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Khan R, Laumet G, Leinninger GM. Hungry for relief: Potential for neurotensin to address comorbid obesity and pain. Appetite 2024; 200:107540. [PMID: 38852785 DOI: 10.1016/j.appet.2024.107540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/11/2024]
Abstract
Chronic pain and obesity frequently occur together. An ideal therapy would alleviate pain without weight gain, and most optimally, could promote weight loss. The neuropeptide neurotensin (Nts) has been separately implicated in reducing weight and pain but could it be a common actionable target for both pain and obesity? Here we review the current knowledge of Nts signaling via its receptors in modulating body weight and pain processing. Evaluating the mechanism by which Nts impacts ingestive behavior, body weight, and analgesia has potential to identify common physiologic mechanisms underlying weight and pain comorbidities, and whether Nts may be common actionable targets for both.
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Affiliation(s)
- Rabail Khan
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Geoffroy Laumet
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA; Department of Physiology, Michigan State University, East Lansing, MI, 48824, USA
| | - Gina M Leinninger
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA; Department of Physiology, Michigan State University, East Lansing, MI, 48824, USA.
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2
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Wei ZX, Cai XX, Fei YD, Wang Q, Hu XL, Li C, Hou JW, Yang YL, Wang YP, Li YG. Ntsr1 contributes to pulmonary hypertension by enhancing endoplasmic reticulum stress via JAK2-STAT3-Thbs1 signaling. Transl Res 2024; 269:64-75. [PMID: 38395391 DOI: 10.1016/j.trsl.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/04/2024] [Accepted: 02/20/2024] [Indexed: 02/25/2024]
Abstract
Pulmonary hypertension (PH) is a severe clinical syndrome with pulmonary vascular remodeling and poor long-term prognosis. Neurotensin receptor 1 (Ntsr1), serve as one of the G protein-coupled receptors (GPCRs), implicates in various biological processes, but the potential effects of Ntsr1 in PH development are unclear. The Sugen/Hypoxia (SuHx) or monocrotaline (MCT) induced rat PH model was used in our study and the PH rats showed aggravated pulmonary artery remodeling and increased right ventricular systolic pressure (RVSP). Our results revealed that Ntsr1 induced endoplasmic reticulum (ER) stress response via ATF6 activation contributed to the development of PH. Moreover, RNA-sequencing (RNA-seq) and phosphoproteomics were performed and the Ntsr1-JAK2-STAT3-thrombospondin 1 (Thbs1)-ATF6 signaling was distinguished as the key pathway. In vitro, pulmonary artery smooth muscle cells (PASMCs) under hypoxia condition showed enhanced proliferation and migration properties, which could be inhibited by Ntsr1 knockdown, JAK2 inhibitor (Fedratinib) treatment, STAT3 inhibitior (Stattic) treatment, Thbs1 knockdown or ATF6 knockdown. In addition, adeno-associated virus 1 (AAV1) were used to knockdown the expression of Ntsr1, Thbs1 or ATF6 in rats and reversed the phenotype of PH. In summary, our results reveal that Ntsr1-JAK2-STAT3-Thbs1 pathway can induce enhanced ER stress via ATF6 activation and increased PASMC proliferation and migration capacities, which can be mechanism of the pulmonary artery remodeling and PH. Targeting Ntsr1 might be a novel therapeutic strategy to ameliorate PH.
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Affiliation(s)
- Zhi-Xing Wei
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Xing-Xing Cai
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Yu-Dong Fei
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Qian Wang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Xiao-Liang Hu
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Cheng Li
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Jian-Wen Hou
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Yu-Li Yang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Yue-Peng Wang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China
| | - Yi-Gang Li
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China.
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3
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Barton JR, Londregan AK, Alexander TD, Entezari AA, Covarrubias M, Waldman SA. Enteroendocrine cell regulation of the gut-brain axis. Front Neurosci 2023; 17:1272955. [PMID: 38027512 PMCID: PMC10662325 DOI: 10.3389/fnins.2023.1272955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Enteroendocrine cells (EECs) are an essential interface between the gut and brain that communicate signals about nutrients, pain, and even information from our microbiome. EECs are hormone-producing cells expressed throughout the gastrointestinal epithelium and have been leveraged by pharmaceuticals like semaglutide (Ozempic, Wegovy), terzepatide (Mounjaro), and retatrutide (Phase 2) for diabetes and weight control, and linaclotide (Linzess) to treat irritable bowel syndrome (IBS) and visceral pain. This review focuses on role of intestinal EECs to communicate signals from the gut lumen to the brain. Canonically, EECs communicate information about the intestinal environment through a variety of hormones, dividing EECs into separate classes based on the hormone each cell type secretes. Recent studies have revealed more diverse hormone profiles and communication modalities for EECs including direct synaptic communication with peripheral neurons. EECs known as neuropod cells rapidly relay signals from gut to brain via a direct communication with vagal and primary sensory neurons. Further, this review discusses the complex information processing machinery within EECs, including receptors that transduce intraluminal signals and the ion channel complement that govern initiation and propagation of these signals. Deeper understanding of EEC physiology is necessary to safely treat devastating and pervasive conditions like irritable bowel syndrome and obesity.
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Affiliation(s)
- Joshua R. Barton
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Annie K. Londregan
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Tyler D. Alexander
- Department of Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ariana A. Entezari
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Manuel Covarrubias
- Department of Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Scott A. Waldman
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
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4
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Shi Y, Chen Y, Deng L, Du K, Lu S, Chen T. Structural Understanding of Peptide-Bound G Protein-Coupled Receptors: Peptide-Target Interactions. J Med Chem 2023; 66:1083-1111. [PMID: 36625741 DOI: 10.1021/acs.jmedchem.2c01309] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The activation of G protein-coupled receptors (GPCRs) is triggered by ligand binding to their orthosteric sites, which induces ligand-specific conformational changes. Agonists and antagonists bound to GPCR orthosteric sites provide detailed information on ligand-binding modes. Among these, peptide ligands play an instrumental role in GPCR pharmacology and have attracted increased attention as therapeutic drugs. The recent breakthrough in GPCR structural biology has resulted in the remarkable availability of peptide-bound GPCR complexes. Despite the several structural similarities shared by these receptors, they exhibit distinct features in terms of peptide recognition and receptor activation. From this perspective, we have summarized the current status of peptide-bound GPCR structural complexes, largely focusing on the interactions between the receptor and its peptide ligand at the orthosteric site. In-depth structural investigations have yielded valuable insights into the molecular mechanisms underlying peptide recognition. This study would contribute to the discovery of GPCR peptide drugs with improved therapeutic effects.
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Affiliation(s)
- Yuxin Shi
- School of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China.,Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China
| | - Yi Chen
- Department of Ultrasound Interventional, Eastern Hepatobiliary Surgery Hospital, Navy Medical University, Shanghai 200433, China
| | - Liping Deng
- School of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
| | - Kui Du
- School of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China
| | - Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University, School of Medicine, Shanghai 200025, China.,Institute of Energy Metabolism and Health, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.,College of Pharmacy, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750004, China
| | - Ting Chen
- Department of Cardiology, Changzheng Hospital, Naval Medical University, Shanghai 200003, China
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5
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Perez-Bonilla P, Ramirez-Virella J, Menon P, Troyano-Rodriguez E, Arriaga SK, Makela A, Bugescu R, Beckstead MJ, Leinninger GM. Developmental or adult-onset deletion of neurotensin receptor-1 from dopamine neurons differentially reduces body weight. Front Neurosci 2022; 16:874316. [PMID: 36213756 PMCID: PMC9537700 DOI: 10.3389/fnins.2022.874316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Central neurotensin signaling via neurotensin receptor-1 (NtsR1) modulates various aspects of physiology, including suppressing feeding and promoting locomotor activity that can support weight loss. However, it remains unclear when and where NtsR1 expression contributes to control of body weight vs. other effects. We previously showed that activating ventral tegmental area (VTA) dopamine (DA) neurons that express NtsR1 promotes weight loss. We therefore hypothesized that deleting NtsR1 from DA neurons would promote weight gain by increasing food intake and decreasing physical activity. In contrast, developmental deletion of NtsR1 from DA neurons (by crossing DATCre mice with NtsR1flox/flox mice) had no impact on the feeding or body weight of mice fed a chow diet, though it augmented locomotor activity. Developmental deletion of NtsR1 from DA neurons protected mice from diet-induced obesity, but not via altering feeding, physical activity, or energy expenditure. Given that NtsR1 may exert distinct roles within development vs. adulthood, we then examined the impact of adult-onset deletion of NtsR1 from VTA DA neurons. We injected adult NtsR1flox/flox mice in the VTA with adeno associated virus to Cre-dependently delete NtsR1 in the VTA (VTAR1Null mice) and compared them to mice with intact NtsR1 (Controls). Again, in contrast to our hypothesis, VTAR1Null mice gained less weight than Controls while on normal chow or high fat diets. Moreover, VTAR1Null mice exhibited blunted feeding after fasting, suggesting a role for NtsR1 in adult VTA DA neurons in coordinating energy need and intake. Altogether, these data suggest that intact expression of NtsR1 in DA neurons is necessary for appropriate regulation of body weight, but a lack of NtsR1 in the developing vs. adult DA system protects from weight gain via different mechanisms. These findings emphasize the need for temporal and site-specific resolution to fully understand the role of NtsR1 within the brain.
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Affiliation(s)
- Patricia Perez-Bonilla
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, United States
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Jariel Ramirez-Virella
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, United States
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Pooja Menon
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Eva Troyano-Rodriguez
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Sydney K. Arriaga
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Anna Makela
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Michael J. Beckstead
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK, United States
| | - Gina M. Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI, United States
- *Correspondence: Gina M. Leinninger,
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Puri S, Kenyon BM, Hamrah P. Immunomodulatory Role of Neuropeptides in the Cornea. Biomedicines 2022; 10:1985. [PMID: 36009532 PMCID: PMC9406019 DOI: 10.3390/biomedicines10081985] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 12/21/2022] Open
Abstract
The transparency of the cornea along with its dense sensory innervation and resident leukocyte populations make it an ideal tissue to study interactions between the nervous and immune systems. The cornea is the most densely innervated tissue of the body and possesses both immune and vascular privilege, in part due to its unique repertoire of resident immune cells. Corneal nerves produce various neuropeptides that have a wide range of functions on immune cells. As research in this area expands, further insights are made into the role of neuropeptides and their immunomodulatory functions in the healthy and diseased cornea. Much remains to be known regarding the details of neuropeptide signaling and how it contributes to pathophysiology, which is likely due to complex interactions among neuropeptides, receptor isoform-specific signaling events, and the inflammatory microenvironment in disease. However, progress in this area has led to an increase in studies that have begun modulating neuropeptide activity for the treatment of corneal diseases with promising results, necessitating the need for a comprehensive review of the literature. This review focuses on the role of neuropeptides in maintaining the homeostasis of the ocular surface, alterations in disease settings, and the possible therapeutic potential of targeting these systems.
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Affiliation(s)
- Sudan Puri
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Brendan M. Kenyon
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
- Departments of Immunology and Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
- Cornea Service, Tufts New England Eye Center, Boston, MA 02111, USA
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7
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Yadav P, Barati Farimani A. Activation Pathways of Neurotensin Receptor 1 Elucidated Using Statistical Machine Learning. ACS Chem Neurosci 2022; 13:1333-1341. [PMID: 35380784 DOI: 10.1021/acschemneuro.2c00154] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Neurotensin receptor 1 (NTSR1) is a G-protein coupled receptor (GPCR) that mediates many biological processes through its interaction with the neurotensin (NTS) peptide. The NTSR1 protein is a clinically significant target as it is involved in the proliferation of cancer cells. Understanding the activation mechanism of NTSR1 is an important prerequisite for exploring the therapeutic potential of targeting NTSR1 and the development of drug molecules specific to NTSR1. Previous studies have been aimed at elucidating the structure of NTSR1 in the active and inactive conformations; however, the intermediate molecular pathway for NTSR1 activation dynamics is largely unknown. In this study, we performed extensive molecular dynamics (MD) simulations of the NTSR1 protein and analyzed its kinetic conformational changes to determine the microswitches that drive NTSR1 activation. To biophysically interpret the high-dimensional simulation trajectories, we used Markov state models and machine learning to elucidate the important and detailed conformational changes in NTSR1. Through the analysis of identified microswitches, we propose a mechanistic pathway for NTSR1 activation.
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Affiliation(s)
- Prakarsh Yadav
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Amir Barati Farimani
- Department of Mechanical Engineering, Biomedical Engineering, Chemical Engineering and Machine Learning Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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8
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Kuwahara Y, Takahashi K, Akai M, Kato I, Kozakai T, Asano S, Inui T, Marunaka Y, Kuwahara A. Minimum biological domain of xenin-25 required to induce anion secretion in the rat ileum. Peptides 2022; 147:170680. [PMID: 34757144 DOI: 10.1016/j.peptides.2021.170680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/28/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022]
Abstract
Xenin-25 has a variety of physiological functions in the gastrointestinal tract, including ion transport and motility. Xenin-25 and neurotensin show sequence homology, especially near their C-terminal regions. The sequence similarity between xenin-25 and neurotensin indicates that the effects of xenin-25 is mediated by the neurotensin receptor but some biological actions of xenin-25 are independent. We have previously reported that xenin-25 modulates intestinal ion transport and colonic smooth muscle activity. However, minimal biological domain of xenin-25 to induce ion transport was not clear. To improve the mechanistic understanding of xenin-25 and to gain additional insights into the functions of xenin-25, the present study was designed to determine the minimal biological domain of xenin-25 required for ion transport in the rat ileum using various truncated xenin fragments and analogues in an Ussing chamber system. The present results demonstrate that the minimum biological domain of xenin-25 to induce Cl-/HCO3- secretion in the ileum contains the C-terminal pentapeptide. Furthermore, Arg at position 21 is important to retain the biological activity of xenin-25 and induces Cl-/HCO3- secretion in the rat ileum.
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Affiliation(s)
- Yuko Kuwahara
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, 525-8577, Japan
| | - Kohei Takahashi
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, 525-8577, Japan
| | - Miho Akai
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, 525-8577, Japan
| | - Ikuo Kato
- Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, 658-8558, Japan
| | - Takaharu Kozakai
- Faculty of Education, Art, and Science, Yamagata University, Yamagata, 990-8560, Japan
| | - Shinji Asano
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, 525-8577, Japan
| | - Toshio Inui
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, 525-8577, Japan; Saisei Mirai Clinics, Moriguchi, 570-0012, Japan
| | - Yoshinori Marunaka
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, 525-8577, Japan; Medical Research Institute, Kyoto Industrial Health Association, Kyoto, 604-8472, Japan
| | - Atsukazu Kuwahara
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, 525-8577, Japan.
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9
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Sánchez ML, Coveñas R. The Neurotensinergic System: A Target for Cancer Treatment. Curr Med Chem 2021; 29:3231-3260. [PMID: 34711154 DOI: 10.2174/0929867328666211027124328] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND The scientific interest regarding the involvement of peptides in cancer has increased in the last years. In tumor cells the overexpression of peptides and their receptors is known and new therapeutic targets for the treatment of cancer have been suggested. The overexpression of the neurotensinergic system has been associated with poor prognosis, tumor size, higher tumor aggressiveness, increased relapse risk and worse sensitivity to chemotherapy agents. OBJECTIVE The aim of this review is to update the findings regarding the involvement of the neurotensinergic system in cancer to suggest anticancer therapeutic strategies targeting this system. The neurotensin (NT) precursor, NT and its receptors (NTR) and the involvement of the neurotensinergic system in lung, breast, prostate, gastric, colon, liver and pancreatic cancers, glioblastoma, neuroendocrine tumors and B-cell leukemia will be mentioned and discussed as well as the signaling pathways mediated by NT. Some research lines to be developed in the future will be suggested such as: molecules regulating the expression of the NT precursor, influence of the diet in the development of tumors, molecules and signaling pathways activated by NT and antitumor therapeutic strategies targeting the neurotensinergic system. CONCLUSION NT, via the NTR, exerts oncogenic (tumor cell proliferation, invasion, migration, angiogenesis) and antiapoptotic effects, whereas NTR antagonists inhibit these effects. NTR expression can be used as a diagnostic tool/therapeutic target and the administration of NTR antagonists as antitumor drugs could be a therapeutic strategy to treat tumors overexpressing NTR.
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Affiliation(s)
- Manuel Lisardo Sánchez
- University of Salamanca, Laboratory of Neuroanatomy of the Peptidergic Systems (Lab. 14), Institute of Neurosciences of Castilla y León (INCYL), Salamanca. Spain
| | - Rafael Coveñas
- University of Salamanca, Laboratory of Neuroanatomy of the Peptidergic Systems (Lab. 14), Institute of Neurosciences of Castilla y León (INCYL), Salamanca. Spain
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10
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Kyriatzis G, Bernard A, Bôle A, Pflieger G, Chalas P, Masse M, Lécorché P, Jacquot G, Ferhat L, Khrestchatisky M. Neurotensin receptor 2 is induced in astrocytes and brain endothelial cells in relation to neuroinflammation following pilocarpine-induced seizures in rats. Glia 2021; 69:2618-2643. [PMID: 34310753 DOI: 10.1002/glia.24062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 12/14/2022]
Abstract
Neurotensin (NT) acts as a primary neurotransmitter and neuromodulator in the CNS and has been involved in a number of CNS pathologies including epilepsy. NT mediates its central and peripheral effects by interacting with the NTSR1, NTSR2, and Sort1/NTSR3 receptor subtypes. To date, little is known about the precise expression of the NT receptors in brain neural cells and their regulation in pathology. In the present work, we studied the cellular distribution of the NTSR2 protein in the rat hippocampus and questioned whether its expression was modulated in conditions of neuroinflammation using a model of temporal lobe epilepsy induced by pilocarpine. This model is characterized by a rapid and intense inflammatory reaction with reactive gliosis in the hippocampus. We show that NTSR2 protein is expressed in hippocampal astrocytes and its expression increases together with astrocyte reactivity following induction of status epilepticus. NTSR2 immunoreactivity is also increased in astrocytes proximal to blood vessels and their end-feet, and in endothelial cells. Proinflammatory factors such as IL1β and LPS induced NTSR2 mRNA and protein in cultured astroglial cells. Antagonizing NTSR2 with SR142948A decreased NTSR2 expression as well as astroglial reactivity. Together, our results suggest that NTSR2 is implicated in astroglial and gliovascular inflammation and that targeting the NTSR2 receptor may open new avenues in the regulation of neuroinflammation in CNS diseases.
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Affiliation(s)
- Grigorios Kyriatzis
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Anne Bernard
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Angélique Bôle
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Guillaume Pflieger
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Petros Chalas
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Maxime Masse
- VECT-HORUS, Faculté de Médecine, Marseille Cedex, France
| | | | | | - Lotfi Ferhat
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Michel Khrestchatisky
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
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11
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Perez-Bonilla P, Santiago-Colon K, Matasovsky J, Ramirez-Virella J, Khan R, Garver H, Fink G, Dorrance AM, Leinninger GM. Activation of ventral tegmental area neurotensin Receptor-1 neurons promotes weight loss. Neuropharmacology 2021; 195:108639. [PMID: 34116109 DOI: 10.1016/j.neuropharm.2021.108639] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 05/17/2021] [Accepted: 06/03/2021] [Indexed: 01/31/2023]
Abstract
Dopamine (DA) neurons in the ventral tegmental area (VTA) modulate physical activity and feeding behaviors that are disrupted in obesity. Yet, the heterogeneity of VTA DA neurons has hindered determination of which ones might be leveraged to support weight loss. We hypothesized that increased activity in the subset of VTA DA neurons expressing neurotensin receptor-1 (NtsR1) might promote weight loss behaviors. To test this, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to activate VTA NtsR1 neurons in normal weight and diet-induced obese mice. Acute activation of VTA NtsR1 neurons (24hr) significantly decreased body weight in normal weight and obese mice by reducing food intake and increasing physical activity. Moreover, daily activation of VTA NtsR1 neurons in obese mice sustained weight loss over 7 days. Activating VTA NtsR1 neurons also suppressed how much mice worked to obtain sucrose rewards, even when there was high motivation to consume. However, VTA NtsR1 neural activation was not reinforcing, nor did it invoke liabilities associated with whole-body NtsR1 agonism such as anxiety, vasodepressor response or hypothermia. Activating VTA NtsR1 neurons therefore promotes dual behaviors that support weight loss without causing adverse effects, and is worth further exploration for managing obesity.
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Affiliation(s)
- Patricia Perez-Bonilla
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, 48114, USA; Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA
| | | | - Jillian Matasovsky
- Department of Physiology and College of Natural Science, Michigan State University, East Lansing, MI, 48114, USA
| | - Jariel Ramirez-Virella
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, 48114, USA; Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA
| | - Rabail Khan
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, 48114, USA
| | - Hannah Garver
- Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA
| | - Gregory Fink
- Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA; College of Osteopathic Medicine, East Lansing, MI, 48114, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA; College of Osteopathic Medicine, East Lansing, MI, 48114, USA
| | - Gina M Leinninger
- Department of Physiology and College of Natural Science, Michigan State University, East Lansing, MI, 48114, USA.
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12
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Wölk E, Stengel A, Schaper SJ, Rose M, Hofmann T. Neurotensin and Xenin Show Positive Correlations With Perceived Stress, Anxiety, Depressiveness and Eating Disorder Symptoms in Female Obese Patients. Front Behav Neurosci 2021; 15:629729. [PMID: 33664656 PMCID: PMC7921165 DOI: 10.3389/fnbeh.2021.629729] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 01/28/2021] [Indexed: 12/25/2022] Open
Abstract
Objective Neurotensin and xenin are two closely related anorexigenic neuropeptides synthesized in the small intestine that exert diverse peripheral and central functions. Both act via the neurotensin-1-receptor. In animal models of obesity reduced central concentrations of these peptides have been found. Dysregulations of the acute and chronic stress response are associated with development and maintenance of obesity. Until now, associations of both peptides with stress, anxiety, depressiveness, and eating disorder symptoms have not been investigated. The aim of the present study was to examine associations of neurotensin and xenin with these psychological characteristics under conditions of obesity. Materials and Methods From 2010 to 2016 we consecutively enrolled 160 inpatients (63 men and 97 women), admitted due to obesity and its mental and somatic comorbidities. Blood withdrawal und psychometric tests (PSQ-20, GAD-7, PHQ-9, and EDI-2) occurred within one week after admission. We measured levels of neurotensin and xenin in plasma by ELISA. Results Mean body mass index was 47.2 ± 9.5 kg/m2. Concentrations of neurotensin and xenin positively correlated with each other (women: r = 0.788, p < 0.001; men: r = 0.731, p < 0.001) and did not significantly differ between sexes (p > 0.05). Women generally displayed higher psychometric values than men (PSQ-20: 58.2 ± 21.7 vs. 47.0 ± 20.8, p = 0.002; GAD-7: 9.7 ± 5.8 vs. 7.1 ± 5.3, p = 0.004; PHQ-9: 11.6 ± 6.6 vs. 8.8 ± 5.9, p = 0.008; EDI-2: 50.5 ± 12.8 vs. 39.7 ± 11.9, p < 0.001). Only women showed positive correlations of both neuropeptides with stress (neurotensin: r = 0.231, p = 0.023; xenin: r = 0.254, p = 0.013), anxiety (neurotensin: r = 0.265, p = 0.009; xenin: r = 0.257, p = 0.012), depressiveness (neurotensin: r = 0.281, p = 0.006; xenin: r = 0.241, p = 0.019) and eating disorder symptoms (neurotensin: r = 0.276, p = 0.007; xenin: r = 0.26, p = 0.011), whereas, men did not (p > 0.05). Conclusion Neurotensin and xenin plasma levels of female obese patients are positively correlated with perceived stress, anxiety, depressiveness, and eating disorder symptoms. These associations could be influenced by higher prevalence of mental disorders in women and by sex hormones. In men, no correlations were observed, which points toward a sex-dependent regulation.
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Affiliation(s)
- Ellen Wölk
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Stengel
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
| | - Selina Johanna Schaper
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Matthias Rose
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Tobias Hofmann
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
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13
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Abstract
Introduction: Neurotensin is a gut-brain peptide hormone, a 13 amino acid neuropeptide found in the central nervous system and in the GI tract. The neurotensinergic system is implicated in various physiological and pathological processes related to neuropsychiatric and metabolic machineries, cancer growth, food, and drug intake. NT mediates its functions through its two G protein-coupled receptors: neurotensin receptor 1 (NTS1/NTSR1) and neurotensin receptor 2 (NTS2/NTSR2). Over the past decade, the role of NTS3/NTSR3/sortilin has also gained importance in human pathologies. Several approaches have appeared dealing with the discovery of compounds able to modulate the functions of this neuropeptide through its receptors for therapeutic gain.Areas covered: The article provides an overview of over four decades of research and details the drug discovery approaches and patented strategies targeting NTSR in the past decade.Expert opinion: Neurotensin is an important neurotransmitter that enables crosstalk with various neurotransmitter and neuroendocrine systems. While significant efforts have been made that have led to selective agonists and antagonists with promising in vitro and in vivo activities, the therapeutic potential of compounds targeting the neurotensinergic system is still to be fully harnessed for successful clinical translation of compounds for the treatment of several pathologies.
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Affiliation(s)
- Malliga R Iyer
- Section on Medicinal Chemistry, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
| | - George Kunos
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
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14
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Neurotensins and their therapeutic potential: research field study. Future Med Chem 2020; 12:1779-1803. [PMID: 33032465 DOI: 10.4155/fmc-2020-0124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The natural tridecapeptide neurotensin has been emerged as a promising therapeutic scaffold for the treatment of neurological diseases and cancer. In this work, we aimed to identify the top 100 most cited original research papers as well as recent key studies related to neurotensins. The Web of Science Core Collection database was searched and the retrieved research articles were analyzed by using the VOSviewer software. The most cited original articles were published between 1973 and 2013. The top-cited article was by Carraway and Leeman reporting the discovery of neurotensin in 1973. The highly cited terms were associated with hypotension and angiotensin-converting-enzyme. The conducted analysis reveals the therapeutic potentials of neurotensin, and further impactful research toward its clinical development is warrantied.
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15
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Campbell GE, Jones EL, Comizzoli P, Duffy DM. Neurotensin stimulates the sperm acrosome reaction and reduces percentages of fertilization in vitro. F&S SCIENCE 2020; 1:27-35. [PMID: 35559737 PMCID: PMC10034862 DOI: 10.1016/j.xfss.2020.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/02/2020] [Accepted: 03/13/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To determine the impact of neurotensin (NTS), a naturally occurring peptide, on the function of human and nonhuman primate sperm. DESIGN Experimental study. SETTING University-based research laboratory. PATIENT(S)/ANIMAL(S) Consenting normozoospermic human donors and cynomolgus macaques. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Sperm acrosome status was assessed. Computer-assisted semen analysis assessed sperm motility, progression, and velocity. Immunocytochemistry and receptor selective agonists were used to identify specific NTS receptors on sperm. Monkey oocytes were obtained after ovarian stimulation, and NTS-treated monkey sperm were used for in vitro fertilization. RESULTS Neurotensin treatment of human sperm stimulated the acrosome reaction in both a dose-dependent (0.1-10 μmol/L) and time-dependent (5-30 minutes) manner. Neurotensin treatment did not alter sperm motility or progression. Both a general NTS receptor antagonist (SR142948) and a NTSR1 selective antagonist (SR48692) reduced the ability of NTS to stimulate the acrosome reaction. The neurotensin receptor NTSR1, but not NTSR2 or SORT1, was detected in monkey sperm using immunostaining. Neurotensin treatment also compromised the ability of sperm to fertilize an oocyte. Percentage of fertilization with untreated monkey sperm and monkey oocytes was 72%. Sperm pre-treated with NTS yielded a significantly lower fertilization rate of 18%. CONCLUSION(S) Neurotensin effectively stimulates the acrosome reaction in human and monkey sperm. Neurotensin produced by the oviduct or cumulus cells may promote natural fertilization. Pretreatment of sperm with NTS significantly reduces fertilization. Exposure of sperm to NTS prior to reaching the oviduct has the potential for contraceptive development. Identification of NTSR1 as the mediator of NTS action provides a specific target for future studies.
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Affiliation(s)
- Genevieve E Campbell
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia
| | - Estella L Jones
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia; Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, Virginia
| | - Pierre Comizzoli
- Smithsonian Conservation Biology Institute, Front Royal, Virginia, and Washington, District of Columbia
| | - Diane M Duffy
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia.
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16
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Brouillette RL, Besserer-Offroy É, Mona CE, Chartier M, Lavenus S, Sousbie M, Belleville K, Longpré JM, Marsault É, Grandbois M, Sarret P. Cell-penetrating pepducins targeting the neurotensin receptor type 1 relieve pain. Pharmacol Res 2020; 155:104750. [PMID: 32151680 DOI: 10.1016/j.phrs.2020.104750] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/12/2020] [Accepted: 03/05/2020] [Indexed: 01/29/2023]
Abstract
Pepducins are cell-penetrating, membrane-tethered lipopeptides designed to target the intracellular region of a G protein-coupled receptor (GPCR) in order to allosterically modulate the receptor's signaling output. In this proof-of-concept study, we explored the pain-relief potential of a pepducin series derived from the first intracellular loop of neurotensin receptor type 1 (NTS1), a class A GPCR that mediates many of the effects of the neurotensin (NT) tridecapeptide, including hypothermia, hypotension and analgesia. We used BRET-based biosensors to determine the pepducins' ability to engage G protein signaling pathways associated with NTS1 activation. We observed partial Gαq and Gα13 activation at a 10 μM concentration, indicating that these pepducins may act as allosteric agonists of NTS1. Additionally, we used surface plasmon resonance (SPR) as a label-free assay to monitor pepducin-induced responses in CHO-K1 cells stably expressing hNTS1. This whole-cell integrated assay enabled us to subdivide our pepducin series into three profile response groups. In order to determine the pepducins' antinociceptive potential, we then screened the series in an acute pain model (tail-flick test) by measuring tail withdrawal latencies to a thermal nociceptive stimulus, following intrathecal (i.t.) pepducin administration (275 nmol/kg). We further evaluated promising pepducins in a tonic pain model (formalin test), as well as in neuropathic (Chronic Constriction Injury) and inflammatory (Complete Freund's Adjuvant) chronic pain models. We report one pepducin, PP-001, that consistently reduced rat nociceptive behaviors, even in chronic pain paradigms. Finally, we designed a TAMRA-tagged version of PP-001 and found by confocal microscopy that the pepducin reached the rat dorsal root ganglia post i.t. injection, thus potentially modulating the activity of NTS1 at this location to produce its analgesic effect. Altogether, these results suggest that NTS1-derived pepducins may represent a promising strategy in pain-relief.
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Affiliation(s)
- Rebecca L Brouillette
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Élie Besserer-Offroy
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada.
| | - Christine E Mona
- Ahmanson Translational Theranostic Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.
| | - Magali Chartier
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Sandrine Lavenus
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Marc Sousbie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Karine Belleville
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Jean-Michel Longpré
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Éric Marsault
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Michel Grandbois
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Philippe Sarret
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC, Canada.
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17
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McCauley HA. Enteroendocrine Regulation of Nutrient Absorption. J Nutr 2020; 150:10-21. [PMID: 31504661 DOI: 10.1093/jn/nxz191] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022] Open
Abstract
Enteroendocrine cells (EECs) in the intestine regulate many aspects of whole-body physiology and metabolism. EECs sense luminal and circulating nutrients and respond by secreting hormones that act on multiple organs and organ systems, such as the brain, gallbladder, and pancreas, to control satiety, digestion, and glucose homeostasis. In addition, EECs act locally, on enteric neurons, endothelial cells, and the gastrointestinal epithelium, to facilitate digestion and absorption of nutrients. Many recent reports raise the possibility that EECs and the enteric nervous system may coordinate to regulate gastrointestinal functions. Loss of all EECs results in chronic malabsorptive diarrhea, placing EECs in a central role regulating nutrient absorption in the gut. Because there is increasing evidence that EECs can directly modulate the efficiency of nutrient absorption, it is possible that EECs are master regulators of a feed-forward loop connecting appetite, digestion, metabolism, and abnormally augmented nutrient absorption that perpetuates metabolic disease. This review focuses on the roles that specific EEC hormones play on glucose, peptide, and lipid absorption within the intestine.
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Affiliation(s)
- Heather A McCauley
- Division of Developmental Biology and the Center for Stem Cell and Organoid Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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18
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Yin W, Li Z, Jin M, Yin YL, de Waal PW, Pal K, Yin Y, Gao X, He Y, Gao J, Wang X, Zhang Y, Zhou H, Melcher K, Jiang Y, Cong Y, Edward Zhou X, Yu X, Eric Xu H. A complex structure of arrestin-2 bound to a G protein-coupled receptor. Cell Res 2019; 29:971-983. [PMID: 31776446 DOI: 10.1038/s41422-019-0256-2] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 11/03/2019] [Indexed: 12/20/2022] Open
Abstract
Arrestins comprise a family of signal regulators of G-protein-coupled receptors (GPCRs), which include arrestins 1 to 4. While arrestins 1 and 4 are visual arrestins dedicated to rhodopsin, arrestins 2 and 3 (Arr2 and Arr3) are β-arrestins known to regulate many nonvisual GPCRs. The dynamic and promiscuous coupling of Arr2 to nonvisual GPCRs has posed technical challenges to tackle the basis of arrestin binding to GPCRs. Here we report the structure of Arr2 in complex with neurotensin receptor 1 (NTSR1), which reveals an overall assembly that is strikingly different from the visual arrestin-rhodopsin complex by a 90° rotation of Arr2 relative to the receptor. In this new configuration, intracellular loop 3 (ICL3) and transmembrane helix 6 (TM6) of the receptor are oriented toward the N-terminal domain of the arrestin, making it possible for GPCRs that lack the C-terminal tail to couple Arr2 through their ICL3. Molecular dynamics simulation and crosslinking data further support the assembly of the Arr2‒NTSR1 complex. Sequence analysis and homology modeling suggest that the Arr2‒NTSR1 complex structure may provide an alternative template for modeling arrestin-GPCR interactions.
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Affiliation(s)
- Wanchao Yin
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Zhihai Li
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,Cryo-Electron Microscopy Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Mingliang Jin
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yu-Ling Yin
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Parker W de Waal
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA
| | - Kuntal Pal
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA.,Department of Biotechnology, School of Life Science and Biotechnology, Adamas University, Kolkata, India
| | - Yanting Yin
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA
| | - Xiang Gao
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA
| | - Yuanzheng He
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA.,Laboratory of Receptor Structure and Signaling, HIT Center for Life Science, Harbin Institute of Technology, Harbin, 150001, China
| | - Jing Gao
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Xiaoxi Wang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yan Zhang
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Hu Zhou
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Karsten Melcher
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA
| | - Yi Jiang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Yao Cong
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - X Edward Zhou
- Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA.
| | - Xuekui Yu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,Cryo-Electron Microscopy Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
| | - H Eric Xu
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,Center for Cancer and Cell Biology, Program for Structural Biology, Van Andel Research Institute, Grand Rapids, MI, 49503, USA.
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19
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Beneficial Effects of Neurotensin in Murine Model of Hapten-Induced Asthma. Int J Mol Sci 2019; 20:ijms20205025. [PMID: 31614422 PMCID: PMC6834300 DOI: 10.3390/ijms20205025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/20/2019] [Accepted: 10/09/2019] [Indexed: 02/07/2023] Open
Abstract
Neurotensin (NT) demonstrates ambiguous activity on inflammatory processes. The present study was undertaken to test the potential anti-inflammatory activity of NT in a murine model of non-atopic asthma and to establish the contribution of NTR1 receptors. Asthma was induced in BALB/c mice by skin sensitization with dinitrofluorobenzene followed by intratracheal hapten provocation. The mice were treated intraperitoneally with NT, SR 142948 (NTR1 receptor antagonist) + NT or NaCl. Twenty-four hours after the challenge, airway responsiveness to nebulized methacholine was measured. Bronchoalveolar lavage fluid (BALF) and lungs were collected for biochemical and immunohistological analysis. NT alleviated airway hyperreactivity and reduced the number of inflammatory cells in BALF. These beneficial effects were inhibited by pretreatment with the NTR1 antagonist. Additionally, NT reduced levels of IL-13 and TNF-α in BALF and IL-17A, IL12p40, RANTES, mouse mast cell protease and malondialdehyde in lung homogenates. SR 142948 reverted only a post-NT TNF-α decrease. NT exhibited anti-inflammatory activity in the hapten-induced asthma. Reduced leukocyte accumulation and airway hyperresponsiveness indicate that this beneficial NT action is mediated through NTR1 receptors. A lack of effect by the NTR1 blockade on mast cell activation, oxidative stress marker and pro-inflammatory cytokine production suggests that other pathways can be involved, which requires further research.
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20
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Kato HE, Zhang Y, Hu H, Suomivuori CM, Kadji FMN, Aoki J, Krishna Kumar K, Fonseca R, Hilger D, Huang W, Latorraca NR, Inoue A, Dror RO, Kobilka BK, Skiniotis G. Conformational transitions of a neurotensin receptor 1-G i1 complex. Nature 2019; 572:80-85. [PMID: 31243364 PMCID: PMC7065593 DOI: 10.1038/s41586-019-1337-6] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 05/31/2019] [Indexed: 01/14/2023]
Abstract
Neurotensin receptor 1 (NTSR1) is a G-protein-coupled receptor (GPCR) that engages multiple subtypes of G protein, and is involved in the regulation of blood pressure, body temperature, weight and the response to pain. Here we present structures of human NTSR1 in complex with the agonist JMV449 and the heterotrimeric Gi1 protein, at a resolution of 3 Å. We identify two conformations: a canonical-state complex that is similar to recently reported GPCR-Gi/o complexes (in which the nucleotide-binding pocket adopts more flexible conformations that may facilitate nucleotide exchange), and a non-canonical state in which the G protein is rotated by about 45 degrees relative to the receptor and exhibits a more rigid nucleotide-binding pocket. In the non-canonical state, NTSR1 exhibits features of both active and inactive conformations, which suggests that the structure may represent an intermediate form along the activation pathway of G proteins. This structural information, complemented by molecular dynamics simulations and functional studies, provides insights into the complex process of G-protein activation.
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Affiliation(s)
- Hideaki E Kato
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Komaba Institute for Science, The University of Tokyo, Tokyo, Japan
| | - Yan Zhang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pathology of Sir Run Run Shaw Hospital, Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, China
| | - Hongli Hu
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Carl-Mikael Suomivuori
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
| | | | - Junken Aoki
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Kaavya Krishna Kumar
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Rasmus Fonseca
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Computer Science, University of Copenhagen, Copenhagen, Denmark
| | - Daniel Hilger
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Weijiao Huang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Naomi R Latorraca
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
- Biophysics Program, Stanford University, Stanford, CA, USA
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Ron O Dror
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
- Biophysics Program, Stanford University, Stanford, CA, USA
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Georgios Skiniotis
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
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21
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Schindler L, Bernhardt G, Keller M. Modifications at Arg and Ile Give Neurotensin(8-13) Derivatives with High Stability and Retained NTS 1 Receptor Affinity. ACS Med Chem Lett 2019; 10:960-965. [PMID: 31223455 DOI: 10.1021/acsmedchemlett.9b00122] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/10/2019] [Indexed: 12/16/2022] Open
Abstract
Due to its expression in various malignant tumors, the neurotensin receptor 1 (NTS1R) has been suggested and explored as a target for tumor diagnosis and therapy. Animal model-based investigations of various radiolabeled NTS1R ligands derived from the hexapeptide neurotensin(8-13) (NT(8-13)), e.g. 68Ga- and 18F-labeled compounds for PET diagnostics, give rise to optimize such radiotracers for clinical use. As NT(8-13) is rapidly degraded in vivo; structural modifications are required in terms of increased metabolic stability. In this study, the stabilization of the peptide backbone of NT(8-13) against enzymatic degradation was systematically explored by performing an N-methyl scan, replacing Ile12 by tert-butylglycine12 (Tle12) and N-terminal acylation. N-Methylation of either arginine, Arg8, or Arg9, combined with the Ile12/Tle12 exchange, proved to be most favorable with respect to NTS1R affinity (K i < 2 nM) and stability in human plasma (t 1/2 > 48 h), a valuable result regarding the development of radiopharmaceuticals derived from NT(8-13).
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Affiliation(s)
- Lisa Schindler
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
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22
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Nagarajan S, Alkayed NJ, Kaul S, Barnes AP. Effect of thermostable mutations on the neurotensin receptor 1 (NTSR1) activation state. J Biomol Struct Dyn 2019; 38:340-353. [DOI: 10.1080/07391102.2019.1573705] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Shanthi Nagarajan
- The Knight Cardiovascular Institute, Oregon Health Science University, Portland, OR, USA
- Medicinal Chemistry Core, Oregon Health Science University, Portland, OR, USA
| | - Nabil J. Alkayed
- The Knight Cardiovascular Institute, Oregon Health Science University, Portland, OR, USA
- Department of Anesthesiology & Perioperative Medicine, Oregon Health Science University Portland, Portland, OR, USA
| | - Sanjiv Kaul
- The Knight Cardiovascular Institute, Oregon Health Science University, Portland, OR, USA
| | - Anthony P. Barnes
- The Knight Cardiovascular Institute, Oregon Health Science University, Portland, OR, USA
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23
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Rezazadeh F, Sadeghzadeh N. Tumor targeting with 99m Tc radiolabeled peptides: Clinical application and recent development. Chem Biol Drug Des 2018; 93:205-221. [PMID: 30299570 DOI: 10.1111/cbdd.13413] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/19/2018] [Accepted: 09/23/2018] [Indexed: 01/16/2023]
Abstract
Targeting overexpressed receptors on the cancer cells with radiolabeled peptides has become very important in nuclear oncology in the recent years. Peptides are small and have easy preparation and easy radiolabeling protocol with no side-effect and toxicity. These properties made them a valuable tool for tumor targeting. Based on the successful imaging of neuroendocrine tumors with 111 In-octreotide, other receptor-targeting peptides such as bombesin (BBN), cholecystokinin/gastrin analogues, neurotensin analogues, glucagon-like peptide-1, and RGD peptides are currently under development or undergoing clinical trials. The most frequently used radionuclides for tumor imaging are 99m Tc and 111 In for single-photon emission computed tomography and 68 Ga and 18 F for positron emission tomography imaging. This review presents some of the 99m Tc-labeled peptides, with regard to their potential for radionuclide imaging of tumors in clinical and preclinical application.
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Affiliation(s)
- Farzaneh Rezazadeh
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran.,Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Nourollah Sadeghzadeh
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
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24
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Woodworth HL, Batchelor HM, Beekly BG, Bugescu R, Brown JA, Kurt G, Fuller PM, Leinninger GM. Neurotensin Receptor-1 Identifies a Subset of Ventral Tegmental Dopamine Neurons that Coordinates Energy Balance. Cell Rep 2018; 20:1881-1892. [PMID: 28834751 DOI: 10.1016/j.celrep.2017.08.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/19/2017] [Accepted: 07/25/2017] [Indexed: 02/06/2023] Open
Abstract
Dopamine (DA) neurons in the ventral tegmental area (VTA) are heterogeneous and differentially regulate ingestive and locomotor behaviors that affect energy balance. Identification of which VTA DA neurons mediate behaviors that limit weight gain has been hindered, however, by the lack of molecular markers to distinguish VTA DA populations. Here, we identified a specific subset of VTA DA neurons that express neurotensin receptor-1 (NtsR1) and preferentially comprise mesolimbic, but not mesocortical, DA neurons. Genetically targeted ablation of VTA NtsR1 neurons uncouples motivated feeding and physical activity, biasing behavior toward energy expenditure and protecting mice from age-related and diet-induced weight gain. VTA NtsR1 neurons thus represent a molecularly defined subset of DA neurons that are essential for the coordination of energy balance. Modulation of VTA NtsR1 neurons may therefore be useful to promote behaviors that prevent the development of obesity.
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Affiliation(s)
- Hillary L Woodworth
- Department of Physiology, Michigan State University, East Lansing, MI 48823, USA
| | - Hannah M Batchelor
- Department of Physiology, Michigan State University, East Lansing, MI 48823, USA
| | - Bethany G Beekly
- Department of Physiology, Michigan State University, East Lansing, MI 48823, USA
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, MI 48823, USA
| | - Juliette A Brown
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48823, USA
| | - Gizem Kurt
- Department of Physiology, Michigan State University, East Lansing, MI 48823, USA
| | - Patrick M Fuller
- Department of Neurology, Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Gina M Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI 48823, USA.
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25
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Tschumi CW, Beckstead MJ. Diverse actions of the modulatory peptide neurotensin on central synaptic transmission. Eur J Neurosci 2018; 49:784-793. [PMID: 29405480 DOI: 10.1111/ejn.13858] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 12/27/2022]
Abstract
Neurotensin (NT) is a 13 amino acid neuropeptide that is expressed throughout the central nervous system and is implicated in the etiology of multiple diseases and disorders. Many primary investigations of NT-induced modulation of neuronal excitability at the level of the synapse have been conducted, but they have not been summarized in review form in nearly 30 years. Therefore, the goal of this review is to discuss the many actions of NT on neuronal excitability across brain regions as well as NT circuit architecture. In the basal ganglia as well as other brain nuclei, NT can act through diverse intracellular signaling cascades to enhance or depress neuronal activity by modulating activity of ion channels, ionotropic and metabotropic neurotransmitter receptors, and presynaptic release of neurotransmitters. Further, NT can produce indirect effects by evoking endocannabinoid release, and recently has itself been identified as a putative retrograde messenger. In the basal ganglia, the diverse actions and circuit architecture of NT signaling allow for input-specific control of reward-related behaviors.
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Affiliation(s)
- Christopher W Tschumi
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104-5005, USA
| | - Michael J Beckstead
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104-5005, USA
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26
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Heitkamp T, Grisshammer R, Börsch M. Towards monitoring conformational changes of the GPCR neurotensin receptor 1 by single-molecule FRET. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2018; 10498. [PMID: 30013286 DOI: 10.1117/12.2286787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neurotensin receptor 1 (NTSR1) is a G protein-coupled receptor that is important for signaling in the brain and the gut. Its agonist ligand neurotensin (NTS), a 13-amino-acid peptide, binds with nanomolar affinity from the extracellular side to NTSR1 and induces conformational changes that trigger intracellular signaling processes. Our goal is to monitor the conformational dynamics of single fluorescently labeled NTSR1. For this, we fused the fluorescent protein mNeonGreen to the C terminus of NTSR1, purified the receptor fusion protein from E. coli membranes, and reconstituted NTSR1 into liposomes with E. coli polar lipids. Using single-molecule anisotropy measurements, NTSR1 was found to be monomeric in liposomes, with a small fraction being dimeric and oligomeric, showing homoFRET. Similar results were obtained for NTSR1 in detergent solution. Furthermore, we demonstrated agonist binding to NTSR1 by time-resolved single-molecule Förster resonance energy transfer (smFRET), using neurotensin labeled with the fluorophore ATTO594.
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Affiliation(s)
- Thomas Heitkamp
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University Jena, Nonnenplan 2 - 4, 07743 Jena, Germany
| | - Reinhard Grisshammer
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - Michael Börsch
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University Jena, Nonnenplan 2 - 4, 07743 Jena, Germany
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27
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Identification of Neurotensin Receptor Expressing Cells in the Ventral Tegmental Area across the Lifespan. eNeuro 2018; 5:eN-NWR-0191-17. [PMID: 29464190 PMCID: PMC5815659 DOI: 10.1523/eneuro.0191-17.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 01/15/2018] [Accepted: 01/25/2018] [Indexed: 11/21/2022] Open
Abstract
Neurotensin (Nts) promotes activation of dopamine (DA) neurons in the ventral tegmental area (VTA) via incompletely understood mechanisms. Nts can signal via the G protein-coupled Nts receptors 1 and 2 (NtsR1 and NtsR2), but the lack of methods to detect NtsR1- and NtsR2-expressing cells has limited mechanistic understanding of Nts action. To overcome this challenge, we generated dual recombinase mice that express FlpO-dependent Cre recombinase in NtsR1 or NtsR2 cells. This strategy permitted temporal control over recombination, such that we could identify NtsR1- or NtsR2-expressing cells and determine whether their distributions differed between the developing and adult brain. Using this system, we found that NtsR1 is transiently expressed in nearly all DA neurons and in many non-DA neurons in the VTA during development. However, NtsR1 expression is more restricted within the adult brain, where only two thirds of VTA DA neurons expressed NtsR1. By contrast, NtsR2 expression remains constant throughout lifespan, but it is predominantly expressed within glia. Anterograde tract tracing revealed that NtsR1 is expressed by mesolimbic, not mesocortical DA neurons, suggesting that VTA NtsR1 neurons may represent a functionally unique subset of VTA DA neurons. Collectively, this work reveals a cellular mechanism by which Nts can directly engage NtsR1-expressing DA neurons to modify DA signaling. Going forward, the dual recombinase strategy developed here will be useful to selectively modulate NtsR1- and NtsR2-expressing cells and to parse their contributions to Nts-mediated behaviors.
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28
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Lénárd L, László K, Kertes E, Ollmann T, Péczely L, Kovács A, Kállai V, Zagorácz O, Gálosi R, Karádi Z. Substance P and neurotensin in the limbic system: Their roles in reinforcement and memory consolidation. Neurosci Biobehav Rev 2018; 85:1-20. [DOI: 10.1016/j.neubiorev.2017.09.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 08/24/2017] [Accepted: 09/02/2017] [Indexed: 12/18/2022]
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29
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Co-localization patterns of neurotensin receptor 1 and tyrosine hydroxylase in brain regions involved in motivation and social behavior in male European starlings. J Chem Neuroanat 2018; 89:1-10. [PMID: 29407461 DOI: 10.1016/j.jchemneu.2018.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/29/2017] [Accepted: 01/29/2018] [Indexed: 12/22/2022]
Abstract
Animals communicate in distinct social contexts to convey information specific to those contexts, such as sexual or agonistic motivation. In seasonally-breeding male songbirds, seasonal changes in day length and increases in testosterone stimulate sexually-motivated song directed at females for courtship and reproduction. Dopamine and testosterone may act in the same brain regions to stimulate sexually-motivated singing. The neuropeptide neurotensin, acting at the neurotensin receptor 1 (NTR1), can strongly influence dopamine transmission. The goal of this study was to gain insight into the degree to which seasonal changes in physiology modify interactions between neurotensin and dopamine to adjust context-appropriate communication. Male European starlings were examined in physiological conditions that stimulate season-typical forms of communication: late summer/early fall non-breeding condition (low testosterone; birds sing infrequently), late fall non-breeding condition (low testosterone; birds produce non-sexually motivated song), and spring breeding condition (high testosterone; males produce sexually-motivated song). Double fluorescent immunolabeling was performed to detect co-localization patterns between tyrosine hydroxylase (TH; the rate-limiting enzyme in dopamine synthesis) and NTR1 in brain regions implicated in motivation and song production (the ventral tegmental area, medial preoptic nucleus, periaqueductal gray, and lateral septum). Co-localization between TH and NTR1 was present in the ventral tegmental area for all physiological conditions, and the number of co-localized cells did not differ across conditions. Immunolabeling for TH and NTR1 was also present in the other examined regions, although no co-localization was seen. These results support the hypothesis that interactions between NTR1 and dopamine in the ventral tegmental area may modulate vocalizations, but suggest that testosterone- or photoperiod-induced changes in NTR1/TH co-localization do not underlie seasonally-appropriate adjustment of communication.
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30
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Schroeder LE, Leinninger GM. Role of central neurotensin in regulating feeding: Implications for the development and treatment of body weight disorders. Biochim Biophys Acta Mol Basis Dis 2017; 1864:900-916. [PMID: 29288794 DOI: 10.1016/j.bbadis.2017.12.036] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/11/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023]
Abstract
The peptide neurotensin (Nts) was discovered within the brain over 40years ago and is implicated in regulating analgesia, body temperature, blood pressure, locomotor activity and feeding. Recent evidence suggests, however, that these disparate processes may be controlled via specific populations of Nts neurons and receptors. The neuronal mediators of Nts anorectic action are now beginning to be understood, and, as such, modulating specific Nts pathways might be useful in treating feeding and body weight disorders. This review considers mechanisms through which Nts normally regulates feeding and how disruptions in Nts signaling might contribute to the disordered feeding and body weight of schizophrenia, Parkinson's disease, anorexia nervosa, and obesity. Defining how Nts specifically mediates feeding vs. other aspects of physiology will inform the design of therapeutics that modify body weight without disrupting other important Nts-mediated physiology.
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Affiliation(s)
- Laura E Schroeder
- Department of Physiology, Michigan State University, East Lansing, MI 48823, United States
| | - Gina M Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI 48823, United States.
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31
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Law IKM, Padua DM, Iliopoulos D, Pothoulakis C. Role of G protein-coupled receptors-microRNA interactions in gastrointestinal pathophysiology. Am J Physiol Gastrointest Liver Physiol 2017; 313:G361-G372. [PMID: 28774868 PMCID: PMC5792214 DOI: 10.1152/ajpgi.00144.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/13/2017] [Accepted: 07/24/2017] [Indexed: 01/31/2023]
Abstract
G protein-coupled receptors (GPCRs) make up the largest transmembrane receptor superfamily in the human genome and are expressed in nearly all gastrointestinal cell types. Coupling of GPCRs and their respective ligands activates various phosphotransferases in the cytoplasm, and, thus, activation of GPCR signaling in intestine regulates many cellular and physiological processes. Studies in microRNAs (miRNAs) demonstrate that they represent critical epigenetic regulators of different pathophysiological responses in different organs and cell types in humans and animals. Here, we reviewed recent research on GPCR-miRNA interactions related to gastrointestinal pathophysiology, such as inflammatory bowel diseases, irritable bowel syndrome, and gastrointestinal cancers. Given that the presence of different types of cells in the gastrointestinal tract suggests the importance of cell-cell interactions in maintaining gastrointestinal homeostasis, we also discuss how GPCR-miRNA interactions regulate gene expression at the cellular level and subsequently modulate gastrointestinal pathophysiology through molecular regulatory circuits and cell-cell interactions. These studies helped identify novel molecular pathways leading to the discovery of potential biomarkers for gastrointestinal diseases.
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Affiliation(s)
- Ivy Ka Man Law
- 1Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California; and
| | - David Miguel Padua
- 1Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California; and
| | - Dimitrios Iliopoulos
- 1Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California; and ,2Center for Systems Biomedicine, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Charalabos Pothoulakis
- Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California; and
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32
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Triarhou LC, Solà C, Mengod G, García-Ladona FJ, Landwehrmeyer B, Ghetti B, Palacios JM. Ventral Mesencephalic Grafts in the Neostriatum of the Weaver Mutant Mouse: Structural Molecule and Receptor Studies. Cell Transplant 2017; 4:39-48. [PMID: 7728332 DOI: 10.1177/096368979500400107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mesencephalic cell suspensions were prepared from E12 wild-type (+/+) mouse embryos and stereotaxically implanted into the dorsal neostriatum of weaver mutant mice (wv/wv), which have a genetic mesostriatal dopamine (DA) deficiency. Survival of DA neurons in the grafts was documented by tyrosine hydroxylase (TH) immunocytochemistry. Axon growth was monitored by immunocytochemistry using a battery of antibody markers, and the cellular localization of structural protein and receptor RNA transcripts was studied by in situ hybridization histochemistry using [32P]oigo-nucleotide probes. The cellw suspension grafts exhibited strong immunoreactivity for neural cell adhesion molecule (N-CAM), growth-associated phosphoprotein GAP-43, micro-tubule-associated protein 2 (MAP2), β-amyloid protein precursor (βAPP), and phosphorylated neurofilament epitopes (clone SMI-31); intermediate-to-high levels of immunoreactivity were seen for synaptophysin. High levels of hybridization were found in the grafts for the RNA transcripts of GAP-43, MAP2, and isoforms βAPP695, βAPP714 and βAPP751 of the βAPP. No hybridization signal was detected in the grafts for DA D2 or neurotensin receptor mRNAs, both of which are normally expressed by nigral DA neurons. DA receptor autoradiography using the D2/D3 agonist [3H]CV 205-502 as a ligand showed no binding in the transplants, indicating an apparent abnormality of grafted cells; neurotensin binding sites, labeled with [125I]neurotensin, were visualized in the suspensions, indicating the possibility that receptors could be present but that RNA message levels might be too low to allow detection. These findings offer a molecular correlate of axonal, dendritic and structural protein expression by transplanted mesencephalic neurons; further, they suggest that specific functional properties of grafted nigral cells are maintained after transplantation, while other aspects of their cellular biology may be compromised.
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Affiliation(s)
- L C Triarhou
- Department of Pathology, Indiana University School of Medicine, Indianapolis 46202, USA
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33
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Grisshammer R. New approaches towards the understanding of integral membrane proteins: A structural perspective on G protein-coupled receptors. Protein Sci 2017; 26:1493-1504. [PMID: 28547763 DOI: 10.1002/pro.3200] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 01/12/2023]
Abstract
Three-dimensional structure determination of integral membrane proteins has advanced in unprecedented detail our understanding of mechanistic events of how ion channels, transporters, receptors, and enzymes function. This exciting progress required a tremendous amount of methods development, as exemplified here with G protein-coupled receptors (GPCRs): Optimizing the production of GPCRs in recombinant hosts; increasing the probability of crystal formation using high-affinity ligands, nanobodies, and minimal G proteins for co-crystallization, thus stabilizing receptors into one conformation; using the T4 lysozyme technology and other fusion partners to promote crystal contacts; advancing crystallization methods including the development of novel detergents, and miniaturization and automation of the lipidic cubic phase crystallization method; the concept of conformational thermostabilization of GPCRs; and developing microfocus X-ray synchrotron technologies to analyze small GPCR crystals. However, despite immense progress to explain how GPCRs function, many receptors pose intractable hurdles to structure determination at this time. Three emerging methods, serial femtosecond crystallography, micro electron diffraction, and single particle electron cryo-microscopy, hold promise to overcome current limitations in structural membrane biology.
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Affiliation(s)
- Reinhard Grisshammer
- Department of Health and Human Services, Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Rockville, Maryland, 20852
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34
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Besserer-Offroy É, Brouillette RL, Lavenus S, Froehlich U, Brumwell A, Murza A, Longpré JM, Marsault É, Grandbois M, Sarret P, Leduc R. The signaling signature of the neurotensin type 1 receptor with endogenous ligands. Eur J Pharmacol 2017; 805:1-13. [DOI: 10.1016/j.ejphar.2017.03.046] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 12/17/2022]
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35
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Kaji I, Akiba Y, Kato I, Maruta K, Kuwahara A, Kaunitz JD. Xenin Augments Duodenal Anion Secretion via Activation of Afferent Neural Pathways. J Pharmacol Exp Ther 2017; 361:151-161. [PMID: 28115552 DOI: 10.1124/jpet.116.238485] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/18/2017] [Indexed: 12/19/2022] Open
Abstract
Xenin-25, a neurotensin (NT)-related anorexigenic gut hormone generated mostly in the duodenal mucosa, is believed to increase the rate of duodenal ion secretion, because xenin-induced diarrhea is not present after Roux-en-Y gastric bypass surgery. Because the local effects of xenin on duodenal ion secretion have remained uninvestigated, we thus examined the neural pathways underlying xenin-induced duodenal anion secretion. Intravenous infusion of xenin-8, a bioactive C-terminal fragment of xenin-25, dose dependently increased the rate of duodenal HCO3- secretion in perfused duodenal loops of anesthetized rats. Xenin was immunolocalized to a subset of enteroendocrine cells in the rat duodenum. The mRNA of the xenin/NT receptor 1 (NTS1) was predominantly expressed in the enteric plexus, nodose and dorsal root ganglia, and in the lamina propria rather than in the epithelium. The serosal application of xenin-8 or xenin-25 rapidly and transiently increased short-circuit current in Ussing-chambered mucosa-submucosa preparations in a concentration-dependent manner in the duodenum and jejunum, but less so in the ileum and colon. The selective antagonist for NTS1, substance P (SP) receptor (NK1), or 5-hydroxytryptamine (5-HT)3, but not NTS2, inhibited the responses to xenin. Xenin-evoked Cl- secretion was reduced by tetrodotoxin (TTX) or capsaicin-pretreatment, and abolished by the inhibitor of TTX-resistant sodium channel Nav1.8 in combination with TTX, suggesting that peripheral xenin augments duodenal HCO3- and Cl- secretion through NTS1 activation on intrinsic and extrinsic afferent nerves, followed by release of SP and 5-HT. Afferent nerve activation by postprandial, peripherally released xenin may account for its secretory effects in the duodenum.
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Affiliation(s)
- Izumi Kaji
- Greater Los Angeles Veterans Affairs Healthcare System Los Angeles, California (I.K., Y.A., J.D.K.); Departments of Medicine (I.K., Y.A., K.M., J.D.K.) and Surgery (J.D.K.), David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Kobe, Japan (I.K.); and Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Japan (A.K.)
| | - Yasutada Akiba
- Greater Los Angeles Veterans Affairs Healthcare System Los Angeles, California (I.K., Y.A., J.D.K.); Departments of Medicine (I.K., Y.A., K.M., J.D.K.) and Surgery (J.D.K.), David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Kobe, Japan (I.K.); and Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Japan (A.K.)
| | - Ikuo Kato
- Greater Los Angeles Veterans Affairs Healthcare System Los Angeles, California (I.K., Y.A., J.D.K.); Departments of Medicine (I.K., Y.A., K.M., J.D.K.) and Surgery (J.D.K.), David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Kobe, Japan (I.K.); and Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Japan (A.K.)
| | - Koji Maruta
- Greater Los Angeles Veterans Affairs Healthcare System Los Angeles, California (I.K., Y.A., J.D.K.); Departments of Medicine (I.K., Y.A., K.M., J.D.K.) and Surgery (J.D.K.), David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Kobe, Japan (I.K.); and Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Japan (A.K.)
| | - Atsukazu Kuwahara
- Greater Los Angeles Veterans Affairs Healthcare System Los Angeles, California (I.K., Y.A., J.D.K.); Departments of Medicine (I.K., Y.A., K.M., J.D.K.) and Surgery (J.D.K.), David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Kobe, Japan (I.K.); and Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Japan (A.K.)
| | - Jonathan D Kaunitz
- Greater Los Angeles Veterans Affairs Healthcare System Los Angeles, California (I.K., Y.A., J.D.K.); Departments of Medicine (I.K., Y.A., K.M., J.D.K.) and Surgery (J.D.K.), David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Kobe, Japan (I.K.); and Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Japan (A.K.)
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36
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Gajjar S, Patel BM. Neuromedin: An insight into its types, receptors and therapeutic opportunities. Pharmacol Rep 2017; 69:438-447. [PMID: 31994106 DOI: 10.1016/j.pharep.2017.01.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/26/2016] [Accepted: 01/18/2017] [Indexed: 12/17/2022]
Abstract
Neuropeptides are small protein used by neurons in signal communications. Neuromedin U was the first neuropeptide discovered from the porcine spinal and showed its potent constricting activities on uterus hence was entitled with neuromedin U. Following neuromedin U another of its isoform was discovered neuromedin S which was observed in suprachiasmatic nucleus hence was entitled neuromedin S. Neuromedin K and neuromedin L are of kanassin class which belong to tachykinin family. Bombesin family consists of neuromedin B and neuromedin C. All these different neuromedins have various physiological roles like constrictive effects on the smooth muscles, control of blood pressure, pain sensations, hunger, bone metastasis and release and regulation of hormones. Over the years various newer physiological roles have been observed thus opening ways for various novel therapeutic treatments. This review aims to provide an overview of important different types of neuromedin, their receptors, signal transduction mechanism and implications for various diseases.
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Simeth NA, Bause M, Dobmeier M, Kling RC, Lachmann D, Hübner H, Einsiedel J, Gmeiner P, König B. NTS2-selective neurotensin mimetics with tetrahydrofuran amino acids. Bioorg Med Chem 2017; 25:350-359. [DOI: 10.1016/j.bmc.2016.10.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/20/2016] [Accepted: 10/31/2016] [Indexed: 01/10/2023]
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Krumm BE, Lee S, Bhattacharya S, Botos I, White CF, Du H, Vaidehi N, Grisshammer R. Structure and dynamics of a constitutively active neurotensin receptor. Sci Rep 2016; 6:38564. [PMID: 27924846 PMCID: PMC5141500 DOI: 10.1038/srep38564] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/03/2016] [Indexed: 11/09/2022] Open
Abstract
Many G protein-coupled receptors show constitutive activity, resulting in the production of a second messenger in the absence of an agonist; and naturally occurring constitutively active mutations in receptors have been implicated in diseases. To gain insight into mechanistic aspects of constitutive activity, we report here the 3.3 Å crystal structure of a constitutively active, agonist-bound neurotensin receptor (NTSR1) and molecular dynamics simulations of agonist-occupied and ligand-free receptor. Comparison with the structure of a NTSR1 variant that has little constitutive activity reveals uncoupling of the ligand-binding domain from conserved connector residues, that effect conformational changes during GPCR activation. Furthermore, molecular dynamics simulations show strong contacts between connector residue side chains and increased flexibility at the intracellular receptor face as features that coincide with robust signalling in cells. The loss of correlation between the binding pocket and conserved connector residues, combined with altered receptor dynamics, possibly explains the reduced neurotensin efficacy in the constitutively active NTSR1 and a facilitated initial engagement with G protein in the absence of agonist.
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Affiliation(s)
- Brian E Krumm
- Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - Sangbae Lee
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Road, Duarte, California 91010, United States
| | - Supriyo Bhattacharya
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Road, Duarte, California 91010, United States
| | - Istvan Botos
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, United States
| | - Courtney F White
- Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - Haijuan Du
- Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - Nagarajan Vaidehi
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Road, Duarte, California 91010, United States
| | - Reinhard Grisshammer
- Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
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39
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Sato S, Huang XP, Kroeze WK, Roth BL. Discovery and Characterization of Novel GPR39 Agonists Allosterically Modulated by Zinc. Mol Pharmacol 2016; 90:726-737. [PMID: 27754899 DOI: 10.1124/mol.116.106112] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/15/2016] [Indexed: 12/19/2022] Open
Abstract
In this study, we identified two previously described kinase inhibitors-3-(4-chloro-2-fluorobenzyl)-2-methyl-N-(3-methyl-1H-pyrazol-5-yl)-8-(morpholinomethyl)imidazo[1,2-b]pyridazin-6-amine (LY2784544) and 1H-benzimidazole-4-carboxylic acid, 2-methyl-1-[[2-methyl-3-(trifluoromethyl)phenyl]methyl]-6-(4-morpholinyl)- (GSK2636771)-as novel GPR39 agonists by unbiased small-molecule-based screening using a β-arrestin recruitment screening approach (PRESTO-Tango). We characterized the signaling of LY2784544 and GSK2636771 and compared their signaling patterns with a previously described "GPR39-selective" agonist N-[3-chloro-4-[[[2-(methylamino)-6-(2-pyridinyl)-4- pyrimidinyl]amino]methyl]phenyl]methanesulfonamide (GPR39-C3) at both canonical and noncanonical signaling pathways. Unexpectedly, all three compounds displayed probe-dependent and pathway-dependent allosteric modulation by concentrations of zinc reported to be physiologic. LY2784544 and GS2636771 at GPR39 in the presence of zinc were generally as potent or more potent than their reported activities against kinases in whole-cell assays. These findings reveal an unexpected role of zinc as an allosteric potentiator of small-molecule-induced activation of GPR39 and expand the list of potential kinase off-targets to include understudied G protein-coupled receptors.
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Affiliation(s)
- Seiji Sato
- Department of Pharmacology (S.S., X.-P.H., W.K.K., B.L.R.) and National Institute of Mental Health Psychoactive Drug Screening Program (X.-P.H., B.L.R.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Xi-Ping Huang
- Department of Pharmacology (S.S., X.-P.H., W.K.K., B.L.R.) and National Institute of Mental Health Psychoactive Drug Screening Program (X.-P.H., B.L.R.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Wesley K Kroeze
- Department of Pharmacology (S.S., X.-P.H., W.K.K., B.L.R.) and National Institute of Mental Health Psychoactive Drug Screening Program (X.-P.H., B.L.R.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Bryan L Roth
- Department of Pharmacology (S.S., X.-P.H., W.K.K., B.L.R.) and National Institute of Mental Health Psychoactive Drug Screening Program (X.-P.H., B.L.R.), School of Medicine, University of North Carolina, Chapel Hill, North Carolina
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40
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41
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Barak LS, Bai Y, Peterson S, Evron T, Urs NM, Peddibhotla S, Hedrick MP, Hershberger P, Maloney PR, Chung TD, Rodriguiz RM, Wetsel WC, Thomas JB, Hanson GR, Pinkerton AB, Caron MG. ML314: A Biased Neurotensin Receptor Ligand for Methamphetamine Abuse. ACS Chem Biol 2016; 11:1880-90. [PMID: 27119457 DOI: 10.1021/acschembio.6b00291] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Pharmacological treatment for methamphetamine addiction will provide important societal benefits. Neurotensin receptor NTR1 and dopamine receptor distributions coincide in brain areas regulating methamphetamine-associated reward, and neurotensin peptides produce behaviors opposing psychostimulants. Therefore, undesirable methamphetamine-associated activities should be treatable with druggable NTR1 agonists, but no such FDA-approved therapeutics exist. We address this limitation with proof-of-concept data for ML314, a small-molecule, brain penetrant, β-arrestin biased, NTR1 agonist. ML314 attenuates amphetamine-like hyperlocomotion in dopamine transporter knockout mice, and in C57BL/6J mice it attenuates methamphetamine-induced hyperlocomotion, potentiates the psychostimulant inhibitory effects of a ghrelin antagonist, and reduces methamphetamine-associated conditioned place preference. In rats, ML314 blocks methamphetamine self-administration. ML314 acts as an allosteric enhancer of endogenous neurotensin, unmasking stoichiometric numbers of hidden NTR1 binding sites in transfected-cell membranes or mouse striatal membranes, while additionally supporting NTR1 endocytosis in cells in the absence of NT peptide. These results indicate ML314 is a viable, preclinical lead for methamphetamine abuse treatment and support an allosteric model of G protein-coupled receptor signaling.
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Affiliation(s)
- Larry S. Barak
- Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Yushi Bai
- Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Sean Peterson
- Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Tama Evron
- Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Nikhil M. Urs
- Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Satyamaheshwar Peddibhotla
- Conrad Prebys Center for Chemical Genomics at Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Michael P. Hedrick
- Conrad Prebys Center for Chemical Genomics at Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, United States
| | - Paul Hershberger
- Conrad Prebys Center for Chemical Genomics at Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Patrick R. Maloney
- Conrad Prebys Center for Chemical Genomics at Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, United States
| | - Thomas D.Y. Chung
- Conrad Prebys Center for Chemical Genomics at Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, United States
| | | | - William C. Wetsel
- Duke University Medical Center, Durham, North Carolina 27710, United States
| | - James B. Thomas
- RTI International, 3040 E
Cornwallis Road, Durham, North Carolina 27709, United States
| | - Glen R. Hanson
- Department
of Pharmacology and Toxicology, University of Utah, 260 S. Campus
Drive, Salt Lake City, Utah 84112, United States
| | - Anthony B. Pinkerton
- Conrad Prebys Center for Chemical Genomics at Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, United States
| | - Marc G. Caron
- Duke University Medical Center, Durham, North Carolina 27710, United States
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42
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Toy-Miou-Leong M, Bachelet CM, Pélaprat D, Rostène W, Forgez P. NT Agonist Regulates Expression of Nuclear High-affinity Neurotensin Receptors. J Histochem Cytochem 2016; 52:335-45. [PMID: 14966200 DOI: 10.1177/002215540405200304] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neurotensin (NT) exerts multiple functions in the central nervous system and peripheral tissues. Its actions are mainly mediated by a high-affinity G-protein-coupled receptor, the NT-1 receptor. In this study we demonstrated a nuclear NT binding site in different cellular models. We first noted that a large percentage of NT-1 receptor cell body immunoreactivity was located in the nuclear soma and nuclear envelope of rat substantia nigra, a brain area rich in NT-containing axon terminals. The NT-1 receptor was also visualized in purified nuclei from CHO cells stably transfected with NT-1 receptor coupled to the enhanced green fluorescence protein by immunocytochemistry. We observed that both the nuclear envelope and the nuclear soma were labeled, and the labeling intensity significantly increased after NT agonist treatment. These results suggested that NT-1 receptors, present in both the nuclear soma and the nuclear envelope, can be modulated by the ligand. Lastly, [125I]-NT binding experiments performed on isolated nuclei from a human lung cancer cell line endogenously expressing NT-1 receptor and NT, LNM35, revealed the existence of nuclear Gpp(NHp)-sensitive binding sites. These binding sites markedly decreased when cells were chronically treated with an NT-1 receptor antagonist, SR 48692. Taken together, these data suggest that the agonist regulates the expression of nuclear NT-1 receptors.
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43
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Kornienko O, Lacson R, Kunapuli P, Schneeweis J, Hoffman I, Smith T, Alberts M, Inglese J, Strulovici B. Miniaturization of Whole Live Cell-Based GPCR Assays Using Microdispensing and Detection Systems. ACTA ACUST UNITED AC 2016; 9:186-95. [PMID: 15140380 DOI: 10.1177/1087057103260070] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cell-based β-lactamase reporter gene assays designed to measure the functional responses of G-protein-coupled receptors (GPCRs) were miniaturized to less than 2 μL total assay volume in a 3456-well microplate. Studies were done to evaluate both receptor agonists and antagonists. The pharmacology of agonists and antagonists for target GPCRs originally developed in a 96-well format was recapitulated in a 3456-well microplate format without compromising data quality or EC50/IC50 precision. These assays were employed in high-throughput screening campaigns, allowing the testing of more than 150,000 compounds in 8 h. The instrumentation used and practical aspects of the assay development are discussed.
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MESH Headings
- Animals
- Biological Assay/instrumentation
- Biological Assay/methods
- Combinatorial Chemistry Techniques
- Cricetinae
- Dose-Response Relationship, Drug
- Drug Evaluation, Preclinical/instrumentation
- Drug Evaluation, Preclinical/methods
- Genes, Reporter
- Humans
- Inhibitory Concentration 50
- Nanotechnology/methods
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, Neurotensin/drug effects
- Receptors, Neurotensin/genetics
- Receptors, Oxytocin/agonists
- Receptors, Oxytocin/antagonists & inhibitors
- Receptors, Oxytocin/genetics
- Reproducibility of Results
- Spectrometry, Fluorescence
- beta-Lactamases/genetics
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Affiliation(s)
- Oleg Kornienko
- Merck Research Laboratories, Department of Automated Biotechnology, North Wales, PA 19454, USA.
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44
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Bolivar JH, Muñoz-García JC, Castro-Dopico T, Dijkman PM, Stansfeld PJ, Watts A. Interaction of lipids with the neurotensin receptor 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1278-87. [DOI: 10.1016/j.bbamem.2016.02.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 02/02/2016] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
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45
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Label-free cell phenotypic profiling and pathway deconvolution of neurotensin receptor-1. Pharmacol Res 2016; 108:39-45. [DOI: 10.1016/j.phrs.2016.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/19/2016] [Accepted: 04/19/2016] [Indexed: 11/18/2022]
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46
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Law IKM, Jensen D, Bunnett NW, Pothoulakis C. Neurotensin-induced miR-133α expression regulates neurotensin receptor 1 recycling through its downstream target aftiphilin. Sci Rep 2016; 6:22195. [PMID: 26902265 PMCID: PMC4763298 DOI: 10.1038/srep22195] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/09/2016] [Indexed: 01/05/2023] Open
Abstract
Neurotensin (NT) triggers signaling in human colonic epithelial cells by activating the G protein-coupled receptor, the neurotensin receptor 1 (NTR1). Activated NTR1 traffics from the plasma membrane to early endosomes, and then recycles. Although sustained NT/NTR1 signaling requires efficient NTR1 recycling, little is known about the regulation of NTR1 recycling. We recently showed that NT/NTR1 signaling increases expression of miR-133α. Herein, we studied the mechanism of NT-regulated miR-133α expression and examined the role of miR-133α in intracellular NTR1 trafficking in human NCM460 colonocytes. We found that NT-induced miR-133α upregulation involves the negative transcription regulator, zinc finger E-box binding homeobox 1. Silencing of miR-133α or overexpression of aftiphilin (AFTPH), a binding target of miR-133α, attenuated NTR1 trafficking to plasma membrane in human colonocytes, without affecting NTR1 internalization. We localized AFTPH to early endosomes and the trans-Golgi network (TGN) in unstimulated human colonic epithelial cells. AFTPH overexpression reduced NTR1 localization in early endosomes and increased expression of proteins related to endosomes and the TGN trafficking pathway. AFTPH overexpression and de-acidification of intracellular vesicles increased NTR1 expression. Our results suggest a novel mechanism of GPCR trafficking in human colonic epithelial cells by which a microRNA, miR-133α regulates NTR1 trafficking through its downstream target AFTPH.
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Affiliation(s)
- Ivy Ka Man Law
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, California, USA
| | - Dane Jensen
- Monash Institute of Pharmaceutical Sciences, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology Parkville, Monash University, Australia
- Department of Anesthesia and Peri-operative Medicine, Monash University, Australia
| | - Nigel W. Bunnett
- Monash Institute of Pharmaceutical Sciences, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology Parkville, Monash University, Australia
- Department of Anesthesia and Peri-operative Medicine, Monash University, Australia
- Department of Pharmacology and Therapeutics, University of Melbourne, Australia
| | - Charalabos Pothoulakis
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, California, USA
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47
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Rouibi K, Bose P, Rompré PP, Warren RA. Ventral Midbrain NTS1 Receptors Mediate Conditioned Reward Induced by the Neurotensin Analog, D-Tyr[11]neurotensin. Front Neurosci 2015; 9:470. [PMID: 26733785 PMCID: PMC4686738 DOI: 10.3389/fnins.2015.00470] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 11/24/2015] [Indexed: 11/13/2022] Open
Abstract
The present study was aimed at characterizing the mechanisms by which neurotensin (NT) is acting within the ventral midbrain to induce a psychostimulant-like effect. In a first experiment, we determine which subtype(s) of NT receptors is/are involved in the reward-inducing effect of ventral midbrain microinjection of NT using the conditioned place-preference (CPP) paradigm. In a second study, we used in vitro patch clamp recording technique to characterize the NT receptor subtype(s) involved in the modulation of glutamatergic neurotransmission (excitatory post-synaptic current, EPSC) in ventral tegmental neurons that expressed (Ih+), or do not express (Ih-), a hyperpolarization-activated cationic current. Behavioral studies were performed with adult male Long-Evans rats while electrophysiological recordings were obtained from brain slices of rat pups aged between 14 and 21 days. Results show that bilateral ventral midbrain microinjections of 1.5 and 3 nmol of D-Tyr[11]NT induced a CPP that was respectively attenuated or blocked by co-injection with 1.2 nmol of the NTS1/NTS2 antagonist, SR142948, and the preferred NTS1 antagonist, SR48692. In electrophysiological experiments, D-Tyr[11]NT (0.01-0.5 μM) attenuated glutamatergic EPSC in Ih+ but enhanced it in Ih- neurons. The attenuation effect (Ih+ neurons) was blocked by SR142948 (0.1 μM) while the enhancement effect (Ih- neurons) was blocked by both antagonists (0.1 μM). These findings suggest that (i) NT is acting on ventral midbrain NTS1 receptors to induce a rewarding effect and (ii) that this psychostimulant-like effect could be due to a direct action of NT on dopamine neurons and/or an enhancement of glutamatergic inputs to non-dopamine (Ih-) neurons.
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Affiliation(s)
- Khalil Rouibi
- Department of Neurosciences, Université de MontréalMontréal, QC, Canada; FRQ-S Research Group in Behavioral Neurobiology, Department of Psychology, Concordia UniversityMontréal, QC, Canada
| | - Poulomee Bose
- Department of Psychiatry, Faculty of Medicine, Université de Montréal Montréal, QC, Canada
| | - Pierre-Paul Rompré
- Department of Neurosciences, Université de MontréalMontréal, QC, Canada; FRQ-S Research Group in Behavioral Neurobiology, Department of Psychology, Concordia UniversityMontréal, QC, Canada
| | - Richard A Warren
- Department of Psychiatry, Faculty of Medicine, Université de Montréal Montréal, QC, Canada
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48
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Padua D, Vu JP, Germano PM, Pisegna JR. The Role of Neuropeptides in Mouse Models of Colitis. J Mol Neurosci 2015; 59:203-10. [PMID: 26646243 DOI: 10.1007/s12031-015-0688-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 11/18/2015] [Indexed: 12/24/2022]
Abstract
Inflammatory bowel disease (IBD) constitutes an important clinically significant condition that results in morbidity and mortality. IBD can be generally classified into either ulcerative colitis (UC) or Crohn's disease (CD) that differs in the clinical and histopathology. The role of neuropeptides in the pathogenesis of these conditions is becoming increasingly recognized for their importance in modulating the inflammatory state. Animal models provide the greatest insight to better understand the pathophysiology of both disorders which will hopefully allow for improved treatment strategies. This review will provide a better understanding of the role of murine models for studying colitis.
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Affiliation(s)
- David Padua
- Division of Digestive Diseases, David Geffen School of Medicine, UCLA, Los Angeles, CA, 90095, USA
| | - John P Vu
- Division of Digestive Diseases, David Geffen School of Medicine, UCLA, Los Angeles, CA, 90095, USA.,Divisions of Pulmonary and Critical Care, Department of Veterans Affairs, VA Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA
| | - Patrizia M Germano
- Divisions of Pulmonary and Critical Care, Department of Veterans Affairs, VA Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA
| | - Joseph R Pisegna
- Division of Gastroenterology, Hepatology and Parenteral Nutrition, Department of Medicine, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA. .,David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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49
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Mascarin A, Valverde IE, Mindt TL. Structure-Activity Relationship Studies of Amino Acid Substitutions in Radiolabeled Neurotensin Conjugates. ChemMedChem 2015; 11:102-7. [PMID: 26593062 DOI: 10.1002/cmdc.201500468] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Indexed: 11/06/2022]
Abstract
Radiolabeled derivatives of the peptide neurotensin (NT) and its binding sequence NT(8-13) have been studied as potential imaging probes and therapeutics for NT-1-receptor-positive cancer. However, a direct comparison of reported NT analogues, even if radiolabeled with the same radionuclide, is difficult because different techniques and models have been used for preclinical evaluations. In an effort to identify a suitable derivative of NT(8-13) for radiotracer development, we herein report a side-by-side in vitro comparison of radiometallated NT derivatives bearing some of the most commonly reported amino acid substitutions in their sequence. Performed investigations include cell internalization experiments, determinations of receptor affinity, measurements of the distribution coefficient, and blood serum stability studies. Of the [(177)Lu]-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-labeled examples studied, analogues of NT(8-13) containing a short hydrophilic tetraethylene glycol (PEG4 ) spacer between the peptide and the radiometal complex, and a minimum number of substitutions of amino acid residues, exhibited the most promising properties in vitro.
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Affiliation(s)
- Alba Mascarin
- Division of Radiopharmaceutical Chemistry, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Ibai E Valverde
- Division of Radiopharmaceutical Chemistry, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland
| | - Thomas L Mindt
- Division of Radiopharmaceutical Chemistry, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland. .,Institute of Pharmaceutical Sciences, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
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50
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Bose P, Rompré PP, Warren RA. Neurotensin enhances glutamatergic EPSCs in VTA neurons by acting on different neurotensin receptors. Peptides 2015; 73:43-50. [PMID: 26296323 DOI: 10.1016/j.peptides.2015.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 08/11/2015] [Accepted: 08/13/2015] [Indexed: 11/26/2022]
Abstract
Neurotensin (NT) is an endogenous neuropeptide that modulates dopamine and glutamate neurotransmission in several limbic regions innervated by neurons located in the ventral tegmental area (VTA). While several studies showed that NT exerted a direct modulation on VTA dopamine neurons less is known about its role in the modulation of glutamatergic neurotransmission in this region. The present study was aimed at characterising the effects of NT on glutamate-mediated responses in different populations of VTA neurons. Using whole cell patch clamp recording technique in horizontal rat brain slices, we measured the amplitude of glutamatergic excitatory post-synaptic currents (EPSCs) evoked by electrical stimulation of VTA afferents before and after application of different concentrations of NT1-13 or its C-terminal fragment, NT8-13. Neurons were classified as either Ih(+) or Ih(-) based on the presence or absence of a hyperpolarisation activated cationic current (Ih). We found that NT1-13 and NT8-13 produced comparable concentration dependent increase in the amplitude of EPSCs in both Ih(+) and Ih(-) neurons. In Ih(+) neurons, the enhancement effect of NT8-13 was blocked by both antagonists, while in Ih(-) neurons it was blocked by the NTS1/NTS2 antagonist, SR142948A, but not the preferred NTS1 antagonist, SR48692. In as much as Ih(-) neurons are non-dopaminergic neurons and Ih(+) neurons represent both dopamine and non-dopamine neurons, we can conclude that NT enhances glutamatergic mediated responses in dopamine, and in a subset of non-dopamine, neurons by acting respectively on NTS1 and an NT receptor other than NTS1.
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Affiliation(s)
- Poulomee Bose
- Department of Psychiatry, University of Montreal, Quebec, Canada
| | | | - Richard A Warren
- Department of Psychiatry, University of Montreal, Quebec, Canada.
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