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Russo AF, Hay DL. CGRP physiology, pharmacology, and therapeutic targets: migraine and beyond. Physiol Rev 2023; 103:1565-1644. [PMID: 36454715 PMCID: PMC9988538 DOI: 10.1152/physrev.00059.2021] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 11/23/2022] [Accepted: 11/27/2022] [Indexed: 12/03/2022] Open
Abstract
Calcitonin gene-related peptide (CGRP) is a neuropeptide with diverse physiological functions. Its two isoforms (α and β) are widely expressed throughout the body in sensory neurons as well as in other cell types, such as motor neurons and neuroendocrine cells. CGRP acts via at least two G protein-coupled receptors that form unusual complexes with receptor activity-modifying proteins. These are the CGRP receptor and the AMY1 receptor; in rodents, additional receptors come into play. Although CGRP is known to produce many effects, the precise molecular identity of the receptor(s) that mediates CGRP effects is seldom clear. Despite the many enigmas still in CGRP biology, therapeutics that target the CGRP axis to treat or prevent migraine are a bench-to-bedside success story. This review provides a contextual background on the regulation and sites of CGRP expression and CGRP receptor pharmacology. The physiological actions of CGRP in the nervous system are discussed, along with updates on CGRP actions in the cardiovascular, pulmonary, gastrointestinal, immune, hematopoietic, and reproductive systems and metabolic effects of CGRP in muscle and adipose tissues. We cover how CGRP in these systems is associated with disease states, most notably migraine. In this context, we discuss how CGRP actions in both the peripheral and central nervous systems provide a basis for therapeutic targeting of CGRP in migraine. Finally, we highlight potentially fertile ground for the development of additional therapeutics and combinatorial strategies that could be designed to modulate CGRP signaling for migraine and other diseases.
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Affiliation(s)
- Andrew F Russo
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa
- Department of Neurology, University of Iowa, Iowa City, Iowa
- Center for the Prevention and Treatment of Visual Loss, Department of Veterans Affairs Health Center, Iowa City, Iowa
| | - Debbie L Hay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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2
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Wagner L, Wolf R, Zeitschel U, Rossner S, Petersén Å, Leavitt BR, Kästner F, Rothermundt M, Gärtner UT, Gündel D, Schlenzig D, Frerker N, Schade J, Manhart S, Rahfeld JU, Demuth HU, von Hörsten S. Proteolytic degradation of neuropeptide Y (NPY) from head to toe: Identification of novel NPY-cleaving peptidases and potential drug interactions in CNS and Periphery. J Neurochem 2015; 135:1019-37. [PMID: 26442809 DOI: 10.1111/jnc.13378] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/09/2015] [Accepted: 09/14/2015] [Indexed: 01/24/2023]
Abstract
The bioactivity of neuropeptide Y (NPY) is either N-terminally modulated with respect to receptor selectivity by dipeptidyl peptidase 4 (DP4)-like enzymes or proteolytic degraded by neprilysin or meprins, thereby abrogating signal transduction. However, neither the subcellular nor the compartmental differentiation of these regulatory mechanisms is fully understood. Using mass spectrometry, selective inhibitors and histochemistry, studies across various cell types, body fluids, and tissues revealed that most frequently DP4-like enzymes, aminopeptidases P, secreted meprin-A (Mep-A), and cathepsin D (CTSD) rapidly hydrolyze NPY, depending on the cell type and tissue under study. Novel degradation of NPY by cathepsins B, D, L, G, S, and tissue kallikrein could also be identified. The expression of DP4, CTSD, and Mep-A at the median eminence indicates that the bioactivity of NPY is regulated by peptidases at the interphase between the periphery and the CNS. Detailed ex vivo studies on human sera and CSF samples recognized CTSD as the major NPY-cleaving enzyme in the CSF, whereas an additional C-terminal truncation by angiotensin-converting enzyme could be detected in serum. The latter finding hints to potential drug interaction between antidiabetic DP4 inhibitors and anti-hypertensive angiotensin-converting enzyme inhibitors, while it ablates suspected hypertensive side effects of only antidiabetic DP4-inhibitors application. The bioactivity of neuropeptide Y (NPY) is either N-terminally modulated with respect to receptor selectivity by dipeptidyl peptidase 4 (DP4)-like enzymes or proteolytic degraded by neprilysin or meprins, thereby abrogating signal transduction. However, neither the subcellular nor the compartmental differentiation of these regulatory mechanisms is fully understood. Using mass spectrometry, selective inhibitors and histochemistry, studies across various cell types, body fluids, and tissues revealed that most frequently DP4-like enzymes, aminopeptidases P, secreted meprin-A (Mep-A), and cathepsin D (CTSD) rapidly hydrolyze NPY, depending on the cell type and tissue under study. Novel degradation of NPY by cathepsins B, D, L, G, S, and tissue kallikrein could also be identified. The expression of DP4, CTSD, and Mep-A at the median eminence indicates that the bioactivity of NPY is regulated by peptidases at the interphase between the periphery and the CNS. Detailed ex vivo studies on human sera and CSF samples recognized CTSD as the major NPY-cleaving enzyme in the CSF, whereas an additional C-terminal truncation by angiotensin-converting enzyme could be detected in serum. The latter finding hints to potential drug interaction between antidiabetic DP4 inhibitors and anti-hypertensive angiotensin-converting enzyme inhibitors, while it ablates suspected hypertensive side effects of only antidiabetic DP4-inhibitors application.
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Affiliation(s)
- Leona Wagner
- Deutschsprachige Selbsthilfegruppe für Alkaptonurie (DSAKU) e.V., Stuttgart, Germany.,Probiodrug AG, Halle, Germany.,Department of Experimental Therapy, Preclinical Experimental Center, Universitätsklinikum Erlangen, Erlangen, Germany
| | | | - Ulrike Zeitschel
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Steffen Rossner
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Åsa Petersén
- Translational Neuroendocrine Research Unit, Lund University, Lund, Sweden
| | - Blair R Leavitt
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia and Children's and Women's Hospital, Vancouver, BC, Canada
| | - Florian Kästner
- Department of Psychiatry, University of Muenster, Muenster, Germany
| | - Matthias Rothermundt
- Department of Psychiatry, University of Muenster, Muenster, Germany.,St. Rochus-Hospital Telgte, Telgte, Germany
| | | | - Daniel Gündel
- Julius Bernstein Institute for Physiology, Martin Luther University of Halle-Wittenberg, Halle, Germany
| | - Dagmar Schlenzig
- Fraunhofer-Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
| | - Nadine Frerker
- Department of Experimental Therapy, Preclinical Experimental Center, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Jutta Schade
- Department of Experimental Therapy, Preclinical Experimental Center, Universitätsklinikum Erlangen, Erlangen, Germany
| | | | - Jens-Ulrich Rahfeld
- Fraunhofer-Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
| | - Hans-Ulrich Demuth
- Fraunhofer-Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
| | - Stephan von Hörsten
- Department of Experimental Therapy, Preclinical Experimental Center, Universitätsklinikum Erlangen, Erlangen, Germany
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3
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The plasminogen activation system in neuroinflammation. Biochim Biophys Acta Mol Basis Dis 2015; 1862:395-402. [PMID: 26493446 DOI: 10.1016/j.bbadis.2015.10.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 10/08/2015] [Accepted: 10/15/2015] [Indexed: 01/30/2023]
Abstract
The plasminogen activation (PA) system consists in a group of proteases and protease inhibitors regulating the activation of the zymogen plasminogen into its proteolytically active form, plasmin. Here, we give an update of the current knowledge about the role of the PA system on different aspects of neuroinflammation. These include modification in blood-brain barrier integrity, leukocyte diapedesis, removal of fibrin deposits in nervous tissues, microglial activation and neutrophil functions. Furthermore, we focus on the molecular mechanisms (some of them independent of plasmin generation and even of proteolysis) and target receptors responsible for these effects. The description of these mechanisms of action may help designing new therapeutic strategies targeting the expression, activity and molecular mediators of the PA system in neurological disorders involving neuroinflammatory processes. This article is part of a Special Issue entitled: Neuro Inflammation edited by Helga E. de Vries and Markus Schwaninger.
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Tissue Plasminogen Activator Expression Is Restricted to Subsets of Excitatory Pyramidal Glutamatergic Neurons. Mol Neurobiol 2015; 53:5000-12. [PMID: 26377106 DOI: 10.1007/s12035-015-9432-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/07/2015] [Indexed: 12/14/2022]
Abstract
Although the extracellular serine protease tissue plasminogen activator (tPA) is involved in pathophysiological processes such as learning and memory, anxiety, epilepsy, stroke, and Alzheimer's disease, information about its regional, cellular, and subcellular distribution in vivo is lacking. In the present study, we observed, in healthy mice and rats, the presence of tPA in endothelial cells, oligodendrocytes, mastocytes, and ependymocytes, but not in pericytes, microglial cells, and astrocytes. Moreover, blockage of the axo-dendritic transport unmasked tPA expression in neurons of cortical and hippocampal areas. Interestingly, combined electrophysiological recordings, single-cell reverse transcription polymerase chain reaction (RT-PCR), and immunohistological analyses revealed that the presence of tPA is restricted to subsets of excitatory pyramidal glutamatergic neurons. We further evidenced that tPA is stored in synaptobrevin-2-positive glutamatergic synaptic vesicles. Based on all these data, we propose the existence of tPA-ergic neurons in the mature brain.
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Santos-Carvalho A, Ambrósio AF, Cavadas C. Neuropeptide Y system in the retina: From localization to function. Prog Retin Eye Res 2015; 47:19-37. [DOI: 10.1016/j.preteyeres.2015.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 03/05/2015] [Accepted: 03/10/2015] [Indexed: 01/10/2023]
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Suenaga M, Furuta A, Wakabayashi K, Saibara T, Matsunaga Y. Monocytic elastase-mediated apolipoprotein-E degradation: Potential involvement of microglial elastase-like proteases in apolipoprotein-E proteolysis in brains with Alzheimers disease. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1010-8. [PMID: 25956321 DOI: 10.1016/j.bbapap.2015.04.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/09/2015] [Accepted: 04/28/2015] [Indexed: 01/07/2023]
Abstract
Impaired clearance of soluble Aβ (amyloid-β) promotes Aβ aggregation in brains with Alzheimer's disease (AD), while apolipoprotein-E (ApoE) in microglia mediates Aβ clearance. We studied the protease responsible for ApoE(4) degradation in human peripheral monocyte extracts, which are from the same lineage as microglia. We detected the hydrolytic activity for ApoE(4) in high-salt extracts with 2 M NaCl and found that the activity was inhibited by a serine protease inhibitor and an elastase-specific inhibitor, but not by other protease inhibitors. The extracts exhibited higher activity for the elastase substrate, and we followed the activity with ion-exchange and gel-filtration chromatography. Through silver staining, we partially purified a protein of 28 kDa, which was clarified as elastase by liquid chromatography-tandem mass spectrometry. These observations suggest that elastase is the key protease for ApoE(4) degradation. We also detected ApoE(4) hydrolytic activity in high-salt extracts in mouse microglial (BV-2) cell lysates, and showed that the ApoE(4) fragments by the BV-2 extracts differed from the fragments by the monocyte extracts. Though the ApoE(4) degradation by the extracts was not inhibited with elastase-specific inhibitors, it was inhibited by an elastase-specific monoclonal antibody, suggesting that elastase-like proteases in microglia differ from those of monocytes. Immunohistochemistry revealed that both elastase and ApoE were expressed in the senile plaques of brains with AD. In vitro studies also disclosed the localization of elastase in the microglial cell line, BV-2. Our results suggest that elastase-like proteases in the microglial cells surrounding Aβ plaques are responsible for ApoE degradation in the brain.
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Affiliation(s)
- Midori Suenaga
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Nishihama, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Akiko Furuta
- Department of Cellular and Molecular Neuropathology, Juntendo University, School of Medicine, Hongo 2-1-1, Bunkyou-ku, Tokyo 113-8421, Japan
| | - Koichi Wakabayashi
- Department of Neuropathology, Institute of Brain Science, Hirosaki University, Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan
| | - Toshiji Saibara
- Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Yoichi Matsunaga
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Nishihama, Yamashiro-cho, Tokushima 770-8514, Japan.
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7
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Morgan CA, Rasmusson AM, Wang S, Hoyt G, Hauger RL, Hazlett G. Neuropeptide-Y, cortisol, and subjective distress in humans exposed to acute stress: replication and extension of previous report. Biol Psychiatry 2002; 52:136-42. [PMID: 12114005 DOI: 10.1016/s0006-3223(02)01319-7] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND We previously reported that stress-related release of cortisol and neuropeptide-Y (NPY) were significantly and positively associated in U.S. Army soldiers participating in survival training. Furthermore, greater levels of NPY were observed in individuals exhibiting fewer psychologic symptoms of dissociation during stress. This study tested whether these findings would be replicated in a sample of U.S. Navy personnel participating in survival school training. METHODS Psychologic as well as salivary and plasma hormone indices were assessed in 25 active duty personnel before, during, and 24 hours after exposure to U.S. Navy survival school stress. RESULTS Cortisol and NPY were significantly and positively associated during stress and 24 hours after stress; NPY and norepinephrine (NE) were significantly and positively related during and 24 hours after stress. There was a significant, negative relationship between psychologic distress and NPY release during stress. Finally, psychologic symptoms of dissociation reported at baseline predicted significantly less NPY release during stress. CONCLUSIONS These data replicate our previous studies demonstrating that acute stress elicits NPY release and that this release is positively associated with cortisol and NE release. These data also replicate our previous finding that greater levels of NPY release are associated with less psychologic distress suggesting that NPY confers anxiolytic activity.
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Affiliation(s)
- Charles A Morgan
- National Center for PTSD, 116A, VA Connecticut Healthcare Systems, West Haven, Connecticut 06516, USA
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8
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Cerdá-Reverter JM, Larhammar D. cNeuropeptide Y family of peptides: Structure, anatomical expression, function, and molecular evolution. Biochem Cell Biol 2000. [DOI: 10.1139/o00-004] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Evolutionary relationships between neuroendocrine peptides are often difficult to resolve across divergent phyla due to independent duplication events in different lineages. Thanks to peptide purification and molecular cloning in many different species, the situation is beginning to clear for the neuropeptide Y (NPY) family, which also includes peptide YY (PYY), the tetrapod pancreatic polypeptide (PP) and the fish pancreatic peptide Y (PY). It has long been assumed that the first duplication to occur in vertebrate evolution generated NPY and PYY, as both of these are found in all gnathostomes as well as lamprey. Evidence from other gene families show that this duplication was probably a chromosome duplication event. The origin of a second PYY peptide found in lamprey remains to be explained. Our recent cloning of NPY, PYY and PY in the sea bass proves that fish PY is a separate gene product. We favour the hypothesis that PY is a duplicate of the PYY gene and that it may have occurred late in fish evolution, as PY has so far only been found in acanthomorph fishes. Thus, this duplication seems to be independent of the one that generate PP from PYY in tetrapods, although both tetrapod PP and fish PY are expressed in the pancreas. Studies in the sea bass and other fish show that PY, in contrast to PP, is expressed in the nervous system. We review the literature on the distribution and functional aspects of the various NPY-family peptides in vertebrates. Key words: neuropeptide Y, pancreatic polypeptide, fish pancreatic peptide, gene duplication.
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Mentlein R. Dipeptidyl-peptidase IV (CD26)--role in the inactivation of regulatory peptides. REGULATORY PEPTIDES 1999; 85:9-24. [PMID: 10588446 DOI: 10.1016/s0167-0115(99)00089-0] [Citation(s) in RCA: 962] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dipeptidyl-peptidase IV (DPP IV/CD26) has a dual function as a regulatory protease and as a binding protein. Its role in the inactivation of bioactive peptides was recognized 20 years ago due to its unique ability to liberate Xaa-Pro or Xaa-Ala dipeptides from the N-terminus of regulatory peptides, but further examples are now emerging from in vitro and vivo experiments. Despite the minimal N-terminal truncation by DPP IV, many mammalian regulatory peptides are inactivated--either totally or only differentially--for certain receptor subtypes. Important DPP IV substrates include neuropeptides like neuropeptide Y or endomorphin, circulating peptide hormones like peptide YY, growth hormone-releasing hormone, glucagon-like peptides(GLP)-1 and -2, gastric inhibitory polypeptide as well as paracrine chemokines like RANTES (regulated on activation normal T cell expressed and secreted), stromal cell-derived factor, eotaxin and macrophage-derived chemokine. Based on these findings the potential clinical uses of selective DPP IV inhibitors or DPP IV-resistant analogues, especially for the insulinotropic hormone GLP-1, have been tested to enhance insulin secretion and to improve glucose tolerance in diabetic animals. Thus, DPP IV appears to be a major physiological regulator for some regulatory peptides, neuropeptides, circulating hormones and chemokines.
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Affiliation(s)
- R Mentlein
- Anatomisches Institut der Universität Kiel, Germany.
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10
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Feindt J, Schmidt A, Mentlein R. Receptors and effects of the inhibitory neuropeptide somatostatin in microglial cells. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 60:228-33. [PMID: 9757047 DOI: 10.1016/s0169-328x(98)00184-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The expression of receptors for the neuropeptide somatostatin was investigated in cultured immunocytochemically pure rat microglial cells. By the reverse transcriptase-polymerase chain reaction, the mRNAs for the receptor subtypes sst2, sst3 and sst4, but not sst1 and sst5 could be detected. To show that these receptors were functionally active, the effects of somatostatin and the metabolically stable, receptor subtype (2, 3 and 5) selective derivative octreotide (SMS 201-995, Sandostatin) on protein phosphorylation and proliferation were evaluated. Somatostatin induced the tyrosine phosphorylation of a 95 kDa protein in microglia. Furthermore, somatostatin or octreotide inhibited the basal as well as the GM-CSF-(granulocyte macrophage colony-stimulating factor) or the IL-3-(interleukin-3)-stimulated proliferation of microglial cells. This effect was dose-dependent, with a half maximum activity of about 0.2-0.3 nM. Somatostatin was relatively stable in the cultures due to protease inhibitors in the serum. The results indicate that microglial cells are targets for the widespread neuropeptide somatostatin and that its receptors can transduce complex signals to microglia.
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Affiliation(s)
- J Feindt
- Anatomisches Institut der Universität Kiel, Olshausenstrasse 40, D-24098, Kiel, Germany
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Hull KL, Fathimani K, Sharma P, Harvey S. Calcitropic peptides: neural perspectives. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1998; 119:389-410. [PMID: 9827010 DOI: 10.1016/s0742-8413(98)00010-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In mammals and higher vertebrates, calcitropic peptides are produced by peripheral endocrine glands: the parathyroid gland (PTH), thyroid or ultimobranchial gland (calcitonin) and the anterior pituitary gland (growth hormone and prolactin). These hormones are, however, also found in the neural tissues of lower vertebrates and invertebrates that lack these endocrine organs, suggesting that neural tissue may be an ancestral site of calcitropic peptide synthesis. Indeed, the demonstration of CNS receptors for these calcitropic peptides and their induction of neurological actions suggest that these hormones arose as neuropeptides. Neural and neuroendocrine roles of some of these calcitropic hormones (calcitonin and parathyroid hormone) and related peptides (calcitonin gene related peptide, stanniocalcin and parathyroid hormone related peptide) are thus the focus of this review.
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Affiliation(s)
- K L Hull
- Department of Physiology, University of Alberta, Edmonton, Canada
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12
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Mentlein R, Lucius R. Methods for the investigation of neuropeptide catabolism and stability in vitro. BRAIN RESEARCH. BRAIN RESEARCH PROTOCOLS 1997; 1:237-46. [PMID: 9385060 DOI: 10.1016/s1385-299x(96)00035-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The protocol describes (i) methods for the investigation of neuropeptide catabolism in the central nervous system (CNS), (ii) the identification of the neuropeptidases involved, and (iii) methods for the determination of neuropeptide stability in vitro. These methods are applicable also to study the degradation of peptide hormones by peripheral cells or tissues. To identify peptide degradation products, nanomolar amounts (micromolar concentrations) of peptides are incubated in synthetic media with cell or tissue cultures. Aliquots of the supernatants are withdrawn after different times, peptide fragments separated and fractionated by reversed-phase HPLC, and identified by peptide chemical methods. The peptidases responsible for this degradation can be identified by the use of specific inhibitors listed in the protocol. For receptor binding assays or the study of peptide effects in physiological, nanomolar concentrations the stability of the peptides in an in vitro system should be checked by addition of radiolabeled peptides (femtomolar or nanomolar concentrations) and monitoring the peptide degradation by a procedure analogous to that established for unlabeled peptides. The addition of more or less specific peptidase inhibitors enhances peptide stability in vitro, and thus it can be assured that a given peptide concentration is maintained during biological assays.
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Affiliation(s)
- R Mentlein
- Anatomisches Institut der Universität Kiel, Germany
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13
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Mark MA, Jarrott B, Colvin LA, MacMillan SJ, Duggan AW. The release of immunoreactive neuropeptide Y in the spinal cord of the anaesthetized rat and cat. Brain Res 1997; 754:195-203. [PMID: 9134976 DOI: 10.1016/s0006-8993(97)00061-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The release of immunoreactive (ir-) neuropeptide Y (NYP) was studied in the anaesthetized rat and cat by means of microprobes bearing immobilized antibodies to the C terminus of NPY. An extensive basal release of ir-NYP was detected throughout the dorsal and upper ventral horn of the rat. This spontaneous release was not significantly altered by sectioning the spinal cord at the thoraco-lumbar junction nor by electrical stimulation of peripheral nerves. Since NPY is virtually absent in primary afferents it is probable that spontaneous release within the spinal cord comes from active NPY-containing intrinsic spinal neurones. In the spinal cat spontaneous release of ir-NPY was detected in the mid-dorsal horn and this was unaltered by peripheral noxious thermal or noxious mechanical stimuli. As in the rat, release from intrinsic spinal neurones is most probable. The extensive spontaneous release of ir-NPY in both species suggests a widespread role in spinal cord function.
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Affiliation(s)
- M A Mark
- Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Summerhall, UK
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14
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Stenfors C, Hellman U, Silberring J. Characterization of endogenous neuropeptide Y in rat hippocampus and its metabolism by nanospray mass spectrometry. J Biol Chem 1997; 272:5747-51. [PMID: 9038187 DOI: 10.1074/jbc.272.9.5747] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Neuropeptide Y (NPY) is a 36-residue-long neuropeptide which has been implicated in the regulation of feeding behavior and modulation of the circadian rhythm. We identified the primary structure of the endogenous NPY-immunoreactive material in the rat hippocampus using a combination of chromatographic techniques and nanospray mass spectrometry. The major component in the brain tissue corresponded to the authentic amidated form of NPY(1-36). The fate of NPY in the central nervous system was studied by subjecting pure peptide to the protease(s) present in hippocampal synaptosomes to reveal potential cleavage site(s). NPY was efficiently metabolized with a single cleavage between Leu30-Ile31. Thus, processing of NPY resulted in formation of the C-terminally truncated fragment NPY(1-30) and its counterpart NPY(31-36). The enzyme revealed properties of aspartic protease, being blocked by pepstatin and having a pH optimum between 4 and 5. The data clarify the structure of NPY and its inactivation pathway in the brain, which is different from that found in the periphery, and may have important consequences in vivo.
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Affiliation(s)
- C Stenfors
- Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden.
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15
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Mentlein R, Roos T. Proteases involved in the metabolism of angiotensin II, bradykinin, calcitonin gene-related peptide (CGRP), and neuropeptide Y by vascular smooth muscle cells. Peptides 1996; 17:709-20. [PMID: 8804084 DOI: 10.1016/0196-9781(96)00066-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To understand the regulation of the vasoactive peptides bradykinin, angiotensin II, calcitonin gene-related peptide (CGRP), and neuropeptide Y (NPY), their proteolytic catabolism by cultured rat aortic vascular smooth muscle cells and A7r5 cells was investigated. Endopeptidase-24.11 (EC 3.4.24.11, CD 10) was responsible for the final inactivation of bradykinin, angiotensin II, and CGRP, but not of NPY, which was degraded by a different metallo-endopeptidase. Exopeptidases, namely the aminopeptidases A (EC 3.4.11.7), N (EC 3.4.11.2, CD 13), and P (EC 3.4.11.9) and the carboxypeptidases M (EC 3.4.17.12) and P (EC 3.4.17.16), were important for their differential, receptor subtype-specific activation or inactivation. Aminopeptidase A and N generated angiotensins III and IV from angiotensin II. Aminopeptidase P liberated the terminal amino acids from bradykinin and NPY, yielding the Y2 receptor specific-agonist NPY(2-36). Carboxypeptidase P produced AT II(1-7) and carboxypeptidase M produced the BK1 receptor agonist [des-Arg9]bradykinin. Thus, peptidases at the surface of vascular smooth muscle cells exert a complex influence on the level of biologically active vasoactive peptides.
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Affiliation(s)
- R Mentlein
- Anatomisches Institut, Universität Kiel, Germany
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