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Lee KH, Ali NF, Lee SH, Zhang Z, Burdick M, Beaulac ZJ, Petruncio G, Li L, Xiang J, Chung EM, Foreman KW, Noble SM, Shim YM, Paige M. Substrate-dependent modulation of the leukotriene A 4 hydrolase aminopeptidase activity and effect in a murine model of acute lung inflammation. Sci Rep 2022; 12:9443. [PMID: 35676292 PMCID: PMC9177663 DOI: 10.1038/s41598-022-13238-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 04/12/2022] [Indexed: 11/09/2022] Open
Abstract
The aminopeptidase activity (AP) of the leukotriene A4 hydrolase (LTA4H) enzyme has emerged as a therapeutic target to modulate host immunity. Initial reports focused on the benefits of augmenting the LTA4H AP activity and clearing its putative pro-inflammatory substrate Pro-Gly-Pro (PGP). However, recent reports have introduced substantial complexity disconnecting the LTA4H modulator 4-methoxydiphenylmethane (4MDM) from PGP as follows: (1) 4MDM inhibits PGP hydrolysis and subsequently inhibition of LTA4H AP activity, and (2) 4MDM activates the same enzyme target in the presence of alternative substrates. Differential modulation of LTA4H by 4MDM was probed in a murine model of acute lung inflammation, which showed that 4MDM modulates the host neutrophilic response independent of clearing PGP. X-ray crystallography showed that 4MDM and PGP bind at the zinc binding pocket and no allosteric binding was observed. We then determined that 4MDM modulation is not dependent on the allosteric binding of the ligand, but on the N-terminal side chain of the peptide. In conclusion, our study revealed that a peptidase therapeutic target can interact with its substrate and ligand in complex biochemical mechanisms. This raises an important consideration when ligands are designed to explain some of the unpredictable outcomes observed in therapeutic discovery targeting LTA4H.
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Affiliation(s)
- Kyung Hyeon Lee
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Nadia Fazal Ali
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Soo Hyeon Lee
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Zhimin Zhang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, PO Box 800546, Charlottesville, VA, 22908, USA
| | - Marie Burdick
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, PO Box 800546, Charlottesville, VA, 22908, USA
| | - Zachary J Beaulac
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Greg Petruncio
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Linxia Li
- Department of Obstetrics and Gynecology, Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine, 358 Datong Road, Shanghai, 200137, China
| | - Jiangdong Xiang
- Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China
| | - Ezra M Chung
- STCube Pharmaceutical, Inc., 401 Professional Dr, Gaithersburg, MD, 20879, USA
| | - Kenneth W Foreman
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Schroeder M Noble
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA.
| | - Yun M Shim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, PO Box 800546, Charlottesville, VA, 22908, USA.
| | - Mikell Paige
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA.
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Qin W, Qu H, Pan L, Sun W, Chen Y, Wu C. Possible mechanism and potential application of anti-opioid effect of diazepam-binding inhibitor. Life Sci 2020; 265:118836. [PMID: 33259865 DOI: 10.1016/j.lfs.2020.118836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 10/22/2022]
Abstract
AIMS Our previous study has demonstrated that porcine diazepam-binding inhibitor (pDBI) and its active fragments, pDBI-16 and pDBI-19, have inhibition effect on morphine analgesia in mice. The present study aimed to investigate the underlying mechanism and potential application of this anti-opioid effect. MATERIALS AND METHODS Effect of DBI on morphine analgesia was examined by the tail electric stimulation vocalization test. Complementary peptides and antiserum were used to further confirm the effect of DBI in morphine tolerance and dependence. Pharmacological and microinjection methods were used to investigate the underlying mechanism. KEY FINDINGS Firstly, pDBI administered either intracerebroventricularly or intravenously dose-dependently inhibited morphine analgesia, while blocking DBI-16 or DBI-19 by the complementary peptides for DBI-16 (CP-DBI-16) or DBI-19 (CP-DBI-19) potentiated it in mice. Secondly, explicit immunoexpression of DBI in the lateral habenular (LHb) was observed in naive rats, and intra-LHb injection of pDBI dose-dependently abolished analgesic effect produced by intra-periaqueductal gray (PAG) injection of morphine in rats. Thirdly, pretreatment with N-Methyl-d-Aspartate receptor (NMDAR) antagonist MK-801 or nitric oxide (NO) synthase inhibitor L-NAME abolished the inhibition effect of pDBI, pDBI-16 or pDBI-19 on morphine analgesia in mice. Finally, antiserum against DBI dose-dependently reversed analgesic tolerance induced by increasing doses of morphine twice daily for 13 days in mice, while CP-DBI-16 or CP-DBI-19 significantly inhibited naloxone-precipitated morphine withdrawal jumping in mice. SIGNIFICANCE Taken together, our results demonstrated that NMDAR/NO signaling and LHb-PAG pathway are crucially involved in the anti-opioid effect of DBI, which could provide a potential biological target for opioid tolerance and dependence.
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Affiliation(s)
- Wangjun Qin
- Department of Pharmacy, China-Japan Friendship Hospital, Beijing 100029, China.
| | - Hong Qu
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Lin Pan
- Institute of Clinical Medical Science, China-Japan Friendship Hospital, Beijing 100029, China
| | - Weiliang Sun
- Institute of Clinical Medical Science, China-Japan Friendship Hospital, Beijing 100029, China
| | - Yuzhen Chen
- Institute of Clinical Medical Science, China-Japan Friendship Hospital, Beijing 100029, China; State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China.
| | - Caihong Wu
- State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China
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Sharma NS, Lal CV, Li JD, Lou XY, Viera L, Abdallah T, King RW, Sethi J, Kanagarajah P, Restrepo-Jaramillo R, Sales-Conniff A, Wei S, Jackson PL, Blalock JE, Gaggar A, Xu X. The neutrophil chemoattractant peptide proline-glycine-proline is associated with acute respiratory distress syndrome. Am J Physiol Lung Cell Mol Physiol 2018; 315:L653-L661. [PMID: 30091378 PMCID: PMC6295514 DOI: 10.1152/ajplung.00308.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 07/24/2018] [Accepted: 08/07/2018] [Indexed: 12/26/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by unrelenting polymorphonuclear neutrophil (PMN) inflammation and vascular permeability. The matrikine proline-glycine-proline (PGP) and acetylated PGP (Ac-PGP) have been shown to induce PMN inflammation and endothelial permeability in vitro and in vivo. In this study, we investigated the presence and role of airway PGP peptides in acute lung injury (ALI)/ARDS. Pseudomonas aeruginosa-derived lipopolysaccharide (LPS) was instilled intratracheally in mice to induce ALI, and increased Ac-PGP with neutrophil inflammation was noted. The PGP inhibitory peptide, arginine-threonine-arginine (RTR), was administered (it) 30 min before or 6 h after LPS injection. Lung injury was evaluated by detecting neutrophil infiltration and permeability changes in the lung. Pre- and posttreatment with RTR significantly inhibited LPS-induced ALI by attenuating lung neutrophil infiltration, pulmonary permeability, and parenchymal inflammation. To evaluate the role of PGP levels in ARDS, minibronchoalveolar lavage was collected from nine ARDS, four cardiogenic edema, and five nonlung disease ventilated patients. PGP levels were measured and correlated with Acute Physiology and Chronic Health Evaluation (APACHE) score, P a O 2 to F I O 2 (P/F), and ventilator days. PGP levels in subjects with ARDS were significantly higher than cardiogenic edema and nonlung disease ventilated patients. Preliminary examination in both ARDS and non-ARDS populations demonstrated PGP levels significantly correlated with P/F ratio, APACHE score, and duration on ventilator. These results demonstrate an increased burden of PGP peptides in ARDS and suggest the need for future studies in ARDS cohorts to examine correlation with key clinical parameters.
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Affiliation(s)
- Nirmal S Sharma
- Center for Advanced Lung Disease and Lung Transplantation, University of South Florida/Tampa General Hospital , Tampa, Florida
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Division of Pulmonary and Critical Care, University of South Florida , Tampa, Florida
| | - Charitharth Vivek Lal
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Department of Pediatrics, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jin-Dong Li
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Medical Service at Birmingham Veterans Affairs Medical Center , Birmingham, Alabama
| | - Xiang-Yang Lou
- Biostatistics Program, Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences , Little Rock, Arkansas
| | - Liliana Viera
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | - Tarek Abdallah
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | - Robert W King
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jaskaran Sethi
- Division of Pulmonary and Critical Care, University of South Florida , Tampa, Florida
| | - Prashanth Kanagarajah
- Division of Pulmonary and Critical Care, University of South Florida , Tampa, Florida
| | | | - Amanda Sales-Conniff
- Division of Pulmonary and Critical Care, University of South Florida , Tampa, Florida
| | - Shi Wei
- Department of Pathology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Patricia L Jackson
- Lung Health Center, University of Alabama at Birmingham , Birmingham, Alabama
| | - J Edwin Blalock
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham , Birmingham, Alabama
- Lung Health Center, University of Alabama at Birmingham , Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Amit Gaggar
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham , Birmingham, Alabama
- Lung Health Center, University of Alabama at Birmingham , Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
- Medical Service at Birmingham Veterans Affairs Medical Center , Birmingham, Alabama
| | - Xin Xu
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Program in Protease and Matrix Biology, Department of Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham , Birmingham, Alabama
- Lung Health Center, University of Alabama at Birmingham , Birmingham, Alabama
- Medical Service at Birmingham Veterans Affairs Medical Center , Birmingham, Alabama
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Akthar S, Patel DF, Beale RC, Peiró T, Xu X, Gaggar A, Jackson PL, Blalock JE, Lloyd CM, Snelgrove RJ. Matrikines are key regulators in modulating the amplitude of lung inflammation in acute pulmonary infection. Nat Commun 2015; 6:8423. [PMID: 26400771 PMCID: PMC4595997 DOI: 10.1038/ncomms9423] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 08/20/2015] [Indexed: 01/17/2023] Open
Abstract
Bioactive matrix fragments (matrikines) have been identified in a myriad of disorders, but their impact on the evolution of airway inflammation has not been demonstrated. We recently described a pathway where the matrikine and neutrophil chemoattractant proline–glycine–proline (PGP) could be degraded by the enzyme leukotriene A4 hydrolase (LTA4H). LTA4H classically functions in the generation of pro-inflammatory leukotriene B4, thus LTA4H exhibits opposing pro- and anti-inflammatory activities. The physiological significance of this secondary anti-inflammatory activity remains unknown. Here we show, using readily resolving pulmonary inflammation models, that loss of this secondary activity leads to more pronounced and sustained inflammation and illness owing to PGP accumulation. PGP elicits an exacerbated neutrophilic inflammation and protease imbalance that further degrades the extracellular matrix, generating fragments that perpetuate inflammation. This highlights a critical role for the secondary anti-inflammatory activity of LTA4H and thus has consequences for the generation of global LTA4H inhibitors currently being developed. Proteases degrade extracellular matrix during inflammation, releasing peptides that can recruit neutrophils. Here the authors show that degradation of such bioactive peptide by the enzyme leukotriene A4 hydrolase is critical to limit pulmonary inflammation during bacterial infection in mice.
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Affiliation(s)
- Samia Akthar
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Dhiren F Patel
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Rebecca C Beale
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Teresa Peiró
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Xin Xu
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham and Lung Health Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 3529, USA
| | - Amit Gaggar
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham and Lung Health Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 3529, USA.,Gregory Fleming James Cystic Fibrosis Center and Program in Protease and Matrix Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.,Birmingham V.A. Medical Center, Birmingham, Alabama 35294, USA
| | - Patricia L Jackson
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham and Lung Health Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 3529, USA
| | - J Edwin Blalock
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham and Lung Health Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 3529, USA.,Birmingham V.A. Medical Center, Birmingham, Alabama 35294, USA
| | - Clare M Lloyd
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Robert J Snelgrove
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
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Abstract
Matrikines originate from the fragmentation of extracellular matrix proteins and regulate cellular activities by interacting with specific receptors. Matrikines are implicated in inflammation, immune responses, organ development, wound repair, angiogenesis, atherosclerosis, tumor progression and metastasis due to their ability to alter cellular migration, chemotaxis, and mitogenesis. Matrix metalloproteinases (MMPs) degrade extracellular matrix components under normal circumstances and in disease processes. Of the 20 MMPs identified, MMP-1, MMP-2, MMP-8, MMP-9, and MMP-12 have been implicated in regulating the matrikines Val-Gly-Val-Ala-Pro-Gly (elastin peptide) and proline-glycine-proline (PGP). Elastin peptide fragments are generated by elastolytic enzymes and have implications in atherosclerosis, neovascularization, chronic obstructive pulmonary disease, skin disease, as well as tumor invasion and spread. PGP is produced through a multistep pathway that liberates the tripeptide fragment from extracellular collagen. PGP is best described for its role in neutrophil chemotaxis and is implicated in the pathogenesis of corneal ulcers and in chronic lung conditions. In chronic cigarette smoke related lung disease, the PGP pathway can become a self-propagating cycle of inflammation through cigarette-smoke mediated inhibition of leukotriene A4 hydrolase, the enzyme responsible for degrading PGP and halting acute inflammation. This review highlights the roles of MMPs in generating these important matrikines.
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Miller AD. Sense–antisense (complementary) peptide interactions and the proteomic code; potential opportunities in biology and pharmaceutical science. Expert Opin Biol Ther 2015; 15:245-67. [DOI: 10.1517/14712598.2015.983069] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
Neutrophils express a variety of collagen receptors at their surface, yet their functional significance remains unclear. Although integrins are essential for neutrophil adhesion and migration on 2-dimensional (2D) surfaces, neutrophils can compensate for the absence of integrins in 3-dimensional (3D) lattices. In contrast, we demonstrate that the inhibition of the tyrosine-kinase collagen receptor discoidin domain receptor 2 (DDR2) has no impact on human primary neutrophil migration on 2D surfaces but is an important regulator of neutrophil chemotaxis in 3D collagen matrices. In this context, we show that DDR2 activation specifically regulates the directional migration of neutrophils in chemoattractant gradients. We further demonstrate that DDR2 regulates directionality through its ability to increase secretion of metalloproteinases and local generation of collagen-derived chemotactic peptide gradients. Our findings highlight the importance of collagen-derived extracellular signaling during neutrophil chemotaxis in 3D matrices.
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Targeting of a common receptor shared by CXCL8 and N-Ac-PGP as a therapeutic strategy to alleviate chronic neutrophilic lung diseases. Eur J Pharmacol 2011; 667:1-5. [PMID: 21669195 DOI: 10.1016/j.ejphar.2011.05.073] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 05/09/2011] [Accepted: 05/27/2011] [Indexed: 12/21/2022]
Abstract
Persistent neutrophilia is implicated in the pathology of several chronic lung diseases and consequently targeting the signals that drive the recruitment of these cells offers a plausible therapeutic strategy. The tripeptide Pro-Gly-Pro (PGP) is a neutrophil chemoattractant derived from extracellular matrix collagen and implicated in diseases such as COPD and cystic fibrosis. It was anticipated that PGP exerts its chemoatactic activity by mimicking key sequences found within classical neutrophil chemokines, such as CXCL8, and binding their receptors, CXCR1/2. Recently, however, the role of CXCR1/2 as the receptors for PGP has been questioned. In this issue of European Journal of Pharmacology, three studies address this controversy and demonstrate CXCR1/2 to be a common receptor for CXCL8 and PGP. Accordingly, these studies demonstrate the therapeutic potential of targeting this shared receptor to simultaneously alleviate neutrophilic inflammation driven by multiple neutrophil chemoattractants.
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Gaggar A, Rowe SM, Matthew H, Blalock JE. Proline-Glycine-Proline (PGP) and High Mobility Group Box Protein-1 (HMGB1): Potential Mediators of Cystic Fibrosis Airway Inflammation. Open Respir Med J 2010. [PMID: 20448817 PMCID: PMC2864429 DOI: 10.2174/1874306401004010032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cystic fibrosis (CF) is chronic lung disease characterized by an unrelenting neutrophil-predominant airway inflammatory response. This inflammation leads to extracellular matrix (ECM) remodeling and eventually to the development of bronchiectasis. While many components of the immune response in CF have been well-characterized, recent data suggests that small molecules may play an important and underappreciated role in this inflammation. This review will examine two novel molecules: proline-glycine-proline (PGP) and high mobility group box protein-1 (HMGB1), and their potential impact in CF lung disease. This review will provide a brief overview of CF lung disease and background on both HMGB1 and PGP. It will then focus on these molecules in a murine model of CF-like airway disease and in human biological specimens from CF individuals. Finally, this manuscript will address possible mechanisms for therapeutic targeting of these bioactive mediators.
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Affiliation(s)
- Amit Gaggar
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, AL
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10
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Gaggar A, Rowe SM, Matthew H, Blalock JE. Proline-Glycine-Proline (PGP) and High Mobility Group Box Protein-1 (HMGB1): Potential Mediators of Cystic Fibrosis Airway Inflammation. Open Respir Med J 2010; 4:32-8. [PMID: 20448817 DOI: 10.2174/1874306401004020032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 11/09/2009] [Accepted: 11/10/2009] [Indexed: 02/03/2023] Open
Abstract
Cystic fibrosis (CF) is chronic lung disease characterized by an unrelenting neutrophil-predominant airway inflammatory response. This inflammation leads to extracellular matrix (ECM) remodeling and eventually to the development of bronchiectasis. While many components of the immune response in CF have been well-characterized, recent data suggests that small molecules may play an important and underappreciated role in this inflammation. This review will examine two novel molecules: proline-glycine-proline (PGP) and high mobility group box protein-1 (HMGB1), and their potential impact in CF lung disease. This review will provide a brief overview of CF lung disease and background on both HMGB1 and PGP. It will then focus on these molecules in a murine model of CF-like airway disease and in human biological specimens from CF individuals. Finally, this manuscript will address possible mechanisms for therapeutic targeting of these bioactive mediators.
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Affiliation(s)
- Amit Gaggar
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, AL
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11
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van Houwelingen AH, Weathington NM, Verweij V, Blalock JE, Nijkamp FP, Folkerts G. Induction of lung emphysema is prevented by L-arginine-threonine-arginine. FASEB J 2008; 22:3403-8. [PMID: 18556462 PMCID: PMC2518250 DOI: 10.1096/fj.07-096230] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 05/15/2008] [Indexed: 11/11/2022]
Abstract
In patients with chronic obstructive pulmonary disease (COPD), an inflammatory process is ongoing in the lungs, with concomitant damage of the alveolar structures and loss of airway function. In this inflammatory process, extracellular matrix degradation is observed. During this lung matrix degradation, small peptide fragments consisting of proline and glycine repeats generated from collagen fibers are liberated from the matrix by matrix metalloproteinases. Chemotactic activities of these collagen-derived peptides such as N-acetyl-proline-glycine-proline (PGP) via CXCR1 and CXCR2 have been reported. We show here that PGP induces neutrophil migration in vivo, which is dose dependent. Moreover, PGP is involved in the development of emphysema-like changes in the airways. The complementary peptide, L-arginine-threonine-arginine (RTR), has been shown to bind to PGP sequences and inhibit neutrophil infiltration. We show that RTR impedes both PGP- and interleukin-8-induced chemotaxis in vitro. In vivo, RTR prevents both migration and activation of neutrophils induced by PGP. Furthermore, RTR completely inhibits PGP-induced lung emphysema, assessed by changes in alveolar enlargement and right ventricular hypertrophy. In conclusion, these data indicate that collagen breakdown products, especially PGP, are important in the pathogenesis of COPD and that PGP antagonism via RTR ameliorates lung emphysema.
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Affiliation(s)
- Anneke H van Houwelingen
- Division of Pharmacology and Pathophysiology, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, P.O. Box 800 82, 3508 TB Utrecht, The Netherlands.
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12
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O'Reilly PJ, Gaggar A, Blalock JE. Interfering with extracellular matrix degradation to blunt inflammation. Curr Opin Pharmacol 2008; 8:242-8. [PMID: 18346936 DOI: 10.1016/j.coph.2008.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 01/31/2008] [Accepted: 02/05/2008] [Indexed: 12/22/2022]
Abstract
Chemoattractant properties of matrix proteins, like collagen and elastin, for neutrophils and monocytes in vitro have long been recognized. This activity often resides in fragments of these proteins. These peptides may play a role in diseases of the lung matrix, such as chronic obstructive pulmonary disease. Recent advances include the elucidation of the structure of chemotactic collagen fragments and the demonstration that their activity may reside in a structural relatedness to CXC chemokines. Collagen and elastin fragments have been demonstrated to have a role in in vivo lung pathophysiology and have been quantified in patients with chronic lung diseases where they may activate autoimmune pathways. Elucidation of these pathways may provide novel biomarkers and therapeutic targets for chronic lung diseases.
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Affiliation(s)
- Philip J O'Reilly
- Division of Pulmonary and Critical Care Medicine, University of Alabama at Birmingham, THT 442, 1530 3rd Avenue South, Birmingham, AL 35294-0006, United States.
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13
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Pfister RR, Sommers CI. L-arginine-threonine-arginine (RTR) tetramer peptide inhibits ulceration in the alkali-injured rabbit cornea. Cornea 2007; 25:1187-92. [PMID: 17172896 DOI: 10.1097/ico.0b013e31802ca33a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Proline-glycine-proline (PGP) peptides have been identified as inflammatory mediators initiating neutrophil invasion into alkali-injured cornea. The complementary peptide, arginine-threonine-arginine (RTR), has been shown to bind to the PGP sequence and impede neutrophil infiltration. A prior study showed that L-RTR tetramer and D-RTR tetramer, used alternately (14 times a day), resulted in significantly reduced incidences of corneal ulceration and severity. The purpose of this experiment is to determine the effectiveness of both tetramers, used separately, compared with control. METHODS Rabbit corneas were exposed to 1 N NaOH for 35 seconds. Sixteen animals were randomly assigned to each of 3 groups: 1) phosphate-buffered saline (PBS), 2) 1.5 mM L-RTR, or 3) 800 microM D-RTR. One drop of each was administered hourly (14 times a day) for 36 days. Additional studies were done to assess neutrophil infiltration into corneas with and without RTR treatment. RESULTS The severity of corneal ulceration in both RTR groups was statistically significantly different from the 21st day of the experiment to the end. As a result of ulcers healing in the L-RTR group, there was a statistically significant reduction in the number of ulcers beginning on day 22 versus control. Although there was healing in the D-RTR group, the incidence of ulcers was not significantly different from control or L-RTR. Morphometric analysis revealed decreased neutrophil (PMN) invasion with RTR treatment compared with PBS control. CONCLUSIONS Binding of the PGP molecules by RTR tetramer seems to deprive the cornea of this neutrophilic chemotactic stimulus, leading to a reduction in the severity and incidence of corneal ulceration.
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Affiliation(s)
- Roswell R Pfister
- Eye Research Foundation, Inc., Eye Research Laboratories, Birmingham, AL, USA.
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