyperpermeability, and mucus hypersecretion. In addition, tachykinins potentiate cholinergic neurotransmission. Proinflammatory effects of these peptides also promote the recruitment, adherence, and activation of granulocytes that may further exacerbate neurogenic inflammation (i.e., neuropeptide-induced plasma extravasation and vasodilation). Enzymatic degradation limits the physiological effects of tachykinins but may be impaired by respiratory infection or other factors. Given their sensitivity to noxious compounds and physical stimuli and their potent effects on airway function, it is possible that neuropeptide-containing sensory nerves play an important role in mediating airway responses in human disease. Supporting this view are the striking phenomenological similarities between hyperpnea-induced bronchoconstriction (HIB) in guinea pigs and HIB in patients with exercise-induced asthma. Endogenous tachykinins released from airway sensory nerves mediate HIB in guinea pigs and also cause hyperpnea-induced bronchovascular hyperpermeability in these animals. On the basis of these observations, it is reasonable to speculate that sensory neuropeptides participate in the pathogenesis of hyperpnea-induced airflow obstruction in human asthmatic subjects as well. PMID:1663932

  10. The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats.

    PubMed

    Kim, Youngkyung; Kim, Eun-Hye; Lee, Kyu Sang; Lee, Koeun; Park, Sung Ho; Na, Sook Hyun; Ko, Cheolwoong; Kim, Junesun; Yooon, Young Wook

    2016-01-01

    This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, 8 mg/50 µl) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord. PMID:26807032

  11. Small peptides as potent mimetics of the protein hormone erythropoietin.

    PubMed

    Wrighton, N C; Farrell, F X; Chang, R; Kashyap, A K; Barbone, F P; Mulcahy, L S; Johnson, D L; Barrett, R W; Jolliffe, L K; Dower, W J

    1996-07-26

    Random phage display peptide libraries and affinity selective methods were used to isolate small peptides that bind to and activate the receptor for the cytokine erythropoietin (EPO). In a panel of in vitro biological assays, the peptides act as full agonists and they can also stimulate erythropoiesis in mice. These agonists are represented by a 14- amino acid disulfide-bonded, cyclic peptide with the minimum consensus sequence YXCXXGPXTWXCXP, where X represents positions allowing occupation by several amino acids. The amino acid sequences of these peptides are not found in the primary sequence of EPO. The signaling pathways activated by these peptides appear to be identical to those induced by the natural ligand. This discovery may form the basis for the design of small molecule mimetics of EPO. PMID:8662529

  12. Neuropeptide receptors provide a signalling pathway for trigeminal modulation of olfactory transduction.

    PubMed

    Daiber, Philipp; Genovese, Federica; Schriever, Valentin A; Hummel, Thomas; Möhrlen, Frank; Frings, Stephan

    2013-02-01

    The mammalian olfactory epithelium contains olfactory receptor neurons and trigeminal sensory endings. The former mediate odor detection, the latter the detection of irritants. The two apparently parallel chemosensory systems are in reality interdependent in various well-documented ways. Psychophysical studies have shown that virtually all odorants can act as irritants, and that most irritants have an odor. Thus, the sensory perception of odorants and irritants is based on simultaneous input from the two systems. Moreover, functional interactions between the olfactory system and the trigeminal system exist on both peripheral and central levels. Here we examine the impact of trigeminal stimulation on the odor response of olfactory receptor neurons. Using an odorant with low trigeminal potency (phenylethyl alcohol) and a non-odorous irritant (CO(2) ), we have explored this interaction in psychophysical experiments with human subjects and in electroolfactogram (EOG) recordings from rats. We have demonstrated that simultaneous activation of the trigeminal system attenuates the perception of odor intensity and distorts the EOG response. On the molecular level, we have identified a route for this cross-modal interaction. The neuropeptide calcitonin-gene related peptide (CGRP), which is released from trigeminal sensory fibres upon irritant stimulation, inhibits the odor response of olfactory receptor neurons. CGRP receptors expressed by these neurons mediate this neuromodulatory effect. This study demonstrates a site of trigeminal-olfactory interaction in the periphery. It reveals a pathway for trigeminal impact on olfactory signal processing that influences odor perception. PMID:23205840

  13. Acupuncture affects regional blood flow in various organs.

    PubMed

    Uchida, Sae; Hotta, Harumi

    2008-06-01

    In this review, our recent studies using anesthetized animals concerning the neural mechanisms of vasodilative effect of acupuncture-like stimulation in various organs are briefly summarized. Responses of cortical cerebral blood flow and uterine blood flow are characterized as non-segmental and segmental reflexes. Among acupuncture-like stimuli delivered to five different segmental areas of the body; afferent inputs to the brain stem (face) and to the spinal cord at the cervical (forepaw), thoracic (chest or abdomen), lumbar (hindpaw) and sacral (perineum) levels, cortical cerebral blood flow was increased by stimuli to face, forepaw and hindpaw. The afferent pathway of the responses is composed of somatic groups III and IV afferent nerves and whose efferent nerve pathway includes intrinsic cholinergic vasodilators originating in the basal forebrain. Uterine blood flow was increased by cutaneous stimulation of the hindpaw and perineal area, with perineal predominance. The afferent pathway of the response is composed of somatic group II, III and IV afferent nerves and the efferent nerve pathway includes the pelvic parasympathetic cholinergic vasodilator nerves. Furthermore, we briefly summarize vasodilative regulation of skeletal muscle blood flow via a calcitonin gene-related peptide (CGRP) induced by antidromic activation of group IV somatic afferent nerves. These findings in healthy but anesthetized animals may be applicable to understanding the neural mechanisms improving blood flow in various organs following clinical acupuncture. PMID:18604254

  14. Chemosensory Functions for Pulmonary Neuroendocrine Cells

    PubMed Central

    Gu, Xiaoling; Karp, Philip H.; Brody, Steven L.; Pierce, Richard A.; Welsh, Michael J.; Holtzman, Michael J.

    2014-01-01

    The mammalian airways are sensitive to inhaled stimuli, and airway diseases are characterized by hypersensitivity to volatile stimuli, such as perfumes, industrial solvents, and others. However, the identity and function of the cells in the airway that can sense volatile chemicals remain uncertain, particularly in humans. Here, we show that solitary pulmonary neuroendocrine cells (PNECs), which are morphologically distinct and physiologically undefined, might serve as chemosensory cells in human airways. This conclusion is based on our finding that some human PNECs expressed members of the olfactory receptor (OR) family in vivo and in primary cell culture, and are anatomically positioned in the airway epithelium to respond to inhaled volatile chemicals. Furthermore, apical exposure of primary-culture human airway epithelial cells to volatile chemicals decreased levels of serotonin in PNECs, and the led to the release of the neuropeptide calcitonin gene-related peptide (CGRP) to the basal medium. These data suggest that volatile stimulation of PNECs can lead to the secretion of factors that are capable of stimulating the corresponding receptors in the lung epithelium. We also found that the distribution of serotonin and neuropeptide receptors may change in chronic obstructive pulmonary disease, suggesting that increased PNEC-dependent chemoresponsiveness might contribute to the altered sensitivity to volatile stimuli in this disease. Together, these data indicate that human airway epithelia harbor specialized cells that respond to volatile chemical stimuli, and may help to explain clinical observations of odorant-induced airway reactions. PMID:24134460

  15. Brain natriutetic peptide test

    MedlinePlus

    ... medlineplus.gov/ency/article/007509.htm Brain natriuretic peptide test To use the sharing features on this page, please enable JavaScript. Brain natriuretic peptide (BNP) test is a blood test that measures ...

  16. Vasoactive intestinal peptide test

    MedlinePlus

    ... medlineplus.gov/ency/article/003508.htm Vasoactive intestinal peptide test To use the sharing features on this page, please enable JavaScript. Vasoactive intestinal peptide (VIP) is a test that measures the amount ...

  17. [SYNTHETIC PEPTIDE VACCINES].

    PubMed

    Sergeyev, O V; Barinsky, I F

    2016-01-01

    An update on the development and trials of synthetic peptide vaccines is reviewed. The review considers the successful examples of specific protection as a result of immunization with synthetic peptides using various protocols. The importance of conformation for the immunogenicity of the peptide is pointed out. An alternative strategy of the protection of the organism against the infection using synthetic peptides is suggested. PMID:27145593

  18. Relaxin family peptides and their receptors.

    PubMed

    Bathgate, R A D; Halls, M L; van der Westhuizen, E T; Callander, G E; Kocan, M; Summers, R J

    2013-01-01

    There are seven relaxin family peptides that are all structurally related to insulin. Relaxin has many roles in female and male reproduction, as a neuropeptide in the central nervous system, as a vasodilator and cardiac stimulant in the cardiovascular system, and as an antifibrotic agent. Insulin-like peptide-3 (INSL3) has clearly defined specialist roles in male and female reproduction, relaxin-3 is primarily a neuropeptide involved in stress and metabolic control, and INSL5 is widely distributed particularly in the gastrointestinal tract. Although they are structurally related to insulin, the relaxin family peptides produce their physiological effects by activating a group of four G protein-coupled receptors (GPCRs), relaxin family peptide receptors 1-4 (RXFP1-4). Relaxin and INSL3 are the cognate ligands for RXFP1 and RXFP2, respectively, that are leucine-rich repeat containing GPCRs. RXFP1 activates a wide spectrum of signaling pathways to generate second messengers that include cAMP and nitric oxide, whereas RXFP2 activates a subset of these pathways. Relaxin-3 and INSL5 are the cognate ligands for RXFP3 and RXFP4 that are closely related to small peptide receptors that when activated inhibit cAMP production and activate MAP kinases. Although there are still many unanswered questions regarding the mode of action of relaxin family peptides, it is clear that they have important physiological roles that could be exploited for therapeutic benefit. PMID:23303914

  19. Effects of opioid peptides on thermoregulation

    SciTech Connect

    Clark, W.G.

    1981-11-01

    In a given species, injected opioid peptides usually cause changes in temperature similar to those caused by nonpeptide opioids. The main effect in those species most studied, the cat, rat, and mouse, is an increase in the level about which body temperature is regulated; there is a coordinated change in the activity of thermoregulatory effectors such that hyperthermia is produced in both hot and cold environments. Larger doses may depress thermoregulation, thereby causing body temperature to decrease in the cold. Elicitation of different patterns of response over a range of environmental temperatures and studies with naloxone and naltrexone indicate that stimulation of a number of different receptors by both peptide and nonpeptide opioids can evoke thermoregulatory responses. ..beta..-Endorphin is readily antagonized by naloxone whereas methionine-enkephalin can act on naloxone-insensitive receptors. Moreover, synthetic peptide analogs do not necessarily evoke the same response as does the related endogenous peptide. The lack of effect of naloxone on body temperature of subjects housed at usual laboratory temperature or on pyrogen-induced increases in body temperature indicates that an action of endogenous peptides on naloxone-sensitive receptors plays little, if any, role in normal thermoregulation or in fever. However, there is some evidence that such an action may be involved in responses to restraint or ambient temperature-induced stress. Further evaluation of possible physiological roles of endogenous opioid peptides will be facilitated when specific antagonists at other types of opioid receptors become available.

  20. PH dependent adhesive peptides

    DOEpatents

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  1. Antimicrobial Peptides in 2014

    PubMed Central

    Wang, Guangshun; Mishra, Biswajit; Lau, Kyle; Lushnikova, Tamara; Golla, Radha; Wang, Xiuqing

    2015-01-01

    This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms. PMID:25806720

  2. Antimicrobial peptides in 2014.

    PubMed

    Wang, Guangshun; Mishra, Biswajit; Lau, Kyle; Lushnikova, Tamara; Golla, Radha; Wang, Xiuqing

    2015-01-01

    This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms. PMID:25806720

  3. Synthetic peptides corresponding to human follicle-stimulating hormone (hFSH)-beta-(1-15) and hFSH-beta-(51-65) induce uptake of 45Ca++ by liposomes: evidence for calcium-conducting transmembrane channel formation

    SciTech Connect

    Grasso, P.; Santa-Coloma, T.A.; Reichert, L.E. Jr. )

    1991-06-01

    We have previously described FSH receptor-mediated influx of 45Ca++ in cultured Sertoli cells from immature rats and receptor-enriched proteoliposomes via activation of voltage-sensitive and voltage-independent calcium channels. We have further shown that this effect of FSH does not require cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding protein or activation of adenylate cyclase. In the present study, we have identified regions of human FSH-beta-subunit which appear to be involved in mediating calcium influx. We screened 11 overlapping peptide amides representing the entire primary structure of hFSH-beta-subunit for their effects on 45Ca++ flux in FSH receptor-enriched proteoliposomes. hFSH-beta-(1-15) and hFSH-beta-(51-65) induced uptake of 45Ca++ in a concentration-related manner. This effect of hFSH-beta-(1-15) and hFSH-beta-(51-65) was also observed in liposomes lacking incorporated FSH receptor. Reducing membrane fluidity by incubating liposomes (containing no receptor) with hFSH-beta-(1-15) or hFSH-beta-(51-65) at temperatures lower than the transition temperatures of their constituent phospholipids resulted in no significant (P greater than 0.05) difference in 45Ca++ uptake. The effectiveness of the calcium ionophore A23187, however, was abolished. Ruthenium red, a voltage-independent calcium channel antagonist, was able to completely block uptake of 45Ca++ induced by hFSH-beta-(1-15) and hFSH-beta-(51-65) whereas nifedipine, a calcium channel blocker specific for L-type voltage-sensitive calcium channels, was without effect. These results suggest that in addition to its effect on voltage-sensitive calcium channel activity, interaction of FSH with its receptor may induce formation of transmembrane aqueous channels which also facilitate influx of extracellular calcium.

  4. Nerve growth factor alters microtubule targeting agent-induced neurotransmitter release but not MTA-induced neurite retraction in sensory neurons.

    PubMed

    Pittman, Sherry K; Gracias, Neilia G; Fehrenbacher, Jill C

    2016-05-01

    Peripheral neuropathy is a dose-limiting side effect of anticancer treatment with the microtubule-targeted agents (MTAs), paclitaxel and epothilone B (EpoB); however, the mechanisms by which the MTAs alter neuronal function and morphology are unknown. We previously demonstrated that paclitaxel alters neuronal sensitivity, in vitro, in the presence of nerve growth factor (NGF). Evidence in the literature suggests that NGF may modulate the neurotoxic effects of paclitaxel. Here, we examine whether NGF modulates changes in neuronal sensitivity and morphology induced by paclitaxel and EpoB. Neuronal sensitivity was assessed using the stimulated release of calcitonin gene-related peptide (CGRP), whereas morphology of established neurites was evaluated using a high content screening system. Dorsal root ganglion cultures, maintained in the absence or presence of NGF, were treated from day 7 to day 12 in culture with paclitaxel (300nM) or EpoB (30nM). Following treatment, the release of CGRP was stimulated using capsaicin or high extracellular potassium. In the presence of NGF, EpoB mimicked the effects of paclitaxel: capsaicin-stimulated release was attenuated, potassium-stimulated release was slightly enhanced and the total peptide content was unchanged. In the absence of NGF, both paclitaxel and EpoB decreased capsaicin- and potassium-stimulated release and the total peptide content, suggesting that NGF may reverse MTA-induced hyposensitivity. Paclitaxel and EpoB both decreased neurite length and branching, and this attenuation was unaffected by NGF in the growth media. These differential effects of NGF on neuronal sensitivity and morphology suggest that neurite retraction is not a causative factor to alter neuronal sensitivity. PMID:26883566

  5. The physiology of the biliary tree. Motility of the gallbladder--part 1.

    PubMed

    Ballal, M A; Sanford, P A

    1999-09-01

    An incomplete picture has emerged of the complex means by which gallbladder motility is controlled under normal and pathophysiological conditions. In the first part of this review an overall account is presented. The mechanisms of cholecystokinin release, its stimulation by dietary factors and peptides elaborated by both pancreas and small intestine are discussed. The inhibition of cholecystokinin release by bile acids and proteases is also described. In the second part attention is focussed on other peptides affecting motility. These include (a) octreotide, effective for treatment of acromegaly, (b) peptide YY, contributing to a "colonic brake', (c) motilin. associated with interdigestive contractions, analogues of which possibly correct gallbladder hypomotility, and (d) substance P and calcitonin gene-related peptide, which facilitate ganglionic transmission after release from extrinsic sensory neurones and alter gallbladder responses to vagal stimulation. The sympathetic nervous system and diabetes mellitus also influence vagal responses. The former, acting presynaptically, may provide a "brake" to prevent vagal overactivity. The latter could cause hypomotility via autonomic neuropathy, although hyperglycaemia, itself, may play a role. The role of nitric oxide, released from neurones also producing vasoactive intestinal peptide is recognized. Both lengthen muscle, the former producing responses without requiring plasma membrane receptors. Gallbladder motility also changes during pregnancy and stone formation. Progesterone and cholesterol can limit G protein actions, thus impairing contractions. Inflammation is associated with abnormal motility. The production of reactive oxygen metabolites, acting directly or releasing prokinetic prostaglandins, may be responsible. It has been proposed that the gastrointestinal tract may be normally in a state of controlled inflammation, primed to react to harmful challenges. PMID:19864732

  6. [Plant signaling peptides. Cysteine-rich peptides].

    PubMed

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation. PMID:26281357

  7. Cell Penetrating Peptides and Cationic Antibacterial Peptides

    PubMed Central

    Rodriguez Plaza, Jonathan G.; Morales-Nava, Rosmarbel; Diener, Christian; Schreiber, Gabriele; Gonzalez, Zyanya D.; Lara Ortiz, Maria Teresa; Ortega Blake, Ivan; Pantoja, Omar; Volkmer, Rudolf; Klipp, Edda; Herrmann, Andreas; Del Rio, Gabriel

    2014-01-01

    Cell penetrating peptides (CPP) and cationic antibacterial peptides (CAP) have similar physicochemical properties and yet it is not understood how such similar peptides display different activities. To address this question, we used Iztli peptide 1 (IP-1) because it has both CPP and CAP activities. Combining experimental and computational modeling of the internalization of IP-1, we show it is not internalized by receptor-mediated endocytosis, yet it permeates into many different cell types, including fungi and human cells. We also show that IP-1 makes pores in the presence of high electrical potential at the membrane, such as those found in bacteria and mitochondria. These results provide the basis to understand the functional redundancy of CPPs and CAPs. PMID:24706763

  8. Plant peptide hormone signalling.

    PubMed

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions. PMID:26374891

  9. Mouse urinary peptides provide a molecular basis for genotype discrimination by nasal sensory neurons.

    PubMed

    Sturm, Theo; Leinders-Zufall, Trese; Maček, Boris; Walzer, Mathias; Jung, Stephan; Pömmerl, Beate; Stevanović, Stefan; Zufall, Frank; Overath, Peter; Rammensee, Hans-Georg

    2013-01-01

    Selected groups of peptides, including those that are presented by major histocompatibility complex (MHC) proteins, have been proposed to transmit information to the olfactory system of vertebrates via their ability to stimulate chemosensory neurons. However, the lack of knowledge about such peptides in natural sources accessible for nasal recognition has been a major barrier for this hypothesis. Here we analyse urinary peptides from selected mouse strains with respect to genotype-related individual differences. We discover many abundant peptides with single amino-acid variations corresponding to genomic differences. The polymorphism of major urinary proteins is reflected by variations in prominent urinary peptides. We also demonstrate an MHC-dependent peptide (SIINFEKL) occurring at very low concentrations in mouse urine. Chemoreceptive neurons in the vomeronasal organ detect and discriminate single amino-acid variation peptides as well as SIINFEKL. Hence, urinary peptides represent a real-time sampling of the expressed genome available for chemosensory assessment by other individuals. PMID:23511480

  10. Interactions of Gastrointestinal Peptides: Ghrelin and Its Anorexigenic Antagonists

    PubMed Central

    Wisser, Anna-Sophia; Habbel, Piet; Wiedenmann, Bertram; Klapp, Burghard F.; Mönnikes, Hubert; Kobelt, Peter

    2010-01-01

    Food intake behaviour and energy homeostasis are strongly regulated by a complex system of humoral factors and nerval structures constituting the brain-gut-axis. To date the only known peripherally produced and centrally acting peptide that stimulates food intake is ghrelin, which is mainly synthesized in the stomach. Recent data indicate that the orexigenic effect of ghrelin might be influenced by other gastrointestinal peptides such as cholecystokinin (CCK), bombesin, desacyl ghrelin, peptide YY (PYY), as well as glucagon-like peptide (GLP). Therefore, we will review on the interactions of ghrelin with several gastrointestinal factors known to be involved in appetite regulation in order to elucidate the interdependency of peripheral orexigenic and anorexigenic peptides in the control of appetite. PMID:20798884

  11. Analogue peptides for the immunotherapy of human acute myeloid leukemia.

    PubMed

    Hofmann, Susanne; Mead, Andrew; Malinovskis, Aleksandrs; Hardwick, Nicola R; Guinn, Barbara-Ann

    2015-11-01

    The use of peptide vaccines, enhanced by adjuvants, has shown some efficacy in clinical trials. However, responses are often short-lived and rarely induce notable memory responses. The reason is that self-antigens have already been presented to the immune system as the tumor develops, leading to tolerance or some degree of host tumor cell destruction. To try to break tolerance against self-antigens, one of the methods employed has been to modify peptides at the anchor residues to enhance their ability to bind major histocompatibility complex molecules, extending their exposure to the T-cell receptor. These modified or analogue peptides have been investigated as stimulators of the immune system in patients with different cancers with variable but sometimes notable success. In this review we describe the background and recent developments in the use of analogue peptides for the immunotherapy of acute myeloid leukemia describing knowledge useful for the application of analogue peptide treatments for other malignancies. PMID:26438084

  12. Rat model of Achilles tendon disorder. A pilot study.

    PubMed

    Messner, K; Wei, Y; Andersson, B; Gillquist, J; Räsänen, T

    1999-01-01

    Three-month-old male rats were subjected 3 times weekly for 1 h to eccentric exercise of one triceps surae muscle (30 stimulations/min) under general anesthesia in order to induce Achilles tendon disorder corresponding to paratenonitis and tendinosis in man. Net muscle work during the sessions ranged between 0.67 and 4.37 mJ (mean 1.72, SD 0.77). After 9 and 13 sessions, respectively, 2 rats started to show gait alterations during the functional test which was performed 2-3 times weekly. These rats were killed after additional sessions which showed a worsening of the limp. The other trained rats and controls did not limp and were killed after 7-11 weeks. Histologic evaluation of the Achilles tendons from the exercised limb showed in the majority of the cases hypervascularization, increased number of nerve filaments and increased immunoreactivity for substance P and calcitonin gene-related peptide. The tendons from the nonstimulated limb looked normal. The distribution of collagen types I and II appeared normal in the tendon and its insertion to the calcaneus. Inflammation of the epi- and paratenon could be provoked in the rat, but tendon changes corresponding to chronic tendinosis did not develop within 11 weeks with the used training regime. The clinical relevance of this model for chronic tendon disease needs to be evaluated further. PMID:10460971

  13. Occurrence of a CGRP-like molecule in siki (Centroscymnus coelolepsis) hydrolysate of industrial origin.

    PubMed

    Martínez-Alvarez, Oscar; Guimas, Laurence; Delannoy, Charles; Fouchereau-Peron, Martine

    2007-07-11

    Fish protein hydrolysates (FPH) may have potential as bioactive components in functional foods as nutraceuticals. This study focused on the identification of calcitonin gene-related peptide (CGRP) molecules in FPH. CGRP is a neuropeptide belonging to the calcitonin/CGRP family and is known as potent arterial and venous vasodilator in humans. Hydrolysates of industrial origin were prepared from siki (Centroscymnus coelolepsis) heads and were analyzed for the presence of CGRP-like molecules using specific radioimmunoassays and radioreceptorassays. The biological activity of the CGRP-related molecules was assessed by their ability to stimulate the adenylate cyclase activity in rat liver membranes. They were finally purified using gel exclusion chromatography and high-performance liquid chromatography (HPLC). These molecules presented a molecular weight around 1500-2500 Da and were obtained with a purification factor of 79. The incorporation of FPH with CGRP-like molecules in functional foods could lead to the development of new useful products for health and nutrition markets. PMID:17579425

  14. Improved peripheral nerve regeneration in streptozotocin-induced diabetic rats by oral lumbrokinase.

    PubMed

    Lee, Han-Chung; Hsu, Yuan-Man; Tsai, Chin-Chuan; Ke, Cherng-Jyh; Yao, Chun-Hsu; Chen, Yueh-Sheng

    2015-01-01

    We assessed the therapeutic effects of lumbrokinase, a group of enzymes extracted from the earthworm, on peripheral-nerve regeneration using well-defined sciatic nerve lesion paradigms in diabetic rats induced by the injection of streptozotocin (STZ). We found that lumbrokinase therapy could improve the rats' circulatory blood flow and promote the regeneration of axons in a silicone rubber conduit after nerve transection. Lumbrokinase treatment could also improve the neuromuscular functions with better nerve conductive performances. Immunohistochemical staining showed that lumbrokinase could dramatically promote calcitonin gene-related peptide (CGRP) expression in the lamina I-II regions in the dorsal horn ipsilateral to the injury and cause a marked increase in the number of macrophages recruited within the distal nerve stumps. In addition, the lumbrokinase could stimulate the secretion of interleukin-1 (IL-1), nerve growth factor (NGF), platelet-derived growth factor (PDGF), and transforming growth factor-β (TGF-β) in dissected diabetic sciatic nerve segments. In conclusion, the administration of lumbrokinase after nerve repair surgery in diabetic rats was found to have remarkable effects on promoting peripheral nerve regeneration and functional recovery. PMID:25787300

  15. Anti-gastritis and wound healing effects of Momordicae Semen extract and its active component.

    PubMed

    Jung, Kiwon; Chin, Young-Won; Chung, Yoon Hee; Park, Yang Hae; Yoo, Hunseung; Min, Dong Sun; Lee, Bongyong; Kim, Jinwoong

    2013-02-01

    Momordicae Semen, Momordica cochinchinensis Springer (Cucurbitaceae), has long been known to effectively relieve boils, rheumatic pain, and hemorrhoids. In this study, we investigated whether Momordicae Semen extract (MSE) has anti-gastritis effects in various rodent models and also explored possible mechanisms for the gastroprotective effects of MSE. MSE provided remarkable protective effects, comparable to those of rebamipide, in ethanol- and diclofenac-induced acute gastritis. In addition, it has demonstrated protective effect in a Helicobacter pylori-insulted chronic gastritis model. MSE also showed wound healing effect on cutaneous injury of mice and stimulated calcitonin gene-related peptide and somatostatin receptors, which may be related to its anti-gastritis effects. In a single oral dose toxicity study, the approximate lethal dose of MSE was determined at >2000 mg/kg/day. The NOAEL was set to be 2000 mg/kg/day from the repeated oral dose toxicity study. Moreover, momordica saponin I, a major ingredient of MSE, treatment decreased gastric mucosa damage indices in the ethanol- and diclofenac-induced acute gastritis models. The results suggest that MSE could be a promising gastroprotective herbal medicine and momordica saponin I might be used as an active marker compound for MSE. PMID:22889079

  16. Pharmacological evidence for CGRP uptake into perivascular capsaicin sensitive nerve terminals

    PubMed Central

    Sams-Nielsen, Anette; Orskov, Cathrine; Jansen-Olesen, Inger

    2001-01-01

    Specific mechanisms, providing reuptake of cathecholamine and amino acid neurotransmitters (e.g. serotonin and glutamate) into cells of the central nervous system are well known, whereas neuronal uptake of neuropeptide transmitters have not previously been reported. In the present study we present evidence for uptake of the 37 amino acid neuropeptide, calcitonin gene-related peptide (CGRP) into perivascular terminals of capsaicin sensitive nerve fibres, innervating the guinea-pig basilar artery. Release of CGRP from perivascular nerve terminals was obtained by capsaicin-induced vanilloid receptor-stimulation and detected as CGRP receptor-mediated dilation of isolated segments of the guinea-pig basilar artery. Following three repeated capsaicin challenges, CGRP-depleted segments were incubated with CGRP. This caused significant reappearance of capsaicin-induced vasodilatory responses. These responses were dependent on duration and concentration of the preceding CGRP incubation and were inhibited by the CGRP receptor antagonist, CGRP8–37. The CGRP-re-depletion was significantly reduced when CGRP8–37 was present during the preceding CGRP incubation. Thus, presynaptic CGRP receptors are likely to be involved in neuronal CGRP uptake. Incubating the artery segments with 125I-CGRP allowed subsequent detection of capsaicin-induced 125I-release. Immunohistochemical experiments showed that only terminal CGRP is subject to capsaicin-induced depletion in vitro, whereas CGRP-immunoreactivity endures in the nerve fibres. PMID:11226146

  17. Decompensated liver cirrhosis and neural regulation of mesenteric vascular tone in rats: role of sympathetic, nitrergic and sensory innervations.

    PubMed

    Sastre, Esther; Caracuel, Laura; Prieto, Isabel; Llévenes, Pablo; Aller, M Ángeles; Arias, Jaime; Balfagón, Gloria; Blanco-Rivero, Javier

    2016-01-01

    We evaluated the possible alterations produced by liver cholestasis (LC), a model of decompensated liver cirrhosis in sympathetic, sensory and nitrergic nerve function in rat superior mesenteric arteries (SMA). The vasoconstrictor response to electrical field stimulation (EFS) was greater in LC animals. Alpha-adrenoceptor antagonist phentolamine and P2 purinoceptor antagonist suramin decreased this response in LC animals more than in control animals. Both non-specific nitric oxide synthase (NOS) L-NAME and calcitonin gene related peptide (CGRP) (8-37) increased the vasoconstrictor response to EFS more strongly in LC than in control segments. Vasomotor responses to noradrenaline (NA) or CGRP were greater in LC segments, while NO analogue DEA-NO induced a similar vasodilation in both experimental groups. The release of NA was not modified, while those of ATP, nitrite and CGRP were increased in segments from LC. Alpha 1 adrenoceptor, Rho kinase (ROCK) 1 and 2 and total myosin phosphatase (MYPT) expressions were not modified, while alpha 2B adrenoceptor, nNOS expression and nNOS and MYPT phosphorylation were increased by LC. Together, these alterations might counteract the increased splanchnic vasodilation observed in the last phases of decompensated liver cirrhosis. PMID:27484028

  18. CGRP inhibits neurons of the bed nucleus of the stria terminalis: implications for the regulation of fear and anxiety.

    PubMed

    Gungor, Nur Zeynep; Pare, Denis

    2014-01-01

    The bed nucleus of the stria terminalis (BNST) is thought to generate anxiety-like states via its projections to autonomic and neuroendocrine regulatory structures of the brain. However, because most BNST cells are GABAergic, they are expected to inhibit target neurons. In contrast with this, infusion of calcitonin gene-related peptide (CGRP) into BNST was reported to potentiate anxiety while activating BNST targets. The present study aimed to shed light on this paradox. The CGRP innervation of BNST originates in the pontine parabrachial nucleus and targets its anterolateral sector (BNST-AL). Thus, we investigated the effects of CGRP on BNST-AL neurons using patch recordings in vitro in male rats. CGRP did not alter the passive properties of BNST-AL cells but increased the amplitude of IPSPs evoked by stimulation of the stria terminalis (ST). However, IPSP paired-pulse ratios were unchanged by CGRP, and there was no correlation between IPSP potentiation and variance, suggesting that CGRP acts postsynaptically. Consistent with this, CGRP hyperpolarized the GABA-A reversal of BNST-AL cells. These results indicate that CGRP increases ST-evoked GABA-A IPSPs and hyperpolarizes their reversal potential through a postsynaptic change in Cl(-) homeostasis. Overall, our findings suggest that CGRP potentiates anxiety-like behaviors and increases neural activity in BNST targets, by inhibiting BNST-AL cells, supporting the conclusion that BNST-AL exerts anxiolytic effects. PMID:24381268

  19. Decompensated liver cirrhosis and neural regulation of mesenteric vascular tone in rats: role of sympathetic, nitrergic and sensory innervations

    PubMed Central

    Sastre, Esther; Caracuel, Laura; Prieto, Isabel; Llévenes, Pablo; Aller, M. Ángeles; Arias, Jaime; Balfagón, Gloria; Blanco-Rivero, Javier

    2016-01-01

    We evaluated the possible alterations produced by liver cholestasis (LC), a model of decompensated liver cirrhosis in sympathetic, sensory and nitrergic nerve function in rat superior mesenteric arteries (SMA). The vasoconstrictor response to electrical field stimulation (EFS) was greater in LC animals. Alpha-adrenoceptor antagonist phentolamine and P2 purinoceptor antagonist suramin decreased this response in LC animals more than in control animals. Both non-specific nitric oxide synthase (NOS) L-NAME and calcitonin gene related peptide (CGRP) (8-37) increased the vasoconstrictor response to EFS more strongly in LC than in control segments. Vasomotor responses to noradrenaline (NA) or CGRP were greater in LC segments, while NO analogue DEA-NO induced a similar vasodilation in both experimental groups. The release of NA was not modified, while those of ATP, nitrite and CGRP were increased in segments from LC. Alpha 1 adrenoceptor, Rho kinase (ROCK) 1 and 2 and total myosin phosphatase (MYPT) expressions were not modified, while alpha 2B adrenoceptor, nNOS expression and nNOS and MYPT phosphorylation were increased by LC. Together, these alterations might counteract the increased splanchnic vasodilation observed in the last phases of decompensated liver cirrhosis. PMID:27484028

  20. New peptides players in metabolic disorders.

    PubMed

    Mierzwicka, Agata; Bolanowski, Marek

    2016-01-01

    Among new peptides responsible for the pathogenesis of metabolic disorders and carbohydrate metabolism, adipokines are of great importance. Adipokines are substances of hormonal character, secreted by adipose tissue. Apart from the well-known adipokines, adropin and preptin are relatively newly discovered, hence their function is not fully understood. They are peptides not secreted by adipose tissue but their role in the metabolic regulations seems to be significant. Preptin is a 34-amino acid peptide, a derivative of proinsulin growth factor II (pro-IGF-II), secreted by pancreatic β cells, considered to be a physiological enhancer of insulin secretion. Additionally, preptin has a stimulating effect on osteoblasts, inducing their proliferation, differentiation and survival. Adropin is a 76-amino acid peptide, encoded by the energy homeostasis associated gene (Enho), mainly in liver and brain, and its expression is dependent on a diet. Adropin is believed to play an important role in metabolic homeostasis, fatty acids metabolism control, insulin resistance prevention, dyslipidemia, and impaired glucose tolerance. The results of studies conducted so far show that the diseases resulting from metabolic syndrome, such as obesity, type 2 diabetes mellitus, polycystic ovary syndrome, non-alcoholic fatty liver disease, or cardiovascular disease are accompanied by significant changes in the concentration of these peptides. It is also important to note that preptin has an anabolic effect on bone tissue, which might be preventive in osteoporosis. PMID:27594563

  1. Glucagon-Like Peptide-1 Gene Therapy

    PubMed Central

    Rowzee, Anne M.; Cawley, Niamh X.; Chiorini, John A.; Di Pasquale, Giovanni

    2011-01-01

    Glucagon-like peptide 1 (GLP-1) is a small peptide component of the prohormone, proglucagon, that is produced in the gut. Exendin-4, a GLP-1 receptor agonist originally isolated from the saliva of H. suspectum or Gila monster, is a peptide that shares sequence and functional homology with GLP-1. Both peptides have been demonstrated to stimulate insulin secretion, inhibit glucagon secretion, promote satiety and slow gastric emptying. As such, GLP-1 and Exendin-4 have become attractive pharmaceutical targets as an adjunctive therapy for individuals with type II diabetes mellitus, with several products currently available clinically. Herein we summarize the cell biology leading to GLP-1 production and secretion from intestinal L-cells and the endocrine functions of this peptide and Exendin-4 in humans. Additionally, gene therapeutic applications of GLP-1 and Exendin-4 are discussed with a focus on recent work using the salivary gland as a gene therapy target organ for the treatment of diabetes mellitus. PMID:21747830

  2. Peptide receptor radionuclide therapy: an overview.

    PubMed

    Dash, Ashutosh; Chakraborty, Sudipta; Pillai, Maroor Raghavan Ambikalmajan; Knapp, Furn F Russ

    2015-03-01

    Peptide receptor radionuclide therapy (PRRT) is a site-directed targeted therapeutic strategy that specifically uses radiolabeled peptides as biological targeting vectors designed to deliver cytotoxic levels of radiation dose to cancer cells, which overexpress specific receptors. Interest in PRRT has steadily grown because of the advantages of targeting cellular receptors in vivo with high sensitivity as well as specificity and treatment at the molecular level. Recent advances in molecular biology have not only stimulated advances in PRRT in a sustainable manner but have also pushed the field significantly forward to several unexplored possibilities. Recent decades have witnessed unprecedented endeavors for developing radiolabeled receptor-binding somatostatin analogs for the treatment of neuroendocrine tumors, which have played an important role in the evolution of PRRT and paved the way for the development of other receptor-targeting peptides. Several peptides targeting a variety of receptors have been identified, demonstrating their potential to catalyze breakthroughs in PRRT. In this review, the authors discuss several of these peptides and their analogs with regard to their applications and potential in radionuclide therapy. The advancement in the availability of combinatorial peptide libraries for peptide designing and screening provides the capability of regulating immunogenicity and chemical manipulability. Moreover, the availability of a wide range of bifunctional chelating agents opens up the scope of convenient radiolabeling. For these reasons, it would be possible to envision a future where the scope of PRRT can be tailored for patient-specific application. While PRRT lies at the interface between many disciplines, this technology is inextricably linked to the availability of the therapeutic radionuclides of required quality and activity levels and hence their production is also reviewed. PMID:25710506

  3. Antihypertensive peptides from curd

    PubMed Central

    Dabarera, Melani Chathurika; Athiththan, Lohini V.; Perera, Rasika P.

    2015-01-01

    Introduction: Curd (Dadhi) peptides reduce hypertension by inhibiting angiotensin converting enzyme (ACE) and serum cholesterol. Peptides vary with bacterial species and milk type used during fermentation. Aim: To isolate and assay the antihypertensive peptides, before and after digestion, in two commercially available curd brands in Sri Lanka. Materials and Methods: Whey (Dadhi Mastu) separated by high-speed centrifugation was isolated using reverse-phase-high- performance liquid chromatography (HPLC). Eluted fractions were analyzed for ACE inhibitory activity using modified Cushman and Cheung method. Curd samples were subjected to enzymatic digestion with pepsin, trypsin, and carboxypeptidase-A at their optimum pH and temperature. Peptides isolated using reverse-phase-HPLC was assayed for ACE inhibitory activity. Results: Whey peptides of both brands gave similar patterns (seven major and five minor peaks) in HPLC elution profile. Smaller peptides concentration was higher in brand 1 and penta-octapeptides in brand 2. Pentapeptide had the highest ACE inhibitory activity (brand 2–90% and brand 1–73%). After digestion, di and tri peptides with similar inhibitory patterns were obtained in both which were higher than before digestion. Thirteen fractions were obtained, where nine fractions showed more than 70% inhibition in both brands with 96% ACE inhibition for a di-peptide. Conclusion: Curd has ACE inhibitory peptides and activity increases after digestion. PMID:27011726

  4. Antimicrobial Peptides in Reptiles

    PubMed Central

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  5. Polycyclic peptide therapeutics.

    PubMed

    Baeriswyl, Vanessa; Heinis, Christian

    2013-03-01

    Owing to their excellent binding properties, high stability, and low off-target toxicity, polycyclic peptides are an attractive molecule format for the development of therapeutics. Currently, only a handful of polycyclic peptides are used in the clinic; examples include the antibiotic vancomycin, the anticancer drugs actinomycin D and romidepsin, and the analgesic agent ziconotide. All clinically used polycyclic peptide drugs are derived from natural sources, such as soil bacteria in the case of vancomycin, actinomycin D and romidepsin, or the venom of a fish-hunting coil snail in the case of ziconotide. Unfortunately, nature provides peptide macrocyclic ligands for only a small fraction of therapeutic targets. For the generation of ligands of targets of choice, researchers have inserted artificial binding sites into natural polycyclic peptide scaffolds, such as cystine knot proteins, using rational design or directed evolution approaches. More recently, large combinatorial libraries of genetically encoded bicyclic peptides have been generated de novo and screened by phage display. In this Minireview, the properties of existing polycyclic peptide drugs are discussed and related to their interesting molecular architectures. Furthermore, technologies that allow the development of unnatural polycyclic peptide ligands are discussed. Recent application of these technologies has generated promising results, suggesting that polycyclic peptide therapeutics could potentially be developed for a broad range of diseases. PMID:23355488

  6. Peptide folding simulations.

    PubMed

    Gnanakaran, S; Nymeyer, Hugh; Portman, John; Sanbonmatsu, Kevin Y; García, Angel E

    2003-04-01

    Developments in the design of small peptides that mimic proteins in complexity, recent advances in nanosecond time-resolved spectroscopy methods to study peptides and the development of modern, highly parallel simulation algorithms have come together to give us a detailed picture of peptide folding dynamics. Two newly implemented simulation techniques, parallel replica dynamics and replica exchange molecular dynamics, can now describe directly from simulations the kinetics and thermodynamics of peptide formation, respectively. Given these developments, the simulation community now has the tools to verify and validate simulation protocols and models (forcefields). PMID:12727509

  7. Cyclic AMP formation in chicken brain: effect of vasoactive intestinal peptide, peptide histidine-isoleucine (PHI), and some PHI-related peptides.

    PubMed

    Dejda, Agnieszka; Matczak, Izabela; Wiktorowska-Owczarek, Anna; Nowak, Jerzy Z

    2003-01-01

    Vasoactive intestinal peptide (chicken form; chVIP), peptide histidine-isoleucine (porcine and rat forms; pPHI and rPHI), D-Phe(4) derivative of porcine PHI (D-Phe(4)-pPHI), peptide histidine-methionine (PHM; human PHI), and helodermin, were tested for their ability to stimulate cAMP production in [(3)H]adenine-prelabeled slices of chick cerebral cortex (CCx) and hypothalamus (HTh). The chVIP (0.1-3 microM) concentration-dependently and potently stimulated cAMP production in HTh and CCx; the responses observed after 3 microM of chVIP were comparable to those produced by 0.1 microM PACAP38. Helodermin (5 microM) moderately but significantly stimulated cAMP formation in both HTh and CCx, whereas pPHI, rPHI, PHM at 5 microM concentration only weakly affected cAMP production in CCx, and were inactive in HTh; D-Phe(4)-pPHI was inactive in both tissues. These data demonstrate that chVIP, PACAP, and to a lesser extent helodermin were capable of potently stimulating cAMP generation in the avian central nervous system. PHI-related peptides showed only weak or no activity, depending on the tissue. PMID:14704471

  8. Insulin C-peptide test

    MedlinePlus

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin produced by the body and insulin injected ...

  9. Expression of neurotransmitters and neurotrophins in neurogenic inflammation of the rat retina.

    PubMed

    Bronzetti, Elena; Artico, M; Kovacs, I; Felici, L M; Magliulo, G; Vignone, D; D'Ambrosio, A; Forte, F; Di Liddo, R; Feher, J

    2007-01-01

    Antidromic stimulation of the rat trigeminal ganglion triggers the release of substance P (SP) and calcitonin gene-related peptide (CGRP) from sensory nerve terminals of the capsaicin sensitive C-fibers. These pro-inflammatory neuropeptides produce a marked hyperemia in the anterior segment of the eye, accompanied by increased intraocular pressure, breakdown of the blood-aqueous barrier and myosis. To assess the effects of neurogenic inflammation on the retina, specifically on the immunostaining of neurotransmitters and neurotrophins, as well as on the expression of neurotrophin receptors in the retina. RT-PCR was also accomplished in control and stimulated animals to confirm the immunohistochemical results. In the electrically stimulated eyes, immunostaining for SP, CGRP, VIP and nNOS demonstrated a marked increase in the RPE/POS (Retinal Pigment Epithelium/Photoreceptor Outer Segments), in the inner and outer granular layers and in the ganglion cells in comparison to the control eyes. CGRP and SP were found increased in stimulated animals and this result has been confirmed by RT- PCR. Changes in neurotrophin immunostaining and in receptor expression were also observed after electric stimulation of trigeminal ganglia. Decrease of BDNF and NT4 in the outer and inner layers and in ganglion cells was particularly marked. In stimulated rat retinas immunostaining and RT-PCR showed a NGF expression increase. Neurotrophin receptors remained substantially unchanged. These studies demonstrated, for the first time, that antidromic stimulation of the trigeminal ganglion and subsequent neurogenic inflammation affect immunostaining of retinal cell neurotransmitter/neuropeptides and neurotrophins as well as the expression of neurotrophin receptors. PMID:18162454

  10. Natriuretic peptides in the regulation of the hypothalamic-pituitary-adrenal axis.

    PubMed

    Porzionato, Andrea; Macchi, Veronica; Rucinski, Marcin; Malendowicz, Ludwik K; De Caro, Raffaele

    2010-01-01

    Atrial (ANP), brain (BNP), and C-type (CNP) natriuretic peptides act by binding to three main subtypes of receptors, named NPR-A, -B, and -C. NPR-A and NPR-B are coupled with guanylate cyclase. Not only NPR-C is involved in removing natriuretic peptides from the circulation but it also acts through inhibition of adenylyl cyclase. NPR-A binds ANP and BNP; NPR-B preferentially binds CNP; and NPR-C binds all natriuretic peptides with similar affinities. All natriuretic peptides and their receptors are widely present in the hypothalamus, pituitary, adrenal cortex, and medulla. In the hypothalamus, they reduce norepinephrine release, inhibit oxytocin, vasopressin, corticotropin-releasing factor, and luteinizing hormone-releasing hormone release. In the hypophysis, natriuretic peptides inhibit basal and induced ACTH release. Conversely, the effects of natriuretic peptides on secretion of growth, luteinizing, and follicle-stimulating hormones are not clear. Natriuretic peptides are known to inhibit basal and stimulated aldosterone secretion, through an increase of intracellular cGMP, and to inhibit the growth of zona glomerulosa. Inhibition or stimulation of glucocorticoid secretion by adrenocortical cells has been reported on the basis of the species involved, and an indirect effect mediated by adrenalmedullary cells has been hypothesized. In the adrenal medulla, natriuretic peptides inhibit catecholamine release and increase catecholamine uptake. It appears that natriuretic peptides may play a role in the pathophysiology of adrenocortical neoplasias and pheochromocytomas. PMID:20797680

  11. Aerosolized Medications for Gene and Peptide Therapy.

    PubMed

    Laube, Beth L

    2015-06-01

    Inhalation therapy has matured to include drugs that: (1) deliver nucleic acids that either lead to the restoration of a gene construct or protein coding sequence in a population of cells or suppress or disrupt production of an abnormal gene product (gene therapy); (2) deliver peptides that target lung diseases such as asthma, sarcoidosis, pulmonary hypertension, and cystic fibrosis; and (3) deliver peptides to treat diseases outside the lung whose target is the systemic circulation (systemic drug delivery). These newer applications for aerosol therapy are the focus of this paper, and I discuss the status of each and the challenges that remain to their successful development. Drugs that are highlighted include: small interfering ribonucleic acid to treat lung cancer and Mycobacterium tuberculosis; vectors carrying the normal alpha-1 antitrypsin gene to treat alpha-1 antitrypsin deficiency; vectors carrying the normal cystic fibrosis transmembrane conductance regulator gene to treat cystic fibrosis; vasoactive intestinal peptide to treat asthma, pulmonary hypertension, and sarcoidosis; glutathione to treat cystic fibrosis; granulocyte-macrophage colony-stimulating factor to treat pulmonary alveolar proteinosis; calcitonin for postmenopausal osteoporosis; and insulin to treat diabetes. The success of these new aerosol applications will depend on many factors, such as: (1) developing gene therapy formulations that are safe for acute and chronic administrations to the lung, (2) improving the delivery of the genetic material beyond the airway mucus barrier and cell membrane and transferring the material to the cell cytoplasm or the cell nucleus, (3) developing aerosol devices that efficiently deliver genetic material and peptides to their lung targets over a short period of time, (4) developing devices that increase aerosol delivery to the lungs of infants, (5) optimizing the bioavailability of systemically delivered peptides, and (6) developing peptide formulations for

  12. The effects of BT/TAMUS 2032 cationic peptide on innate immunity and susceptibility of young chickens to extraintestinal Salmonella enterica serovar Enteritidis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The BT/TAMUS 2032 cationic peptides are a group of related cationic peptides produced by a Gram-positive bacterium. Cationic amphiphilic peptides have been found to stimulate or prime the innate immune responses in mammals. The innate immune system of poultry is functionally inefficient during the ...

  13. A biologically active peptide mimetic of N-acetylgalactosamine/galactose

    PubMed Central

    Eggink, Laura L; Hoober, J Kenneth

    2009-01-01

    Background Glycosylated proteins and lipids are important regulatory factors whose functions can be altered by addition or removal of sugars to the glycan structure. The glycans are recognized by sugar-binding lectins that serve as receptors on the surface of many cells and facilitate initiation of an intracellular signal that changes the properties of the cells. We identified a peptide that mimics the ligand of an N-acetylgalactosamine (GalNAc)-specific lectin and asked whether the peptide would express specific biological activity. Findings A 12-mer phage display library was screened with a GalNAc-specific lectin to identify an amino acid sequence that binds to the lectin. Phage particles that were eluted from the lectin with free GalNAc were considered to have been bound to a GalNAc-binding site. Peptides were synthesized with the selected sequence as a quadravalent structure to facilitate receptor crosslinking. Treatment of human peripheral blood mononuclear cells for 24 h with the peptide stimulated secretion of interleukin-8 (IL-8) but not of IL-1β, IL-6, IL-10, or tumor necrosis factor-α (TNF-α). The secretion of IL-21 was stimulated as strongly with the peptide as with interferon-γ. Conclusion The data indicate that the quadravalent peptide has biological activity with a degree of specificity. These effects occurred at concentrations in the nanomolar range, in contrast to free sugars that generally bind to proteins in the micro- to millimolar range. PMID:19284521

  14. Tumor-Penetrating Peptides

    PubMed Central

    Teesalu, Tambet; Sugahara, Kazuki N.; Ruoslahti, Erkki

    2013-01-01

    Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC), contains the integrin-binding RGD motif. RGD mediates tumor-homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR) motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular “zip code” of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies, and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is present in the

  15. Epoxyeicosatrienoic Acids (EETs) are Endogenous Regulators of Vasoactive Neuropeptide Release from Trigeminal Ganglion Neurons

    PubMed Central

    Iliff, Jeffrey J.; Fairbanks, Stacy L.; Balkowiec, Agnieszka; Alkayed, Nabil J.

    2010-01-01

    Epoxyeicosatrienoic acids (EETs) are bioactive eicosanoids produced from arachidonic acid by cytochrome P450 epoxygenases. We previously described the expression of CYP-2J epoxygenase in rat trigeminal ganglion neurons and that EETs signaling is involved in cerebrovascular dilation resulting from perivascular nerve stimulation. Herein we evaluate the presence of the EETs signaling pathway in trigeminal ganglion neurons and their role in modulating the release of calcitonin gene-related peptide (CGRP) by trigeminal ganglion neurons. Liquid chromatography tandem mass spectrometry identified the presence of each of the four EETs regio-isomers within primary trigeminal ganglion neurons. Stimulation for one hour with the transient receptor potential vanilloid-1 channel agonist capsaicin (100 nmol/L) or depolarizing K+ (60 mmol/L) increased CGRP release as measured by ELISA. Stimulation-evoked CGRP release was attenuated by 30 min pre-treatment with the EETs antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, 10 μmol/L). K+ stimulation elevated CGRP release 2.9 ± 0.3-fold above control levels, while in the presence of 14,15-EEZE K+-evoked CGRP release was significantly reduced to 1.1 ± 0.2-fold above control release (p<0.01 ANOVA, n=6). 14,15-EEZE likewise attenuated capsaicin-evoked CGRP release from trigeminal ganglion neurons (p<0.05 ANOVA, n=6). Similarly, pre-treatment with the CYP epoxygenase inhibitor attenuated stimulation-evoked CGRP release. These data demonstrate that EETs are endogenous constituents of rat trigeminal ganglion neurons and suggest that they may act as intracellular regulators of neuropeptide release, which may have important clinical implications for treatment of migraine, stroke and vasospasm after subarachnoid hemorrhage. PMID:20950340

  16. Epoxyeicosatrienoic acids are endogenous regulators of vasoactive neuropeptide release from trigeminal ganglion neurons.

    PubMed

    Iliff, Jeffrey J; Fairbanks, Stacy L; Balkowiec, Agnieszka; Alkayed, Nabil J

    2010-12-01

    Epoxyeicosatrienoic acids (EETs) are bioactive eicosanoids produced from arachidonic acid by cytochrome P450 epoxygenases. We previously described the expression of cytochrome P450-2J epoxygenase in rat trigeminal ganglion neurons and that EETs signaling is involved in cerebrovascular dilation resulting from perivascular nerve stimulation. In this study, we evaluate the presence of the EETs signaling pathway in trigeminal ganglion neurons and their role in modulating the release of calcitonin gene-related peptide (CGRP) by trigeminal ganglion neurons. Liquid chromatography tandem mass spectrometry identified the presence of each of the four EETs regio-isomers within primary trigeminal ganglion neurons. Stimulation for 1 h with the transient receptor potential vanilloid-1 channel agonist capsaicin (100 nmol/L) or depolarizing K(+) (60 mmol/L) increased CGRP release as measured by ELISA. Stimulation-evoked CGRP release was attenuated by 30 min pre-treatment with the EETs antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, 10 μmol/L). K(+) stimulation elevated CGRP release 2.9 ± 0.3-fold above control levels, whereas in the presence of 14,15-EEZE K(+)-evoked CGRP release was significantly reduced to 1.1 ± 0.2-fold above control release (p < 0.01 anova, n = 6). 14,15-EEZE likewise attenuated capsaicin-evoked CGRP release from trigeminal ganglion neurons (p < 0.05 anova, n = 6). Similarly, pre-treatment with the cytochrome P450 epoxygenase inhibitor attenuated stimulation-evoked CGRP release. These data demonstrate that EETs are endogenous constituents of rat trigeminal ganglion neurons and suggest that they may act as intracellular regulators of neuropeptide release, which may have important clinical implications for treatment of migraine, stroke and vasospasm after subarachnoid hemorrhage. PMID:20950340

  17. Effectiveness of electroacupuncture at Zusanli (ST36) on the immunohistochemical density of enteroendocrine cells related to gastrointestinal function.

    PubMed

    Lee, Chang Hyun; Kim, Dae-Keun; Yook, Tae-Han; Sasaki, Motoki; Kitamura, Nobuo

    2012-04-01

    The purpose of this study was to examine the effects of electroacupuncture at Zusanli on the immunohistochemical density of enteroendocrine cells related to gastrointestinal function. The authors investigated the histochemical changes of mucous substances and immunohistochemical density of gastrin, serotonin, calcitonin gene-related peptide (CGRP), insulin, and pancreatic polypeptide (PP) secreting cells in rats. Staining density of mucous substances and the enteroendocrine cells of the gastrointestinal tract was observed with histochemical and immunohistochemical methods. Stainless steel needles with a diameter of 0.25 mm were inserted into Zusanli (St36, 5mm below the head of the fibula under the knee joint, and 2mm lateral to the anterior tubercle of the tibia) and connected to an electrical stimulator. The electroacupuncture (EA) stimulation was delivered for 30 minutes at 10 mA, 2 Hz in EA stimulation (2EA group) or 4 Hz in EA stimulation (4EA group) in each experimental group. In 4EA stimulation at the Zusanli, staining density of Alcian blue-periodic acid-Schiff on mucous substances of the stomach body was stronger than those of the 2EA and control groups. Periodic acid-Schiff staining density of pyloric mucosa in the 4EA group was stronger than that of the 2EA and control groups. The immunohistochemical staining density of gastrin, serotonin, and CGRP-secreting cells of pylorus in the 2EA and 4EA groups was stronger than that of the control group. Immunohistochemical staining density of insulin and PP secreting cells of islets of the pancreas in the 2EA and 4EA groups was stronger than that of the control group. These results suggest that EA stimulus at St36 has the potential to influence gastric mucous substances and enteroendocrine cells (gastrin, serotonin, CGRP, insulin, and PP) that subsequently modulate digestive functions. PMID:22483184

  18. Cancer therapy with alpha-emitters labeled peptides.

    PubMed

    Dadachova, Ekaterina

    2010-05-01

    Actively targeted alpha-particles offer specific tumor cell killing action with less collateral damage to surrounding normal tissues than beta-emitters. During the last decade, radiolabeled peptides that bind to different receptors on the tumors have been investigated as potential therapeutic agents both in the preclinical and clinical settings. Advantages of radiolabeled peptides over antibodies include relatively straightforward chemical synthesis, versatility, easier radiolabeling, rapid clearance from the circulation, faster penetration and more uniform distribution into tissues, and less immunogenicity. Rapid internalization of the radiolabeled peptides with equally rapid re-expression of the cell surface target is a highly desirable property that enhances the total delivery of these radionuclides into malignant sites. Peptides, such as octreotide, alpha-melanocyte-stimulating hormone analogues, arginine-glycine-aspartic acid-containing peptides, bombesin derivatives, and others may all be feasible for use with alpha-emitters. The on-going preclinical work has primarily concentrated on octreotide and octreotate analogues labeled with Bismuth-213 and Astatine-211. In addition, alpha-melanocyte-stimulating hormone analogue has been labeled with Lead-212/Bismuth-212 in vivo generator and demonstrated the encouraging therapeutic efficacy in treatment of experimental melanoma. Obstacles that continue to obstruct widespread acceptance of alpha-emitter-labeled peptides are primarily the supply of these radionuclides and concerns about potential kidney toxicity. New sources and methods for production of these medically valuable radionuclides and better understanding of mechanisms related to the peptide renal uptake and clearance should speed up the introduction of alpha-emitter-labeled peptides into the clinic. PMID:20350629

  19. Synthetic antimicrobial peptide design.

    PubMed

    Powell, W A; Catranis, C M; Maynard, C A

    1995-01-01

    To guide the design of potential plant pathogen-resistance genes, synthetic variants of naturally occurring antimicrobial gene products were evaluated. Five 20-amino acid (ESF1, ESF4, ESF5, ESF6, ESF13), one 18-amino acid (ESF12), and one 17-amino acid (ESF17) amphipathic peptide sequences were designed, synthesized, and tested with in vitro bioassays. Positive charges on the hydrophilic side of the peptide were shown to be essential for antifungal activity, yet the number of positive charges could be varied with little or no change in activity. The size could be reduced to 18 amino acids, but at 17 amino acids a significant reduction in activity was observed. ESF1, 5, 6, and 12 peptides were inhibitory to the germination of conidia from Cryphonectria parasitica, Fusarium oxysporum f. sp. lycopersici, and Septoria musiva but did not inhibit the germination of pollen from Castanea mollissima and Salix lucida. ESF12 also had no effect on the germination of Malus sylvestris and Lycopersicon esculentum pollen, but inhibited the growth of the bacteria Agrobacterium tumefaciens, Erwinia amylovora, and Pseudomonas syringae. The minimal inhibitory concentrations of the active ESF peptides were similar to those of the naturally occurring control peptides, magainin II and cecropin B. The significant differential in sensitivity between the microbes and plant cells indicated that the active ESF peptides are potentially useful models for designing plant pathogen-resistance genes. PMID:7579625

  20. Antimitotic peptides and depsipeptides.

    PubMed

    Hamel, Ernest; Covell, David G

    2002-01-01

    Tubulin is the target for an ever increasing number of unusual peptides and depsipeptides that were originally isolated from a wide variety of organisms. Since tubulin is the major component of cellular microtubules, which maintain cell shape in interphase and form the mitotic spindle, most of these compounds are highly toxic to mammalian cells. These peptides and depsipeptides disrupt cellular microtubules and prevent formation of a functional spindle, resulting in the accumulation of cultured cells in the G2/M phase of the cell cycle through specific inhibition of mitosis. At the biochemical level, the compounds all inhibit the assembly of tubulin into polymer and, in the cases where it has been studied, strongly suppress microtubule dynamics at low concentrations. In most cases the peptides and depsipeptides inhibit the binding of vinblastine and vincristine to tubulin in a noncompetitive manner, inhibit tubulin-dependent GTP hydrolysis, and interfere with nucleotide turnover at the exchangeable GTP site on beta-tubulin. Most of the peptides and depsipeptides induce tubulin to form oligomers of aberrant morphology, including tubulin rings that vary in diameter depending on the (depsi) peptide under study. The purpose of this review is to give an overview of the cellular, biochemical, in vivo, and SAR aspects of this group of compounds. We also summarize initial efforts by computer modeling to decipher a pharmacophore among the diverse structures of these peptides and depsipeptides. PMID:12678750

  1. Glucagon-like peptide 1: a potent glycogenic hormone.

    PubMed

    Valverde, I; Morales, M; Clemente, F; López-Delgado, M I; Delgado, E; Perea, A; Villanueva-Peñacarrillo, M L

    1994-08-01

    GLP-1(7-36)amide is an insulinotropic peptide derived from the intestinal post-translational proglucagon process, the release of which is increased mainly after a carbohydrate meal; also, its anti-diabetogenic effect in normal and diabetic states has been reported. In this study, GLP-1(7-36)amide stimulates the formation of glycogen from glucose in isolated rat hepatocytes, such a glycogenic effect being achieved with physiological concentrations of the peptide. The GLP-1(7-36)amide-induced glycogenesis is abolished by glucagon, and it is accompanied by stimulation of the glycogen synthase alpha activity and by a decrease in the basal and glucagon-stimulated cyclic AMP content. These findings could explain, at least in part, the GLP-1(7-36)amide insulin-independent plasma glucose lowering effect. PMID:8050588

  2. The nature of peptide interactions with acid end-group PLGAs and facile aqueous-based microencapsulation of therapeutic peptides

    PubMed Central

    Sophocleous, Andreas M.; Desai, Kashappa-Goud H.; Mazzara, J. Maxwell; Tong, Ling; Cheng, Ji-Xin; Olsen, Karl F.; Schwendeman, Steven P.

    2013-01-01

    An important poorly understood phenomenon in controlled-release depots involves the strong interaction between common cationic peptides and low Mw free acid end-group poly(lactic-co-glycolic acids) (PLGAs) used to achieve continuous peptide release kinetics. The kinetics of peptide sorption to PLGA was examined by incubating peptide solutions of 0.2-4 mM octreotide or leuprolide acetate salts in 0.1 M HEPES buffer, pH 7.4, with polymer particles or films at 4-37 °C for 24 h. The extent of absorption/loading of peptides in PLGA particles/films was assayed by two-phase extraction and amino acid analysis. Confocal Raman microspectroscopy and stimulated Raman scattering (SRS) and laser scanning confocal imaging techniques were used to examine peptide penetration in the polymer phase. The release of sorbed peptide from leuprolide-PLGA particles was evaluated both in vitro (PBST + 0.02% sodium azide, 37 °C) and in vivo (male Sprague-Dawley rats). We found that when the PLGA-COOH chains are sufficiently mobilized, therapeutic peptides not only bind at the surface, a common belief to date, but can also internalized and distributed throughout the polymer phase at physiological temperature forming a salt with low-molecular weight PLGA-COOH. Importantly, absorption of leuprolide into low MW PLGA-COOH particles yielded ~17 wt% leuprolide loading in the polymer (i.e., ~70% of PLGA-COOH acids occupied), and the absorbed peptide was released from the polymer for > 2 weeks in a controlled fashion in vitro and as indicated by sustained testosterone suppression in male Sprague-Dawley rats. This new approach, which bypasses the traditional encapsulation method and associated production cost, opens up the potential for facile production of low-cost controlled-release injectable depots for leuprolide and related peptides. PMID:24021356

  3. [A comparative study of the activity of a natural peptide complex in the kidneys and its synthetic analogs in autoimmune nephritis].

    PubMed

    Geĭko, O A; Bobrova, N A; Kaĭdashev, I P

    1998-01-01

    The activity of the natural peptide complex of the kidneys and of its synthetic analogs (PEKDLRK, PEKDSRK, PEKDDRL) in autoimmune nephritis was studied on golden hamsters. All the peptides under study demonstrated therapeutic activity but were characterized by peculiarity of their effect. The peptide PEKDLRK possessed the most marked capacity for stimulating phagocytic reactions, PEKDDRL apparently activated the system of natural killers. It is concluded that the study of peptides-analogs as potential drugs is promising. PMID:9783109

  4. Role of amphipathicity and hydrophobicity in the balance between hemolysis and peptide-membrane interactions of three related antimicrobial peptides.

    PubMed

    Hollmann, Axel; Martínez, Melina; Noguera, Martín E; Augusto, Marcelo T; Disalvo, Anibal; Santos, Nuno C; Semorile, Liliana; Maffía, Paulo C

    2016-05-01

    Cationic antimicrobial peptides (CAMPs) represent important self defense molecules in many organisms, including humans. These peptides have a broad spectrum of activities, killing or neutralizing many Gram-negative and Gram-positive bacteria. The emergence of multidrug resistant microbes has stimulated research on the development of alternative antibiotics. In the search for new antibiotics, cationic antimicrobial peptides (CAMPs) offer a viable alternative to conventional antibiotics, as they physically disrupt the bacterial membranes, leading to lysis of microbial membranes and eventually cell death. In particular, the group of linear α-helical cationic peptides has attracted increasing interest from clinical as well as basic research during the last decade. In this work, we studied the biophysical and microbiological characteristics of three new designed CAMPs. We modified a previously studied CAMP sequence, in order to increase or diminish the hydrophobic face, changing the position of two lysines or replacing three leucines, respectively. These mutations modified the hydrophobic moment of the resulting peptides and allowed us to study the importance of this parameter in the membrane interactions of the peptides. The structural properties of the peptides were also correlated with their membrane-disruptive abilities, antimicrobial activities and hemolysis of human red blood cells. PMID:26896660

  5. Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula.

    PubMed

    Mohd-Radzman, Nadiatul A; Binos, Steve; Truong, Thy T; Imin, Nijat; Mariani, Michael; Djordjevic, Michael A

    2015-08-01

    Small, post-translationally modified and secreted peptides regulate diverse plant developmental processes. Due to low natural abundance, it is difficult to isolate and identify these peptides. Using an improved peptide isolation protocol and Orbitrap mass spectrometry, nine 15-amino-acid CEP peptides were identified that corresponded to the two domains encoded by Medicago truncatula CEP1 (MtCEP1). Novel arabinosylated and hydroxylated peptides were identified in root cultures overexpressing MtCEP1. The five most abundant CEP peptides were hydroxylated and these species were detected also in low amounts in vector control samples. Synthetic peptides with different hydroxylation patterns differentially affected root development. Notably, the domain 1 peptide hydroxylated at Pro4 and Pro11 (D1:HyP4,11) imparted the strongest inhibition of lateral root emergence when grown with 5mM KNO3 and stimulated the highest increase in nodule number when grown with 0mM KNO3. Inhibition of lateral root emergence by D1:HyP4,11 was not alleviated by removing peptide exposure. In contrast, the domain 2 peptide hydroxylated at Pro11 (D2:HyP11) increased stage III-IV lateral root primordium numbers by 6-fold (P < 0.001) which failed to emerge. Auxin addition at levels which stimulated lateral root formation in wild-type plants had little or no ameliorating effect on CEP peptide-mediated inhibition of lateral root formation or emergence. Both peptides increased and altered the root staining pattern of the auxin-responsive reporter GH3:GUS suggesting CEPs alter auxin sensitivity or distribution. The results showed that CEP primary sequence and post-translational modifications influence peptide activities and the improved isolation procedure effectively and reproducibly identifies and characterises CEPs. PMID:25711701

  6. Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula

    PubMed Central

    Mohd-Radzman, Nadiatul A.; Binos, Steve; Truong, Thy T.; Imin, Nijat; Mariani, Michael; Djordjevic, Michael A.

    2015-01-01

    Small, post-translationally modified and secreted peptides regulate diverse plant developmental processes. Due to low natural abundance, it is difficult to isolate and identify these peptides. Using an improved peptide isolation protocol and Orbitrap mass spectrometry, nine 15-amino-acid CEP peptides were identified that corresponded to the two domains encoded by Medicago truncatula CEP1 (MtCEP1). Novel arabinosylated and hydroxylated peptides were identified in root cultures overexpressing MtCEP1. The five most abundant CEP peptides were hydroxylated and these species were detected also in low amounts in vector control samples. Synthetic peptides with different hydroxylation patterns differentially affected root development. Notably, the domain 1 peptide hydroxylated at Pro4 and Pro11 (D1:HyP4,11) imparted the strongest inhibition of lateral root emergence when grown with 5mM KNO3 and stimulated the highest increase in nodule number when grown with 0mM KNO3. Inhibition of lateral root emergence by D1:HyP4,11 was not alleviated by removing peptide exposure. In contrast, the domain 2 peptide hydroxylated at Pro11 (D2:HyP11) increased stage III–IV lateral root primordium numbers by 6-fold (P < 0.001) which failed to emerge. Auxin addition at levels which stimulated lateral root formation in wild-type plants had little or no ameliorating effect on CEP peptide-mediated inhibition of lateral root formation or emergence. Both peptides increased and altered the root staining pattern of the auxin-responsive reporter GH3:GUS suggesting CEPs alter auxin sensitivity or distribution. The results showed that CEP primary sequence and post-translational modifications influence peptide activities and the improved isolation procedure effectively and reproducibly identifies and characterises CEPs. PMID:25711701

  7. Depletion of cutaneous peptidergic innervation in HIV-associated xerosis.

    PubMed

    Rowe, A; Mallon, E; Rosenberger, P; Barrett, M; Walsh, J; Bunker, C B

    1999-03-01

    Severe xerosis occurs in approximately 20% of human immunodeficiency virus seropositive patients. Changes in cutaneous innervation have been found in various inflammatory skin diseases and in xerotic skin in familial amyloid. We have therefore carried out a quantitative examination of the cutaneous peptidergic innervation in human immunodeficiency virus-associated xerosis. Immunohistochemistry and image analysis quantitation were used to compare total cutaneous innervation (protein gene product 9.5), calcitonin gene-related peptide, substance P, and vasoactive intestinal peptide peptidergic fibers, at two sites in the skin of human immunodeficiency virus-associated xerosis patients (upper arm, n = 12; upper leg, n = 11) and site-matched seronegative controls (upper arm, n = 10; upper leg, n = 10). Measurement of lengths of fibers of each type was carried out for each subject in the epidermis and papillary dermis, and around the sweat glands. Immunostained mast cells in these areas were counted. Epidermal integrity and maturation were assessed by immunostaining for involucrin. There were significant (Mann-Whitney U test; p < 0.02) decreases in total lengths of protein gene product 9.5 fibers in both epidermis/papillary dermis and sweat gland fields; of calcitonin gene-related peptide innervation in the epidermis/papillary dermis; and of substance P innervation of the sweat glands. There were no differences in the distribution of mast cells, or in the epidermal expression of involucrin. Depletion of the calcitonin gene-related peptide innervation may affect the nutrient blood supply of the upper dermis, and the integrity and function of basal epidermis and Langerhans cells. Diminished substance P innervation of the sweat glands may affect their secretory activity. Both of these changes may be implicated in the development of xerosis. PMID:10084303

  8. Natriuretic peptide receptors in the fetal rat.

    PubMed

    Brown, J; Zuo, Z

    1995-08-01

    In vitro autoradiography of rat fetuses from embryonic days 12-19 (E12-E19) showed widespread high-affinity specific binding sites for natriuretic peptides. The sites on E16 somites avidly bound C-type natriuretic peptide [CNP-(1-22)] as well as C-ANP, a synthetic ligand that selects the C-type natriuretic peptide receptor (NPR-C). Most somitic binding sites had high affinity for atrial natriuretic peptide [ANP-(1-28)], confirming their resemblance to NPR-C. A few had a lower apparent affinity for ANP-(1-28), suggesting that they might be NPR-B. CNP-(1-22) was more powerful than ANP-(1-28) as an agonist of guanosine 3',5'-cyclic monophosphate production in somites, and ATP augmented the action of CNP-(1-22). These observations further suggest the presence of NPR-B. However, with cross-linking of 3-[125I]iodo-0-tyrosyl rat CNP-(1-22) to somitic membranes followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, only a single 64-kDa binding protein was detected under reducing conditions. This is not consistent with intact approximately 120-kDa NPR-B. In vitro autoradiography of the binding of natriuretic peptides to E16 liver implied the presence of NPR-A and NPR-C-like receptors. Hepatic guanosine 3',5'-cyclic monophosphate production was most powerfully stimulated by ANP-(1-28), as expected for NPR-A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis also identified NPR-A and NPR-C-like proteins in E16 hepatic membranes. Thus different NPRs are expressed by specific fetal tissues. This may be developmentally significant. PMID:7653543

  9. Somatostatin immunoreactive cells in lesional psoriatic human skin during peptide T treatment.

    PubMed

    Johansson, O; Hilliges, M; Talme, T; Marcusson, J A; Wetterberg, L

    1994-03-01

    Peptide T has been shown to be an effective treatment in psoriasis. The mechanism through which peptide T works in psoriasis is at present unknown. Furthermore, a clearance of psoriasis has also been registered using the inhibitory peptide somatostatin. These observations all focus on the fact that peptide T, somatostatin, and/or other peptides, might provide a clue to understanding the etiology and pathogenesis of psoriasis. Therefore, the effect of peptide T administration on somatostatin containing cutaneous cell populations was investigated. Ten psoriatic patients were treated with peptide T (D-Ala-peptide T amide; 2 mg/day i.v.) for 28 days. Serial biopsies were obtained from the psoriatic lesions before, once weekly during and 4 weeks after discontinuation of the peptide T treatment. An indirect immunofluorescence procedure was performed using a polyclonal antiserum against somatostatin. Clinically, most of the patients responded successfully to the treatment. Immunohistochemical investigations of the serial biopsies revealed the appearance of extensive changes in the number of dermal somatostatin immunoreactive dendritic cells. We believe that peptide T may stimulate the local synthesis and/or release of somatostatin, or proliferation and/or migration of certain dendritic cell populations in psoriatic lesions during healing. Since the benefits of peptide T treatment of psoriatic patients parallel earlier investigations using somatostatin infusions, it is likely that somatostatin given exogenously or synthesized/released endogenously plays a vital role in inducing the healing process.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7911613

  10. Diazepam binding inhibitor is a potent cholecystokinin-releasing peptide in the intestine.

    PubMed Central

    Herzig, K H; Schön, I; Tatemoto, K; Ohe, Y; Li, Y; Fölsch, U R; Owyang, C

    1996-01-01

    Pancreatic proteases in the duodenum inhibit the release of cholecystokinin (CCK) and thus exert feedback control of pancreatic exocrine secretion. Exclusion of proteases from the duodenum either by the diversion of bile-pancreatic juice or by the addition of protease inhibitors stimulates exocrine pancreatic secretion. The mechanism by which pancreatic proteases in the duodenum regulate CCK secretion is unknown. In this study, we isolated a trypsin-sensitive peptide that is secreted intraduodenally, releases CCK, and stimulates pancreatic enzyme secretion in rats. This peptide was found to be identical to the porcine diazepam binding inhibitor by peptide sequencing and mass spectrometry analysis. Intraduodenal infusion of 200 ng of synthetic porcine diazepam binding inhibitor1-86 in rats significantly stimulated pancreatic amylase output. Infusion of the CCK antagonist MK-329 completely blocked the diazepam binding inhibitor-stimulated amylase secretion. Similarly, diazepam binding inhibitor33-52 [corrected] also stimulated CCK release and pancreatic secretion in a dose-dependent manner although it was 100 times less potent than the whole peptide. Using a perfusion system containing isolated mucosal cells from the proximal intestine of rats, porcine diazepam binding inhibitor 10(-12) M) dose dependently stimulated CCK secretion. In separate studies, it was demonstrated that luminal secretion of the diazepam binding inhibitor immunoreactivity (7.5 X 10(11) M) could be detected in rat's intestinal washing following the diversion of bile-pancreatic juice. The secretion of this peptide was inhibited by atropine. In conclusion, we have isolated and characterized a CCK-releasing peptide that has a sequence identical to the porcine diazepam binding inhibitor from pig intestinal mucosa and that stimulates CCK release when administered intraduodenally in rat. This peptide may mediate feedback regulation of pancreatic enzyme secretion. Images Fig. 1 PMID:8755579

  11. Novel peptide recognized by RhoA GTPase.

    PubMed

    Drulis-Fajdasz, Dominika; Jelen, Filip; Oleksy, Arkadiusz; Otlewski, Jacek

    2006-01-01

    A phage-displayed random 7-mer disulfide bridge-constrained peptide library was used to map the surface of the RhoA GTPase and to find peptides able to recognize RhoA switch regions. Several peptide sequences were selected after four rounds of enrichment, giving a high signal in ELISA against RhoA-GDP. A detailed analysis of one such selected peptide, called R2 (CWSFPGYAC), is reported. The RhoA-R2 interaction was investigated using fluorescence spectroscopy, chemical denaturation, and determination of the kinetics of nucleotide exchange and GTP hydrolysis in the presence of RhoA regulatory proteins. All measurements indicate that the affinity of the R2 peptide for RhoA is in the micromolar range and that R2 behaves as an inhibitor of: i) GDP binding to the apo form of RhoA (Mg2+-and nucleotide-free form of the GTPase), ii) nucleotide exchange stimulated by GEF (DH/PH tandem from PDZRhoGEF), and iii) GTP hydrolysis stimulated by the BH domain of GrafGAP protein. PMID:17019437

  12. Electromembrane extraction of peptides.

    PubMed

    Balchen, Marte; Reubsaet, Léon; Pedersen-Bjergaard, Stig

    2008-06-20

    Rapid extraction of eight different peptides using electromembrane extraction (EME) was demonstrated for the first time. During an extraction time of 5 min, the model peptides migrated from a 500 microL aqueous acidic sample solution, through a thin supported liquid membrane (SLM) of an organic liquid sustained in the pores in the wall of a porous hollow fiber, and into a 25 microL aqueous acidic acceptor solution present inside the lumen of the hollow fiber. The driving force of the extraction was a 50 V potential sustained across the SLM, with the positive electrode in the sample and the negative electrode in the acceptor solution. The nature and the composition of the SLM were highly important for the EME process, and a mixture of 1-octanol and 15% di(2-ethylhexyl) phosphate was found to work properly. Using 1mM HCl as background electrolyte in the sample and 100 mM HCl in the acceptor solution, and agitation at 1050 rpm, enrichment up to 11 times was achieved. Recoveries were found to be dependent on the structure of the peptide, indicating that the polarity and the number of ionized groups were important parameters affecting the extraction efficiency. The experimental findings suggested that electromembrane extraction of peptides is possible and may be a valuable tool for future extraction of peptides. PMID:18479691

  13. Antimicrobial Peptides from Plants.

    PubMed

    Tam, James P; Wang, Shujing; Wong, Ka H; Tan, Wei Liang

    2015-01-01

    Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms. PMID:26580629

  14. Antimicrobial Peptides from Plants

    PubMed Central

    Tam, James P.; Wang, Shujing; Wong, Ka H.; Tan, Wei Liang

    2015-01-01

    Plant antimicrobial peptides (AMPs) have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs) of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic), lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms. PMID:26580629

  15. Discovery of Novel Peptides Regulating Competence Development in Streptococcus mutans

    PubMed Central

    Ahn, Sang-Joon; Kaspar, Justin; Kim, Jeong Nam; Seaton, Kinda

    2014-01-01

    A MarR-like transcriptional repressor (RcrR) and two predicted ABC efflux pumps (RcrPQ) encoded by a single operon were recently shown to be dominant regulators of stress tolerance and development of genetic competence in the oral pathogen Streptococcus mutans. Here, we focused on polar (ΔrcrR-P) and nonpolar (ΔrcrR-NP) rcrR mutants, which are hyper- and nontransformable, respectively, to dissect the mechanisms by which these mutations impact competence. We discovered two open reading frames (ORFs) in the 3′ end of the rcrQ gene that encode peptides of 27 and 42 amino acids (aa) which are also dramatically upregulated in the ΔrcrR-NP strain. Deletion of, or start codon mutations in, the ORFs for the peptides in the ΔrcrR-NP background restored competence and sensitivity to competence-stimulating peptide (CSP) to levels seen in the ΔrcrR-P strain. Overexpression of the peptides adversely affected competence development. Importantly, overexpression of mutant derivatives of the ABC exporters that lacked the peptides also resulted in impaired competence. FLAG-tagged versions of the peptides could be detected in S. mutans, and FLAG tagging of the peptides impaired their function. The competence phenotypes associated with the various mutations, and with overexpression of the peptides and ABC transporters, were correlated with the levels of ComX protein in cells. Collectively, these studies revealed multiple novel mechanisms for regulation of competence development by the components of the rcrRPQ operon. Given their intimate role in competence and stress tolerance, the rcrRPQ-encoded peptides may prove to be useful targets for therapeutics to diminish the virulence of S. mutans. PMID:25135217

  16. Immunohistochemical studies of neurochemical markers in normal human buccal mucosa.

    PubMed

    Hilliges, M; Hellman, M; Ahlström, U; Johansson, O

    1994-04-01

    The content of various substances, such as regulatory peptides, hormones and structural proteins, was investigated in normal buccal mucosa using indirect immunofluorescence. Thin nerve fibres, which from a morphological point of view were most probably sensory, showed immunoreactivity for substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide K (NPK) and neurokinin A (NKA). Also galanin (GAL), gamma-melanocyte stimulating hormone (gamma-MSH) and somatostatin (SOM) stained thin fibres were found in the propria, which were, however, few in number and the gamma-MSH staining was weak. CGRP, vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine amide (PHI) and neuropeptide Y (NPY) immunoreactive nerve fibres were observed in close connection to blood vessels. SOM positive cells with processes were found, mostly scattered, in the connective tissue. A population of cells within the epithelium also showed somatostatin immunoreactivity. Protein S-100 (S-100) stained distinct populations of cells at two separate locations. In the propria, cells with one or two slender processes were seen, being mostly single but sometimes forming groups. In the epithelium, dendritic cells with many processes with or without 'spines' were observed, mainly located to the basal layer of the lamina epithelialis. Single nerve fibres and nerve bundles were also stained. Neurofilament (NF) positive fibres, singly and in bundles, as well as endorgan-like structures were seen. Neuron-specific enolase (NSE) and protein gene product 9.5 (PGP 9.5) both stained the same structures, namely single fibres, nerve bundles, nerves surrounding vessels and innervating muscles and glands (if present in the section), as well as Merkel cells. Also with these two markers endorgan-like structures were seen. No clear innervation of the epithelium could be observed with the markers used. No methionine-enkephalin (ENK) or synaptophysin (SYN) immunoreactive material was found. PMID:7523335

  17. Tumor necrosis factor-α increases brain-derived neurotrophic factor expression in trigeminal ganglion neurons in an activity-dependent manner.

    PubMed

    Bałkowiec-Iskra, E; Vermehren-Schmaedick, A; Balkowiec, A

    2011-04-28

    Many chronic trigeminal pain conditions, such as migraine or temporo-mandibular disorders, are associated with inflammation within peripheral endings of trigeminal ganglion (TG) sensory neurons. A critical role in mechanisms of neuroinflammation is attributed to proinflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α (TNFα) that also contribute to mechanisms of persistent neuropathic pain resulting from nerve injury. However, the mechanisms of cytokine-mediated synaptic plasticity and nociceptor sensitization are not completely understood. In the present study, we examined the effects of TNFα on neuronal expression of brain-derived neurotrophic factor (BDNF), whose role in synaptic plasticity and sensitization of nociceptive pathways is well documented. We show that 4- and 24-h treatment with TNFα increases BDNF mRNA and protein, respectively, in neuron-enriched dissociated cultures of rat TG. TNFα increases the phosphorylated form of the cyclic AMP-responsive element binding protein (CREB), a transcription factor involved in regulation of BDNF expression in neurons, and activates transcription of BDNF exon IV (former exon III) and, to a lesser extent, exon VI (former exon IV), but not exon I. TNFα-mediated increase in BDNF expression is accompanied by increase in calcitonin gene-related peptide (CGRP), which is consistent with previously published studies, and indicates that both peptides are similarly regulated in TG neurons by inflammatory mediators. The effect of TNFα on BDNF expression is dependent on sodium influx through TTX-sensitive channels and on p38-mitogen-activated protein kinase. Moreover, electrical stimulation and forskolin, known to increase intracellular cAMP, potentiate the TNFα-mediated upregulation of BDNF expression. This study provides new evidence for a direct action of proinflammatory cytokines on TG primary sensory neurons, and reveals a mechanism through which TNFα stimulates de novo synthesis of BDNF in

  18. TUMOR NECROSIS FACTOR-α INCREASES BDNF EXPRESSION IN TRIGEMINAL GANGLION NEURONS IN AN ACTIVITY-DEPENDENT MANNER

    PubMed Central

    Bałkowiec-Iskra, Ewa; Vermehren-Schmaedick, Anke; Balkowiec, Agnieszka

    2011-01-01

    Many chronic trigeminal pain conditions, such as migraine or temporo-mandibular disorders, are associated with inflammation within peripheral endings of trigeminal ganglion (TG) sensory neurons. A critical role in mechanisms of neuroinflammation is attributed to proinflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α (TNFα) that also contribute to mechanisms of persistent neuropathic pain resulting from nerve injury. However, the mechanisms of cytokine-mediated synaptic plasticity and nociceptor sensitization are not completely understood. In the present study, we examined the effects of TNFα on neuronal expression of brain-derived neurotrophic factor (BDNF), whose role in synaptic plasticity and sensitization of nociceptive pathways is well documented. We show that 4- and 24-hr treatment with TNFα increases BDNF mRNA and protein, respectively, in neuron-enriched dissociated cultures of rat TG. TNFα increases the phosphorylated form of the cyclic adenosine monophosphate-responsive element binding protein (CREB), a transcription factor involved in regulation of BDNF expression in neurons, and activates transcription of BDNF exon IV (former exon III) and, to a lesser extent, exon VI (former exon IV), but not exon I. TNFα-mediated increase in BDNF expression was accompanied by increase in calcitonin gene-related peptide (CGRP), which is consistent with previously published studies, and indicates that both peptides are similarly regulated in TG neurons by inflammatory mediators. The effect of TNFα on BDNF expression is dependent on sodium influx through TTX-sensitive channels and on p38-mitogen-activated protein kinase. Moreover, electrical stimulation and forskolin, known to increase intracellular cAMP, potentiate the TNFα-mediated upregulation of BDNF expression. This study provides new evidence for a direct action of proinflammatory cytokines on TG primary sensory neurons, and reveals a mechanism through which TNFα stimulates de novo

  19. Nanoparticle Delivered Human Biliverdin Reductase-Based Peptide Increases Glucose Uptake by Activating IRK/Akt/GSK3 Axis: The Peptide Is Effective in the Cell and Wild-Type and Diabetic Ob/Ob Mice

    PubMed Central

    Gibbs, Peter E. M.; Miralem, Tihomir; Lerner-Marmarosh, Nicole; Maines, Mahin D.

    2016-01-01

    Insulin's stimulation of glucose uptake by binding to the IRK extracellular domain is compromised in diabetes. We have recently described an unprecedented approach to stimulating glucose uptake. KYCCSRK (P2) peptide, corresponding to the C-terminal segment of hBVR, was effective in binding to and inducing conformational change in the IRK intracellular kinase domain. Although myristoylated P2, made of L-amino acids, was effective in cell culture, its use for animal studies was unsuitable. We developed a peptidase-resistant formulation of the peptide that was efficient in both mice and cell culture systems. The peptide was constructed of D-amino acids, in reverse order, and blocked at both termini. Delivery of the encapsulated peptide to HepG2 and HSKM cells was confirmed by its prolonged effect on stimulation of glucose uptake (>6 h). The peptide improved glucose clearance in both wild-type and Ob/Ob mice; it lowered blood glucose levels and suppressed glucose-stimulated insulin secretion. IRK activity was stimulated in the liver of treated mice and in cultured cells. The peptide potentiated function of IRK's downstream effector, Akt-GSK3-(α, β) axis. Thus, P2-based approach can be used for improving glucose uptake by cells. Also, it allows for screening peptides in vitro and in animal models for treatment of diabetes. PMID:27294151

  20. Synthetic antibiofilm peptides.

    PubMed

    de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete; Franco, Octavio Luiz; Hancock, Robert E W

    2016-05-01

    Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. PMID:26724202

  1. Signal peptide of cellulase.

    PubMed

    Yan, Shaomin; Wu, Guang

    2014-06-01

    Cellulase is an enzyme playing a crucial role in biotechnology industries ranging from textile to biofuel because of tremendous amount of cellulose produced in plant. In order to improve cellulase productivity, huge resource has been spent in search for good cellulases from microorganism in remote areas and in creation of ideal cellulase by engineering. However, not much attention is given to the secretion of cellulases from cell into extracellular space, where a cellulase plays its enzymatic role. In this minireview, the signal peptides, which lead secreted proteins to specific secretion systems and scatter in literature, are reviewed. The patterns of signal peptides are checked against 4,101 cellulases documented in UniProtKB, the largest protein database in the world, to determine how these cellulases are secreted. Simultaneous review on both literature and cellulases from the database not only provides updated knowledge on signal peptides but also indicates the gap in our research. PMID:24743986

  2. Optical Stimulation of Neurons

    PubMed Central

    Thompson, Alexander C.; Stoddart, Paul R.; Jansen, E. Duco

    2014-01-01

    Our capacity to interface with the nervous system remains overwhelmingly reliant on electrical stimulation devices, such as electrode arrays and cuff electrodes that can stimulate both central and peripheral nervous systems. However, electrical stimulation has to deal with multiple challenges, including selectivity, spatial resolution, mechanical stability, implant-induced injury and the subsequent inflammatory response. Optical stimulation techniques may avoid some of these challenges by providing more selective stimulation, higher spatial resolution and reduced invasiveness of the device, while also avoiding the electrical artefacts that complicate recordings of electrically stimulated neuronal activity. This review explores the current status of optical stimulation techniques, including optogenetic methods, photoactive molecule approaches and infrared neural stimulation, together with emerging techniques such as hybrid optical-electrical stimulation, nanoparticle enhanced stimulation and optoelectric methods. Infrared neural stimulation is particularly emphasised, due to the potential for direct activation of neural tissue by infrared light, as opposed to techniques that rely on the introduction of exogenous light responsive materials. However, infrared neural stimulation remains imperfectly understood, and techniques for accurately delivering light are still under development. While the various techniques reviewed here confirm the overall feasibility of optical stimulation, a number of challenges remain to be overcome before they can deliver their full potential. PMID:26322269

  3. Biomimetic peptide nanosensors.

    PubMed

    Cui, Yue; Kim, Sang N; Naik, Rajesh R; McAlpine, Michael C

    2012-05-15

    The development of a miniaturized sensing platform tailored for sensitive and selective detection of a variety of biochemical analytes could offer transformative fundamental and technological opportunities. Due to their high surface-to-volume ratios, nanoscale materials are extremely sensitive sensors. Likewise, peptides represent robust substrates for selective recognition due to the potential for broad chemical diversity within their relatively compact size. Here we explore the possibilities of linking peptides to nanosensors for the selective detection of biochemical targets. Such systems raise a number of interesting fundamental challenges: What are the peptide sequences, and how can rational design be used to derive selective binders? What nanomaterials should be used, and what are some strategies for assembling hybrid nanosensors? What role does molecular modeling play in elucidating response mechanisms? What is the resulting performance of these sensors, in terms of sensitivity, selectivity, and response time? What are some potential applications? This Account will highlight our early attempts to address these research challenges. Specifically, we use natural peptide sequences or sequences identified from phage display as capture elements. The sensors are based on a variety of nanomaterials including nanowires, graphene, and carbon nanotubes. We couple peptides to the nanomaterial surfaces via traditional surface functionalization methods or self-assembly. Molecular modeling provides detailed insights into the hybrid nanostructure, as well as the sensor detection mechanisms. The peptide nanosensors can distinguish chemically camouflaged mixtures of vapors and detect chemical warfare agents with sensitivities as low as parts-per-billion levels. Finally, we anticipate future uses of this technology in biomedicine: for example, devices based on these sensors could detect disease from the molecular components in human breath. Overall, these results provide a

  4. ACTH (cosyntropin) stimulation test

    MedlinePlus

    ... The ACTH stimulation test measures how well the adrenal glands respond to adrenocorticotropic hormone ( ACTH ). ACTH is a ... produced in the pituitary gland that stimulates the adrenal glands to release a hormone called cortisol. How the ...

  5. Multidimensional signatures in antimicrobial peptides

    PubMed Central

    Yount, Nannette Y.; Yeaman, Michael R.

    2004-01-01

    Conventional analyses distinguish between antimicrobial peptides by differences in amino acid sequence. Yet structural paradigms common to broader classes of these molecules have not been established. The current analyses examined the potential conservation of structural themes in antimicrobial peptides from evolutionarily diverse organisms. Using proteomics, an antimicrobial peptide signature was discovered to integrate stereospecific sequence patterns and a hallmark three-dimensional motif. This striking multidimensional signature is conserved among disulfide-containing antimicrobial peptides spanning biological kingdoms, and it transcends motifs previously limited to defined peptide subclasses. Experimental data validating this model enabled the identification of previously unrecognized antimicrobial activity in peptides of known identity. The multidimensional signature model provides a unifying structural theme in broad classes of antimicrobial peptides, will facilitate discovery of antimicrobial peptides as yet unknown, and offers insights into the evolution of molecular determinants in these and related host defense effector molecules. PMID:15118082

  6. Current Understanding of Guanylin Peptides Actions

    PubMed Central

    2013-01-01

    Guanylin peptides (GPs) family includes guanylin (GN), uroguanylin (UGN), lymphoguanylin, and recently discovered renoguanylin. This growing family is proposed to be intestinal natriuretic peptides. After ingestion of a salty meal, GN and UGN are secreted into the intestinal lumen, where they inhibit sodium absorption and induce anion and water secretion. At the same conditions, those hormones stimulate renal electrolyte excretion by inducing natriuresis, kaliuresis, and diuresis and therefore prevent hypernatremia and hypervolemia after salty meals. In the intestine, a well-known receptor for GPs is guanylate cyclase C (GC-C) whose activation increases intracellular concentration of cGMP. However, in the kidney of GC-C-deficient mice, effects of GPs are unaltered, which could be by new cGMP-independent signaling pathway (G-protein-coupled receptor). This is not unusual as atrial natriuretic peptide also activates two different types of receptors: guanylate cylcase A and clearance receptor which is also G-protein coupled receptor. Physiological role of GPs in other organs (liver, pancreas, lung, sweat glands, and male reproductive system) needs to be discovered. However, it is known that they are involved in pathological conditions like cystic fibrosis, asthma, intestinal tumors, kidney and heart failure, obesity, and metabolic syndrome. PMID:24967239

  7. Effects of peptide YY on gallbladder motility

    SciTech Connect

    Conter, R.L.; Roslyn, J.J.; Taylor, I.L.

    1987-06-01

    The effects of peptide YY (PYY) on cholecystokinin-stimulated gallbladder contraction were investigated in the prairie dog model. Twelve animals underwent laparotomy with catheter placement into the gallbladder and common bile duct (vent). The gallbladder was continuously perfused with (/sup 14/C)polyethylene glycol-labeled lactated Ringer at 0.03 ml/min, and vent effluent was collected at 2.5-min intervals. All animals received 20 min of intravenous infusion of cholecystokinin octapeptide (CCK-OP), 2.5 ng x kg/sup -1/ x min/sup -1/, immediately followed by 60-min infusions of either lactated Ringer (LR) or synthetic PYY, 10 or 50 ng x kg/sup -1/ x min/sup -1/. When LR was infused after CCK-OP, gallbladder filling increased by 15.4 +/- 10.5% with minimal changes in gallbladder pressure. Infusion of PYY/sub 10/ resulted in a significant increase in gallbladder volume and filling with a significant decrease in intragallbladder pressure. Similar findings were noted with PYY/sub 50/. These data indicate that synthetic PYY significantly augments gallbladder filling after CCK-OP-stimulated gallbladder contraction. These finding, coupled with the observation that PYY inhibits pancreatic secretion, suggest that this peptide may be the anti-CCK hormone and may have an important role in regulating biliary activity postprandially.

  8. Design and Engineering Strategies for Synthetic Antimicrobial Peptides

    NASA Astrophysics Data System (ADS)

    Tossi, Alessandro

    Thousands of antimicrobial peptides (AMPs) of prokaryotic, fungal, plant, or animal origin have been identified, and their potential as lead compounds for the design of novel therapeutic agents in the treatment of infection, for stimulating the immune system, or in countering septic shock has been widely recognized. Added to this is their possible use in prophylaxis of infectious diseases for animal or plant protection, for disinfection of surgical instruments or industrial surfaces, and for food preservation among other commercially important applications. Since the early eighties, AMPs have been subject to a vast number of studies aimed at understanding what determines their potency and spectrum of activities against bacterial or fungal pathogens, and at maximizing these while limiting cytotoxic activities toward host cells. Much research has also been directed toward understanding specific mechanisms of action underlying the antimicrobial activity and selectivity, to be able to redesign the peptides for optimal performance. A central theme in the mode of action of many AMPs is their dynamic interaction with biological membranes, which involves various properties of these peptides such as, among others, surface hydrophobicity and polarity, charge, structure, and induced conformational variations. These features are often intimately interconnected so that engineering peptides to independently adjust any one property in particular is not an easy task. However, solid-phase peptide synthesis allows the use of a large repertoire of nonproteinogenic amino acids that can be used in the rational design of peptides to finely tune structural and physicochemical properties and precisely probe structure-function relationships.

  9. New insights into the bioactivity of peptides from probiotics.

    PubMed

    Mandal, Santi M; Pati, Bikas R; Chakraborty, Ranadhir; Franco, Octavio L

    2016-01-01

    Probiotics are unique bacteria that offer several therapeutic benefits to human beings when administered in optimum amounts. Probiotics are able to produce antimicrobial substances, which stimulate the body's immune responses. Here, we review in detail the anti-infective peptides derived from probiotics and their potential immunomodulatory and anti-inflammatory activities, including a major role in cross-talk between probiotics and gut microbiota under adverse conditions. Insights from the engineered cell surface of probiotics may provide novel anti-infective therapy by heterologous expression of receptor peptides of bacterial toxins. It may be possible to use antigenic peptides from viral pathogens as live vaccines. Another possibility is to generate antiviral peptides that bind directly to virus particles, while some peptides exert anti-inflammatory and anticancer effects. Some extracellular polymeric substances might serve as anti-infective peptides. These avenues of treatment have remained largely unexplored to date, despite their potential in generating powerful anti-inflammatory and anti-infective products. PMID:27100351

  10. Brain Peptides and Psychopharmacology

    ERIC Educational Resources Information Center

    Arehart-Treichel, Joan

    1976-01-01

    Proteins isolated from the brain and used as drugs can improve and apparently even transfer mental states and behavior. Much of the pioneering work and recent research with humans and animals is reviewed and crucial questions that are being posed about the psychologically active peptides are related. (BT)

  11. Antagonistic peptide technology for functional dissection of CLE peptides revisited

    PubMed Central

    Czyzewicz, Nathan; Wildhagen, Mari; Cattaneo, Pietro; Stahl, Yvonne; Pinto, Karine Gustavo; Aalen, Reidunn B.; Butenko, Melinka A.; Simon, Rüdiger; Hardtke, Christian S.; De Smet, Ive

    2015-01-01

    In the Arabidopsis thaliana genome, over 1000 putative genes encoding small, presumably secreted, signalling peptides can be recognized. However, a major obstacle in identifying the function of genes encoding small signalling peptides is the limited number of available loss-of-function mutants. To overcome this, a promising new tool, antagonistic peptide technology, was recently developed. Here, this antagonistic peptide technology was tested on selected CLE peptides and the related IDA peptide and its usefulness in the context of studies of peptide function discussed. Based on the analyses, it was concluded that the antagonistic peptide approach is not the ultimate means to overcome redundancy or lack of loss-of-function lines. However, information collected using antagonistic peptide approaches (in the broad sense) can be very useful, but these approaches do not work in all cases and require a deep insight on the interaction between the ligand and its receptor to be successful. This, as well as peptide ligand structure considerations, should be taken into account before ordering a wide range of synthetic peptide variants and/or generating transgenic plants. PMID:26136270

  12. Antagonistic peptide technology for functional dissection of CLE peptides revisited.

    PubMed

    Czyzewicz, Nathan; Wildhagen, Mari; Cattaneo, Pietro; Stahl, Yvonne; Pinto, Karine Gustavo; Aalen, Reidunn B; Butenko, Melinka A; Simon, Rüdiger; Hardtke, Christian S; De Smet, Ive

    2015-08-01

    In the Arabidopsis thaliana genome, over 1000 putative genes encoding small, presumably secreted, signalling peptides can be recognized. However, a major obstacle in identifying the function of genes encoding small signalling peptides is the limited number of available loss-of-function mutants. To overcome this, a promising new tool, antagonistic peptide technology, was recently developed. Here, this antagonistic peptide technology was tested on selected CLE peptides and the related IDA peptide and its usefulness in the context of studies of peptide function discussed. Based on the analyses, it was concluded that the antagonistic peptide approach is not the ultimate means to overcome redundancy or lack of loss-of-function lines. However, information collected using antagonistic peptide approaches (in the broad sense) can be very useful, but these approaches do not work in all cases and require a deep insight on the interaction between the ligand and its receptor to be successful. This, as well as peptide ligand structure considerations, should be taken into account before ordering a wide range of synthetic peptide variants and/or generating transgenic plants. PMID:26136270

  13. Topiramate inhibits trigeminovascular activation: an intravital microscopy study

    PubMed Central

    Akerman, Simon; Goadsby, Peter J

    2005-01-01

    Activation, or the altered perception of activation, of trigeminal nerves that innervate the cranial vasculature is considered to be a pivotal component of the pathophysiology of acute migraine. Calcitonin gene-related peptide (CGRP) levels are increased during migraine and after trigeminal nerve stimulation in the cat. Both CGRP and nitric oxide (NO) infusion causes headache and delayed migraine in migraineurs. Neurogenic stimulation of a cranial window, CGRP and NO injection all cause meningeal artery dilation in the rat when viewed using intravital microscopy. Topiramate is an antiepileptic drug with established efficacy as a migraine preventive, and has recently been shown to inhibit neurons of the trigeminocervical complex after superior sagittal sinus stimulation. In this study, we used intravital microscopy with neurogenic dural vasodilation, and CGRP- and NO-induced dilation to examine whether intravenous topiramate has effects on the trigeminovascular system. Topiramate was able to attentuate neurogenic dural vasodilation maximally after 15 min by 52% at 30 mg kg−1 (t5=6.78, n=6); there was no significant inhibition at 10 mg kg−1. There was also significant attenuation of the NO-induced dilation maximally after 15 min, at both 10 and 30 mg kg−1 by 21% (t6=6.09, n=7) and 41% (t6=5.3, n=7), respectively. CGRP-induced dilation was not inhibited at either dose of topiramate. The study demonstrates that topiramate is likely to inhibit neurogenic dural vasodilation by inhibiting the release of CGRP from prejunctional trigeminal neurons, thus attenuating the dural vasodilation. Topiramate is not able to act postsynaptically at the blood vessels themselves as the CGRP-induced dilation was not attenuated. The data are consistent with an effect of topiramate on trigeminovascular activation which may form part of its preventive antimigraine mechanisms of action. PMID:15980877

  14. Spinal astrocytic activation contributes to both induction and maintenance of pituitary adenylate cyclase-activating polypeptide type 1 receptor-induced long-lasting mechanical allodynia in mice

    PubMed Central

    Yokai, Masafumi; Miyata, Atsuro

    2016-01-01

    Background Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptors are present in the spinal dorsal horn and dorsal root ganglia, suggesting an important role of PACAP–PACAP receptors signaling system in the modulation of spinal nociceptive transmission. We have previously reported that a single intrathecal injection of PACAP or a PACAP specific (PAC1) receptor selective agonist, maxadilan, in mice induced dose-dependent aversive behaviors, which lasted more than 30 min, and suggested that the maintenance of the nociceptive behaviors was associated with the spinal astrocytic activation. Results We found that a single intrathecal administration of PACAP or maxadilan also produced long-lasting hind paw mechanical allodynia, which persisted at least 84 days without affecting thermal nociceptive threshold. In contrast, intrathecal application of vasoactive intestinal polypeptide did not change mechanical threshold, and substance P, calcitonin gene-related peptide, or N-methyl-D-aspartate induced only transient mechanical allodynia, which disappeared within 21 days. Western blot and immunohistochemical analyses with an astrocytic marker, glial fibrillary acidic protein, revealed that the spinal PAC1 receptor stimulation caused sustained astrocytic activation, which also lasted more than 84 days. Intrathecal co-administration of L-α-aminoadipate, an astroglial toxin, with PACAP or maxadilan almost completely prevented the induction of the mechanical allodynia. Furthermore, intrathecal treatment of L-α-aminoadipate at 84 days after the PAC1 stimulation transiently reversed the mechanical allodynia accompanied by the reduction of glial fibrillary acidic protein expression level. Conclusion Our data suggest that spinal astrocytic activation triggered by the PAC1 receptor stimulation contributes to both induction and maintenance of the long-term mechanical allodynia. PMID:27175011

  15. Biochemical functionalization of peptide nanotubes with phage displayed peptides

    NASA Astrophysics Data System (ADS)

    Swaminathan, Swathi; Cui, Yue

    2016-09-01

    The development of a general approach for the biochemical functionalization of peptide nanotubes (PNTs) could open up existing opportunities in both fundamental studies as well as a variety of applications. PNTs are spontaneously assembled organic nanostructures made from peptides. Phage display has emerged as a powerful approach for identifying selective peptide binding motifs. Here, we demonstrate for the first time the biochemical functionalization of PNTs via peptides identified from a phage display peptide library. The phage-displayed peptides are shown to recognize PNTs. These advances further allow for the development of bifunctional peptides for the capture of bacteria and the self-assembly of silver particles onto PNTs. We anticipate that these results could provide significant opportunities for using PNTs in both fundamental studies and practical applications, including sensors and biosensors nanoelectronics, energy storage devices, drug delivery, and tissue engineering.

  16. Biochemical functionalization of peptide nanotubes with phage displayed peptides.

    PubMed

    Swaminathan, Swathi; Cui, Yue

    2016-09-01

    The development of a general approach for the biochemical functionalization of peptide nanotubes (PNTs) could open up existing opportunities in both fundamental studies as well as a variety of applications. PNTs are spontaneously assembled organic nanostructures made from peptides. Phage display has emerged as a powerful approach for identifying selective peptide binding motifs. Here, we demonstrate for the first time the biochemical functionalization of PNTs via peptides identified from a phage display peptide library. The phage-displayed peptides are shown to recognize PNTs. These advances further allow for the development of bifunctional peptides for the capture of bacteria and the self-assembly of silver particles onto PNTs. We anticipate that these results could provide significant opportunities for using PNTs in both fundamental studies and practical applications, including sensors and biosensors nanoelectronics, energy storage devices, drug delivery, and tissue engineering. PMID:27479451

  17. [Progression of the mechanism study on experimental migraine treated with acupuncture in rat model].

    PubMed

    Liu, Lu; Pei, Pei; Wang, Linpeng

    2016-03-01

    In the paper, by taking acupuncture and migraine as the key words to retrieve CNKI and PubMed database, the literature analysis was done on the mechanism study on experimental migraine treated with acupuncture in rat model. The results showed that acupuncture mechanism study focused on the regulation and control of the relevant neurotransmitters/neuromodulators of migraine, such as calcitonin gene-related peptide (CGRP), serotonin (5-HT), nitric oxide (NO), etc. Moreover, in the paper, the review had been done on the neurotransmitters/neuromodulators involved in the study. PMID:27344850

  18. Discovery of BMS-846372, a Potent and Orally Active Human CGRP Receptor Antagonist for the Treatment of Migraine.

    PubMed

    Luo, Guanglin; Chen, Ling; Conway, Charles M; Denton, Rex; Keavy, Deborah; Gulianello, Michael; Huang, Yanling; Kostich, Walter; Lentz, Kimberley A; Mercer, Stephen E; Schartman, Richard; Signor, Laura; Browning, Marc; Macor, John E; Dubowchik, Gene M

    2012-04-12

    Calcitonin gene-related peptide (CGRP) receptor antagonists have been clinically shown to be effective in the treatment of migraine, but identification of potent and orally bioavailable compounds has been challenging. Herein, we describe the conceptualization, synthesis, and preclinical characterization of a potent, orally active CGRP receptor antagonist 5 (BMS-846372). Compound 5 has good oral bioavailability in rat, dog, and cynomolgus monkeys and overall attractive preclinical properties including strong (>50% inhibition) exposure-dependent in vivo efficacy in a marmoset migraine model. PMID:24900474

  19. Discovery of BMS-846372, a Potent and Orally Active Human CGRP Receptor Antagonist for the Treatment of Migraine

    PubMed Central

    2012-01-01

    Calcitonin gene-related peptide (CGRP) receptor antagonists have been clinically shown to be effective in the treatment of migraine, but identification of potent and orally bioavailable compounds has been challenging. Herein, we describe the conceptualization, synthesis, and preclinical characterization of a potent, orally active CGRP receptor antagonist 5 (BMS-846372). Compound 5 has good oral bioavailability in rat, dog, and cynomolgus monkeys and overall attractive preclinical properties including strong (>50% inhibition) exposure-dependent in vivo efficacy in a marmoset migraine model. PMID:24900474

  20. CGRP as a neuropeptide in migraine: lessons from mice

    PubMed Central

    Russo, Andrew F

    2015-01-01

    Migraine is a neurological disorder that is far more than just a bad headache. A hallmark of migraine is altered sensory perception. A likely contributor to this altered perception is the neuropeptide calcitonin gene-related peptide (CGRP). Over the past decade, CGRP has become firmly established as a key player in migraine. Although the mechanisms and sites of action by which CGRP might trigger migraine remain speculative, recent advances with mouse models provide some hints. This brief review focuses on how CGRP might act as both a central and peripheral neuromodulator to contribute to the migraine-like symptom of light aversive behaviour in mice. PMID:26032833

  1. Antimicrobial peptides: premises and promises.

    PubMed

    Reddy, K V R; Yedery, R D; Aranha, C

    2004-12-01

    Antimicrobial peptides (AMPs) are an important component of the natural defences of most living organisms against invading pathogens. These are relatively small (< 10kDa), cationic and amphipathic peptides of variable length, sequence and structure. During the past two decades several AMPs have been isolated from a wide variety of animals, both vertebrates and invertebrates, and plants as well as from bacteria and fungi. Most of these peptides are obtained from different sources like macrophages, neutrophils, epithelial cells, haemocytes, fat body, reproductive tract, etc. These peptides exhibit broad-spectrum activity against a wide range of microorganisms including Gram-positive and Gram-negative bacteria, protozoa, yeast, fungi and viruses. A few peptides have also been found to be cytotoxic to sperm and tumour cells. AMPs are classified based on the three dimensional structural studies carried out with the help of NMR. The peptides are broadly classified into five major groups namely (a) peptides that form alpha-helical structures, (b) peptides rich in cysteine residues, (c) peptides that form beta-sheet, (d) peptides rich in regular amino acids namely histatin, arginine and proline and (e) peptides composed of rare and modified amino acids. Most of these peptides are believed to act by disrupting the plasma membrane leading to the lysis of the cell. AMPs have been found to be excellent candidates for developing novel antimicrobial agents and a few of these peptides show antimicrobial activity against pathogens causing sexually transmitted infection (STI), including HIV/HSV. Peptides, namely magainin and nisin have been shown to demonstrate contraceptive properties in vitro and in vivo. A few peptides have already entered clinical trials for the treatment of impetigo, diabetic foot ulcers and gastric helicobacter infections. In this review, we discuss the source, structures and mode of action with special reference to therapeutic considerations of various AMPs

  2. Phage-displayed peptide libraries

    PubMed Central

    Zwick, Michael B; Shen, Juqun; Scott, Jamie K

    2014-01-01

    Over the past year, significant advances have been achieved through the use of phage-displayed peptide libraries. A wide variety of bioactive molecules, including antibodies, receptors and enzymes, have selected high-affinity and/or highly-specific peptide ligands from a number of different types of peptide library. The demonstrated therapeutic potential of some of these peptides, as well as new insights into protein structure and function that peptide ligands have provided, highlight the progress made within this rapidly-expanding field. PMID:9720267

  3. Antibody Production with Synthetic Peptides.

    PubMed

    Lee, Bao-Shiang; Huang, Jin-Sheng; Jayathilaka, Lasanthi P; Lee, Jenny; Gupta, Shalini

    2016-01-01

    Peptides (usually 10-20 amino acid residues in length) can be used as effectively as proteins in raising antibodies producing both polyclonal and monoclonal antibodies routinely with titers higher than 20,000. Peptide antigens do not function as immunogens unless they are conjugated to proteins. Production of high quality antipeptide antibodies is dependent upon peptide sequence selection, the success of peptide synthesis, peptide-carrier protein conjugation, the humoral immune response in the host animal, the adjuvant used, the peptide dose administered, the injection method, and the purification of the antibody. Peptide sequence selection is probably the most critical step in the production of antipeptide antibodies. Although the process for designing peptide antigens is not exact, several guidelines and computational B-cell epitope prediction methods can help maximize the likelihood of producing antipeptide antibodies that recognize the protein. Antibodies raised by peptides have become essential tools in life science research. Virtually all phospho-specific antibodies are now produced using phosphopeptides as antigens. Typically, 5-20 mg of peptide is enough for antipeptide antibody production. It takes 3 months to produce a polyclonal antipeptide antibody in rabbits that yields ~100 mL of serum which corresponds to ~8-10 mg of the specific antibody after affinity purification using a peptide column. PMID:27515072

  4. Immunogenicity of polysaccharides conjugated to peptides containing T- and B-cell epitopes.

    PubMed Central

    Lett, E; Gangloff, S; Zimmermann, M; Wachsmann, D; Klein, J P

    1994-01-01

    To develop a general model of polysaccharide-peptide vaccine, we have investigated the efficiency of linear peptides derived from protein SR, and adhesin of the I/II protein antigen family of oral streptococci, to act as carriers for two T cell-independent polysaccharides: serogroup f polysaccharide from Streptococcus mutans OMZ 175 (poly f) and Saccharomyces cerevisiae mannan. Peptide 3 (YEKEPTPPTRTPDQ) and peptide 6 (TPEDPTDPTDPQDPSS), accessible on the native SR protein as demonstrated by their reactivity in enzyme-linked immunosorbent assays with rat antisera raised against protein SR, correspond to immunodominant regions of SR. Peptide 3 contains at least one B- and one T-cell epitope, as demonstrated by its ability to induce peptide- and SR-specific antibody responses without any carrier and to stimulate the proliferation of rat lymph node cells primed either with free peptide or native SR, whereas peptide 6 contains only B-cell epitope(s). Peptide 3 was then covalently coupled though reductive amination to either poly f or mannan, and peptide 6 was coupled to poly f. Subcutaneous immunizations of rats with poly f-peptide 3 or mannan-peptide 3 conjugates produced a systemic immunoglobulin M (IgM) and IgG antibody response, and the elicited antibodies reacted with free poly f or mannan, peptide 3, protein SR, and S. mutans or S. cerevisiae whole cells. Rats immunized with poly f-peptide 6 did not develop any antipeptide or anti-SR response. Furthermore, a booster immunization of animals with poly f-peptide 3 or mannan-peptide 3 conjugates induced high titers of anti-peptide 3, anti-poly f, and antimannan antibodies, which occurred quickly. The response is anamnestic for the peptide and the polysaccharides and is characterized by an Ig switch from IgM to IgG. The data presented here confirm that the presence of B- and T-cell epitopes is necessary to induce an anamnestic antipeptide response and that a peptide containing relevant B- and T-cell epitopes can act

  5. Concepts for Biologically Active Peptides

    PubMed Central

    Kastin, Abba J.; Pan, Weihong

    2012-01-01

    Here we review a unique aspect of CNS research on biologically active peptides that started against a background of prevalent dogmas but ended by exerting considerable influence on the field. During the course of refuting some doctrines, we introduced several concepts that were unconventional and paradigm-shifting at the time. We showed that (1) hypothalamic peptides can act ‘up’ on the brain as well as ‘down’ on the pituitary, (2) peripheral peptides can affect the brain, (3) peptides can cross the blood-brain barrier, (4) the actions of peptides can persist longer than their half-lives in blood, (5) perinatal administration of peptides can exert actions persisting into adulthood, (6) a single peptide can have more than one action, (7) dose-response relationships of peptides need not be linear, (8) the brain produces antiopiate as well as opiate peptides, (9) there is a selective high affinity endogenous peptide ligand for the mu-opiate receptor, (10) a peptide’s name does not restrict its effects, and (11) astrocytes assume an active role in response to metabolic disturbance and hyperleptinemia. The evolving questions in our laboratories reflect the diligent effort of the neuropeptide community to identify the roles of peptides in the CNS. The next decade is expected to see greater progress in the following areas: (a) interactions of peptides with other molecules in the CNS; (b) peptide involvement in cell-cell interactions; and (c) peptides in neuropsychiatric, autoimmune, and neurodegenerative diseases. The development of peptidomics and gene silencing approaches will expedite the formation of many new concepts in a new era. PMID:20726835

  6. Natriuretic peptides in fish physiology.

    PubMed

    Loretz, C A; Pollina, C

    2000-02-01

    Natriuretic peptides exist in the fishes as a family of structurally-related isohormones including atrial natriuretic peptide (ANP), C-type natriuretic peptide (CNP) and ventricular natriuretic peptide (VNP); to date, brain natriuretic peptide (or B-type natriuretic peptide, BNP) has not been definitively identified in the fishes. Based on nucleotide and amino acid sequence similarity, the natriuretic peptide family of isohormones may have evolved from a neuromodulatory, CNP-like brain peptide. The primary sites of synthesis for the circulating hormones are the heart and brain; additional extracardiac and extracranial sites, including the intestine, synthesize and release natriuretic peptides locally for paracrine regulation of various physiological functions. Membrane-bound, guanylyl cyclase-coupled natriuretic peptide receptors (A- and B-types) are generally implicated in mediating natriuretic peptide effects via the production of cyclic GMP as the intracellular messenger. C- and D-type natriuretic peptide receptors lacking the guanylyl cyclase domain may influence target cell function through G(i) protein-coupled inhibition of membrane adenylyl cyclase activity, and they likely also act as clearance receptors for circulating hormone. In the few systems examined using homologous or piscine reagents, differential receptor binding and tissue responsiveness to specific natriuretic peptide isohormones is demonstrated. Similar to their acute physiological effects in mammals, natriuretic peptides are vasorelaxant in all fishes examined. In contrast to mammals, where natriuretic peptides act through natriuresis and diuresis to bring about long-term reductions in blood volume and blood pressure, in fishes the primary action appears to be the extrusion of excess salt at the gills and rectal gland, and the limiting of drinking-coupled salt uptake by the alimentary system. In teleosts, both hypernatremia and hypervolemia are effective stimuli for cardiac secretion of

  7. Transcriptional and Functional Characterization of the G Protein-Coupled Receptor Repertoire of Gastric Somatostatin Cells.

    PubMed

    Egerod, Kristoffer L; Engelstoft, Maja S; Lund, Mari L; Grunddal, Kaare V; Zhao, Mirabella; Barir-Jensen, Dominique; Nygaard, Eva B; Petersen, Natalia; Holst, Jens J; Schwartz, Thue W

    2015-11-01

    In the stomach, somatostatin (SST) acts as a general paracrine negative regulator of exocrine secretion of gastric acid and pepsinogen and endocrine secretion of gastrin, ghrelin, and histamine. Using reporter mice expressing red fluorescent protein (RFP) under control of the SST promotor, we have characterized the G protein-coupled receptors expressed in gastric Sst-RFP-positive cells and probed their effects on SST secretion in primary cell cultures. Surprisingly, besides SST, amylin and PYY were also highly enriched in the SST cells. Several receptors found to regulate SST secretion were highly expressed and/or enriched. 1) The metabolite receptors calcium-sensing receptor and free fatty acid receptor 4 (GPR120) functioned as positive and negative regulators, respectively. 2) Among the neurotransmitter receptors, adrenergic receptors α1a, α2a, α2b, and β1 were all highly expressed, with norepinephrine and isoproterenol acting as positive regulators. The muscarinic receptor M3 acted as a positive regulator, whereas M4 was conceivably a negative regulator. 3) Of the hormone receptors, the GLP-1 and GIP receptors, CCKb (stimulated by both CCK and gastrin) and surprisingly the melanocortin MC1 receptor were all positive regulators. 4) The neuropeptide receptors for calcitonin gene-related peptide, adrenomedullin, and vasoactive intestinal peptide acted as positive regulators, no effect was observed using galanin and nociceptin although transcripts for the corresponding receptors appeared highly expressed. 5) The SST receptors 1 and 2 functioned in an autocrine negative feedback loop. Thus, the article provides a comprehensive map of receptors through which SST secretion is regulated by hormones, neurotransmitters, neuropeptides and metabolites that act directly on the SST cells in the gastric mucosa. PMID:26181106

  8. Understanding migraine: Potential role of neurogenic inflammation

    PubMed Central

    Malhotra, Rakesh

    2016-01-01

    Neurogenic inflammation, a well-defined pathophysiologial process is characterized by the release of potent vasoactive neuropeptides, predominantly calcitonin gene-related peptide (CGRP), substance P (SP), and neurokinin A from activated peripheral nociceptive sensory nerve terminals (usually C and A delta-fibers). These peptides lead to a cascade of inflammatory tissue responses including arteriolar vasodilation, plasma protein extravasation, and degranulation of mast cells in their peripheral target tissue. Neurogenic inflammatory processes have long been implicated as a possible mechanism involved in the pathophysiology of various human diseases of the nervous system, respiratory system, gastrointestinal tract, urogenital tract, and skin. The recent development of several innovative experimental migraine models has provided evidence suggestive of the involvement of neuropeptides (SP, neurokinin A, and CGRP) in migraine headache. Antidromic stimulation of nociceptive fibers of the trigeminal nerve resulted in a neurogenic inflammatory response with marked increase in plasma protein extravasation from dural blood vessels by the release of various sensory neuropeptides. Several clinically effective abortive antimigraine medications, such as ergots and triptans, have been shown to attenuate the release of neuropeptide and neurogenic plasma protein extravasation. These findings provide support for the validity of using animal models to investigate mechanisms of neurogenic inflammation in migraine. These also further strengthen the notion of migraine being a neuroinflammatory disease. In the clinical context, there is a paucity of knowledge and awareness among physicians regarding the role of neurogenic inflammation in migraine. Improved understanding of the molecular biology, pharmacology, and pathophysiology of neurogenic inflammation may provide the practitioner the context-specific feedback to identify the novel and most effective therapeutic approach to treatment

  9. Understanding migraine: Potential role of neurogenic inflammation.

    PubMed

    Malhotra, Rakesh

    2016-01-01

    Neurogenic inflammation, a well-defined pathophysiologial process is characterized by the release of potent vasoactive neuropeptides, predominantly calcitonin gene-related peptide (CGRP), substance P (SP), and neurokinin A from activated peripheral nociceptive sensory nerve terminals (usually C and A delta-fibers). These peptides lead to a cascade of inflammatory tissue responses including arteriolar vasodilation, plasma protein extravasation, and degranulation of mast cells in their peripheral target tissue. Neurogenic inflammatory processes have long been implicated as a possible mechanism involved in the pathophysiology of various human diseases of the nervous system, respiratory system, gastrointestinal tract, urogenital tract, and skin. The recent development of several innovative experimental migraine models has provided evidence suggestive of the involvement of neuropeptides (SP, neurokinin A, and CGRP) in migraine headache. Antidromic stimulation of nociceptive fibers of the trigeminal nerve resulted in a neurogenic inflammatory response with marked increase in plasma protein extravasation from dural blood vessels by the release of various sensory neuropeptides. Several clinically effective abortive antimigraine medications, such as ergots and triptans, have been shown to attenuate the release of neuropeptide and neurogenic plasma protein extravasation. These findings provide support for the validity of using animal models to investigate mechanisms of neurogenic inflammation in migraine. These also further strengthen the notion of migraine being a neuroinflammatory disease. In the clinical context, there is a paucity of knowledge and awareness among physicians regarding the role of neurogenic inflammation in migraine. Improved understanding of the molecular biology, pharmacology, and pathophysiology of neurogenic inflammation may provide the practitioner the context-specific feedback to identify the novel and most effective therapeutic approach to treatment

  10. Bradykinin Induces TRPV1 Exocytotic Recruitment in Peptidergic Nociceptors

    PubMed Central

    Mathivanan, Sakthikumar; Devesa, Isabel; Changeux, Jean-Pierre; Ferrer-Montiel, Antonio

    2016-01-01

    Transient receptor potential vanilloid I (TRPV1) sensitization in peripheral nociceptors is a prominent phenomenon that occurs in inflammatory pain conditions. Pro-algesic agents can potentiate TRPV1 activity in nociceptors through both stimulation of its channel gating and mobilization of channels to the neuronal surface in a context dependent manner. A recent study reported that ATP-induced TRPV1 sensitization in peptidergic nociceptors involves the exocytotic release of channels trafficked by large dense core vesicles (LDCVs) that cargo alpha-calcitonin gene related peptide alpha (αCGRP). We hypothesized that, similar to ATP, bradykinin may also use different mechanisms to sensitize TRPV1 channels in peptidergic and non-peptidergic nociceptors. We found that bradykinin notably enhances the excitability of peptidergic nociceptors, and sensitizes TRPV1, primarily through the bradykinin receptor 2 pathway. Notably, bradykinin sensitization of TRPV1 in peptidergic nociceptors was significantly blocked by inhibiting Ca2+-dependent neuronal exocytosis. In addition, silencing αCGRP gene expression, but not substance P, drastically reduced bradykinin-induced TRPV1 sensitization in peptidergic nociceptors. Taken together, these findings indicate that bradykinin-induced sensitization of TRPV1 in peptidergic nociceptors is partially mediated by the exocytotic mobilization of new channels trafficked by αCGRP-loaded LDCVs to the neuronal membrane. Our findings further imply a central role of αCGRP peptidergic nociceptors in peripheral algesic sensitization, and substantiate that inhibition of LDCVs exocytosis is a valuable therapeutic strategy to treat pain, as it concurrently reduces the release of pro-inflammatory peptides and the membrane recruitment of thermoTRP channels. PMID:27445816

  11. The use of an IL-1 receptor antagonist peptide to control inflammation in the treatment of corneal limbal epithelial stem cell deficiency.

    PubMed

    Fok, E; Sandeman, S R; Guildford, A L; Martin, Y H

    2015-01-01

    Corneal limbal stem cell deficiency (LSCD) may be treated using ex vivo limbal epithelial stem cells (LESCs) derived from cadaveric donor tissue. However, continuing challenges exist around tissue availability, inflammation, and transplant rejection. Lipopolysaccharide (LPS) or recombinant human IL-1β stimulated primary human keratocyte and LESC models were used to investigate the anti-inflammatory properties of a short chain, IL-1 receptor antagonist peptide for use in LESC sheet growth to control inflammation. The peptide was characterized using mass spectroscopy and high performance liquid chromatography. Peptide cytotoxicity, patterns of cell cytokine expression in response to LPS or IL-1β stimulation, and peptide suppression of this response were investigated by MTS/LDH assays, ELISA, and q-PCR. Cell differences in LPS stimulated toll-like receptor 4 expression were investigated using immunocytochemistry. A significant reduction in rIL-1β stimulated inflammatory cytokine production occurred following LESC and keratocyte incubation with anti-inflammatory peptide and in LPS stimulated IL-6 and IL-8 production following keratocyte incubation with peptide (1 mg/mL) (P < 0.05). LESCs produced no cytokine response to LPS stimulation and showed no TLR4 expression. The peptide supported LESC growth when adhered to a silicone hydrogel contact lens indicating potential use in improved LESC grafting through suppression of inflammation. PMID:25705668

  12. An analogue peptide from the Cancer/Testis antigen PASD1 induces CD8+ T cell responses against naturally processed peptide

    PubMed Central

    Hardwick, Nicola; Buchan, Sarah; Ingram, Wendy; Khan, Ghazala; Vittes, Gisella; Rice, Jason; Pulford, Karen; Mufti, Ghulam; Stevenson, Freda; Guinn, Barbara-ann

    2013-01-01

    We have previously identified the novel Cancer/Testis antigen PASD1 by immunoscreening a testis library with pooled acute myeloid leukemia (AML) patient sera. To develop a cytotoxic T lymphocyte (CTL)-inducing vaccine, we have now investigated the carboxy-terminal region, known to contain serological determinants, for MHC class I (HLA-A⋆0201)-binding peptides. Algorithm-selected natural peptides failed to show detectable HLA-A⋆0201 binding in T2 assays. However, anchor-modified analogue peptides showed enhanced binding, with decreased off-rates. Analogue peptide-loaded antigen-presenting cells (APCs) induced IFN-γ production by T cells from normal donors and patients. In addition, peptide-specific T cells could be expanded from cancer patients by stimulation with the PASD1 analogue peptide Pa14. For clinical application, a DNA fusion gene vaccine encoding Pa14 was designed and tested in “humanized” mice. Splenocytes from vaccinated mice showed in vitro cytotoxicity against tumour cells, either exogenously loaded with the corresponding wild-type peptide (Pw8) or expressing endogenously processed PASD1 protein. We show for the first time that a DNA vaccine encoding an altered PASD1 epitope can induce CTLs to target the natural peptide expressed by human tumour cells. PMID:23882161

  13. Stimulant Use Disorders.

    PubMed

    Park, Taryn M; Haning, William F

    2016-07-01

    Compared with other illicit substances, stimulants are not commonly used by adolescents; however, they represent a serious concern regarding substance use among youths. This article uses methamphetamine as a model for stimulant use in adolescents; cocaine and prescription stimulants are also mentioned. Methamphetamine use among adolescents and young adults is a serious health concern with potentially long-term physical, cognitive, and psychiatric consequences. Brain development and the effects of misusing stimulants align such that usage in adolescents can more dangerous than during adulthood. It seems helpful to keep in mind the differences between adolescents and young adults when implementing interventions. PMID:27338967

  14. Detection of C-Peptide in Urine as a Measure of Ongoing Beta Cell Function.

    PubMed

    McDonald, T J; Perry, M H

    2016-01-01

    C-peptide is a protein secreted by the pancreatic beta cells in equimolar quantities with insulin, following the cleavage of proinsulin into insulin. Measurement of C-peptide is used as a surrogate marker of endogenous insulin secretory capacity. Assessing C-peptide levels can be useful in classifying the subtype of diabetes as well as assessing potential treatment choices in the management of diabetes.Standard measures of C-peptide involve blood samples collected either fasted or, most often, after a fixed stimulus (such as oral glucose, mixed meal, or IV glucagon). Despite the established clinical utility of blood C-peptide measurement, its widespread use is limited. In many instances this is due to perceived practical restrictions associated with sample collection.Urine C-peptide measurement is an attractive noninvasive alternative to blood measures of beta-cell function. Urine C-peptide creatinine ratio measured in a single post stimulated sample has been shown to be a robust, reproducible measure of endogenous C-peptide which is stable for three days at room temperature when collected in boric acid. Modern high sensitivity immunoassay technologies have facilitated measurement of C-peptide down to single picomolar concentrations. PMID:27083170

  15. Multiple Factors Related to the Secretion of Glucagon-Like Peptide-1

    PubMed Central

    Wang, XingChun; Liu, Huan; Chen, Jiaqi; Li, Yan; Qu, Shen

    2015-01-01

    The glucagon-like peptide-1 is secreted by intestinal L cells in response to nutrient ingestion. It regulates the secretion and sensitivity of insulin while suppressing glucagon secretion and decreasing postprandial glucose levels. It also improves beta-cell proliferation and prevents beta-cell apoptosis induced by cytotoxic agents. Additionally, glucagon-like peptide-1 delays gastric emptying and suppresses appetite. The impaired secretion of glucagon-like peptide-1 has negative influence on diabetes, hyperlipidemia, and insulin resistance related diseases. Thus, glucagon-like peptide-1-based therapies (glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) are now well accepted in the management of type 2 diabetes. The levels of glucagon-like peptide-1 are influenced by multiple factors including a variety of nutrients. The component of a meal acts as potent stimulants of glucagon-like peptide-1 secretion. The levels of its secretion change with the intake of different nutrients. Some drugs also have influence on GLP-1 secretion. Bariatric surgery may improve metabolism through the action on GLP-1 levels. In recent years, there has been a great interest in developing effective methods to regulate glucagon-like peptide-1 secretion. This review summarizes the literature on glucagon-like peptide-1 and related factors affecting its levels. PMID:26366173

  16. Atypical Signaling and Functional Desensitization Response of MAS Receptor to Peptide Ligands

    PubMed Central

    Tirupula, Kalyan C.; Desnoyer, Russell; Speth, Robert C.; Karnik, Sadashiva S.

    2014-01-01

    MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1–7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1–7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data

  17. Aliphatic acid-conjugated antimicrobial peptides--potential agents with anti-tumor, multidrug resistance-reversing activity and enhanced stability.

    PubMed

    Deng, Xin; Qiu, Qianqian; Ma, Ke; Wang, Xuekun; Huang, Wenlong; Qian, Hai

    2015-07-28

    Compared with traditional therapeutics, antimicrobial peptides as novel anti-tumor agents have prominent advantages of higher specificity and circumvention of multi-drug resistance. In a previous study, we found that B1, an antimicrobial peptide derived from Cathelicidin-BF15, presented specific anti-tumor activity against several tumor cells. Since aliphatic chain-conjugated peptides have shown ameliorative activity and stability, we conjugated aliphatic acids with different lengths to the amino terminal of B1. All the conjugated peptides exhibited improved anti-tumor activity over B1. Further investigations revealed that the peptides were capable of disrupting the cell membrane, stimulating cytochrome c release into the cytosol, which results in apoptosis. The peptides also acted against multidrug resistant cells and had multidrug resistance-reversing effects. Additionally, conjugation of aliphatic acid enhanced the peptide stability in plasma. In summary, aliphatic acid-modified peptides might be promising anti-tumor agents in the future. PMID:26083110

  18. Porcine myofibrillar proteins as potential precursors of bioactive peptides - an in silico study.

    PubMed

    Kęska, Paulina; Stadnik, Joanna

    2016-06-15

    Selected porcine myofibrillar proteins have been assessed as potential precursors of bioactive peptides based on in silico analysis. The potential of protein sequences for releasing peptides was evaluated by determining the profile of their potential biological activity and the frequency of occurrence of fragments with a given activity using the BIOPEP database. Digestive enzymes: pepsin, trypsin and chymotrypsin have been used for the in silico proteolysis with the use of the "Enzyme(s) action" tool in BIOPEP. After simulated gastrointestinal digestion the tested sequences of pig myofibrillar proteins are a potential source of a total of 399 peptides with activities such as enzyme inhibition, antioxidative, hypotensive, stimulating or regulating various body functions and antiamnestic activities. Within the intact proteins and after simulated gastrointestinal digestion, dipeptidyl peptidase IV inhibitory peptide sequences were the most frequently observed. The results indicate that pork myofibrillar proteins are a promising source of peptides with biological activity. PMID:27247979

  19. Comparative Effect of ACTH and Related Peptides on Proliferation and Growth of Rat Adrenal Gland

    PubMed Central

    Lotfi, Claudimara Ferini Pacicco; de Mendonca, Pedro O. R.

    2016-01-01

    Pro-opiomelanocortin (POMC) is a polypeptide precursor known to yield biologically active peptides related to a range of functions. These active peptides include the adrenocorticotropic hormone (ACTH), which is essential for maintenance of adrenal growth and steroidogenesis, and the alpha-melanocyte stimulation hormone, which plays a key role in energy homeostasis. However, the role of the highly conserved N-terminal region of POMC peptide fragments has begun to be unraveled only recently. Here, we review the cascade of events involved in regulation of proliferation and growth of murine adrenal cortex triggered by ACTH and other POMC-derived peptides. Key findings regarding signaling pathways and modulation of genes and proteins required for the regulation of adrenal growth are summarized. We have outlined the known mechanisms as well as future challenges for research on the regulation of adrenal proliferation and growth triggered by these peptides. PMID:27242663

  20. Cigarette smoke has sensory effects through nicotinic and TRPA1 but not TRPV1 receptors on the isolated mouse trachea and larynx.

    PubMed

    Kichko, Tatjana I; Kobal, Gerd; Reeh, Peter W

    2015-10-15

    Cigarette smoke (CS) exposes chemosensory nerves in the airways to a multitude of chemicals, some acting through the irritant receptors TRPV1 and TRPA1 but potentially also through nicotinic acetylcholine receptors (nAChR). Our aim was to characterize the differences in sensory neuronal effects of CS, gas phase, and particulate matter as well as of typical constituents, such as nicotine and reactive carbonyls. Isolated mouse trachea and larynx were employed to measure release of calcitonin gene-related peptide (CGRP) as an index of sensory neuron activation evoked by CS, by filtered CS gas phase essentially free of nicotine, and by dilute total particulate matter (TPM) containing defined nicotine concentrations. With CS stimulation of the superfused trachea, TRPV1 null mutants showed about the same large responses as wild-type mice, whereas both TRPA1(-/-) and double knockouts exhibited 80% reduction; the retained 20% response was abolished by mecamylamine (10 μM), indicating a distinct contribution of nAChRs. These phenotypes were accentuated by using TPM to stimulate the immersed trachea; 50% of response was retained in TRPA1(-/-) and abolished by mecamylamine. In contrast, the gas phase acted like a sheer TRPA1 agonist, consistent with its composition, among other compounds, of volatile reactive carbonyls like formaldehyde and acrolein. In the trachea, the gas phase and CS were equally effective in releasing CGRP, whereas the larynx showed much larger CS than gas phase responses. Thus nicotinic receptors contribute to the sensory effects of cigarette smoke on the trachea, which are dominated by TRPA1. How this translates to human perception affords future research. PMID:26472811

  1. Role of opioid receptors in neurogenic dural vasodilation and sensitization of trigeminal neurones in anaesthetized rats

    PubMed Central

    Williamson, D J; Shepheard, S L; Cook, D A; Hargreaves, R J; Hill, R G; Cumberbatch, M J

    2001-01-01

    Migraine headache is thought to be caused by a distension of meningeal blood vessels, the activation of trigeminal sensory neurones and the the development of a central sensitization within the trigeminal nucleus caudalis (TNC). It has been proposed that clinically effective 5-HT1B/1D agonists act peripherally to inhibit the release of calcitonin gene-related peptide (CGRP) and neurogenic dural vasodilation, and to attenuate nociceptive neurotransmission within the TNC. Since opioids are also effective anti-migraine agents the present studies investigated the role of opioids within the trigemino-vascular system in anaesthetised rats. Electrical stimulation of the dura mater evoked neurogenic dural vasodilation which was significantly inhibited by morphine (1 mg kg−1) the selective μ-opioid agonist DAGO (10 μg kg−1) and the mixed agonist/antagonist butorphanol (1 mg kg−1) but not by the κ- and δ-opioid agonists (±) U50488H (100 μg kg−1) and DPDPE (1 mg kg−1). Morphine had no effect on CGRP-evoked dural vasodilation. In electrophysiological studies morphine (1 – 10 mg kg−1) significantly attenuated brainstem neuronal activity in response to electrical stimulation of the dura by 65% at 10 mg kg−1. Morphine (3 mg kg−1) also inhibited the TNC neuronal sensitization following CGRP-evoked dilation. The present studies have demonstrated that opioids block the nociceptive neurotransmission within the trigeminal nucleus caudalis and in addition inhibit neurogenic dural vasodilation via an action on μ-opioid receptors located on trigeminal sensory fibres innervating dural blood vessels. These peripheral and central actions are similar to those of the ‘triptan' 5-HT1B/1D agonists and could account for the anti-migraine actions of opioids. PMID:11454653

  2. Cigarette smoke has sensory effects through nicotinic and TRPA1 but not TRPV1 receptors on the isolated mouse trachea and larynx

    PubMed Central

    Kichko, Tatjana I.; Kobal, Gerd

    2015-01-01

    Cigarette smoke (CS) exposes chemosensory nerves in the airways to a multitude of chemicals, some acting through the irritant receptors TRPV1 and TRPA1 but potentially also through nicotinic acetylcholine receptors (nAChR). Our aim was to characterize the differences in sensory neuronal effects of CS, gas phase, and particulate matter as well as of typical constituents, such as nicotine and reactive carbonyls. Isolated mouse trachea and larynx were employed to measure release of calcitonin gene-related peptide (CGRP) as an index of sensory neuron activation evoked by CS, by filtered CS gas phase essentially free of nicotine, and by dilute total particulate matter (TPM) containing defined nicotine concentrations. With CS stimulation of the superfused trachea, TRPV1 null mutants showed about the same large responses as wild-type mice, whereas both TRPA1−/− and double knockouts exhibited 80% reduction; the retained 20% response was abolished by mecamylamine (10 μM), indicating a distinct contribution of nAChRs. These phenotypes were accentuated by using TPM to stimulate the immersed trachea; 50% of response was retained in TRPA1−/− and abolished by mecamylamine. In contrast, the gas phase acted like a sheer TRPA1 agonist, consistent with its composition, among other compounds, of volatile reactive carbonyls like formaldehyde and acrolein. In the trachea, the gas phase and CS were equally effective in releasing CGRP, whereas the larynx showed much larger CS than gas phase responses. Thus nicotinic receptors contribute to the sensory effects of cigarette smoke on the trachea, which are dominated by TRPA1. How this translates to human perception affords future research. PMID:26472811

  3. Soluble epoxide hydrolase limits mechanical hyperalgesia during inflammation

    PubMed Central

    2011-01-01

    Background Cytochrome-P450 (CYP450) epoxygenases metabolise arachidonic acid (AA) into four different biologically active epoxyeicosatrienoic acid (EET) regioisomers. Three of the EETs (i.e., 8,9-, 11,12- and 14,15-EET) are rapidly hydrolysed by the enzyme soluble epoxide hydrolase (sEH). Here, we investigated the role of sEH in nociceptive processing during peripheral inflammation. Results In dorsal root ganglia (DRG), we found that sEH is expressed in medium and large diameter neurofilament 200-positive neurons. Isolated DRG-neurons from sEH-/- mice showed higher EET and lower DHET levels. Upon AA stimulation, the largest changes in EET levels occurred in culture media, indicating both that cell associated EET concentrations quickly reach saturation and EET-hydrolyzing activity mostly effects extracellular EET signaling. In vivo, DRGs from sEH-deficient mice exhibited elevated 8,9-, 11,12- and 14,15-EET-levels. Interestingly, EET levels did not increase at the site of zymosan-induced inflammation. Cellular imaging experiments revealed direct calcium flux responses to 8,9-EET in a subpopulation of nociceptors. In addition, 8,9-EET sensitized AITC-induced calcium increases in DRG neurons and AITC-induced calcitonin gene related peptide (CGRP) release from sciatic nerve axons, indicating that 8,9-EET sensitizes TRPA1-expressing neurons, which are known to contribute to mechanical hyperalgesia. Supporting this, sEH-/- mice showed increased nociceptive responses to mechanical stimulation during zymosan-induced inflammation and 8,9-EET injection reduced mechanical thresholds in naive mice. Conclusion Our results show that the sEH can regulate mechanical hyperalgesia during inflammation by inactivating 8,9-EET, which sensitizes TRPA1-expressing nociceptors. Therefore we suggest that influencing the CYP450 pathway, which is actually highly considered to treat cardiovascular diseases, may cause pain side effects. PMID:21970373

  4. 5-HT7 Receptors Are Not Involved in Neuropeptide Release in Primary Cultured Rat Trigeminal Ganglion Neurons.

    PubMed

    Wang, Xiaojuan; Hu, Rong; Liang, Jianbo; Li, Ze; Sun, Weiwen; Pan, Xiaoping

    2016-06-01

    Migraine is a common but complex neurological disorder. Its precise mechanisms are not fully understood. Increasing indirect evidence indicates that 5-HT7 receptors may be involved; however, their role remains unknown. Our previous in vivo study showed that selective blockade of 5-HT7 receptors caused decreased serum levels of calcitonin gene-related peptide (CGRP) in the external jugular vein following electrical stimulation of the trigeminal ganglion (TG) in an animal model of migraine. In the present study, we used an in vitro model of cultured TG cells to further investigate whether 5-HT7 receptors are directly responsible for the release of CGRP and substance P from TG neurons. We stimulated rat primary cultured TG neurons with capsaicin or potassium chloride (KCl) to mimic neurogenic inflammation, resulting in release of CGRP and substance P. 5-HT7 receptors were abundantly expressed in TG neurons. Greater than 93 % of 5-HT7 receptor-positive neurons co-expressed CGRP and 56 % co-expressed substance P. Both the capsaicin- and KCl-induced release of CGRP and substance P were unaffected by pretreatment of cultured TG cells with the selective 5-HT7 receptor agonist AS19 and antagonist SB269970. This study demonstrates for the first time that 5-HT7 receptors are abundantly co-expressed with CGRP and substance P in rat primary TG neurons and suggests that they are not responsible for the release of CGRP and substance P from cultured TG neurons evoked by capsaicin or KCl. PMID:26892478

  5. Protons modulate perivascular axo-axonal neurotransmission in the rat mesenteric artery

    PubMed Central

    Takatori, Shingo; Hirai, Kazuhiro; Ozaki, Shuichiro; Tangsucharit, Panot; Fukushima-Miyashita, Satoko; Goda, Mitsuhiro; Hashikawa-Hobara, Narumi; Ono, Nobufumi; Kawasaki, Hiromu

    2014-01-01

    Background and Purpose Previous studies have demonstrated that nicotine releases protons from adrenergic nerves via stimulation of nicotinic ACh receptors and activates transient receptor potential vanilloid-1 (TRPV1) receptors located on calcitonin gene-related peptide (CGRP)-containing (CGRPergic) vasodilator nerves, resulting in vasodilatation. The present study investigated whether perivascular nerves release protons, which modulate axon-axonal neurotransmission. Experiment Approach Perfusion pressure and pH levels of perfusate in rat-perfused mesenteric vascular beds without endothelium were measured with a pressure transducer and a pH meter respectively. Key Results Periarterial nerve stimulation (PNS) initially induced vasoconstriction, which was followed by long-lasting vasodilatation and decreased pH levels in the perfusate. Cold-storage denervation of the preparation abolished the decreased pH and vascular responses to PNS. The adrenergic neuron blocker guanethidine inhibited PNS-induced vasoconstriction and effects on pH, but not PNS-induced vasodilatation. Capsaicin (CGRP depletor), capsazepine and ruthenium red (TRPV1 inhibitors) attenuated the PNS-induced decrease in pH and vasodilatation. In denuded preparations, ACh caused long-lasting vasodilatation and lowered pH; these effects were inhibited by capsaicin pretreatment and atropine, but not by guanethidine or mecamylamine. Capsaicin injection induced vasodilatation and a reduction in pH, which were abolished by ruthenium red. The use of a fluorescent pH indicator demonstrated that application of nicotine, ACh and capsaicin outside small mesenteric arteries reduced perivascular pH levels and these effects were abolished in a Ca2+-free medium. Conclusion and Implication These results suggest that protons are released from perivascular adrenergic and CGRPergic nerves upon PNS and these protons modulate transmission in CGRPergic nerves. PMID:25117291

  6. Functional properties of submucosal venules in the rat stomach.

    PubMed

    Mitsui, Retsu; Hashitani, Hikaru

    2015-06-01

    Venules in the stomach may have intrinsic properties for maintaining active microcirculation drainage even during gastric filling. Properties of spontaneous and nerve-mediated activity of submucosal venules in the rat stomach were investigated. Changes in vasodiameter and intracellular Ca(2+) in venular smooth muscle cells (SMCs) were monitored by video tracking and Fluo-8 Ca(2+) imaging, respectively. Venular SMCs developed synchronous spontaneous Ca(2+) transients and corresponding rhythmic constrictions of the venules. Nominally Ca(2+)-free solution or an L-type Ca(2+) channel blocker (1 μM nifedipine) disrupted the Ca(2+) transient synchrony and abolished spontaneous constrictions. Spontaneous constrictions were also prevented by inhibitors of sarcoplasmic reticulum Ca(2+)-ATPase (10 μM cyclopiazonic acid (CPA)), IP3 receptors (100 μM 2-APB) or Ca(2+)-activated Cl(-) channels (100 μM niflumic acid). Transmural nerve stimulation (TNS) induced a long-lasting venular constriction that was abolished by α-adrenoceptor antagonist (1 μM phentolamine), while TNS evoked a sympathetic transient constriction of arterioles that was abolished by a combination of phentolamine and a P2 purinoceptor antagonist (10 μM pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS)). Consistently, P2X1 purinoceptor immunoreactivity was detected in arteriolar but not venular SMCs. Primary afferent nerve stimulation (300 nM capsaicin) caused a venular dilatation by releasing calcitonin gene-related peptide. Thus, Ca(2+) release from the sarcoplasmic reticulum may play a fundamental role in the generation of spontaneous Ca(2+) transients, while electrical coupling amongst venular SMCs via L-type Ca(2+) channel activation appears to be critical for Ca(2+) transient synchrony as well as spontaneous contractions. Sympathetic venular constrictions appear to be exclusively mediated by noradrenaline due to the lack of P2X1 receptor in venular SMCs. PMID:25066613

  7. Pharmacological Evidence that Histamine H3 Receptors Mediate Histamine-Induced Inhibition of the Vagal Bradycardic Out-flow in Pithed Rats.

    PubMed

    García, Mónica; García-Pedraza, José Ángel; Villalón, Carlos M; Morán, Asunción

    2016-02-01

    In vivo stimulation of cardiac vagal neurons induces bradycardia by acetylcholine (ACh) release. As vagal release of ACh may be modulated by autoreceptors (muscarinic M2 ) and heteroreceptors (including serotonin 5-HT1 ), this study has analysed the pharmacological profile of the receptors involved in histamine-induced inhibition of the vagal bradycardic out-flow in pithed rats. For this purpose, 180 male Wistar rats were pithed, artificially ventilated and pre-treated (i.v.) with 1 mg/kg atenolol, followed by i.v. administration of physiological saline (1 ml/kg), histamine (10, 50, 100 and 200 μg/kg) or the selective histamine H1 (2-pyridylethylamine), H2 (dimaprit), H3 (methimepip) and H4 (VUF 8430) receptor agonists (1, 10, 50 and 100 μg/kg each). Under these conditions, electrical stimulation (3, 6 and 9 Hz; 15 ± 3 V and 1 ms) of the vagus nerve resulted in frequency-dependent bradycardic responses, which were (i) unchanged during the infusions of saline, 2-pyridylethylamine, dimaprit or VUF 8430; and (ii) dose-dependently inhibited by histamine or methimepip. Moreover, the inhibition of the bradycardia caused by 50 μg/kg of either histamine or methimepip (which failed to inhibit the bradycardic responses to i.v. bolus injections of acetylcholine; 1-10 μg/kg) was abolished by the H3 receptor antagonist JNJ 10181457 (1 mg/kg, i.v.). In conclusion, our results suggest that histamine-induced inhibition of the vagal bradycardic out-flow in pithed rats is mainly mediated by pre-junctional activation of histamine H3 receptors, as previously demonstrated for the vasopressor sympathetic out-flow and the vasodepressor sensory CGRPergic (calcitonin gene-related peptide) out-flow. PMID:26301462

  8. Eccentric Muscle Contraction and Stretching Evoke Mechanical Hyperalgesia and Modulate CGRP and P2X3 Expression in a Functionally Relevant Manner

    PubMed Central

    Dessem, Dean; Ambalavanar, Ranjinidevi; Evancho, Melena; Moutanni, Aicha; Yallampalli, Chandrasekhar; Bai, Guang

    2010-01-01

    Non-invasive, movement-based models were used to investigate muscle pain. In rats, the masseter muscle was rapidly stretched or electrically stimulated during forced lengthening to produce eccentric muscle contractions (EC). Both EC and stretching disrupted scattered myofibers and produced intramuscular plasma extravasation. Pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) and vascular endothelial growth factor (VEGF) were elevated in the masseter 24h following EC. At 48h, neutrophils increased and ED1 macrophages infiltrated myofibers while ED2 macrophages were abundant at 4d. Mechanical hyperalgesia was evident in the ipsilateral head 4h-4d after a single bout of EC and for 7d following multiple bouts (1 bout/d for 4d). Calcitonin gene-related peptide (CGRP) mRNA increased in the trigeminal ganglion 24h following EC while immunoreactive CGRP decreased. By 2d, CGRP-muscle afferent numbers equaled naive numbers implying that CGRP is released following EC and replenished within 2d. EC elevated P2X3 mRNA and increased P2X3-muscle afferent neuron number for 12d while electrical stimulation without muscle contraction altered neither CGRP nor P2X3 mRNA levels. Muscle stretching produced hyperalgesia for 2d whereas contraction alone produced no hyperalgesia. Stretching increased CGRP mRNA at 24h but not CGRP-muscle afferent number at 2–12d. In contrast, stretching significantly increased the number of P2X3-muscle afferent neurons for 12d. The sustained, elevated P2X3 expression evoked by EC and stretching may enhance nociceptor responsiveness to ATP released during subsequent myofiber damage. Movement-based actions such as EC and muscle stretching produce unique tissue responses and modulate neuropeptide and nociceptive receptor expression in a manner particularly relevant to repeated muscle damage. PMID:20207080

  9. Glucagonlike Peptide 2 Analogue Teduglutide

    PubMed Central

    Chaturvedi, Lakshmi S.; Basson, Marc D.

    2015-01-01

    IMPORTANCE Short bowel syndrome occurs when a shortened intestine cannot absorb sufficient nutrients or fluids. Teduglutide is a recombinant analogue of human glucagonlike peptide 2 that reduces dependence on parenteral nutrition in patients with short bowel syndrome by promoting enterocytic proliferation, increasing the absorptive surface area. However, enterocyte function depends not only on the number of cells that are present but also on differentiated features that facilitate nutrient absorption and digestion. OBJECTIVE To test the hypothesis that teduglutide impairs human intestinal epithelial differentiation. DESIGN AND SETTING We investigated the effects of teduglutide in the modulation of proliferation and differentiation in human Caco-2 intestinal epithelial cells at a basic science laboratory. This was an in vitro study using Caco-2 cells, a human-derived intestinal epithelial cell line commonly used to model enterocytic biology. EXPOSURE Cells were exposed to teduglutide or vehicle control. MAINOUTCOMESAND MEASURES We analyzed the cell cycle by bromodeoxyuridine incorporation or propidium iodide staining and flow cytometry and measured cell proliferation by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. We used quantitative reverse transcription–polymerase chain reaction to assay the expression of the enterocytic differentiation markers villin, sucrase-isomaltase, glucose transporter 2 (GLUT2), and dipeptidyl peptidase 4 (DPP-4), as well as that of the putative differentiation signals schlafen 12 (SLFN12) and caudal-related homeobox intestine-specific transcription factor (Cdx2). Villin promoter activity was measured by a luciferase-based assay. RESULTS The MTS assay demonstrated that teduglutide increased cell numbers by a mean (SD) of 10% (2%) over untreated controls at a maximal 500nM (n = 6, P < .05). Teduglutide increased bromodeoxyuridine-positive cells vs untreated controls by a mean (SD

  10. An Investigation on a Novel Anti-tumor Fusion Peptide of FSH33-53-IIKK

    PubMed Central

    Yang, Runlin; Liu, Ping; Pan, Donghui; zhang, Pengjun; Bai, Zhicheng; Xu, Yuping; Wang, Lizhen; Yan, Junjie; Yan, Yongjun; Liu, Xingdang; Yang, Min

    2016-01-01

    A novel fusion peptide FSH33-53-IIKK was designed and expected to combine the follicle stimulating hormone receptor (FSHR) targeting and tumor toxicity. In vitro and in vivo study showed the anti-tumor activity of FSH33-53-IIKK was enhanced compared to that of IIKK only. FSH33-53-IIKK could inhibit the growth of tumor via apoptosis and autophagy pathways. In summary, combining the tumor marker-target peptide and anti-tumor peptide together may be an efficient way to search for better anti-tumor candidates. PMID:27313792

  11. An Investigation on a Novel Anti-tumor Fusion Peptide of FSH33-53-IIKK.

    PubMed

    Yang, Runlin; Liu, Ping; Pan, Donghui; Zhang, Pengjun; Bai, Zhicheng; Xu, Yuping; Wang, Lizhen; Yan, Junjie; Yan, Yongjun; Liu, Xingdang; Yang, Min

    2016-01-01

    A novel fusion peptide FSH33-53-IIKK was designed and expected to combine the follicle stimulating hormone receptor (FSHR) targeting and tumor toxicity. In vitro and in vivo study showed the anti-tumor activity of FSH33-53-IIKK was enhanced compared to that of IIKK only. FSH33-53-IIKK could inhibit the growth of tumor via apoptosis and autophagy pathways. In summary, combining the tumor marker-target peptide and anti-tumor peptide together may be an efficient way to search for better anti-tumor candidates. PMID:27313792

  12. Peptides from regenerating central nervous system promote specific populations of macroglia.

    PubMed Central

    Giulian, D; Tomozawa, Y; Hindman, H; Allen, R L

    1985-01-01

    The regenerating central nervous system of goldfish contains peptides referred to as glia-promoting factors (GPFs) that stimulate the proliferation of mammalian macroglia. We find that, in vitro, GPF1 and GPF3 promote the appearance of oligodendroglia and GPF2 and GPF4 stimulate proliferation of astroglia. The activities of GPF1, GPF3, and GPF4 increase during regeneration of the goldfish visual system. These results suggest that brain peptides may play a role in the recovery of the injured central nervous system by regulating the growth and development of specific macroglial populations. Images PMID:3858882

  13. Directed evolution of FLS2 towards novel flagellin peptide recognition

    DOE PAGESBeta

    Helft, Laura; Thompson, Mikayla; Bent, Andrew F.

    2016-06-06

    Microbe-associated molecular patterns (MAMPs) are molecules, or domains within molecules, that are conserved across microbial taxa and can be recognized by a plant or animal immune system. Although MAMP receptors have evolved to recognize conserved epitopes, the MAMPs in some microbial species or strains have diverged sufficiently to render them unrecognizable by some host immune systems. In this study, we carried out in vitro evolution of the Arabidopsis thaliana flagellin receptor FLAGELLIN-SENSING 2 (FLS2) to isolate derivatives that recognize one or more flagellin peptides from bacteria for which the wild type Arabidopsis FLS2 confers little or no response. A targetedmore » approach generated amino acid variation at FLS2 residues in a region previously implicated in flagellin recognition. The primary screen tested for elevated response to the canonical flagellin peptide from Pseudomonas aeruginosa, flg22. From this pool, we then identified five alleles of FLS2 that confer modest (quantitatively partial) recognition of an Erwinia amylovora flagellin peptide. Use of this Erwinia-based flagellin peptide to stimulate Arabidopsis plants expressing the resulting FLS2 alleles did not lead to a detectable reduction of virulent P. syringae pv. tomato growth. However, combination of two identified mutations into a single allele further increased FLS2-mediated responses to the E. amylovora flagellin peptide. As a result, these studies demonstrate the potential to raise the sensitivity of MAMP receptors toward particular targets.« less

  14. Directed Evolution of FLS2 towards Novel Flagellin Peptide Recognition.

    PubMed

    Helft, Laura; Thompson, Mikayla; Bent, Andrew F

    2016-01-01

    Microbe-associated molecular patterns (MAMPs) are molecules, or domains within molecules, that are conserved across microbial taxa and can be recognized by a plant or animal immune system. Although MAMP receptors have evolved to recognize conserved epitopes, the MAMPs in some microbial species or strains have diverged sufficiently to render them unrecognizable by some host immune systems. In this study, we carried out in vitro evolution of the Arabidopsis thaliana flagellin receptor FLAGELLIN-SENSING 2 (FLS2) to isolate derivatives that recognize one or more flagellin peptides from bacteria for which the wild-type Arabidopsis FLS2 confers little or no response. A targeted approach generated amino acid variation at FLS2 residues in a region previously implicated in flagellin recognition. The primary screen tested for elevated response to the canonical flagellin peptide from Pseudomonas aeruginosa, flg22. From this pool, we then identified five alleles of FLS2 that confer modest (quantitatively partial) recognition of an Erwinia amylovora flagellin peptide. Use of this Erwinia-based flagellin peptide to stimulate Arabidopsis plants expressing the resulting FLS2 alleles did not lead to a detectable reduction of virulent P. syringae pv. tomato growth. However, combination of two identified mutations into a single allele further increased FLS2-mediated responses to the E. amylovora flagellin peptide. These studies demonstrate the potential to raise the sensitivity of MAMP receptors toward particular targets. PMID:27270917

  15. Directed Evolution of FLS2 towards Novel Flagellin Peptide Recognition

    PubMed Central

    Helft, Laura; Thompson, Mikayla

    2016-01-01

    Microbe-associated molecular patterns (MAMPs) are molecules, or domains within molecules, that are conserved across microbial taxa and can be recognized by a plant or animal immune system. Although MAMP receptors have evolved to recognize conserved epitopes, the MAMPs in some microbial species or strains have diverged sufficiently to render them unrecognizable by some host immune systems. In this study, we carried out in vitro evolution of the Arabidopsis thaliana flagellin receptor FLAGELLIN-SENSING 2 (FLS2) to isolate derivatives that recognize one or more flagellin peptides from bacteria for which the wild-type Arabidopsis FLS2 confers little or no response. A targeted approach generated amino acid variation at FLS2 residues in a region previously implicated in flagellin recognition. The primary screen tested for elevated response to the canonical flagellin peptide from Pseudomonas aeruginosa, flg22. From this pool, we then identified five alleles of FLS2 that confer modest (quantitatively partial) recognition of an Erwinia amylovora flagellin peptide. Use of this Erwinia-based flagellin peptide to stimulate Arabidopsis plants expressing the resulting FLS2 alleles did not lead to a detectable reduction of virulent P. syringae pv. tomato growth. However, combination of two identified mutations into a single allele further increased FLS2-mediated responses to the E. amylovora flagellin peptide. These studies demonstrate the potential to raise the sensitivity of MAMP receptors toward particular targets. PMID:27270917

  16. Cloning, expression, and purification of a new antimicrobial peptide gene from Musca domestica larva.

    PubMed

    Pei, Zhihua; Sun, Xiaoning; Tang, Yan; Wang, Kai; Gao, Yunhang; Ma, Hongxia

    2014-10-01

    Musca domestica (Diptera: Muscidae), the housefly, exhibits unique immune defences and can produce antimicrobial peptides upon stimulation with bacteria. Based on the cDNA library constructed using the suppression subtractive hybridization (SSH) method, a 198-bp antimicrobial peptide gene, which we named MDAP-2, was amplified by rapid amplification of cDNA ends (RACE) from M. domestica larvae stimulated with Salmonella pullorum (Enterobacteriaceae: Salmonella). In the present study, the full-length MDAP-2 gene was cloned and inserted into a His-tagged Escherichia coli prokaryotic expression system to enable production of the recombinant peptide. The recombinant MDAP-2 peptide was purified using Ni-NTA HisTrap FF crude column chromatography. The bacteriostatic activity of the recombinant purified MDAP-2 protein was assessed. The results indicated that MDAP-2 had in vitro antibacterial activity against all of the tested Gram- bacteria from clinical isolates, including E. coli (Enterobacteriaceae: Escherichia), one strain of S. pullorum (Enterobacteriaceae: Salmonella), and one strain of Pasteurella multocida. DNA sequencing and BLAST analysis showed that the MDAP-2 antimicrobial peptide gene was not homologous to any other antimicrobial peptide genes in GenBank. The antibacterial mechanisms of the newly discovered MDAP-2 peptide warrant further study. PMID:25020259

  17. Host-defense and trefoil factor family peptides in skin secretions of the Mawa clawed frog Xenopus boumbaensis (Pipidae).

    PubMed

    Conlon, J Michael; Mechkarska, Milena; Kolodziejek, Jolanta; Leprince, Jérôme; Coquet, Laurent; Jouenne, Thierry; Vaudry, Hubert; Nowotny, Norbert; King, Jay D

    2015-10-01

    Peptidomic analysis of norepinephrine-stimulated skin secretions from the octoploid Mawa clawed frog Xenopus boumbaensis Loumont, 1983 led to the identification and characterization of 15 host-defense peptides belonging to the magainin (two peptides), peptide glycine-leucine-amide (PGLa; three peptides), xenopsin precursor fragment (XPF; three peptides), caerulein precursor fragment (CPF; two peptides), and caerulein precursor fragment-related peptide (CPF-RP; five peptides) families. In addition, caerulein and three peptides with structural similarity to the trefoil factor family (TFF) peptides, xP2 and xP4 from Xenopus laevis were also present in the secretions. Consistent with data from comparisons of the nucleotides sequence of mitochondrial and nuclear genes, the primary structures of the peptides suggest a close phylogenetic relationship between X. boumbaensis and the octoploid frogs Xenopus amieti and Xenopus andrei. As the three species occupy disjunct ranges within Cameroon, it is suggested that they diverged from a common ancestor by allopatric speciation. PMID:25849343

  18. Identification of Four-Jointed Box 1 (FJX1)-Specific Peptides for Immunotherapy of Nasopharyngeal Carcinoma

    PubMed Central

    Chai, San Jiun; Yap, Yoke Yeow; Foo, Yoke Ching; Yap, Lee Fah; Ponniah, Sathibalan; Teo, Soo Hwang; Cheong, Sok Ching; Patel, Vyomesh; Lim, Kue Peng

    2015-01-01

    Nasopharyngeal carcinoma (NPC) is highly prevalent in South East Asia and China. The poor outcome is due to late presentation, recurrence, distant metastasis and limited therapeutic options. For improved treatment outcome, immunotherapeutic approaches focusing on dendritic and autologous cytotoxic T-cell based therapies have been developed, but cost and infrastructure remain barriers for implementing these in low-resource settings. As our prior observations had found that four-jointed box 1 (FJX1), a tumor antigen, is overexpressed in NPCs, we investigated if short 9–20 amino acid sequence specific peptides matching to FJX1 requiring only intramuscular immunization to train host immune systems would be a better treatment option for this disease. Thus, we designed 8 FJX1-specific peptides and implemented an assay system to first, assess the binding of these peptides to HLA-A2 molecules on T2 cells. After, ELISPOT assays were used to determine the peptides immunogenicity and ability to induce potential cytotoxicity activity towards cancer cells. Also, T-cell proliferation assay was used to evaluate the potential of MHC class II peptides to stimulate the expansion of isolated T-cells. Our results demonstrate that these peptides are immunogenic and peptide stimulated T-cells were able to induce peptide-specific cytolytic activity specifically against FJX1-expressing cancer cells. In addition, we demonstrated that the MHC class II peptides were capable of inducing T-cell proliferation. Our results suggest that these peptides are capable of inducing specific cytotoxic cytokines secretion against FJX1-expressing cancer cells and serve as a potential vaccine-based therapy for NPC patients. PMID:26536470

  19. Peptide Aptamers: Development and Applications

    PubMed Central

    Reverdatto, Sergey; Burz, David S.; Shekhtman, Alexander

    2015-01-01

    Peptide aptamers are small combinatorial proteins that are selected to bind to specific sites on their target molecules. Peptide aptamers consist of short, 5-20 amino acid residues long sequences, typically embedded as a loop within a stable protein scaffold. Various peptide aptamer scaffolds and in vitro and in vivo selection techniques are reviewed with emphasis on specific biomedical, bioimaging, and bioanalytical applications. PMID:25866267

  20. Macrocyclization of Unprotected Peptide Isocyanates.

    PubMed

    Vinogradov, Alexander A; Choo, Zi-Ning; Totaro, Kyle A; Pentelute, Bradley L

    2016-03-18

    A chemistry for the facile two-component macrocyclization of unprotected peptide isocyanates is described. Starting from peptides containing two glutamic acid γ-hydrazide residues, isocyanates can be readily accessed and cyclized with hydrazides of dicarboxylic acids. The choice of a nucleophilic linker allows for the facile modulation of biochemical properties of a macrocyclic peptide. Four cyclic NYAD-1 analogues were synthesized using the described method and displayed a range of biological activities. PMID:26948900

  1. Biodiscovery of aluminum binding peptides

    NASA Astrophysics Data System (ADS)

    Adams, Bryn L.; Sarkes, Deborah A.; Finch, Amethist S.; Hurley, Margaret M.; Stratis-Cullum, Dimitra

    2013-05-01

    Cell surface peptide display systems are large and diverse libraries of peptides (7-15 amino acids) which are presented by a display scaffold hosted by a phage (virus), bacteria, or yeast cell. This allows the selfsustaining peptide libraries to be rapidly screened for high affinity binders to a given target of interest, and those binders quickly identified. Peptide display systems have traditionally been utilized in conjunction with organic-based targets, such as protein toxins or carbon nanotubes. However, this technology has been expanded for use with inorganic targets, such as metals, for biofabrication, hybrid material assembly and corrosion prevention. While most current peptide display systems employ viruses to host the display scaffold, we have recently shown that a bacterial host, Escherichia coli, displaying peptides in the ubiquitous, membrane protein scaffold eCPX can also provide specific peptide binders to an organic target. We have, for the first time, extended the use of this bacterial peptide display system for the biodiscovery of aluminum binding 15mer peptides. We will present the process of biopanning with macroscopic inorganic targets, binder enrichment, and binder isolation and discovery.

  2. Improving Peptide Applications Using Nanotechnology.

    PubMed

    Narayanaswamy, Radhika; Wang, Tao; Torchilin, Vladimir P

    2016-01-01

    Peptides are being successfully used in various fields including therapy and drug delivery. With advancement in nanotechnology and targeted delivery carrier systems, suitable modification of peptides has enabled achievement of many desirable goals over-riding some of the major disadvantages associated with the delivery of peptides in vivo. Conjugation or physical encapsulation of peptides to various nanocarriers, such as liposomes, micelles and solid-lipid nanoparticles, has improved their in vivo performance multi-fold. The amenability of peptides to modification in chemistry and functionalization with suitable nanocarriers are very relevant aspects in their use and have led to the use of 'smart' nanoparticles with suitable linker chemistries that favor peptide targeting or release at the desired sites, minimizing off-target effects. This review focuses on how nanotechnology has been used to improve the number of peptide applications. The paper also focuses on the chemistry behind peptide conjugation to nanocarriers, the commonly employed linker chemistries and the several improvements that have already been achieved in the areas of peptide use with the help of nanotechnology. PMID:26279082

  3. Peptides that influence membrane topology

    NASA Astrophysics Data System (ADS)

    Wong, Gerard C. L.

    2014-03-01

    We examine the mechanism of a range of polypeptides that influence membrane topology, including antimicrobial peptides, cell penetrating peptides, viral fusion peptides, and apoptosis proteins, and show how a combination of geometry, coordination chemistry, and soft matter physics can be used to approach a unified understanding. We will also show how such peptides can impact biomedical problems such as auto-immune diseases (psoriasis, lupus), infectious diseases (viral and bacterial infections), and mitochondrial pathologies (under-regulated apoptosis leads to neurodegenerative diseases whereas over-regulated apoptosis leads to cancer.)

  4. Cholecystokinin, glucose dependent insulinotropic peptide and glucagon-like peptide 1 secretion in children with anorexia nervosa and simple obesity.

    PubMed

    Tomasik, Przemyslaw J; Sztefko, Krystyna; Starzyk, Jerzy

    2004-12-01

    Cholecystokinin (CCK), glucose dependent insulinotropic peptide (GIP), and glucagon-like peptide 1 (GLP-1) regulate satiety as enterogastrons and incretins. They also directly affect the satiety centers. Therefore, these peptides may participate in the pathogenesis of eating disorders. CCK, GIP, and GLP-1 secretion were studied in 13 adolescent girls suffering from simple obesity, 13 girls with anorexia nervosa, and 10 healthy girls. Each girl was subjected to an oral glucose tolerance test (OGTT) and standard meal test. Blood was collected before stimulation and at 15, 30, 60, and 120 min. The concentrations of all peptides were determined by RIA commercial kits. Fasting and postprandial levels of these peptides as well as integrated outputs were measured. High postprandial levels of CCK observed in the girls with anorexia may aggravate the course of this disease by intensifying nausea and vomiting. Low postprandial level of GLP-1 in girls with simple obesity may be responsible for excessive ingestion of food and weaker inhibition of gastric emptying, which also leads to obesity. PMID:15645696

  5. Ligand-independent activation of peroxisome proliferator-activated receptor-gamma by insulin and C-peptide in kidney proximal tubular cells: dependent on phosphatidylinositol 3-kinase activity.

    PubMed

    Al-Rasheed, Nawal M; Chana, Ravinder S; Baines, Richard J; Willars, Gary B; Brunskill, Nigel J

    2004-11-26

    Peroxisome proliferator-activated receptor gamma (PPARgamma) has key roles in the regulation of adipogenesis, inflammation, and lipid and glucose metabolism. C-peptide is believed to be inert and without appreciable biological functions. Recent studies suggest that C-peptide possesses multiple functions. The present study investigated the effects of insulin and C-peptide on PPARgamma transcriptional activity in opossum kidney proximal tubular cells. Both insulin and C-peptide induced a concentration-dependent stimulation of PPARgamma transcriptional activity. Both agents substantially augmented thiazolidinedione-stimulated PPARgamma transcriptional activity. Neither insulin nor C-peptide had any effect on the expression levels of PPARgamma. GW9662, a PPARgamma antagonist, blocked PPARgamma activation by thiazolidinediones but had no effect on either insulin- or C-peptide-stimulated PPARgamma transcriptional activity. Co-transfection of opossum kidney cells with dominant negative mitogen-activated protein kinase kinase significantly depressed basal PPARgamma transcriptional activity but had no effect on that induced by either insulin or C-peptide. Both insulin- and C-peptide-stimulated PPARgamma transcriptional activity were attenuated by wortmannin and by expression of a dominant negative phosphatidylinositol (PI) 3-kinase p85 regulatory subunit. In addition PI 3-kinase-dependent phosphorylation of PPARgamma was observed after stimulation by C-peptide or insulin. C-peptide effects but not insulin on PPARgamma transcriptional activity were abolished by pertussis toxin pretreatment. Finally both C-peptide and insulin positively control the expression of the PPARgamma-regulated CD36 scavenger receptor in human THP-1 monocytes. We concluded that insulin and C-peptide can stimulate PPARgamma activity in a ligand-independent fashion and that this effect is mediated by PI 3-kinase. These results support a new and potentially important physiological role for C-peptide in

  6. Music acupuncture stimulation method.

    PubMed

    Brătilă, F; Moldovan, C

    2007-01-01

    Harmonic Medicine is the model using the theory that the body rhythms synchronize to an outer rhythm applied for therapeutic purpose, can restores the energy balance in acupuncture channels and organs and the condition of well-being. The purpose of this scientific work was to demonstrate the role played by harmonic sounds in the stimulation of the Lung (LU) Meridian (Shoutaiyin Feijing) and of the Kidney (KI) Meridian (Zushaoyin Shenjing). It was used an original method that included: measurement and electronic sound stimulation of the Meridian Entry Point, measurement of Meridian Exit Point, computer data processing, bio feed-back adjustment of the music stimulation parameters. After data processing, it was found that the sound stimulation of the Lung Meridian Frequency is optimal between 122 Hz and 128 Hz, with an average of 124 Hz (87% of the subjects) and for Kidney Meridian from 118 Hz to 121 Hz, with an average of 120 Hz (67% of the subjects). The acupuncture stimulation was more intense for female subjects (> 7%) than for the male ones. We preliminarily consider that an informational resonance phenomenon can be developed between the acupuncture music stimulation frequency and the cellular dipole frequency, being a really "resonant frequency signature" of an acupoint. The harmonic generation and the electronic excitation or low-excitation status of an acupuncture point may be considered as a resonance mechanism. By this kind of acupunctural stimulation, a symphony may act and play a healer role. PMID:18767418

  7. Soluble peptide-MHC monomers cause activation of CD8+ T cells through transfer of the peptide to T cell MHC molecules

    NASA Astrophysics Data System (ADS)

    Ge, Qing; Stone, Jennifer D.; Thompson, M. Todd; Cochran, Jennifer R.; Rushe, Mia; Eisen, Herman N.; Chen, Jianzhu; Stern, Lawrence J.

    2002-10-01

    T cell receptor (TCR)-mediated activation of CD4+ T cells is known to require multivalent engagement of the TCR by, for example, oligomeric peptide-MHC complexes. In contrast, for CD8+ T cells, there is evidence for TCR-mediated activation by univalent engagement of the TCR. We have here compared oligomeric and monomeric Ld and Kb peptide-MHC complexes and free peptide as stimulators of CD8+ T cells expressing the 2C TCR. We found that the monomers are indeed effective in activating naïve and effector CD8+ T cells, but through an unexpected mechanism that involves transfer of peptide from soluble monomers to T cell endogenous MHC (Kb) molecules. The result is that T cells, acting as antigen-presenting cells, are able to activate other naïve T cells.

  8. Recognition of Bacterial Signal Peptides by Mammalian Formyl Peptide Receptors

    PubMed Central

    Bufe, Bernd; Schumann, Timo; Kappl, Reinhard; Bogeski, Ivan; Kummerow, Carsten; Podgórska, Marta; Smola, Sigrun; Hoth, Markus; Zufall, Frank

    2015-01-01

    Formyl peptide receptors (FPRs) are G-protein-coupled receptors that function as chemoattractant receptors in innate immune responses. Here we perform systematic structure-function analyses of FPRs from six mammalian species using structurally diverse FPR peptide agonists and identify a common set of conserved agonist properties with typical features of pathogen-associated molecular patterns. Guided by these results, we discover that bacterial signal peptides, normally used to translocate proteins across cytoplasmic membranes, are a vast family of natural FPR agonists. N-terminally formylated signal peptide fragments with variable sequence and length activate human and mouse FPR1 and FPR2 at low nanomolar concentrations, thus establishing FPR1 and FPR2 as sensitive and broad signal peptide receptors. The vomeronasal receptor mFpr-rs1 and its sequence orthologue hFPR3 also react to signal peptides but are much more narrowly tuned in signal peptide recognition. Furthermore, all signal peptides examined here function as potent activators of the innate immune system. They elicit robust, FPR-dependent calcium mobilization in human and mouse leukocytes and trigger a range of classical innate defense mechanisms, such as the production of reactive oxygen species, metalloprotease release, and chemotaxis. Thus, bacterial signal peptides constitute a novel class of immune activators that are likely to contribute to mammalian immune defense against bacteria. This evolutionarily conserved detection mechanism combines structural promiscuity with high specificity and enables discrimination between bacterial and eukaryotic signal sequences. With at least 175,542 predicted sequences, bacterial signal peptides represent the largest and structurally most heterogeneous class of G-protein-coupled receptor agonists currently known for the innate immune system. PMID:25605714

  9. Phytosulfokine peptide signalling.

    PubMed

    Sauter, Margret

    2015-08-01

    Phytosulfokine (PSK) belongs to the group of plant peptide growth factors. It is a disulfated pentapeptide encoded by precursor genes that are ubiquitously present in higher plants, suggestive of universal functions. Processing of the prepropro