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Viennois E, Pujada A, Zen J, Merlin D. Function, Regulation, and Pathophysiological Relevance of the POT Superfamily, Specifically PepT1 in Inflammatory Bowel Disease. Compr Physiol 2018; 8:731-760. [PMID: 29687900 DOI: 10.1002/cphy.c170032] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mammalian members of the proton-coupled oligopeptide transporter family are integral membrane proteins that mediate the cellular uptake of di/tripeptides and peptide-like drugs and couple substrate translocation to the movement of H+ , with the transmembrane electrochemical proton gradient providing the driving force. Peptide transporters are responsible for the (re)absorption of dietary and/or bacterial di- and tripeptides in the intestine and kidney and maintaining homeostasis of neuropeptides in the brain. These proteins additionally contribute to absorption of a number of pharmacologically important compounds. In this overview article, we have provided updated information on the structure, function, expression, localization, and activities of PepT1 (SLC15A1), PepT2 (SLC15A2), PhT1 (SLC15A4), and PhT2 (SLC15A3). Peptide transporters, in particular, PepT1 are discussed as drug-delivery systems in addition to their implications in health and disease. Particular emphasis has been placed on the involvement of PepT1 in the physiopathology of the gastrointestinal tract, specifically, its role in inflammatory bowel diseases. © 2018 American Physiological Society. Compr Physiol 8:731-760, 2018.
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Affiliation(s)
- Emilie Viennois
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA
| | - Adani Pujada
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA
| | - Jane Zen
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA
| | - Didier Merlin
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA.,Veterans Affairs Medical Center, Decatur, Georgia, USA
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Viennois E, Ingersoll SA, Ayyadurai S, Zhao Y, Wang L, Zhang M, Han MK, Garg P, Xiao B, Merlin D. Critical role of PepT1 in promoting colitis-associated cancer and therapeutic benefits of the anti-inflammatory PepT1-mediated tripeptide KPV in a murine model. Cell Mol Gastroenterol Hepatol 2016; 2:340-357. [PMID: 27458604 PMCID: PMC4957955 DOI: 10.1016/j.jcmgh.2016.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS The human intestinal peptide transporter 1, hPepT1, is expressed in the small intestine at low levels in the healthy colon and upregulated during inflammatory bowel disease. hPepT1 plays a role in mouse colitis and human studies have demonstrated that chronic intestinal inflammation leads to colorectal cancer (colitis-associated cancer; CAC). Hence, we assessed here the role of PepT1 in CAC. METHODS Mice with hPepT1 overexpression in intestinal epithelial cells (TG) or PepT1 (PepT1-KO) deletion were used and CAC was induced by AOM/DSS. RESULTS TG mice had larger tumor sizes, increased tumor burdens, and increased intestinal inflammation compared to WT mice. Conversely, tumor number and size and intestinal inflammation were significantly decreased in PepT1-KO mice. Proliferating crypt cells were increased in TG mice and decreased in PepT1-KO mice. Analysis of human colonic biopsies revealed an increased expression of PepT1 in patients with colorectal cancer, suggesting that PepT1 might be targeted for the treatment of CAC. The use of an anti-inflammatory tripeptide KPV (Lys-Pro-Val) transported by PepT1 was able to prevent carcinogenesis in WT mice. When administered to PepT1-KO mice, KPV did not trigger any of the inhibitory effect on tumorigenesis observed in WT mice. CONCLUSIONS The observations that pepT1 was highly expressed in human colorectal tumor and that its overexpression and deletion in mice increased and decreased colitis associated tumorigenesis, respectively, suggest that PepT1 is a potential therapeutic target for the treatment of colitis associated tumorigenesis.
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Affiliation(s)
- Emilie Viennois
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
- Veterans Affairs Medical Center, Decatur, Georgia
- Correspondence Address correspondence to: Emilie Viennois, PhD, Institute for Biomedical Sciences, Georgia State University, 100 Piedmont Avenue, PSC 757, Atlanta, Georgia 30303. fax: (404) 413-3580.Institute for Biomedical SciencesGeorgia State University100 Piedmont AvenuePSC 757AtlantaGeorgia 30303
| | - Sarah A. Ingersoll
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Saravanan Ayyadurai
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Yuan Zhao
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
- Department of Gastroenterology, Zhongshan Hospital, Fudan University, China
| | - Lixin Wang
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
- Veterans Affairs Medical Center, Decatur, Georgia
| | - Mingzhen Zhang
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Moon K. Han
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Pallavi Garg
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Bo Xiao
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Didier Merlin
- Institute for Biomedical Sciences, Center Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
- Veterans Affairs Medical Center, Decatur, Georgia
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Li X, Burger S, O'Connor AJ, Ong L, Karas JA, Gras SL. An enzyme-responsive controlled release system based on a dual-functional peptide. Chem Commun (Camb) 2016; 52:5112-5. [DOI: 10.1039/c5cc10480g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A new controlled release system was developed by loading a dual-functional peptide on a mesoporous silica material.
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Affiliation(s)
- X. Li
- Particulate Fluids Processing Centre
- Department of Chemical and Biomolecular Engineering
- The University of Melbourne
- Parkville
- Australia
| | - S. Burger
- Particulate Fluids Processing Centre
- Department of Chemical and Biomolecular Engineering
- The University of Melbourne
- Parkville
- Australia
| | - A. J. O'Connor
- Particulate Fluids Processing Centre
- Department of Chemical and Biomolecular Engineering
- The University of Melbourne
- Parkville
- Australia
| | - L. Ong
- Particulate Fluids Processing Centre
- Department of Chemical and Biomolecular Engineering
- The University of Melbourne
- Parkville
- Australia
| | - J. A. Karas
- The Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
- Parkville
- Australia
- The School of Chemistry
| | - S. L. Gras
- Particulate Fluids Processing Centre
- Department of Chemical and Biomolecular Engineering
- The University of Melbourne
- Parkville
- Australia
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Pintér E, Pozsgai G, Hajna Z, Helyes Z, Szolcsányi J. Neuropeptide receptors as potential drug targets in the treatment of inflammatory conditions. Br J Clin Pharmacol 2015; 77:5-20. [PMID: 23432438 DOI: 10.1111/bcp.12097] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 02/08/2013] [Indexed: 12/19/2022] Open
Abstract
Cross-talk between the nervous, endocrine and immune systems exists via regulator molecules, such as neuropeptides, hormones and cytokines. A number of neuropeptides have been implicated in the genesis of inflammation, such as tachykinins and calcitonin gene-related peptide. Development of their receptor antagonists could be a promising approach to anti-inflammatory pharmacotherapy. Anti-inflammatory neuropeptides, such as vasoactive intestinal peptide, pituitary adenylate cyclase-activating polypeptide, α-melanocyte-stimulating hormone, urocortin, adrenomedullin, somatostatin, cortistatin, ghrelin, galanin and opioid peptides, are also released and act on their own receptors on the neurons as well as on different inflammatory and immune cells. The aim of the present review is to summarize the most prominent data of preclinical animal studies concerning the main pharmacological effects of ligands acting on the neuropeptide receptors. Promising therapeutic impacts of these compounds as potential candidates for the development of novel types of anti-inflammatory drugs are also discussed.
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Affiliation(s)
- Erika Pintér
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Szigeti u. 12., H-7624, Pécs, Hungary; János Szentágothai Research Centre, University of Pécs, Ifjúság u. 20., H-7624, Pécs, Hungary
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Curbing Inflammation through Endogenous Pathways: Focus on Melanocortin Peptides. Int J Inflam 2013; 2013:985815. [PMID: 23738228 PMCID: PMC3664505 DOI: 10.1155/2013/985815] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/11/2013] [Accepted: 04/14/2013] [Indexed: 12/26/2022] Open
Abstract
The resolution of inflammation is now known to be an active process, armed with a multitude of mediators both lipid and protein in nature. Melanocortins are peptides endowed with considerable promise with their proresolution and anti-inflammatory effects in preclinical models of inflammatory disease, with tissue protective effects. These peptides and their targets are appealing because they can be seen as a natural way of inducing these effects as they harness endogenous pathways of control. Whereas most of the information generated about these mediators derives from several acute models of inflammation (such as zymosan induced peritonitis), there is some indication that these mediators may inhibit chronic inflammation by modulating cytokines, chemokines, and leukocyte apoptosis. In addition, proresolving mediators and their mimics have often been tested alongside therapeutic protocols, hence have been tested in settings more relevant to real life clinical scenarios. We provide here an overview on some of these mediators with a focus on melanocortin peptides and receptors, proposing that they may unveil new opportunities for innovative treatments of inflammatory arthritis.
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Ingersoll SA, Ayyadurai S, Charania MA, Laroui H, Yan Y, Merlin D. The role and pathophysiological relevance of membrane transporter PepT1 in intestinal inflammation and inflammatory bowel disease. Am J Physiol Gastrointest Liver Physiol 2012; 302:G484-92. [PMID: 22194420 PMCID: PMC3311434 DOI: 10.1152/ajpgi.00477.2011] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 12/21/2011] [Indexed: 01/31/2023]
Abstract
Intestinal inflammation is characterized by epithelial disruption, leading to loss of barrier function and the recruitment of immune cells, including neutrophils. Although the mechanisms are not yet completely understood, interactions between environmental and immunological factors are thought to be critical in the initiation and progression of intestinal inflammation. In recent years, it has become apparent that the di/tripeptide transporter PepT1 may play an important role in the pathogenesis of such inflammation. In healthy individuals, PepT1 is primarily expressed in the small intestine and transports di/tripeptides for metabolic purposes. However, during chronic inflammation such as that associated with inflammatory bowel disease, PepT1 expression is upregulated in the colon, wherein the protein is normally expressed either minimally or not at all. Several recent studies have shown that PepT1 binds to and transports various bacterial di/tripeptides into colon cells, leading to activation of downstream proinflammatory responses via peptide interactions with innate immune receptors. In the present review, we examine the relationship between colonic PepT1-mediated peptide transport in the colon and activation of innate immune responses during disease. It is important to understand the mechanisms of PepT1 action during chronic intestinal inflammation to develop future therapies addressing inappropriate immune activation in the colon.
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Affiliation(s)
- Sarah A Ingersoll
- Center for Diagnostics & Therapeutics, Department of Biology, Georgia State University, Atlanta, 30302-5090, USA.
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Patel HB, Leoni G, Melendez TM, Sampaio ALF, Perretti M. Melanocortin Control of Cell Trafficking in Vascular Inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 681:88-106. [DOI: 10.1007/978-1-4419-6354-3_7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Dalmasso G, Charrier-Hisamuddin L, Nguyen HTT, Yan Y, Sitaraman S, Merlin D. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology 2008; 134:166-78. [PMID: 18061177 PMCID: PMC2431115 DOI: 10.1053/j.gastro.2007.10.026] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 10/04/2007] [Indexed: 01/11/2023]
Abstract
BACKGROUND & AIMS KPV is a tripeptide (Lys-Pro-Val), which possesses anti-inflammatory properties; however, its mechanisms of action still remain unknown. PepT1 is a di/tripeptide transporter normally expressed in the small intestine and induced in colon during inflammatory bowel disease (IBD). The aim of this study was to 1) investigate whether the KPV anti-inflammatory effect is PepT1-mediated in intestinal epithelian and immune cells, and 2) examine the anti-inflammatory effects in two models of mice colitis. METHODS Human intestinal epithelial cells Caco2-BBE, HT29-Cl.19A, and human T cells (Jurkat) were stimulated with pro-inflammatory cytokines in the present or absence of KPV. KPV anti-inflammatory effect was assessed using a NF-kappaB luciferase gene reporter, Western blot, real-time RT-PCR and ELISA. Uptake experiments were performed using cold KPV as a competitor for PepT1 radiolabelled substrate or using [(3)H]KPV to determine kinetic characteristics of KPV uptake. Anti-inflammatory effect of KPV was also investigated in DSS- and TNBS-induced colitis in mice. KPV was added to drinking water and inflammation was assessed at the histologic level and by proinflammatory cytokine mRNA expression. RESULTS Nanomolar concentrations of KPV inhibit the activation of NF-kappaB and MAP kinase inflammatory signaling pathways, and reduce pro-inflammatory cytokine secretion. We found that KPV acts via PepT1 expressed in immune and intestinal epithelial cells. Furthermore, oral administration of KPV reduces the incidence of DSS- and TNBS-induced colitis indicated by a decrease in pro-inflammatory cytokine expression. CONCLUSIONS This study indicates tht KPV is transported into cells by PepT1 and might be a new therapeutic agent for IBD.
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Schiöth HB, Muceniece R, Mutule I, Wikberg JES. New melanocortin 1 receptor binding motif based on the C-terminal sequence of alpha-melanocyte-stimulating hormone. Basic Clin Pharmacol Toxicol 2007; 99:287-93. [PMID: 17040213 DOI: 10.1111/j.1742-7843.2006.pto_459.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The C-terminal tripeptide of the alpha-melanocyte stimulating hormone (alpha-MSH11-13) possesses strong antiinflammatory activity without known cellular target. In order to better understand the structural requirements for function of such motif, we designed, synthesized and tested out Trp- and Tyr-containing analogues of the alpha-MSH11-13. Seven alpha-MSH11-13 analogues were synthesized and characterized for their binding to the melanocortin receptors recombinantly expressed in insect (Sf9) cells, infected with baculovirus carrying corresponding MC receptor DNA. We also tested these analogues on B16-F1 mouse melanoma cells endogenously expressing the MC1 receptor for binding and for ability to increase cAMP levels as well as on COS-7 cells transfected with the human MC receptors. The data indicate that HS401 (Ac-Tyr-Lys-Pro-Val-NH2) and HS402 (Ac-Lys-Pro-Val-Tyr-NH2) selectively bound to the MC1 receptor and stimulated cAMP generation in a concentration dependent way while the other Tyr- and Trp-containing alpha-MSH11-13 analogues neither bound to MC receptors nor stimulated cAMP. We have thus identified new MC receptor binding motif derived from the C-terminal sequence of alpha-MSH. The tetrapeptides have novel properties as the both act via MC-ergic pathways and also carry the anti-inflammatory alpha-MSH11-13 message sequence.
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Affiliation(s)
- Helgi B Schiöth
- Department of Neuroscience, Uppsala University, BMC, Uppsala, Sweden.
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