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Bhargava A. Unraveling corticotropin-releasing factor family-orchestrated signaling and function in both sexes. VITAMINS AND HORMONES 2023; 123:27-65. [PMID: 37717988 DOI: 10.1016/bs.vh.2023.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Stress responses to physical, psychological, environmental, or cellular stressors, has two arms: initiation and recovery. Corticotropin-releasing factor (CRF) is primarily responsible for regulating and/or initiating stress responses via, whereas urocortins (UCNs) are involved in the recovery response to stress via feedback inhibition. Stress is a loaded, polysemous word and is experienced in a myriad of ways. Some stressors are good for an individual, in fact essential, whereas other stressors are associated with bad outcomes. Perceived stress, like beauty, lies in the eye of the beholder, and hence the same stressor can result in individual-specific outcomes. In mammals, there are two main biological sexes with reproduction as primary function. Reproduction and nutrition can also be viewed as stressors; based on a body of work from my laboratory, we propose that the functions of all other organs have co-evolved to optimize and facilitate an individual's nutritional and reproductive functions. Hence, sex differences in physiologically relevant outcomes are innate and occur at all levels- molecular, endocrine, immune, and (patho)physiological. CRF and three UCNs are peptide hormones that mediate their physiological effects by binding to two known G protein-coupled receptors (GPCRs), CRF1 and CRF2. Expression and function of CRF family of hormones and their receptors is likely to be sexually dimorphic in all organs. In this chapter, based on the large body of work from others and my laboratory, an overview of the CRF family with special emphasis on sex-specific actions of peripherally expressed CRF2 receptor in health and disease is provided.
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Affiliation(s)
- Aditi Bhargava
- Center for Reproductive Sciences, Department of Obstetrics and Gynecology, University of California San Francisco, San Francisco, CA, United States.
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2
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Dos Santos Claro PA, Silbermins M, Inda C, Silberstein S. CRHR1 endocytosis: Spatiotemporal regulation of receptor signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 196:229-260. [PMID: 36813360 DOI: 10.1016/bs.pmbts.2022.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Corticotropin releasing hormone (CRH) is crucial for basal and stress-initiated reactions in the hypothalamic-pituitary-adrenal axis (HPA) and extrahypothalamic brain circuits, where it acts as a neuromodulator to organize behavioral and humoral responses to stress. We review and describe cellular components and molecular mechanisms involved in CRH system signaling through G protein-coupled receptors (GPCRs) CRHR1 and CRHR2, under the current view of GPCR signaling from the plasma membrane but also from intracellular compartments, which establish the bases of signal resolution in space and time. Focus is placed on latest studies of CRHR1 signaling in physiologically significant contexts of the neurohormone function that disclosed new mechanistic features of cAMP production and ERK1/2 activation. We also introduce in a brief overview the pathophysiological function of the CRH system, underlining the need for a complete characterization of CRHRs signaling to design new and specific therapies for stress-related disorders.
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Affiliation(s)
- Paula A Dos Santos Claro
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Micaela Silbermins
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina; Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carolina Inda
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; Octamer SRL, Buenos Aires, Argentina
| | - Susana Silberstein
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina; Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Qu J, Fourman S, Fitzgerald M, Liu M, Nair S, Oses-Prieto J, Burlingame A, Morris JH, Davidson WS, Tso P, Bhargava A. Low-density lipoprotein receptor-related protein 1 (LRP1) is a novel receptor for apolipoprotein A4 (APOA4) in adipose tissue. Sci Rep 2021; 11:13289. [PMID: 34168225 PMCID: PMC8225859 DOI: 10.1038/s41598-021-92711-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 06/11/2021] [Indexed: 11/29/2022] Open
Abstract
Apolipoprotein A4 (APOA4) is one of the most abundant and versatile apolipoproteins facilitating lipid transport and metabolism. APOA4 is synthesized in the small intestine, packaged onto chylomicrons, secreted into intestinal lymph and transported via circulation to several tissues, including adipose. Since its discovery nearly 4 decades ago, to date, only platelet integrin αIIbβ3 has been identified as APOA4 receptor in the plasma. Using co-immunoprecipitation coupled with mass spectrometry, we probed the APOA4 interactome in mouse gonadal fat tissue, where ApoA4 gene is not transcribed but APOA4 protein is abundant. We demonstrate that lipoprotein receptor-related protein 1 (LRP1) is the cognate receptor for APOA4 in adipose tissue. LRP1 colocalized with APOA4 in adipocytes; it interacted with APOA4 under fasting condition and their interaction was enhanced during lipid feeding concomitant with increased APOA4 levels in plasma. In 3T3-L1 mature adipocytes, APOA4 promoted glucose uptake both in absence and presence of insulin in a dose-dependent manner. Knockdown of LRP1 abrogated APOA4-induced glucose uptake as well as activation of phosphatidylinositol 3 kinase (PI3K)-mediated protein kinase B (AKT). Taken together, we identified LRP1 as a novel receptor for APOA4 in promoting glucose uptake. Considering both APOA4 and LRP1 are multifunctional players in lipid and glucose metabolism, our finding opens up a door to better understand the molecular mechanisms along APOA4-LRP1 axis, whose dysregulation leads to obesity, cardiovascular disease, and diabetes.
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Affiliation(s)
- Jie Qu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2180 E Galbraith Road, Cincinnati, 45237-0507, USA
| | - Sarah Fourman
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2180 E Galbraith Road, Cincinnati, 45237-0507, USA
| | - Maureen Fitzgerald
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2180 E Galbraith Road, Cincinnati, 45237-0507, USA
| | - Min Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2180 E Galbraith Road, Cincinnati, 45237-0507, USA
| | - Supna Nair
- Departments of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, CA, 94158, USA
| | - Juan Oses-Prieto
- Departments of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, CA, 94158, USA
| | - Alma Burlingame
- Departments of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, CA, 94158, USA
| | - John H Morris
- Departments of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, CA, 94158, USA
| | - W Sean Davidson
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2180 E Galbraith Road, Cincinnati, 45237-0507, USA
| | - Patrick Tso
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, 2180 E Galbraith Road, Cincinnati, 45237-0507, USA
| | - Aditi Bhargava
- Department of Obstetrics and Gynecology, Center for Reproductive Sciences, University of California San Francisco, 513 Parnassus Avenue, Rm HSE1636, San Francisco, CA, 94143-0556, USA.
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Liu S, Karo A, Agterberg S, Hua H, Bhargava A. Effects of stress-related peptides on chloride secretion in the mouse proximal colon. Neurogastroenterol Motil 2021; 33:e14021. [PMID: 33118282 DOI: 10.1111/nmo.14021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 09/22/2020] [Accepted: 10/01/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Stress increases intestinal secretion and exacerbates symptoms of irritable bowel syndrome (IBS). Peripherally derived corticotropin-releasing factor (CRF) is known to mediate stress-induced intestinal secretion, presumably by activation of CRF1 receptors in the gut. The present study aimed to ascertain the role of CRF2 activation in intestinal secretion by three other members of CRF peptide family, urocortin (UCN) 1-3, in wild type (WT) and CRF2 knockout (Crhr2-/- ) mice. METHODS Mucosal/submucosal preparations from proximal colon of WT and Crhr2-/- mice of both sexes were mounted in Ussing chambers for measurement of short-circuit current (Isc ) as an indicator of ion secretion. KEY RESULTS Male mice demonstrated a significantly higher baseline Isc than female in both WT and Crhr2-/- genotypes. CRF and UCN1-3 (1 μM) caused greater increases in colonic Isc (ΔIsc ) in male than female. Colonic Isc response to the selective CRF1 agonist, stressin1, was similar in both sexes. In male mice, the selective CRF2 agonists (UCN2 and UCN3) caused significantly greater ΔIsc than CRF and stressin1. UCN2- and UCN3-evoked ΔISC was significantly reduced in preparations pretreated with the selective CRF2 antagonist antisauvagine-30 and in Crhr2-/- mice. The prosecretory effects of urocortins were due to increases in Cl- secretion and involved enteric neurons and mast cells. CONCLUSIONS AND INFERENCE The findings revealed sex differences in baseline colonic secretion and responses to stress-related peptides. CRF2 receptors play a more prominent role in colonic secretion in male mice. The greater baseline secretion and responses to UCNs may contribute to the higher prevalence of diarrhea-predominant IBS in males.
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Affiliation(s)
- Sumei Liu
- Department of Biology, College of Science and Health, University of Wisconsin-La Crosse, La Crosse, WI, USA
| | - Aaron Karo
- Department of Biology, College of Science and Health, University of Wisconsin-La Crosse, La Crosse, WI, USA
| | - Sita Agterberg
- Department of Biology, College of Science and Health, University of Wisconsin-La Crosse, La Crosse, WI, USA
| | - Howard Hua
- Department of Biology, College of Science and Health, University of Wisconsin-La Crosse, La Crosse, WI, USA
| | - Aditi Bhargava
- Department of OBGYN, Center for Reproductive Sciences, University of California San Francisco, San Francisco, CA, USA
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Corticotropin-Releasing Factor Family: A Stress Hormone-Receptor System's Emerging Role in Mediating Sex-Specific Signaling. Cells 2020; 9:cells9040839. [PMID: 32244319 PMCID: PMC7226788 DOI: 10.3390/cells9040839] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/25/2020] [Accepted: 03/28/2020] [Indexed: 12/14/2022] Open
Abstract
No organ in the body is impervious to the effects of stress, and a coordinated response from all organs is essential to deal with stressors. A dysregulated stress response that fails to bring systems back to homeostasis leads to compromised function and ultimately a diseased state. The components of the corticotropin-releasing factor (CRF) family, an ancient and evolutionarily conserved stress hormone-receptor system, helps both initiate stress responses and bring systems back to homeostasis once the stressors are removed. The mammalian CRF family comprises of four known agonists, CRF and urocortins (UCN1–3), and two known G protein-coupled receptors (GPCRs), CRF1 and CRF2. Evolutionarily, precursors of CRF- and urocortin-like peptides and their receptors were involved in osmoregulation/diuretic functions, in addition to nutrient sensing. Both CRF and UCN1 peptide hormones as well as their receptors appeared after a duplication event nearly 400 million years ago. All four agonists and both CRF receptors show sex-specific changes in expression and/or function, and single nucleotide polymorphisms are associated with a plethora of human diseases. CRF receptors harbor N-terminal cleavable peptide sequences, conferring biased ligand properties. CRF receptors have the ability to heteromerize with each other as well as with other GPCRs. Taken together, CRF receptors and their agonists due to their versatile functional adaptability mediate nuanced responses and are uniquely positioned to orchestrate sex-specific signaling and function in several tissues.
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Tapia JC, Niechi I. Endothelin-converting enzyme-1 in cancer aggressiveness. Cancer Lett 2019; 452:152-157. [DOI: 10.1016/j.canlet.2019.03.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 03/20/2019] [Accepted: 03/20/2019] [Indexed: 12/29/2022]
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Endothelin-converting enzyme-1 regulates glucagon-like peptide-1 receptor signalling and resensitisation. Biochem J 2019; 476:513-533. [PMID: 30626614 DOI: 10.1042/bcj20180853] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 02/08/2023]
Abstract
Following nutrient ingestion, glucagon-like peptide 1 (GLP-1) is secreted from intestinal L-cells and mediates anti-diabetic effects, most notably stimulating glucose-dependent insulin release from pancreatic β-cells but also inhibiting glucagon release, promoting satiety and weight reduction and potentially enhancing or preserving β-cell mass. These effects are mediated by the GLP-1 receptor (GLP-1R), which is a therapeutic target in type 2 diabetes. Although agonism at the GLP-1R has been well studied, desensitisation and resensitisation are perhaps less well explored. An understanding of these events is important, particularly in the design and use of novel receptor ligands. Here, using either HEK293 cells expressing the recombinant human GLP-1R or the pancreatic β-cell line, INS-1E with endogenous expressesion of the GLP-1R, we demonstrate GLP-1R desensitisation and subsequent resensitisation following removal of extracellular GLP-1 7-36 amide. Resensitisation is dependent on receptor internalisation, endosomal acidification and receptor recycling. Resensitisation is also regulated by endothelin-converting enzyme-1 (ECE-1) activity, most likely through proteolysis of GLP-1 in endosomes and the facilitation of GLP-1R dephosphorylation and recycling. Inhibition of ECE-1 activity also increases GLP-1-induced activation of extracellular signal-regulated kinase and generation of cAMP, suggesting processes dependent upon the lifetime of the internalised ligand-receptor complex.
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Paruthiyil S, Hagiwara SI, Kundassery K, Bhargava A. Sexually dimorphic metabolic responses mediated by CRF 2 receptor during nutritional stress in mice. Biol Sex Differ 2018; 9:49. [PMID: 30400826 PMCID: PMC6218963 DOI: 10.1186/s13293-018-0208-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/21/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Chronic stress is a major contributor in the development of metabolic syndrome and associated diseases, such as diabetes. High-fat diet (HFD) and sex are known modifiers of metabolic parameters. Peptide hormones corticotropin-releasing factor (CRF) and urocortins (UCN) mediate stress responses via activation and feedback to the hypothalamic-pituitary-adrenal (HPA) axis. UCN3 is a marker of pancreatic β-cell differentiation, and UCN2 is known to ameliorate glucose levels in mice rendered diabetic with HFD. CRF receptor 2 (CRF2) is the only known cognate receptor for UCN2/3. Here, we ascertained the role of CRF2 in glucose clearance, insulin sensitivity, and other parameters associated with metabolic syndrome in a mouse model of nutritional stress. METHODS Wild-type (WT) and Crhr2-/- (null) mice of both sexes were fed either normal chow diet or HFD. After 8 weeks, blood glucose levels in response to glucose and insulin challenge were determined. Change in body and fat mass, plasma insulin, and lipid profile were assessed. Histological evaluation of liver sections was performed. RESULTS Here, we show that genotype (Crhr2), sex, and diet were all independent variables in the regulation of blood glucose levels, body and fat mass gain/redistribution, and insulin resistance. Surprisingly, CRF2-deficient mice (Crhr2-/-) male mice showed similarly impaired glucose clearance on HFD and chow. HFD-fed female Crhr2-/- mice redistributed their fat depots that were distinct from wild-type females and male mice on either diet. Blood cholesterol and low-density lipoprotein (LDL) levels were elevated significantly in male Crhr2-/- mice; female Crhr2-/- mice were protected. Male, but not female Crhr2-/- mice developed peripheral insulin resistance. HFD, but not chow-fed wild-type male mice developed hepatic macrovesicular steatosis. In contrast, livers of Crhr2-/- male mice showed microvesicular steatosis on either diet, whereas livers of female mice on this 8-week HFD regimen did not develop steatosis. CONCLUSIONS CRF2 receptor dysregulation is a sexually dimorphic risk factor in development of pre-diabetic and metabolic symptoms.
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Affiliation(s)
- Sreenivasan Paruthiyil
- Department of Obstetrics and Gynecology, Center for reproductive Sciences, and the Osher Center for Integrative Medicine, University of California San Francisco, 513 Parnassus Ave., HSE1645, Box 0556, San Francisco, CA, 94143-0556, USA
| | - Shin-Ichiro Hagiwara
- Department of Obstetrics and Gynecology, Center for reproductive Sciences, and the Osher Center for Integrative Medicine, University of California San Francisco, 513 Parnassus Ave., HSE1645, Box 0556, San Francisco, CA, 94143-0556, USA
| | - Keshav Kundassery
- Department of Obstetrics and Gynecology, Center for reproductive Sciences, and the Osher Center for Integrative Medicine, University of California San Francisco, 513 Parnassus Ave., HSE1645, Box 0556, San Francisco, CA, 94143-0556, USA
| | - Aditi Bhargava
- Department of Obstetrics and Gynecology, Center for reproductive Sciences, and the Osher Center for Integrative Medicine, University of California San Francisco, 513 Parnassus Ave., HSE1645, Box 0556, San Francisco, CA, 94143-0556, USA.
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Deussing JM, Chen A. The Corticotropin-Releasing Factor Family: Physiology of the Stress Response. Physiol Rev 2018; 98:2225-2286. [DOI: 10.1152/physrev.00042.2017] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The physiological stress response is responsible for the maintenance of homeostasis in the presence of real or perceived challenges. In this function, the brain activates adaptive responses that involve numerous neural circuits and effector molecules to adapt to the current and future demands. A maladaptive stress response has been linked to the etiology of a variety of disorders, such as anxiety and mood disorders, eating disorders, and the metabolic syndrome. The neuropeptide corticotropin-releasing factor (CRF) and its relatives, the urocortins 1–3, in concert with their receptors (CRFR1, CRFR2), have emerged as central components of the physiological stress response. This central peptidergic system impinges on a broad spectrum of physiological processes that are the basis for successful adaptation and concomitantly integrate autonomic, neuroendocrine, and behavioral stress responses. This review focuses on the physiology of CRF-related peptides and their cognate receptors with the aim of providing a comprehensive up-to-date overview of the field. We describe the major molecular features covering aspects of gene expression and regulation, structural properties, and molecular interactions, as well as mechanisms of signal transduction and their surveillance. In addition, we discuss the large body of published experimental studies focusing on state-of-the-art genetic approaches with high temporal and spatial precision, which collectively aimed to dissect the contribution of CRF-related ligands and receptors to different levels of the stress response. We discuss the controversies in the field and unravel knowledge gaps that might pave the way for future research directions and open up novel opportunities for therapeutic intervention.
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Affiliation(s)
- Jan M. Deussing
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; and Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Chen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany; and Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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Alhosaini K, Bahattab O, Qassam H, Challiss RAJ, Willars GB. Ligand-Specific Signaling Profiles and Resensitization Mechanisms of the Neuromedin U2 Receptor. Mol Pharmacol 2018; 94:674-688. [PMID: 29724789 DOI: 10.1124/mol.117.111070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/24/2018] [Indexed: 11/22/2022] Open
Abstract
The structurally related, but distinct neuropeptides, neuromedin U (NmU) and neuromedin S (NmS) are ligands of two G protein-coupled NmU receptors (NMU1 and NMU2). Hypothalamic NMU2 regulates feeding behavior and energy expenditure and has therapeutic potential as an anti-obesity target, making an understanding of its signaling and regulation of particular interest. NMU2 binds both NmU and NmS with high affinity, resulting in receptor-ligand co-internalization. We have investigated whether receptor trafficking events post-internalization are biased by the ligand bound and can therefore influence signaling function. Using recombinant cell lines expressing human NMU2, we demonstrate that acute Ca2+ signaling responses to NmU or NmS are indistinguishable and that restoration of responsiveness (resensitization) requires receptor internalization and endosomal acidification. The rate of NMU2 resensitization is faster following NmU compared with NmS exposure, but is similar if endothelin-converting enzyme-1 activity is inhibited or knocked down. Although acute activation of extracellular signal-regulated kinase (ERK) is also similar, activation by NMU2 is longer lasting if NmS is the ligand. Furthermore, when cells are briefly challenged before removal of free, but not receptor-bound ligand, activation of ERK and p38 mitogen-activated protein kinase by NmS is more sustained. However, only NmU responses are potentiated and extended by endothelin-converting enzyme-1 inhibition. These data indicate that differential intracellular ligand processing produces different signaling and receptor resensitization profiles and add to the findings of other studies demonstrating that intracellular ligand processing can shape receptor behavior and signal transduction.
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Affiliation(s)
- Khaled Alhosaini
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Omar Bahattab
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Heider Qassam
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - R A John Challiss
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Gary B Willars
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
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Giamouridis D, Gao MH, Lai NC, Tan Z, Kim YC, Guo T, Miyanohara A, Blankesteijn WM, Biessen E, Hammond HK. Effects of Urocortin 2 Versus Urocortin 3 Gene Transfer on Left Ventricular Function and Glucose Disposal. JACC Basic Transl Sci 2018; 3:249-264. [PMID: 30062211 PMCID: PMC6059348 DOI: 10.1016/j.jacbts.2017.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/13/2017] [Accepted: 12/21/2017] [Indexed: 12/20/2022]
Abstract
UCn2 and UCn3 peptides have recently been infused to treat patients with heart failure (HF) but are limited by their short half-lives. A 1-time intravenous injection of virus vectors encoding UCn2 or UCn3 provided sustained increases in plasma concentrations of the peptides. This was associated with increases in both systolic and diastolic left ventricular (LV) function, mediated by increased LV SERCA2a expression and Ca2+ handling. UCn2, but not UCn3, gene transfer reduced fasting glucose and increased glucose disposal. These findings support UCn2 and UCn3 gene transfer as potential treatments for HF and indicate that UCn2 may be an optimal selection in patients with diabetes and HF.
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Key Words
- AAV, adeno-associated virus
- CO, cardiac output
- CRF, corticotropin-releasing factor
- CRHR, corticotropin-releasing hormone receptor
- CaMKII, Ca2+/calmodulin-dependent protein kinase II
- EDD, end-diastolic diameter
- EF, ejection fraction
- ESD, end-systolic diameter
- ESPVR, end-systolic pressure-volume relationship
- HF, heart failure
- IP, intraperitoneal
- IV, intravenous
- LV, left ventricle/ventricular
- PKA, protein kinase A
- RYR2, ryanodine receptor 2
- SERCA2a, sarco/endoplasmic reticulum Ca2+-ATPase
- Tau, time constant of left ventricular pressure decline
- UCn2, urocortin 2
- UCn3, urocortin 3
- VCFc, velocity of circumferential fiber shortening corrected for heart rate
- adeno-associated virus
- cAMP, 3′,5′-cyclic adenosine monophosphate
- contractile function
- diastolic function
- gc, genome copies
- gene therapy
- insulin sensitivity
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Affiliation(s)
- Dimosthenis Giamouridis
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht University, Maastricht, the Netherlands
| | - Mei Hua Gao
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - N. Chin Lai
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Zhen Tan
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Young Chul Kim
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Tracy Guo
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
| | - Atsushi Miyanohara
- Department of Medicine, University of California San Diego, San Diego, California
| | - W. Matthijs Blankesteijn
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht University, Maastricht, the Netherlands
| | - Erik Biessen
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht University, Maastricht, the Netherlands
| | - H. Kirk Hammond
- Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, California
- Department of Medicine, University of California San Diego, San Diego, California
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Inda C, Armando NG, Dos Santos Claro PA, Silberstein S. Endocrinology and the brain: corticotropin-releasing hormone signaling. Endocr Connect 2017; 6:R99-R120. [PMID: 28710078 PMCID: PMC5551434 DOI: 10.1530/ec-17-0111] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 07/14/2017] [Indexed: 01/01/2023]
Abstract
Corticotropin-releasing hormone (CRH) is a key player of basal and stress-activated responses in the hypothalamic-pituitary-adrenal axis (HPA) and in extrahypothalamic circuits, where it functions as a neuromodulator to orchestrate humoral and behavioral adaptive responses to stress. This review describes molecular components and cellular mechanisms involved in CRH signaling downstream of its G protein-coupled receptors (GPCRs) CRHR1 and CRHR2 and summarizes recent findings that challenge the classical view of GPCR signaling and impact on our understanding of CRHRs function. Special emphasis is placed on recent studies of CRH signaling that revealed new mechanistic aspects of cAMP generation and ERK1/2 activation in physiologically relevant contexts of the neurohormone action. In addition, we present an overview of the pathophysiological role of the CRH system, which highlights the need for a precise definition of CRHRs signaling at molecular level to identify novel targets for pharmacological intervention in neuroendocrine tissues and specific brain areas involved in CRH-related disorders.
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Affiliation(s)
- Carolina Inda
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
- DFBMCFacultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Natalia G Armando
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - Paula A Dos Santos Claro
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - Susana Silberstein
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
- DFBMCFacultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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13
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Hasdemir B, Mahajan S, Oses-Prieto J, Chand S, Woolley M, Burlingame A, Grammatopoulos DK, Bhargava A. Actin cytoskeleton-dependent regulation of corticotropin-releasing factor receptor heteromers. Mol Biol Cell 2017; 28:2386-2399. [PMID: 28701349 PMCID: PMC5576902 DOI: 10.1091/mbc.e16-11-0778] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 06/30/2017] [Accepted: 07/07/2017] [Indexed: 01/02/2023] Open
Abstract
A physical interaction is shown between CRF1R and CRF2R, two class B G protein–coupled receptors that mediate stress and immune responses. Trafficking of CRF2R but not CRF1R is actin dependent, and coexpression of the two receptors alters actin-independent trafficking. Receptor cross-talk alters agonist binding and signaling. Stress responses are highly nuanced and variable, but how this diversity is achieved by modulating receptor function is largely unknown. Corticotropin-releasing factor receptors (CRFRs), class B G protein–coupled receptors, are pivotal in mediating stress responses. Here we show that the two known CRFRs interact to form heteromeric complexes in HEK293 cells coexpressing both CRFRs and in vivo in mouse pancreas. Coimmunoprecipitation and mass spectrometry confirmed the presence of both CRF1R and CRF2βR, along with actin in these heteromeric complexes. Inhibition of actin filament polymerization prevented the transport of CRF2βR to the cell surface but had no effect on CRF1R. Transport of CRF1R when coexpressed with CRF2βR became actin dependent. Simultaneous stimulation of cells coexpressing CRF1R+CRF2βR with their respective high-affinity agonists, CRF+urocortin2, resulted in approximately twofold increases in peak Ca2+ responses, whereas stimulation with urocortin1 that binds both receptors with 10-fold higher affinity did not. The ability of CRFRs to form heteromeric complexes in association with regulatory proteins is one mechanism to achieve diverse and nuanced function.
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Affiliation(s)
- Burcu Hasdemir
- Osher Center for Integrative Medicine, University of California, San Francisco, San Francisco, CA 94143.,Department of Obstetrics & Gynecology, University of California, San Francisco, San Francisco, CA 94143
| | - Shilpi Mahajan
- Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Juan Oses-Prieto
- Departments of Pediatrics, Pharmacology, and Chemistry, University of California, San Francisco, San Francisco, CA 94143
| | - Shreya Chand
- Departments of Pediatrics, Pharmacology, and Chemistry, University of California, San Francisco, San Francisco, CA 94143
| | - Michael Woolley
- Translational and Systems Medicine, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Alma Burlingame
- Departments of Pediatrics, Pharmacology, and Chemistry, University of California, San Francisco, San Francisco, CA 94143
| | - Dimitris K Grammatopoulos
- Translational and Systems Medicine, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Aditi Bhargava
- Osher Center for Integrative Medicine, University of California, San Francisco, San Francisco, CA 94143 .,Department of Surgery, University of California, San Francisco, San Francisco, CA 94143.,Department of Obstetrics & Gynecology, University of California, San Francisco, San Francisco, CA 94143
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14
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Miners JS, Love S. Endothelin-converting enzymes degrade α-synuclein and are reduced in dementia with Lewy bodies. J Neurochem 2017; 141:275-286. [PMID: 28171705 DOI: 10.1111/jnc.13974] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 01/17/2017] [Accepted: 01/26/2017] [Indexed: 01/12/2023]
Abstract
We have examined the roles of the endothelin-converting enzyme-1 and -2 (ECE-1 and ECE-2) in the homeostasis of α-synuclein (α-syn) and pathogenesis of Lewy body disease. The ECEs are named for their ability to convert inactive big endothelin to the vasoactive peptide endothelin-1 (EDN1). We have found that ECE-1 and ECE-2 cleave and degrade α-syn in vitro and siRNA-mediated knockdown of ECE-1 and ECE-2 in SH-SY5Y neuroblastoma cells significantly increased α-syn both intracellularly (within the cell lysate) (p < 0.05 for both ECE-1 and -2) and extracellularly (in the surrounding medium) (p < 0.05 for ECE-1 and p = 0.07 for ECE-2). Double immunofluorescent labelling showed co-localization of ECE-1 and ECE-2 with α-syn within the endolysosomal system (confirmed by a proximity ligation assay). To assess the possible relevance of these findings to human Lewy body disease, we measured ECE-1 and ECE-2 levels by sandwich ELISA in post-mortem samples of cingulate cortex (a region with a predilection for Lewy body pathology) in dementia with Lewy bodies (DLB) and age-matched controls. ECE-1 (p < 0.001) and ECE-2 (p < 0.01) levels were significantly reduced in DLB and both enzymes correlated inversely with the severity of Lewy body pathology as indicated by the level of α-syn phosphorylated at Ser129 (r = -0.54, p < 0.01 for ECE-1 and r = -0.49, p < 0.05 for ECE-2). Our novel findings suggest a role for ECEs in the metabolism of α-syn that could contribute to the development and progression of DLB.
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Affiliation(s)
| | - Seth Love
- Dementia Research Group, University of Bristol, Bristol, UK
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15
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Nederpelt I, Bunnik J, IJzerman AP, Heitman LH. Kinetic Profile of Neuropeptide–Receptor Interactions. Trends Neurosci 2016; 39:830-839. [DOI: 10.1016/j.tins.2016.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 01/18/2023]
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16
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GluN2B N-methyl-D-aspartate receptor and excitatory amino acid transporter 3 are upregulated in primary sensory neurons after 7 days of morphine administration in rats: implication for opiate-induced hyperalgesia. Pain 2016; 157:147-158. [PMID: 26335908 DOI: 10.1097/j.pain.0000000000000342] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The contribution of the peripheral nervous system to opiate-induced hyperalgesia (OIH) is not well understood. In this study, we determined the changes in excitability of primary sensory neurons after sustained morphine administration for 7 days. Changes in the expression of glutamate receptors and glutamate transporters after morphine administration were ascertained in dorsal root ganglions. Patch clamp recordings from intact dorsal root ganglions (ex vivo preparation) of morphine-treated rats showed increased excitability of small diameter (≤30 μm) neurons with respect to rheobase and membrane threshold, whereas the excitability of large diameter (>30 μm) neurons remained unchanged. Small diameter neurons also displayed increased responses to glutamate, which were mediated mainly by GluN2B containing N-methyl-D-aspartate (NMDA) receptors, and to a lesser degree by the neuronal excitatory amino acid transporter 3/excitatory amino acid carrier 1. Coadministration in vivo of the GluN2B selective antagonist Ro 25-6981 with morphine for 7 days prevented the appearance of OIH and increased morphine-induced analgesia. Administration of morphine for 7 days led to an increased expression of GluN2B and excitatory amino acid transporter 3/excitatory amino acid carrier 1, but not of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate, kainate, or group I metabotropic glutamate receptors, or of the vesicular glutamate transporter 2. These results suggest that peripheral glutamatergic neurotransmission contributes to OIH and that GluN2B subunit of NMDA receptors in the periphery may be a target for therapy.
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17
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Hasdemir B, Mhaske P, Paruthiyil S, Garnett EA, Heyman MB, Matloubian M, Bhargava A. Sex- and corticotropin-releasing factor receptor 2- dependent actions of urocortin 1 during inflammation. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1244-57. [PMID: 27053649 DOI: 10.1152/ajpregu.00445.2015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 03/25/2016] [Indexed: 12/20/2022]
Abstract
We investigated whether corticotropin-releasing factor receptor 2 (CRF2) and its high-affinity agonist urocortin 1 (Ucn1) mediate sex-specific signaling and immune responses. Intrarectal trinitrobenzene sulfonic acid was used to induce experimental colitis in wild-type, CRF2 knockout (CRF2KO), and heterozygous (CRF2Ht) mice of both sexes. Changes in plasma extravasation, organ weight, survival, immune cell numbers, inflammatory cytokines, and the MAPK signaling pathway were assessed. Stored intestinal biopsies from patients with Crohn's disease (CD) and age- and sex-matched individuals without inflammatory bowel disease (IBD) were examined by immunofluorescence and confocal microscopy to characterize Ucn1 and CRF receptor expression. CRF2Ht mice of both sexes showed decreased survival during colitis compared with other genotypes. Ucn1 improved survival in male mice alone. Ucn1 restored colon length and spleen and adrenal weight and decreased colonic TNF-α, IL-6, and IL-1β levels in male CRF2Ht mice alone. CRF2Ht mice of both sexes showed decreased phosphorylation of MAPK p38 and heat shock protein 27 (Hsp27) levels. Ucn1 restored p-Hsp27 levels in male CRF2Ht mice alone. Expression of the chaperone protein Hsp90 decreased during colitis, except in male CRF2Ht mice. Taken together, our data indicate that sex shows significant interaction with genotype and Ucn1 during colitis. Human duodenal and colonic biopsies revealed that sex-specific differences exist in levels of CRF receptors and Ucn1 expression in patients with CD compared with the matched non-IBD subjects. To conclude, Ucn1 mediates sex-specific immune and cellular signaling responses via CRF2, emphasizing the need for inclusion of females in preclinical studies.
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Affiliation(s)
- Burcu Hasdemir
- Department of Surgery, University of California, San Francisco; The Osher Center for Integrative Medicine, University of California, San Francisco
| | - Pallavi Mhaske
- Department of Surgery, University of California, San Francisco
| | | | | | - Melvin B Heyman
- Department of Pediatrics, University of California, San Francisco
| | - Mehrdad Matloubian
- Division of Rheumatology and Rosalind Russell and Ephraim P. Engleman Arthritis Research Center, University of California, San Francisco
| | - Aditi Bhargava
- Department of Surgery, University of California, San Francisco; The Osher Center for Integrative Medicine, University of California, San Francisco;
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18
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Poole DP, Lieu T, Pelayo JC, Eriksson EM, Veldhuis NA, Bunnett NW. Inflammation-induced abnormalities in the subcellular localization and trafficking of the neurokinin 1 receptor in the enteric nervous system. Am J Physiol Gastrointest Liver Physiol 2015; 309:G248-59. [PMID: 26138465 PMCID: PMC4537929 DOI: 10.1152/ajpgi.00118.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/24/2015] [Indexed: 01/31/2023]
Abstract
Activated G protein-coupled receptors traffic to endosomes and are sorted to recycling or degradative pathways. Endosomes are also a site of receptor signaling of sustained and pathophysiologically important processes, including inflammation. However, the mechanisms of endosomal sorting of receptors and the impact of disease on trafficking have not been fully defined. We examined the effects of inflammation on the subcellular distribution and trafficking of the substance P (SP) neurokinin 1 receptor (NK1R) in enteric neurons. We studied NK1R trafficking in enteric neurons of the mouse colon using immunofluorescence and confocal microscopy. The impact of inflammation was studied in IL10(-/-)-piroxicam and trinitrobenzenesulfonic acid colitis models. NK1R was localized to the plasma membrane of myenteric and submucosal neurons of the uninflamed colon. SP evoked NK1R endocytosis and recycling. Deletion of β-arrestin2, which associates with the activated NK1R, accelerated recycling. Inhibition of endothelin-converting enzyme-1 (ECE-1), which degrades endosomal SP, prevented recycling. Inflammation was associated with NK1R endocytosis in myenteric but not submucosal neurons. Whereas the NK1R in uninflamed neurons recycled within 60 min, NK1R recycling in inflamed neurons was delayed for >120 min, suggesting defective recycling machinery. Inflammation was associated with β-arrestin2 upregulation and ECE-1 downregulation, which may contribute to the defective NK1R recycling. We conclude that inflammation evokes redistribution of NK1R from the plasma membrane to endosomes of myenteric neurons through enhanced SP release and defective NK1R recycling. Defective recycling may be secondary to upregulation of β-arrestin2 and downregulation of ECE-1. Internalized NK1R may generate sustained proinflammatory signals that disrupt normal neuronal functions.
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Affiliation(s)
- Daniel P Poole
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia; ARC Center of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Victoria, Australia;
| | - TinaMarie Lieu
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Juan Carlos Pelayo
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Emily M Eriksson
- Population Health & Immunity, Walter and Eliza Hall Institute, Parkville, Victoria, Australia; and Department of Laboratory Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Nicholas A Veldhuis
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; ARC Center of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Victoria, Australia; Department of Genetics, The University of Melbourne, Parkville, Victoria, Australia
| | - Nigel W Bunnett
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; ARC Center of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Victoria, Australia; Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia; Department of Anaesthesia and Peri-operative Medicine, Monash University, Victoria, Australia
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19
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Gupta A, Fujita W, Gomes I, Bobeck E, Devi LA. Endothelin-converting enzyme 2 differentially regulates opioid receptor activity. Br J Pharmacol 2014; 172:704-19. [PMID: 24990314 DOI: 10.1111/bph.12833] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND AND PURPOSE Opioid receptor function is modulated by post-activation events such as receptor endocytosis, recycling and/or degradation. While it is generally understood that the peptide ligand gets co-endocytosed with the receptor, relatively few studies have investigated the role of the endocytosed peptide and peptide processing enzymes in regulating receptor function. In this study, we focused on endothelin-converting enzyme 2 (ECE2), a member of the neprilysin family of metallopeptidases that exhibits an acidic pH optimum, localizes to an intracellular compartment and selectively processes neuropeptides including opioid peptides in vitro, and examined its role in modulating μ receptor recycling and resensitization. EXPERIMENTAL APPROACH The effect of ECE2 inhibition on hydrolysis of the endocytosed peptide was examined using thin-layer chromatography and on μ opioid receptor trafficking using either elisa or microscopy. The effect of ECE2 inhibition on receptor signalling was measured using a cAMP assay and, in vivo, on antinociception induced by intrathecally administered opioids by the tail-flick assay. KEY RESULTS The highly selective ECE2 inhibitor, S136492, significantly impaired μ receptor recycling and signalling by only those ligands that are ECE2 substrates and this was seen both in heterologous cells and in cells endogenously co-expressing μ receptors with ECE2. We also found that ECE2 inhibition attenuated antinociception mediated only by opioid peptides that are ECE2 substrates. CONCLUSIONS AND IMPLICATIONS These results suggest that ECE2, by selectively processing endogenous opioid peptides in the endocytic compartment, plays a role in modulating opioid receptor activity. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
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Affiliation(s)
- A Gupta
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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20
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Gupta A, Gomes I, Wardman J, Devi LA. Opioid receptor function is regulated by post-endocytic peptide processing. J Biol Chem 2014; 289:19613-26. [PMID: 24847082 DOI: 10.1074/jbc.m113.537704] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Most neuroendocrine peptides are generated in the secretory compartment by proteolysis of the precursors at classical cleavage sites consisting of basic residues by well studied endopeptidases belonging to the subtilisin superfamily. In contrast, a subset of bioactive peptides is generated by processing at non-classical cleavage sites that do not contain basic residues. Neither the peptidases responsible for non-classical cleavages nor the compartment involved in such processing has been well established. Members of the endothelin-converting enzyme (ECE) family are considered good candidate enzymes because they exhibit functional properties that are consistent with such a role. In this study we have explored a role for ECE2 in endocytic processing of δ opioid peptides and its effect on modulating δ opioid receptor function by using selective inhibitors of ECE2 that we had identified previously by homology modeling and virtual screening of a library of small molecules. We found that agonist treatment led to intracellular co-localization of ECE2 with δ opioid receptors. Furthermore, selective inhibitors of ECE2 and reagents that increase the pH of the acidic compartment impaired receptor recycling by protecting the endocytosed peptide from degradation. This, in turn, led to a substantial decrease in surface receptor signaling. Finally, we showed that treatment of primary neurons with the ECE2 inhibitor during recycling led to increased intracellular co-localization of the receptors and ECE2, which in turn led to decreased receptor recycling and signaling by the surface receptors. Together, these results support a role for differential modulation of opioid receptor signaling by post-endocytic processing of peptide agonists by ECE2.
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Affiliation(s)
- Achla Gupta
- From the Department of Pharmacology and Systems Therapeutics and
| | - Ivone Gomes
- From the Department of Pharmacology and Systems Therapeutics and
| | - Jonathan Wardman
- From the Department of Pharmacology and Systems Therapeutics and
| | - Lakshmi A Devi
- From the Department of Pharmacology and Systems Therapeutics and the Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029
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21
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Increased response to glutamate in small diameter dorsal root ganglion neurons after sciatic nerve injury. PLoS One 2014; 9:e95491. [PMID: 24748330 PMCID: PMC3991716 DOI: 10.1371/journal.pone.0095491] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 03/26/2014] [Indexed: 12/24/2022] Open
Abstract
Glutamate in the peripheral nervous system is involved in neuropathic pain, yet we know little how nerve injury alters responses to this neurotransmitter in primary sensory neurons. We recorded neuronal responses from the ex-vivo preparations of the dorsal root ganglia (DRG) one week following a chronic constriction injury (CCI) of the sciatic nerve in adult rats. We found that small diameter DRG neurons (<30 µm) exhibited increased excitability that was associated with decreased membrane threshold and rheobase, whereas responses in large diameter neurons (>30 µm) were unaffected. Puff application of either glutamate, or the selective ionotropic glutamate receptor agonists alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainic acid (KA), or the group I metabotropic receptor (mGluR) agonist (S)-3,5-dihydroxyphenylglycine (DHPG), induced larger inward currents in CCI DRGs compared to those from uninjured rats. N-methyl-D-aspartate (NMDA)-induced currents were unchanged. In addition to larger inward currents following CCI, a greater number of neurons responded to glutamate, AMPA, NMDA, and DHPG, but not to KA. Western blot analysis of the DRGs revealed that CCI resulted in a 35% increase in GluA1 and a 60% decrease in GluA2, the AMPA receptor subunits, compared to uninjured controls. mGluR1 receptor expression increased by 60% in the membrane fraction, whereas mGluR5 receptor subunit expression remained unchanged after CCI. These results show that following nerve injury, small diameter DRG neurons, many of which are nociceptive, have increased excitability and an increased response to glutamate that is associated with changes in receptor expression at the neuronal membrane. Our findings provide further evidence that glutamatergic transmission in the periphery plays a role in nociception.
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22
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Mahajan S, Liao M, Barkan P, Takahashi K, Bhargava A. Urocortin 3 expression at baseline and during inflammation in the colon: corticotropin releasing factor receptors cross-talk. Peptides 2014; 54:58-66. [PMID: 24462512 PMCID: PMC4006935 DOI: 10.1016/j.peptides.2014.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/11/2014] [Accepted: 01/13/2014] [Indexed: 02/07/2023]
Abstract
Urocortins (Ucn1-3), members of the corticotropin-releasing factor (CRF) family of neuropeptides, are emerging as potent immunomodulators. Localized, cellular expression of Ucn1 and Ucn2, but not Ucn3, has been demonstrated during inflammation. Here, we investigated the role of Ucn3 in a rat model of Crohn's colitis and the relative contribution of CRF receptors (CRF1 and CRF2) in regulating Ucn3 expression at baseline and during inflammation. Ucn3 mRNA and peptide were ubiquitously expressed throughout the GI tract in naïve rats. Ucn3 immunoreactivity was seen in epithelial cells and myenteric neurons. On day 1 of colitis, Ucn3 mRNA levels decreased by 80% and did not recover to baseline even by day 9. Next, we ascertained pro- or anti-inflammatory actions of Ucn3 during colitis. Surprisingly, unlike observed anti-inflammatory actions of Ucn1, exogenous Ucn3 did not alter histopathological outcomes during colitis and neither did it alter levels of pro-inflammatory cytokines IL-6 and TNF-α. At baseline, colon-specific knockdown of CRF1, but not CRF2 decreased Ucn3 mRNA by 78%, whereas during colitis, Ucn3 mRNA levels increased after CRF1 knockdown. In cultured cells, co-expression of CRF1+CRF2 attenuated Ucn3-stimulated intracellular Ca(2+) peak by 48% as compared to cells expressing CRF2 alone. Phosphorylation of p38 kinase increased by 250% during colitis and was significantly attenuated after Ucn3 administration. Thus, our results suggest that a balanced and coordinated expression of CRF receptors is required for proper regulation of Ucn3 at baseline and during inflammation.
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Affiliation(s)
- Shilpi Mahajan
- Department of Surgery, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Min Liao
- Department of Surgery, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Paris Barkan
- Department of Surgery, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA; Jefferson Medical College, 1025 Walnut Street, Philadelphia, PA 19107, USA(1)
| | - Kazuhiro Takahashi
- Department of Endocrinology and Applied Medical Science, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan
| | - Aditi Bhargava
- Department of Surgery, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.
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23
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Kubat E, Mahajan S, Liao M, Ackerman L, Ohara PT, Grady EF, Bhargava A. Corticotropin-releasing factor receptor 2 mediates sex-specific cellular stress responses. Mol Med 2013; 19:212-22. [PMID: 23835907 DOI: 10.2119/molmed.2013.00036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 07/01/2013] [Indexed: 01/11/2023] Open
Abstract
Although females suffer twice as much as males from stress-related disorders, sex-specific participating and pathogenic cellular stress mechanisms remain uncharacterized. Using corticotropin-releasing factor receptor 2-deficient (Crhr2-/-) and wild-type (WT) mice, we show that CRF receptor type 2 (CRF2) and its high-affinity ligand, urocortin 1 (Ucn1), are key mediators of the endoplasmic reticulum (ER) stress response in a murine model of acute pancreatic inflammation. Ucn1 was expressed de novo in acinar cells of male, but not female WT mice during acute inflammation. Upon insult, acinar Ucn1 induction was markedly attenuated in male but not female Crhr2-/- mice. Crhr2-/- mice of both sexes show exacerbated acinar cell inflammation and necrosis. Electron microscopy showed mild ER damage in WT male mice and markedly distorted ER structure in Crhr2-/- male mice during pancreatitis. WT and Crhr2-/- female mice showed similarly distorted ER ultrastructure that was less severe than distortion seen in Crhr2-/- male mice. Damage in ER structure was accompanied by increased ubiquitination, peIF2, and mistargeted localization of vimentin in WT mice that was further exacerbated in Crhr2-/- mice of both sexes during pancreatitis. Exogenous Ucn1 rescued many aspects of histological damage and cellular stress response, including restoration of ER structure in male WT and Crhr2-/- mice, but not in females. Instead, females often showed increased damage. Thus, specific cellular pathways involved in coping and resolution seem to be distinct to each sex. Our results demonstrate the importance of identifying sex-specific pathogenic mechanisms and their value in designing effective therapeutics.
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Affiliation(s)
- Eric Kubat
- Department of Surgery, University of California San Francisco, San Francisco, California 94143, USA
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24
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Cottrell GS. Roles of proteolysis in regulation of GPCR function. Br J Pharmacol 2013; 168:576-90. [PMID: 23043558 DOI: 10.1111/j.1476-5381.2012.02234.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 09/03/2012] [Accepted: 09/24/2012] [Indexed: 12/18/2022] Open
Abstract
The enzymatic activity of peptidases must be tightly regulated to prevent uncontrolled hydrolysis of peptide bonds, which could have devastating effects on biological systems. Peptidases are often generated as inactive propeptidases, secreted with endogenous inhibitors, or they are compartmentalized. Propeptidases become active after proteolytic removal of N-terminal activation peptides by other peptidases. Some peptidases only become active towards substrates only at certain pHs, thus confining activity to specific compartments or conditions. This review discusses the different roles proteolysis plays in regulating GPCRs. At the cell-surface, certain GPCRs are regulated by the hydrolytic inactivation of bioactive peptides by membrane-anchored peptidases, which prevent signalling. Conversely, cell-surface peptidases can also generate bioactive peptides, which directly activate GPCRs. Alternatively, cell-surface peptidases activated by GPCRs, can generate bioactive peptides to cause transactivation of receptor tyrosine kinases, thereby promoting signalling. Certain peptidases can signal directly to cells, by cleaving GPCR to initiate intracellular signalling cascades. Intracellular peptidases also regulate GPCRs; lysosomal peptidases destroy GPCRs in lysosomes to permanently terminate signalling and mediate down-regulation; endosomal peptidases cleave internalized peptide agonists to regulate GPCR recycling, resensitization and signalling; and soluble intracellular peptidases also participate in GPCR function by regulating the ubiquitination state of GPCRs, thereby altering GPCR signalling and fate. Although the use of peptidase inhibitors has already brought success in the treatment of diseases such as hypertension, the discovery of new regulatory mechanisms involving proteolysis that control GPCRs may provide additional targets to modulate dysregulated GPCR signalling in disease.
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Affiliation(s)
- G S Cottrell
- Reading School of Pharmacy, University of Reading, Reading, UK.
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