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Puri S, Kenyon BM, Hamrah P. Immunomodulatory Role of Neuropeptides in the Cornea. Biomedicines 2022; 10:1985. [PMID: 36009532 PMCID: PMC9406019 DOI: 10.3390/biomedicines10081985] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 12/21/2022] Open
Abstract
The transparency of the cornea along with its dense sensory innervation and resident leukocyte populations make it an ideal tissue to study interactions between the nervous and immune systems. The cornea is the most densely innervated tissue of the body and possesses both immune and vascular privilege, in part due to its unique repertoire of resident immune cells. Corneal nerves produce various neuropeptides that have a wide range of functions on immune cells. As research in this area expands, further insights are made into the role of neuropeptides and their immunomodulatory functions in the healthy and diseased cornea. Much remains to be known regarding the details of neuropeptide signaling and how it contributes to pathophysiology, which is likely due to complex interactions among neuropeptides, receptor isoform-specific signaling events, and the inflammatory microenvironment in disease. However, progress in this area has led to an increase in studies that have begun modulating neuropeptide activity for the treatment of corneal diseases with promising results, necessitating the need for a comprehensive review of the literature. This review focuses on the role of neuropeptides in maintaining the homeostasis of the ocular surface, alterations in disease settings, and the possible therapeutic potential of targeting these systems.
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Affiliation(s)
- Sudan Puri
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Brendan M. Kenyon
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
- Departments of Immunology and Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
- Cornea Service, Tufts New England Eye Center, Boston, MA 02111, USA
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Domingues MF, de Assis DR, Piovesan AR, Belo CAD, da Costa JC. Peptide YY (3-36) modulates intracellular calcium through activation of the phosphatidylinositol pathway in hippocampal neurons. Neuropeptides 2018; 67:1-8. [PMID: 29157865 DOI: 10.1016/j.npep.2017.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 11/03/2017] [Accepted: 11/05/2017] [Indexed: 10/18/2022]
Abstract
Peptide YY (PYY) belongs to the neuropeptide Y (NPY) family, which also includes the pancreatic polypeptide (PP) and NPY. PYY is secreted by the intestinal L cells, being present in the blood stream in two active forms capable of crossing the blood brain barrier, PYY (1-36) and its cleavage product, PYY (3-36). PYY is a selective agonist for the Y2 receptor (Y2R) and these receptors are abundant in the hippocampus. Here we investigated the mechanisms by which PYY (3-36) regulates intracellular Ca2+ concentrations ([Ca2+]i) in hippocampal neurons by employing a calcium imaging technique in hippocampal cultures. Alterations in [Ca2+]i were detected by changes in the Fluo-4 AM reagent emission. PYY (3-36) significantly increased [Ca2+] from the concentration of 10-11M as compared to the controls (infusion of HEPES-buffered solution (HBS) solution alone). The PYY (3-36)-increase in [Ca2+]i remained unchanged even in Ca2+-free extracellular solutions. Sarcoplasmic/endoplasmic reticulum Ca2+-ATPase pump (SERCA pump) inhibition partially prevent the PYY (3-36)-increase of [Ca2+]i and inositol 1,4,5-triphosphate receptor (IP3R) inhibition also decreased the PYY (3-36)-increase of [Ca2+]i. Taken together, our data strongly suggest that PYY (3-36) mobilizes calcium from the neuronal endoplasmic reticulum (ER) stores towards the cytoplasm. Next, we showed that PYY (3-36) inhibited high K+-induced increases of [Ca2+]i, suggesting that PYY (3-36) could also act by activating G-protein coupled inwardly rectifying potassium K+ channels. Finally, the co-infusion of the Y2 receptor (Y2R) antagonist BIIE0246 with PYY (3-36) abolished the [Ca2+]i increase induced by the peptide, suggesting that PYY (3-36)-induced [Ca2+]i increase in hippocampal neurons occurs via Y2Rs.
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Affiliation(s)
- Michelle Flores Domingues
- Graduate Program in Cellular and Molecular Biology - Center for Biotechnology, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Brazil; Brain Institute (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
| | - Dênis Reis de Assis
- Brain Institute (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
| | - Angela Regina Piovesan
- Graduate Program in Cellular and Molecular Biology - Center for Biotechnology, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Brazil; Brain Institute (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
| | - Cháriston André Dal Belo
- Brain Institute (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil; Laboratory of Neurobiology and Toxinology, LANETOX, Universidade Federal do Pampa, UNIPAMPA, São Gabriel, Brazil; Graduate Program in Biological Sciences: Biochemical Toxicology, PPGBTox, Universidade Federal de Santa Maria, UFSM, Santa Maria, Brazil.
| | - Jaderson Costa da Costa
- Brain Institute (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
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Pedragosa-Badia X, Stichel J, Beck-Sickinger AG. Neuropeptide Y receptors: how to get subtype selectivity. Front Endocrinol (Lausanne) 2013; 4:5. [PMID: 23382728 PMCID: PMC3563083 DOI: 10.3389/fendo.2013.00005] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 01/09/2013] [Indexed: 11/13/2022] Open
Abstract
The neuropeptide Y (NPY) system is a multireceptor/multiligand system consisting of four receptors in humans (hY(1), hY(2), hY(4), hY(5)) and three agonists (NPY, PYY, PP) that activate these receptors with different potency. The relevance of this system in diseases like obesity or cancer, and the different role that each receptor plays influencing different biological processes makes this system suitable for the design of subtype selectivity studies. In this review we focus on the latest findings within the NPY system, we summarize recent mutagenesis studies, structure activity relationship studies, receptor chimera, and selective ligands focusing also on the binding mode of the native agonists.
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Affiliation(s)
| | | | - Annette G. Beck-Sickinger
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität LeipzigLeipzig, Germany
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On the segregation of protein ionic residues by charge type. Amino Acids 2012; 43:2231-47. [PMID: 23081700 DOI: 10.1007/s00726-012-1418-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 10/06/2012] [Indexed: 10/27/2022]
Abstract
Based on ubiquitous presence of large ionic motifs and clusters in proteins involved in gene transcription and protein synthesis, we analyzed the distribution of ionizable sidechains in a broad selection of proteins with regulatory, metabolic, structural and adhesive functions, in agonist, antagonist, toxin and antimicrobial peptides, and in self-excising inteins and intron-derived proteins and sequence constructs. All tested groups, regardless of taxa or sequence size, show considerable segregation of ionizable sidechains into same type charge (homoionic) tracts. These segments in most cases exceed half of the sequence length and comprise more than two-thirds of all ionizable sidechains. This distribution of ionic residues apparently reflects a fundamental advantage of sorted electrostatic contacts in association of sequence elements within and between polypeptides, as well as in interaction with polynucleotides. While large ionic densities are encountered in highly interactive proteins, the average ionic density in most sets does not change appreciably with size of the homoionic segments, which supports the segregation as a modular feature favoring association.
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Garcia FD, Coquerel Q, do Rego JC, Cravezic A, Bole-Feysot C, Kiive E, Déchelotte P, Harro J, Fetissov SO. Anti-neuropeptide Y plasma immunoglobulins in relation to mood and appetite in depressive disorder. Psychoneuroendocrinology 2012; 37:1457-67. [PMID: 22365482 DOI: 10.1016/j.psyneuen.2012.01.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/31/2012] [Accepted: 01/31/2012] [Indexed: 12/27/2022]
Abstract
Depression and eating disorders are frequently associated, but the molecular pathways responsible for co-occurrence of altered mood, appetite and body weight are not yet fully understood. Neuropeptide Y (NPY) has potent antidepressant and orexigenic properties and low central NPY levels have been reported in major depression. In the present study, we hypothesized that in patients with major depression alteration of mood, appetite and body weight may be related to NPY-reactive autoantibodies (autoAbs). To test this hypothesis, we compared plasma levels and affinities of NPY-reactive autoAbs between patients with major depression and healthy controls. Then, to evaluate if changes of NPY autoAb properties can be causally related to altered mood and appetite, we developed central and peripheral passive transfer models of human autoAbs in mice and studied depressive-like behavior in forced-swim test and food intake. We found that plasma levels of NPY IgG autoAbs were lower in patients with moderate but not with mild depression correlating negatively with the Montgomery-Åsberg Depression Rating Scale scores and with immobility time of the forced-swim test in mice after peripheral injection of autoAbs. No significant differences in NPY IgG autoAb affinities between patients with depression and controls were found, but higher affinity of IgG autoAbs for NPY was associated with lower body mass index and prevented NPY-induced orexigenic response in mice after their central injection. These data suggest that changes of plasma levels of anti-NPY autoAbs are relevant to altered mood, while changes of their affinity may participate in altered appetite and body weight in patients with depressive disorder.
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Affiliation(s)
- Frederico D Garcia
- Nutrition, Gut and Brain Laboratory, Inserm U1073, Institute for Research and Innovation in Biomedicine-IRIB, Rouen University, Normandy 76183, France
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