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Castellini G, Merola GP, Baccaredda Boy O, Pecoraro V, Bozza B, Cassioli E, Rossi E, Bessi V, Sorbi S, Nacmias B, Ricca V. Emotional dysregulation, alexithymia and neuroticism: a systematic review on the genetic basis of a subset of psychological traits. Psychiatr Genet 2023; 33:79-101. [PMID: 36729042 PMCID: PMC10158611 DOI: 10.1097/ypg.0000000000000335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/24/2022] [Indexed: 02/03/2023]
Abstract
Neuroticism, alexithymia and emotion dysregulation are key traits and known risk factors for several psychiatric conditions. In this systematic review, the aim is to evaluate the genetic contribution to these psychological phenotypes. A systematic review of articles found in PubMed was conducted. Search terms included 'genetic', 'GWAS', 'neuroticism', 'alexithymia' and 'emotion dysregulation'. Risk of bias was assessed utilizing the STREGA checklist. Two hundred two papers were selected from existing literature based on the inclusion and exclusion criteria. Among these, 27 were genome-wide studies and 175 were genetic association studies. Single gene association studies focused on selected groups of genes, mostly involved in neurotransmission, with conflicting results. GWAS studies on neuroticism, on the other hand, found several relevant and replicated intergenic and intronic loci affecting the expression and regulation of crucial and well-known genes (such as DRD2 and CRHR1). Mutations in genes coding for trascriptional factors were also found to be associated with neuroticism (DCC, XKR6, TCF4, RBFOX1), as well as a noncoding regulatory RNA (LINC00461). On the other hand, little GWAS data are available on alexythima and emotional dysregulation.
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Affiliation(s)
| | | | | | | | | | | | | | - Valentina Bessi
- Neurology Unit, Department of Health Sciences, University of Florence, Florence, Italy
| | - Sandro Sorbi
- Neurology Unit, Department of Health Sciences, University of Florence, Florence, Italy
| | - Benedetta Nacmias
- Neurology Unit, Department of Health Sciences, University of Florence, Florence, Italy
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2
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Pluimer BR, Colt M, Zhao Z. G Protein-Coupled Receptors in the Mammalian Blood-Brain Barrier. Front Cell Neurosci 2020; 14:139. [PMID: 32581715 PMCID: PMC7283493 DOI: 10.3389/fncel.2020.00139] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/22/2020] [Indexed: 12/18/2022] Open
Abstract
The mammalian neurovascular unit (NVU) is comprised of neurons, glia, and vascular cells. The NVU is the nexus between the cardiovascular and central nervous system (CNS). The central component of the NVU is the blood-brain barrier (BBB) which consists of a monolayer of tightly connected endothelial cells covered by pericytes and further surrounded by astrocytic endfeet. In addition to preventing the diffusion of toxic species into the CNS, the BBB endothelium serves as a dynamic regulatory system facilitating the transport of molecules from the bloodstream to the brain and vis versa. The structural integrity and transport functions of the BBB are maintained, in part, by an orchestra of membrane receptors and transporters including members of the superfamily of G protein-coupled receptors (GPCRs). Here, we provide an overview of GPCRs known to regulate mammalian BBB structure and function and discuss how dysregulation of these pathways plays a role in various neurodegenerative diseases.
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Affiliation(s)
- Brock R. Pluimer
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Mark Colt
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Zhen Zhao
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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3
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Yarur HE, González MP, Verbel‐Vergara D, Andrés ME, Gysling K. Cross‐talk between dopamine D1 and corticotropin releasing factor type 2 receptors leads to occlusion of their ERK1/2 signaling. J Neurochem 2020; 155:264-273. [DOI: 10.1111/jnc.15016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 02/04/2020] [Accepted: 03/12/2020] [Indexed: 01/24/2023]
Affiliation(s)
- Hector E. Yarur
- Department of Cellular and Molecular Biology Faculty of Biological Sciences Pontificia Universidad Católica de Chile Santiago Chile
| | - Marcela P. González
- Department of Cellular and Molecular Biology Faculty of Biological Sciences Pontificia Universidad Católica de Chile Santiago Chile
| | - Daniel Verbel‐Vergara
- Department of Cellular and Molecular Biology Faculty of Biological Sciences Pontificia Universidad Católica de Chile Santiago Chile
| | - María E. Andrés
- Department of Cellular and Molecular Biology Faculty of Biological Sciences Pontificia Universidad Católica de Chile Santiago Chile
| | - Katia Gysling
- Department of Cellular and Molecular Biology Faculty of Biological Sciences Pontificia Universidad Católica de Chile Santiago Chile
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4
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Cao C, Zhou J, Wu X, Qian Y, Hong Y, Mu J, Jin L, Zhu C, Li S. Activation of CRHR1 contributes to cerebral endothelial barrier impairment via cPLA2 phosphorylation in experimental ischemic stroke. Cell Signal 2020; 66:109467. [DOI: 10.1016/j.cellsig.2019.109467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 11/27/2022]
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5
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Natural and synthetic peptides in the cardiovascular diseases: An update on diagnostic and therapeutic potentials. Arch Biochem Biophys 2018; 662:15-32. [PMID: 30481494 DOI: 10.1016/j.abb.2018.11.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/31/2018] [Accepted: 11/21/2018] [Indexed: 02/07/2023]
Abstract
Several peptides play an important role in physiological and pathological conditions into the cardiovascular system. In addition to well-known vasoactive agents such as angiotensin II, endothelin, serotonin or natriuretic peptides, the vasoconstrictor Urotensin-II (Uro-II) and the vasodilators Urocortins (UCNs) and Adrenomedullin (AM) have been implicated in the control of vascular tone and blood pressure as well as in cardiovascular disease states including congestive heart failure, atherosclerosis, coronary artery disease, and pulmonary and systemic hypertension. Therefore these peptides, together with their receptors, become important therapeutic targets in cardiovascular diseases (CVDs). Circulating levels of these agents in the blood are markedly modified in patients with specific CVDs compared with those in healthy patients, becoming also potential biomarkers for these pathologies. This review will provide an overview of current knowledge about the physiological roles of Uro-II, UCN and AM in the cardiovascular system and their implications in cardiovascular diseases. It will further focus on the structural modifications carried out on original peptide sequences in the search of analogues with improved physiochemical properties as well as in the delivery methods. Finally, we have overviewed the possible application of these peptides and/or their precursors as biomarkers of CVDs.
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Urocortin 2 is associated with abdominal aortic aneurysm and mediates anti-proliferative effects on vascular smooth muscle cells via corticotrophin releasing factor receptor 2. Clin Sci (Lond) 2013; 126:517-27. [DOI: 10.1042/cs20130425] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
There are no current effective drug therapies for abdominal aortic aneurysm, an important cause of death in older adults. Our study suggests that urocortin 2 participates in the disease process and may serve as a putative therapeutic target.
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7
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Huang HY, Liu DD, Chang HF, Chen WF, Hsu HR, Kuo JS, Wang MJ. Histone deacetylase inhibition mediates urocortin-induced antiproliferation and neuronal differentiation in neural stem cells. Stem Cells 2013; 30:2760-73. [PMID: 22961741 DOI: 10.1002/stem.1226] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 08/14/2012] [Indexed: 01/15/2023]
Abstract
During cortical development, cell proliferation and cell cycle exit are carefully regulated to ensure that the appropriate numbers of cells are produced. Urocortin (UCN) is a member of the corticotrophin releasing hormone (CRH) family of neuropeptides that regulates stress responses. UCN is widely distributed in adult rat brain. However, the expression and function of UCN in embryonic brain is, as yet, unclear. Here, we show that UCN is endogenously expressed in proliferative zones of the developing cerebral cortex and its receptors are exhibited in neural stem cells (NSCs), thus implicating the neuropeptide in cell cycle regulation. Treatment of cultured NSCs or organotypic slice cultures with UCN markedly reduced cell proliferation. Furthermore, blocking of endogenous UCN/CRHRs system either by treatment with CRHRs antagonists or by neutralization of secreted UCN with anti-UCN antibody increased NSCs proliferation. Cell cycle kinetics analysis demonstrated that UCN lengthened the total cell cycle duration via increasing the G1 phase and accelerated cell cycle exit. UCN directly inhibited the histone deacetylase (HDAC) activity and induced a robust increase in histone H3 acetylation levels. Using pharmacological and RNA interference approaches, we further demonstrated that antiproliferative action of UCN appeared to be mediated through a HDAC inhibition-induced p21 upregulation. Moreover, UCN treatment in vitro and in vivo led to an increase in neuronal differentiation of NSCs. These findings suggest that UCN might contribute to regulate NSCs proliferation and differentiation during cortical neurogenesis.
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Affiliation(s)
- Hsin-Yi Huang
- Department of Medical Research, Neuro-Medical Scientific Center, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
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8
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Zhao Y, Wang MY, Hao K, Chen XQ, Du JZ. CRHR1 mediates p53 transcription induced by high altitude hypoxia through ERK 1/2 signaling in rat hepatic cells. Peptides 2013; 44:8-14. [PMID: 23538210 DOI: 10.1016/j.peptides.2013.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 01/14/2023]
Abstract
We have previously reported that hypoxia activates corticotrophin-releasing hormone (CRH) and the expression of its type-1 receptor (CRHR1) and induces disorders of the brain-endocrine-immune network. p53 is activated by hypoxia and involved in tumorigenesis and apoptosis. Whether CRHR1 regulates p53 transactivation to further influence apoptotic genes remains unclear. Here, we showed that hypoxia at a simulated altitude of 5km or 7km for 8 and 24h increased p53 protein and mRNA, and reduced apoptotic bax and IGFBP3 gene expression while upregulating the cell-arrest gene p21 for 8h in rat liver cells. The upregulation of p53 mRNA and downregulation of bax mRNA induced by hypoxia were blocked by pretreatment with the specific CRHR1 antagonist CP-154,526, but the downregulation of IGFBP3 and upregulation of p21 mRNA were not. Furthermore, CRH stimulated p53 mRNA via the ERK 1/2 pathway in the BRL-3A cell line and this was blocked by the ERK 1/2 antagonist U0126. These data provide novel evidence that the CRHR1-triggered ERK 1/2 pathway is involved in the activation of p53 and suppression of the apoptotic bax gene by hypoxia in rat liver.
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Affiliation(s)
- Yang Zhao
- Division of Neurobiology and Physiology, Department of Basic Medical Sciences, School of Medicine, Zhejiang University, Hangzhou 310058, China
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9
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Tillinger A, Nostramo R, Kvetnansky R, Serova L, Sabban EL. Stress-induced changes in gene expression of urocortin 2 and other CRH peptides in rat adrenal medulla: involvement of glucocorticoids. J Neurochem 2013; 125:185-92. [DOI: 10.1111/jnc.12152] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 12/31/2012] [Accepted: 01/02/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Andrej Tillinger
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla New York USA
| | - Regina Nostramo
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla New York USA
| | - Richard Kvetnansky
- Institute of Experimental Endocrinology; Slovak Academy of Sciences; Bratislava Slovakia
| | - Lidia Serova
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla New York USA
| | - Esther L. Sabban
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla New York USA
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Pan W, Stone KP, Hsuchou H, Manda VK, Zhang Y, Kastin AJ. Cytokine signaling modulates blood-brain barrier function. Curr Pharm Des 2013; 17:3729-40. [PMID: 21834767 DOI: 10.2174/138161211798220918] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/30/2011] [Accepted: 09/26/2011] [Indexed: 02/06/2023]
Abstract
The blood-brain barrier (BBB) provides a vast interface for cytokines to affect CNS function. The BBB is a target for therapeutic intervention. It is essential, therefore, to understand how cytokines interact with each other at the level of the BBB and how secondary signals modulate CNS functions beyond the BBB. The interactions between cytokines and lipids, however, have not been fully addressed at the level of the BBB. Here, we summarize current understanding of the localization of cytokine receptors and transporters in specific membrane microdomains, particularly lipid rafts, on the luminal (apical) surface of the microvascular endothelial cells composing the BBB. We then illustrate the clinical context of cytokine effects on the BBB by neuroendocrine regulation and amplification of inflammatory signals. Two unusual aspects discussed are signaling crosstalk by different classes of cytokines and genetic regulation of drug efflux transporters. We also introduce a novel area of focus on how cytokines may act through nuclear hormone receptors to modulate efflux transporters and other targets. A specific example discussed is the ATP-binding cassette transporter-1 (ABCA-1) that regulates lipid metabolism. Overall, cytokine signaling at the level of the BBB is a crucial feature of the dynamic regulation that can rapidly change BBB function and affect brain health and disease.
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Affiliation(s)
- Weihong Pan
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
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11
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Wang L, Stengel A, Goebel-Stengel M, Shaikh A, Yuan PQ, Taché Y. Intravenous injection of urocortin 1 induces a CRF2 mediated increase in circulating ghrelin and glucose levels through distinct mechanisms in rats. Peptides 2013; 39. [PMID: 23183626 PMCID: PMC3599411 DOI: 10.1016/j.peptides.2012.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Urocortins (Ucns) injected peripherally decrease food intake and gastric emptying through peripheral CRF(2) receptors in rodents. However, whether Ucns influence circulating levels of the orexigenic and prokinetic hormone, ghrelin has been little investigated. We examined plasma levels of ghrelin and blood glucose after intravenous (iv) injection of Ucn 1, the CRF receptor subtype involved and underlying mechanisms in ad libitum fed rats equipped with a chronic iv cannula. Ucn 1 (10 μg/kg, iv) induced a rapid onset and long lasting increase in ghrelin levels reaching 68% and 219% at 0.5 and 3h post injection respectively and a 5-h hyperglycemic response. The selective CRF(2) agonist, Ucn 2 (3 μg/kg, iv) increased fasting acyl (3h: 49%) and des-acyl ghrelin levels (3h: 30%) compared to vehicle while the preferential CRF(1) agonist, CRF (3 μg/kg, iv) had no effect. Ucn 1's stimulatory actions were blocked by the selective CRF(2) antagonist, astressin(2)-B (100 μg/kg, iv). Hexamethonium (10 mg/kg, sc) prevented Ucn 1-induced rise in total ghrelin levels while not altering the hyperglycemic response. These data indicate that systemic injection of Ucns induces a CRF(2)-mediated increase in circulating ghrelin levels likely via indirect actions on gastric ghrelin cells that involves a nicotinic pathway independently from the hyperglycemic response.
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Affiliation(s)
- Lixin Wang
- CURE/Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at University of California Los Angeles, Los Angeles, CA 90073, USA.
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12
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Fekete EM, Zhao Y, Szücs A, Sabino V, Cottone P, Rivier J, Vale WW, Koob GF, Zorrilla EP. Systemic urocortin 2, but not urocortin 1 or stressin 1-A, suppresses feeding via CRF2 receptors without malaise and stress. Br J Pharmacol 2012; 164:1959-75. [PMID: 21627635 DOI: 10.1111/j.1476-5381.2011.01512.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Infusion of corticotropin-releasing factor (CRF)/urocortin (Ucn) family peptides suppresses feeding in mice. We examined whether rats show peripheral CRF/Ucn-induced anorexia and determined its behavioural and pharmacological bases. EXPERIMENTAL APPROACH Male Wistar rats (n= 5-12 per group) were administered (i.p.) CRF receptor agonists with different subtype affinities. Food intake, formation of conditioned taste aversion and corticosterone levels were assessed. In addition, Ucn 1- and Ucn 2-induced anorexia was studied in fasted CRF(2) knockout (n= 11) and wild-type (n= 13) mice. KEY RESULTS Ucn 1, non-selective CRF receptor agonist, reduced food intake most potently (~0.32 nmol·kg(-1) ) and efficaciously (up to 70% reduction) in fasted and fed rats. The peptides' rank-order of anorexic potency was Ucn 1 ≥ Ucn 2 > >stressin(1) -A > Ucn 3, and efficacy, Ucn 1 > stressin(1) -A > Ucn 2 = Ucn 3. Ucn 1 reduced meal frequency and size, facilitated feeding bout termination and slowed eating rate. Stressin(1) -A (CRF(1) agonist) reduced meal size; Ucn 2 (CRF(2) agonist) reduced meal frequency. Stressin(1) -A and Ucn 1, but not Ucn 2, produced a conditioned taste aversion, reduced feeding efficiency and weight regain and elicited diarrhoea. Ucn 1, but not Ucn 2, also increased corticosterone levels. Ucn 1 and Ucn 2 reduced feeding in wild-type, but not CRF(2) knockout, mice. CONCLUSIONS AND IMPLICATIONS CRF(1) agonists, Ucn 1 and stressin(1) -A, reduced feeding and induced interoceptive stress, whereas Ucn 2 potently suppressed feeding via a CRF(2) -dependent mechanism without eliciting malaise. Consistent with their pharmacological differences, peripheral urocortins have diverse effects on appetite.
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Affiliation(s)
- E M Fekete
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Lutfy K, Aimiuwu O, Mangubat M, Shin CS, Nerio N, Gomez R, Liu Y, Friedman TC. Nicotine stimulates secretion of corticosterone via both CRH and AVP receptors. J Neurochem 2012; 120:1108-16. [PMID: 22191943 DOI: 10.1111/j.1471-4159.2011.07633.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Corticosterone-releasing hormone (CRH) and arginine vasopressin (AVP) are crucial components of the hypothalamic-pituitary-adrenal axis that stimulates the release of adrenocorticotropic hormone from the pituitary and mediate the stress response. CRH binds to two subtypes of CRH receptors (CRH-R1 and CRH-R2) that are present in both central and peripheral tissues. We used the CRH-R1-specific antagonist, antalarmin (ANT), the CRH-R1 and CRH-R2 peptide antagonist, astressin (AST), and the CRH-R2-specific peptide antagonist, astressin2b (AST2b), to determine which CRH receptor is involved in the nicotine-stimulated secretion of corticosterone. Male C57BL/6 mice were administered ANT (20 mg/kg, i.p.), AST (0.3 mg/kg, i.p.), AST2b (0.3 mg/kg, i.p.) or vehicle prior to administration of nicotine (1.0 mg/kg, s.c.), CRH (10 μg/kg, s.c.), AVP (10 μg/kg, s.c.) or saline (s.c.), killed 15 min later and trunk blood collected and assayed for corticosterone plasma levels. We found that CRH enhanced corticosterone release, and this response was blocked by both AST and ANT. Nicotine also increased corticosterone secretion, but this effect persisted in the presence of either CRH antagonist. Furthermore, AST but not ANT or AST2b decreased corticosterone levels associated with stress of handling and injection. We also assessed the role of AVP V(1b) -specific receptor antagonist, SSR149415 alone and in combination with AST and AST2b. Although the AVP antagonist did not alter basal or nicotine-stimulated corticosterone secretion, it attenuated the AVP-induced stimulation of corticosterone and its combination with AST but not AST2b completely abolished nicotine-mediated stimulation of corticosterone secretion. Our results demonstrate that the nicotine-induced stimulation of the hypothalamic-pituitary-adrenal axis is mediated by both the CRH-R and the AVP V(1b) receptor and when the CRH receptor is blocked, nicotine may utilize the AVP V(1b) receptor to mediate secretion of corticosterone. These results argue in favor of the development of specific antagonists that block both AVP and CRH receptors to decrease the pleasurable component of nicotine, which may be mediated by corticosterone.
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Affiliation(s)
- Kabirullah Lutfy
- Division of Endocrinology, Molecular Medicine and Metabolism, Department of Internal Medicine, Charles R. Drew University of Medicine & Sciences-David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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14
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Liew HK, Hsu CW, Wang MJ, Kuo JS, Li TY, Peng HF, Wang JY, Pang CY. Therapeutic benefit of urocortin in rats with intracerebral hemorrhage. J Neurosurg 2012; 116:193-200. [DOI: 10.3171/2011.8.jns101637] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Intracerebral hemorrhage (ICH) accounts for about 15% of all deaths due to stroke. It frequently causes brain edema, leading to an expansion of brain volume that exerts a negative impact on ICH outcomes. The ICH-induced brain edema involves inflammatory mechanisms. The authors' in vitro study shows that urocortin (UCN) exhibits antiinflammatory and neuroprotective effects. Therefore, the neuroprotective effect of UCN on ICH in rats was investigated.
Methods
Intracerebral hemorrhage was induced by an infusion of bacteria collagenase type VII-S or autologous blood into the unilateral striatum of anesthetized rats. At 1 hour after the induction of ICH, UCN (0.05, 0.5, and 5 μg) was infused into the lateral ventricle on the ipsilateral side. The authors examined the injury area, brain water content, blood-brain barrier permeability, and neurological function.
Results
The UCN, administered in the ipsilateral lateral ventricle, was able to penetrate into the injured striatum. Posttreatment with UCN reduced the injury area, brain edema, and blood-brain barrier permeability and improved neurological deficits of rats with ICH.
Conclusions
Posttreatment with UCN through improving neurological deficits of rats with ICH dose dependently provided a potential therapeutic agent for patients with ICH or other brain injuries.
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Affiliation(s)
- Hock-Kean Liew
- 1Departments of Medical Research and
- 3Graduate Institute of Life Sciences, National Defense Medical Center; and
| | - Chih-Wei Hsu
- 2Emergency Medicine, Tzu Chi General Hospital
- 6School of Medicine, Tzu Chi University, Hualien
| | - Mei-Jen Wang
- 1Departments of Medical Research and
- 4Graduate Institute of Medical Sciences, and
| | - Jon-Son Kuo
- 4Graduate Institute of Medical Sciences, and
| | | | | | - Jia-Yi Wang
- 3Graduate Institute of Life Sciences, National Defense Medical Center; and
- 5Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
| | - Cheng-Yoong Pang
- 1Departments of Medical Research and
- 4Graduate Institute of Medical Sciences, and
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Abstract
Steroidogenic factor 1 (SF-1; officially designated NR5a1) is a member of a nuclear receptor superfamily with important roles in the development of endocrine systems. Studies with global and tissue-specific (i.e. central nervous system) knockout mice have revealed several roles of SF-1 in brain. These include morphological effects on the development of the ventromedial nucleus of the hypothalamus and functional effects on body weight regulation through modulation of physical activity, anxiety-like behaviours and female sexual behaviours. Although such defects are almost certainly a result of the absence of SF-1 acting as a transcription factor in the hypothalamus, global SF-1 knockout mice also represent a model for studying the sex differences in the brain that develop in the absence of exposure to foetal sex steroid hormones as a result of the absence of gonads. In the present review, current knowledge of the roles of SF-1 protein in the central nervous system is discussed.
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Affiliation(s)
- T Büdefeld
- Centre for Animal Genomics, Veterinary Faculty, University of Ljubljana, Ljubljana, Slovenia
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16
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Emeto TI, Moxon JV, Rush C, Woodward L, Golledge J. Relevance of urocortins to cardiovascular disease. J Mol Cell Cardiol 2011; 51:299-307. [PMID: 21689660 DOI: 10.1016/j.yjmcc.2011.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/26/2011] [Accepted: 06/02/2011] [Indexed: 11/19/2022]
Abstract
Acquired cardiovascular diseases such as coronary heart disease, peripheral artery disease and related vascular problems contribute to more than one-third of worldwide morbidity and mortality. In many instances, particularly in the under developed world, cardiovascular diseases are diagnosed at a late stage limiting the scope for improving outcomes. A range of therapies already exist for established cardiovascular disease, although there is significant interest in further understanding disease pathogenesis in order to improve diagnosis and achieve primary and secondary therapeutic goals. The urocortins are a group of recently defined peptide members of the corticotrophin-releasing factor family. Previous pre-clinical work and human association studies suggest that urocortins have potential to exert some beneficial and other detrimental effects on the heart and major blood vessels. More current evidence however favours beneficial effects of urocortins, for example these peptides have been shown to inhibit production of reactive oxygen species and vascular cell apoptosis, and thus may have potential to antagonise the progression of cardiovascular disease. This review summarises published data on the potential role of urocortins in cardiovascular disease.
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Affiliation(s)
- Theophilus I Emeto
- Vascular Biology Unit, School of Medicine and Dentistry, James Cook University, Townsville, QLD 4811, Australia
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17
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Kastin AJ, Pan W. Concepts for biologically active peptides. Curr Pharm Des 2011; 16:3390-400. [PMID: 20726835 DOI: 10.2174/138161210793563491] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Accepted: 08/12/2010] [Indexed: 12/21/2022]
Abstract
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.
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Affiliation(s)
- Abba J Kastin
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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Neonatal maternal separation in the rat impacts on the stress responsivity of central corticotropin-releasing factor receptors in adulthood. Psychopharmacology (Berl) 2011; 214:221-9. [PMID: 20499051 DOI: 10.1007/s00213-010-1885-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 05/07/2010] [Indexed: 12/30/2022]
Abstract
RATIONALE Adverse events during early developmental stages can induce persistent changes in central stress circuits, leading to increased stress sensitivity in adulthood, as is apparent in the maternally separated (MS) rat model. It is widely accepted that the stress peptide corticotropin-releasing factor (CRF) by binding to CRF1 and 2 receptors (CRFR1 and CRFR2) is key to these phenotypic changes. OBJECTIVES These studies aim to investigate the effects of maternal separation on central expression of CRFR1 and CRFR2 under basal conditions and following an acute psychological stressor in adulthood. METHODS Western blotting techniques were employed to examine changes in receptor expression in the hypothalamus, pre-frontal and frontal cortices, amygdala and hippocampus of MS rats as compared to controls. Additionally, the effects of an acute psychological stressor (open field exposure) on these changes were assessed. RESULTS Under basal conditions, CRFR1 was elevated in the hypothalamus of MS rats. Exposure to an acute stress had limited effects in non-separated animals but induced significant changes in CRFR1 in the hypothalamus, pre-frontal cortex and hippocampus of MS rats. Additionally, stress-induced increases in CRFR2 were observed in the amygdala of MS rats. CONCLUSIONS These data demonstrate the discrete and significant alterations in how the brain CRF system responds to acute stress following maternal separation. These studies illustrate that early life perturbations induce persistent changes in central CRF receptor expression and increased sensitivity to stress, which may contribute to the stress-related behavioural changes observed in these animals.
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Borges LE, Horne AW, McDonald SE, Shaw JLV, Lourenco PC, Petraglia F, Critchley HOD. Attenuated tubal and endometrial urocortin 1 and corticotropin-releasing hormone receptor expression in ectopic pregnancy. Reprod Sci 2011; 18:261-8. [PMID: 20978183 PMCID: PMC3042128 DOI: 10.1177/1933719110385132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Fallopian tube (FT) and endometrial urocortin 1 (Ucn1) and corticotropin-releasing hormone (CRH)-receptor (CRH-R1/CRH-R2) expression were examined using quantitative real-time polymerase chain reaction (RT-PCR) and immunohistochemistry in nonpregnant and pregnant women (intrauterine, IUP; ectopic pregnancy, EP). Tubal Ucn1 messenger RNA (mRNA) expression was higher in luteal compared to follicular phase (P < .01) and equivalent to follicular phase in FT from EP. Tubal CRH-R1/CRH-R2 mRNA was lower in luteal phase (P < .05) and in FT from EP compared to follicular phase (P < .01). Ucn1 mRNA was lower in endometrium from EP compared to IUP (P < .05). Corticotropin-releasing hormone-R1 mRNA was higher in endometrium from EP compared to viable IUP (P < .05). No differences were observed in CRH-R2 expression. Corticotropin-releasing hormone-R1 protein was primarily localized to epithelium of FT and endometrium. Quantitative analysis of tubal CRH-R1 protein expression reflected that seen at the mRNA level but endometrial expression was equivocal. The demonstration of attenuated tubal/endometrial Ucn1/CRH-R expression in EP further supports a role of the CRH-family in embryo implantation.
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Affiliation(s)
- L E Borges
- Department of Pediatrics, Obstetrics and Reproductive Medicine, Section of Obstetrics and Gynecology, University of Siena, Siena, Italy
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Tu H, Hsuchou H, Kastin AJ, Wu X, Pan W. Unique leptin trafficking by a tailless receptor. FASEB J 2010; 24:2281-91. [PMID: 20223942 DOI: 10.1096/fj.09-143487] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Impairment in blood-to-brain transport of leptin is a major cause as well as consequence of obesity. Leptin crosses the blood-brain barrier by transcytosis rather than undergoing intracellular degradation. Results from previous studies have indicated that the membrane juxtapositional cytoplasmic sequence of the leptin receptor ObR is responsible for leptin transport. To identify the specific structural domains, we generated a series of ObR truncates with different lengths of the intracellular sequence, overexpressed them in 3 types of mammalian cells including cerebral endothelia, and quantified leptin binding and endocytosis. All mutant ObRs were able to bind and mediate the internalization of leptin. Surprisingly, ObR860, a construct with no cytoplasmic sequence, could act like the classical ObRa transporter in internalizing leptin. There were some cell type-dependent variations in the intracellular trafficking of Alexa-labeled leptin when mediated by ObR860 or ObRa because of differential involvement of membrane microdomains, as shown by use of the clathrin inhibitor chlorpromazine and the dynamin inhibitor Dynasore. The clathrin- and dynamin-mediated endocytosis of leptin contrasts with the lack of effect of the caveolae inhibitors nystatin and filipin. Thus, leptin-induced internalization of the ligand-receptor complex can occur without specific sorting signals in the cytoplasmic region of ObR. This novel finding may have significant implications for leptin transport.
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Affiliation(s)
- Hong Tu
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA
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21
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Hsuchou H, Kastin AJ, Wu X, Tu H, Pan W. Corticotropin-releasing hormone receptor-1 in cerebral microvessels changes during development and influences urocortin transport across the blood-brain barrier. Endocrinology 2010; 151:1221-7. [PMID: 20032050 PMCID: PMC2840693 DOI: 10.1210/en.2009-1039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we tested the hypothesis that receptor-mediated transport of urocortin across the blood-brain barrier (BBB) undergoes developmental changes. Urocortin is a peptide produced by both selective brain regions and peripheral organs, and it is involved in feeding, memory, mood, cardiovascular functions, and immune regulation. In BBB studies with multiple-time regression analysis, we found that neonatal mice had a significant influx of (125)I-urocortin. By contrast, adult mice did not transport urocortin across the BBB. Quantitative RT-PCR showed that corticotropin-releasing hormone receptor (CRHR)-1 was developmentally regulated in enriched cerebral microvessels as well as hypothalamus, being significantly higher in neonatal than adult mice. This change was less dramatic in agouti viable yellow mice, a strain that develops adult-onset obesity. The level of expression of CRHR1 mRNA was 33-fold higher in the microvessels than in hypothalamic homogenates. The mRNA for CRHR2 was less abundant in both regions and less prone to changes with development or the agouti viable yellow mutation. Supported by previous findings of receptor-mediated endocytosis of urocortin, these results suggest that permeation of urocortin across the BBB is dependent on the level of CRHR1 expression in cerebral microvessels. These novel findings of differential regulation of CRH receptor subtypes help elucidate developmental processes in the brain, particularly for the urocortin system.
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Affiliation(s)
- Hung Hsuchou
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA
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22
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Urocortin in second trimester amniotic fluid: its role as predictor of preterm labor. Mediators Inflamm 2009; 2009:947981. [PMID: 19893766 PMCID: PMC2773374 DOI: 10.1155/2009/947981] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Revised: 06/27/2009] [Accepted: 08/20/2009] [Indexed: 11/18/2022] Open
Abstract
Backgound. The existence of a “placental clock” which determines the duration of gestation has been previously proposed. It is related to placental CRH secretion and is
active from an early phase in human pregnancy. Urocortin is a specific ligand for the
corticotropin-releasing factor (CRF) receptor expressed by human trophoblast and
fetal membranes. The purpose of this study was to evaluate whether urocortin
concentrations in the early second trimester amniotic fluid might serve to predict
preterm delivery. Method. The urocortin concentrations in early second trimester amniotic fluid were
measured in 41 pregnancies with term delivery and in 41 pregnancies with preterm
delivery by using an immunoradiometric assay. Conditional logistic regression
analysis was used for statistical analysis. Results. Mean amniotic fluid urocortin concentrations in women with preterm labor were 1.55 ± 0.63 ng/mL while those in women with term labor were 1.6 ± 0.49 ng/mL
(p: NS). No statistical significant results were found when comparing amniotic fluid
urocortin concentrations in women with preterm premature rupture of membranes
leading to preterm labor (n = 19) to women with term delivery without premature
rupture of membranes. Conclusion. These results suggest that urocortin concentrations in the amniotic fluid
of genetic amniocentesis are not predictive of preterm labor and birth.
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Huang HY, Lin SZ, Chen WF, Li KW, Kuo JS, Wang MJ. Urocortin modulates dopaminergic neuronal survival via inhibition of glycogen synthase kinase-3β and histone deacetylase. Neurobiol Aging 2009; 32:1662-77. [PMID: 19875195 DOI: 10.1016/j.neurobiolaging.2009.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 08/19/2009] [Accepted: 09/27/2009] [Indexed: 11/27/2022]
Abstract
Urocortin (UCN) is a member of the corticotropin-releasing hormone (CRH) family of neuropeptides that regulates stress responses. Although UCN is principally expressed in dopaminergic neurons in rat substantia nigra (SN), the function of UCN in modulating dopaminergic neuronal survival remains unclear. Using primary mesencephalic cultures, we demonstrated that dopaminergic neurons underwent spontaneous cell death when their age increased in culture. Treatment of mesencephalic cultures with UCN markedly prolonged the survival of dopaminergic neurons, whereas neutralization of UCN with anti-UCN antibody accelerated dopaminergic neurons degeneration. UCN increased intracellular cAMP levels followed by phosphorylating glycogen synthase kinase-3β (GSK-3β) on Ser9. Moreover, UCN directly inhibited the histone deacetylase (HDAC) activity and induced a robust increase in histone H3 acetylation levels. Using pharmacological approaches, we further demonstrated that inhibition of GSK-3β and HDAC contributes to UCN-mediated neuroprotection. These results suggest that dopaminergic neuron-derived UCN might be involved in an autocrine protective signaling mechanism.
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Affiliation(s)
- Hsin-Yi Huang
- Department of Research, Neuro-Medical Scientific Center, Buddhist Tzu Chi General Hospital, Hualien 970, Taiwan, ROC
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Pan W, Yu C, Hsuchou H, Khan RS, Kastin AJ. Cerebral microvascular IL15 is a novel mediator of TNF action. J Neurochem 2009; 111:819-27. [PMID: 19719822 DOI: 10.1111/j.1471-4159.2009.06371.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The blood-brain barrier is a gatekeeper and modulatory interface for the CNS. Cerebral endothelial cells are the major component of the blood-brain barrier, and they modify inflammatory signals from the circulation to the CNS by production and secretion of secondary substances. The inflammatory mediators induced by tumor necrosis factor alpha (TNF) were determined by microarray analysis of RBE4 cerebral endothelial cells, at 0, 6, 12, or 24 h after TNF treatment. Interleukin (IL)-15 and its receptors were among the most robustly up-regulated genes. This was confirmed by real-time RT-PCR and western blotting. The three subunits of the IL15 receptor complex (IL15Ralpha, IL2Rbeta, and IL2Rgamma) showed differential regulation by TNF in their time course and amplitude of increased expression. Consistent with increased expression of the specific high affinity receptor IL15Ralpha, TNF increased cellular uptake of (125)I-IL15 and enhanced the fluorescent intensity of Alexa568-IL15 in RBE4 cells. TNF treatment in mice also increased the level of expression of IL15 receptors in enriched cerebral microvessels. We conclude that the cerebral microvascular IL15 system is a novel inflammatory mediator that transduces the actions of TNF.
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Affiliation(s)
- Weihong Pan
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA.
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25
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Zhang Y, Wu X, He Y, Kastin AJ, Hsuchou H, Rosenblum CI, Pan W. Melanocortin potentiates leptin-induced STAT3 signaling via MAPK pathway. J Neurochem 2009; 110:390-9. [PMID: 19457101 DOI: 10.1111/j.1471-4159.2009.06144.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The co-existence of receptors for leptin and melanocortin in cerebral microvessels suggests possible interactions between leptin and alpha-melanocyte stimulating hormone (MSH) signaling. In this study, we showed that ObRb and melanocortin receptor MC3R and MC4R were present in enriched cerebral microvessels. To test the interactions between ObRb and MC3R or MC4R-mediated cellular signaling, we over-expressed these plasmids in RBE4 cerebral microvascular endothelial cells and HEK293 cells in culture. Activation of signal transducers and activators of transcription-3 (STAT3) in response to leptin was determined by western blotting and luciferase reporter assays. Production of cAMP downstream to melanocortin receptors was determined with a chemiluminescent ELISA kit. alphaMSH, which increased intracellular cAMP, also potentiated leptin-induced STAT3 activation. This potentiation was abolished by a specific MEK inhibitor, indicating the involvement of the mitogen-activated kinase pathway. Reversely, the effect of leptin on alphaMSH-induced cAMP production was minimal. Thus, melanocortin specifically potentiated STAT3 signaling downstream to ObRb by cross-talk with mitogen-activated kinase. The cooperation of ObRb and G protein-coupled receptors in cellular signaling may have considerable biological implications not restricted to feeding and obesity.
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Affiliation(s)
- Yan Zhang
- Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA
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Yata A, Nakabayashi K, Wakahashi S, Maruo N, Ohara N, Maruo T. Suppression of progesterone production by stresscopin/urocortin 3 in cultured human granulosa-lutein cells. Hum Reprod 2009; 24:1748-53. [DOI: 10.1093/humrep/dep063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kastin AJ, Pan W. Blood-brain barrier and feeding: regulatory roles of saturable transport systems for ingestive peptides. Curr Pharm Des 2008; 14:1615-9. [PMID: 18673203 DOI: 10.2174/138161208784705423] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The two main ways for peptides in the peripheral body to enter the brain are by either saturable transport or passive diffusion across the blood-brain barrier (BBB). Saturable transport systems have the advantage of being responsive to physiological and pathological stimuli. Since saturable systems can regulate peptide entry into the brain, they have the potential to play controlling roles in feeding behavior. For therapeutic applications, however, saturable systems have the disadvantage of functioning as a threshold to limit access of large amounts of peptides into the brain. This pharmacological problem presumably would not be encountered for peptides crossing the BBB by passive diffusion, a process dependent on physicochemical properties. Thus, the gatekeeper function of the BBB can be expanded to a primary governing role, especially for entry of ingestive peptides subject to their respective saturable transport systems.
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Affiliation(s)
- Abba J Kastin
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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The role of urocortin in gynecological and obstetrical conditions. Arch Gynecol Obstet 2008; 279:613-9. [DOI: 10.1007/s00404-008-0782-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Accepted: 08/21/2008] [Indexed: 11/30/2022]
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Pan W, Kastin AJ. Urocortin and the brain. Prog Neurobiol 2007; 84:148-56. [PMID: 18078706 DOI: 10.1016/j.pneurobio.2007.10.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 09/17/2007] [Accepted: 10/31/2007] [Indexed: 01/01/2023]
Abstract
Urocortin is a member of the corticotropin-releasing hormone (CRH) family of peptides. In the brain, its potent suppression of food intake is mediated by CRH receptors (CRHR). Urocortin also participates in the regulation of anxiety, learning, memory, and body temperature, and it shows neuroprotection. This review will summarize the location of urocortin-producing neurons and their projections, the pharmacological evidence of its actions in the CNS, and information acquired from knockout mice. Urocortin interacts with leptin, neuropeptide Y, orexin, and corticotropin in the brain. Also produced by the GI tract, heart, and immune cells, urocortin has blood concentrations ranging from 13 to 152 pg/ml. Blood-borne urocortin stimulates the cerebral endothelial cells composing the blood-brain barrier and crosses the blood-brain barrier by a unique transport system. Overall, urocortin acts on a broad neuronal substrate as a neuromodulator important for basic survival.
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Affiliation(s)
- Weihong Pan
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, United States.
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Pan W, Tu H, Yu C, Hsuchou H, Yang Y, Kastin AJ. Differential role of TNF receptors in cellular trafficking of intact TNF. Cell Physiol Biochem 2007; 20:559-68. [PMID: 17762182 DOI: 10.1159/000107539] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Although ligand signaling and degradation within the cell have received much attention, few studies have quantified the role of receptors on the transcytosis of ligand into and out of the cell in intact form. Accordingly, we determined the differential role of the two receptors for tumor necrosis factor alpha (TNFR1, TNFR2) on cellular transcytosis. METHODS TNFR1 and TNFR2 were overexpressed in HEK293 cells by transient transfection. Cell surface binding, endocytosis, and exocytosis of (125)I-TNF were quantified. Degradation was determined by acid precipitation and size-exclusion chromatography. RESULTS TNFR1- mediated uptake of TNF was faster than TNFR2-mediated uptake of TNF. TNFR2, however, exhibited greater capacity, leading to a higher percentage release of TNF into the exocytosis medium. Rather than being degraded, most of the TNF inside the cell remained intact for 1 h. Both receptors exerted protective roles against degradation, but there was no cooperativity between them. CONCLUSION The effects of TNFR1 and TNFR2 in shepherding TNF across the cell illustrate the differential roles of receptors on the cellular trafficking of the ligand in intact form so as to facilitate its biological effects.
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Affiliation(s)
- Weihong Pan
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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Pan W, Tu H, Hsuchou H, Daniel J, Kastin AJ. Unexpected amplification of leptin-induced Stat3 signaling by urocortin: implications for obesity. J Mol Neurosci 2007; 33:232-8. [PMID: 17952632 DOI: 10.1007/s12031-007-0071-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 08/02/2007] [Indexed: 12/25/2022]
Abstract
Cooperativity among ingestive peptides reflects attempts by the body to finely control its weight. Urocortin, like leptin, is a potent suppressor of food intake, and they interact at the blood-brain barrier (BBB). After injection into the hypothalamus, urocortin can stimulate the release of leptin in the periphery. It is not known, however, whether urocortin, known to signal through adenylate cyclase and elevate cAMP, can potentiate signal transducer and activator of transcription (Stat) 1 and 3 signaling known to mediate the actions of leptin. We examined the interactions between urocortin and leptin signaling in two cellular systems: HEK293 cells and cerebral microvessel endothelial RBE4 cells, a model of the BBB. Both cell lines have low basal levels of CRHR1 and CRHR2 (receptors for urocortin) and ObRs (receptors for leptin). The cells were cotransfected with the receptors and luciferase reporters to determine the level of Stat1 or Stat3 activation 6 h after treatment with leptin, urocortin, or both. Urocortin induced significant Stat3 but not Stat1 activation, mediated by either CRHR1 or CRHR2. Leptin signaling by ObRb caused a large increase of both Stat1 and Stat3, and this was significantly potentiated by the addition of urocortin, being more robust for Stat3 than Stat1. The interactions of leptin and urocortin were not reciprocal, as leptin failed to further increase urocortin-mediated cAMP production. By unexpectedly potentiating leptin signaling through Stat, urocortin amplifies the cellular response of leptin. This novel phenomenon suggests that urocortin can play an important compensatory role during leptin resistance in obesity.
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Affiliation(s)
- Weihong Pan
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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Tu H, Pan W, Feucht L, Kastin AJ. Convergent trafficking pattern of leptin after endocytosis mediated by ObRa-ObRd. J Cell Physiol 2007; 212:215-22. [PMID: 17323382 DOI: 10.1002/jcp.21020] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The cellular effects of leptin are dependent on the receptor subtypes that mediate the signaling and fate of endocytosed leptin inside the cells. In this study, we examined the differences in receptor expression, endocytosis, intracellular degradation, and exocytosis of a trace amount of leptin in cells overexpressing ObRb and short forms of the leptin receptor. The relative contribution of proteasomes and lysosomes in the intracellular fate of leptin was also determined. There were three unusual findings: (1) all receptor subtypes could mediate the binding and endocytosis of leptin, although ObRb was expressed at a lower level than ObRa, ObRc, and ObRd after transient transfection. This indicates that ObRb can be a transporting receptor. (2) Once internalized, the intracellular degradation pattern and exocytosis of leptin were independent of the receptor subtype. (3) Endocytosed leptin could remain intact for at least 1 h. This stability was further enhanced by inhibition of lysosomal activity. Thus, the intracellular pool of intact leptin may allow prolonged biological functions for this adipokine.
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Affiliation(s)
- Hong Tu
- Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA
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Abstract
Just as the blood-brain barrier (BBB) is not a static barrier, the adipocytes are not inert storage depots. Adipokines are peptides or polypeptides produced by white adipose tissue; they play important roles in normal physiology as well as in the metabolic syndrome. Adipokines secreted into the circulation can interact with the BBB and exert potent CNS effects. The specific transport systems for two important adipokines, leptin and tumor necrosis factor alpha, have been characterized during the past decade. By contrast, transforming growth factor beta-1 and adiponectin do not show specific permeation across the BBB, but modulate endothelial functions. Still others, like interleukin-6, may reach the brain but are rapidly degraded. This review summarizes current knowledge and recent findings of the rapidly growing family of adipokines and their interactions with the BBB.
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Affiliation(s)
- Weihong Pan
- Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, United States.
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