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Carroll OR, Pillar AL, Brown AC, Feng M, Chen H, Donovan C. Advances in respiratory physiology in mouse models of experimental asthma. Front Physiol 2023; 14:1099719. [PMID: 37008013 PMCID: PMC10060990 DOI: 10.3389/fphys.2023.1099719] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/07/2023] [Indexed: 03/18/2023] Open
Abstract
Recent advances in mouse models of experimental asthma coupled with vast improvements in systems that assess respiratory physiology have considerably increased the accuracy and human relevance of the outputs from these studies. In fact, these models have become important pre-clinical testing platforms with proven value and their capacity to be rapidly adapted to interrogate emerging clinical concepts, including the recent discovery of different asthma phenotypes and endotypes, has accelerated the discovery of disease-causing mechanisms and increased our understanding of asthma pathogenesis and the associated effects on lung physiology. In this review, we discuss key distinctions in respiratory physiology between asthma and severe asthma, including the magnitude of airway hyperresponsiveness and recently discovered disease drivers that underpin this phenomenon such as structural changes, airway remodeling, airway smooth muscle hypertrophy, altered airway smooth muscle calcium signaling, and inflammation. We also explore state-of-the-art mouse lung function measurement techniques that accurately recapitulate the human scenario as well as recent advances in precision cut lung slices and cell culture systems. Furthermore, we consider how these techniques have been applied to recently developed mouse models of asthma, severe asthma, and asthma-chronic obstructive pulmonary disease overlap, to examine the effects of clinically relevant exposures (including ovalbumin, house dust mite antigen in the absence or presence of cigarette smoke, cockroach allergen, pollen, and respiratory microbes) and to increase our understanding of lung physiology in these diseases and identify new therapeutic targets. Lastly, we focus on recent studies that examine the effects of diet on asthma outcomes, including high fat diet and asthma, low iron diet during pregnancy and predisposition to asthma development in offspring, and environmental exposures on asthma outcomes. We conclude our review with a discussion of new clinical concepts in asthma and severe asthma that warrant investigation and how we could utilize mouse models and advanced lung physiology measurement systems to identify factors and mechanisms with potential for therapeutic targeting.
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Affiliation(s)
- Olivia R. Carroll
- Hunter Medical Research Institute, The University of Newcastle, Newcastle, NSW, Australia
| | - Amber L. Pillar
- Hunter Medical Research Institute, The University of Newcastle, Newcastle, NSW, Australia
| | - Alexandra C. Brown
- Hunter Medical Research Institute, The University of Newcastle, Newcastle, NSW, Australia
| | - Min Feng
- Faculty of Science, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Hui Chen
- Faculty of Science, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Chantal Donovan
- Hunter Medical Research Institute, The University of Newcastle, Newcastle, NSW, Australia
- Faculty of Science, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
- *Correspondence: Chantal Donovan,
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2
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Wieczfinska J, Pawliczak R. Relaxin Affects Airway Remodeling Genes Expression through Various Signal Pathways Connected with Transcription Factors. Int J Mol Sci 2022; 23:ijms23158413. [PMID: 35955554 PMCID: PMC9368845 DOI: 10.3390/ijms23158413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 01/27/2023] Open
Abstract
Fibrosis is one of the parameters of lung tissue remodeling in asthma. Relaxin has emerged as a natural suppressor of fibrosis, showing efficacy in the prevention of a multiple models of fibrosis. Therefore, the aim of this study was to analyze the aptitudes of relaxin, in the context of its immunomodulatory properties, in the development of airway remodeling. WI-38 and HFL1 fibroblasts, as well as epithelial cells (NHBE), were incubated with relaxin. Additionally, remodeling conditions were induced with two serotypes of rhinovirus (HRV). The expression of the genes contributing to airway remodeling were determined. Moreover, NF-κB, c-Myc, and STAT3 were knocked down to analyze the pathways involved in airway remodeling. Relaxin decreased the mRNA expression of collagen I and TGF-β and increased the expression of MMP-9 (p < 0.05). Relaxin also decreased HRV-induced expression of collagen I and α-SMA (p < 0.05). Moreover, all the analyzed transcription factors—NF-κB, c-Myc, and STAT3—have shown its influence on the pathways connected with relaxin action. Though relaxin requires further study, our results suggest that this natural compound offers great potential for inhibition of the development, or even reversing, of factors related to airway remodeling. The presented contribution of the investigated transcription factors in this process additionally increases its potential possibilities through a variety of its activity pathways.
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3
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Li N, He Y, Yang G, Yu Q, Li M. Role of TRPC1 channels in pressure-mediated activation of airway remodeling. Respir Res 2019; 20:91. [PMID: 31092255 PMCID: PMC6518742 DOI: 10.1186/s12931-019-1050-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/15/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Bronchoconstriction and cough, a characteristic of the asthmatic response, leads to development of compressive stresses in the airway wall. We hypothesized that progressively pathological high mechanical stress could act on mechanosensitive cation channels, such as transient receptor potential channel 1 (TRPC1) and then contributes to airway remodeling. METHODS We imitate the pathological airway pressure in vitro using cyclic stretch at 10 and 15% elongation. Ca2+ imaging was applied to measure the activity of TRPC1 after bronchial epithelial cells exposed to cyclic stretch for 0, 0.5, 1, 1.5, 2, 2.5 h. To further clarify the function of channnel TRPC1 in the process of mechano-transduction in airway remodeling, the experiment in vivo was implemented. The TRPC1 siRNA and budesonide were applied separately to asthmatic models. The morphological changes were measured by HE and Massion method. The expression levels of TRPC1 were evaluated by real-time PCR, western blot and immunohistochemistry. The protein expression level of IL-13, TGF-β1 and MMP-9 in BALF were measured by ELISA. RESULTS The result showed that cyclic stretch for 15% elongation at 1.5 h could maximize the activity of TRPC1 channel. This influx in Ca2+ was blocked by TRPC1 siRNA. Higher TRPC1 expression was observed in the bronchial epithelial layer of ovalbumin induced asthmatic models. The knockdown of TRPC1 with TRPC1 siRNA was associated with a hampered airway remodeling process, such as decreased bronchial wall thickness and smooth muscle hypertrophy/hyperplasia, a decreased ECM deposition area and inflammation infiltration around airway wall. Meantime, expression of IL-13, TGF-β1 and MMP-9 in OVA+TRPC1 siRNA also showed reduced level. TRPC1 intervention treatment showed similar anti-remodeling therapeutic effect with budesonide. CONCLUSIONS These results demonstrate that most TRPC1 channels expressed in bronchial epithelial cells mediate the mechanotransduction mechanism. TRPC1 inducing abnormal Ca2+ signal mediates receptor-stimulated and mechanical stimulus-induced airway remodeling. The inhibition of TRPC1 channel could produce similar therapeutic effect as glucocortisteroid to curb the development of asthmatic airway remodeling.
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Affiliation(s)
- Na Li
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010 People’s Republic of China
| | - Ye He
- Department of Geriatrics, Sichuan Provincial People’s Hospital, Sichuan Academy of Medical Science, Chengdu, Sichuan Province 610072 People’s Republic of China
| | - Gang Yang
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400010 People’s Republic of China
| | - Qian Yu
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010 People’s Republic of China
| | - Minchao Li
- Department of Respiratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010 People’s Republic of China
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4
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Aguilera-Aguirre L, Hao W, Pan L, Li X, Saavedra-Molina A, Bacsi A, Radak Z, Sur S, Brasier AR, Ba X, Boldogh I. Pollen-induced oxidative DNA damage response regulates miRNAs controlling allergic inflammation. Am J Physiol Lung Cell Mol Physiol 2017; 313:L1058-L1068. [PMID: 28798252 PMCID: PMC5814700 DOI: 10.1152/ajplung.00141.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/31/2017] [Accepted: 08/07/2017] [Indexed: 12/20/2022] Open
Abstract
A mucosal oxidative burst is a hallmark response to pollen exposure that promotes allergic inflammatory responses. Reactive species constituents of oxidative stress signal via the modification of cellular molecules including nucleic acids. One of the most abundant forms of oxidative genomic base damage is 8-oxo-7,8-dihydroguanine (8-oxoG), which is removed from DNA by 8-oxoguanine DNA glycosylase 1 (OGG1). OGG1 in complex with 8-oxoG acts as a GDP-GTP exchange factor and induces acute inflammation; however, the mechanism(s) by which OGG1 signaling regulates allergic airway inflammation is not known. Here, we postulate that the OGG1 signaling pathway differentially altered the levels of small regulatory RNAs and increased the expression of T helper 2 (Th2) cytokines in ragweed pollen extract (RWPE)-challenged lungs. To determine this, the lungs of sensitized mice expressing or lacking OGG1 were challenged with RWPE and/or with OGG1's excision product 8-oxoG. The responses in lungs were assessed by next-generation sequencing, as well as various molecular and histological approaches. The results showed that RWPE challenge induced oxidative burst and damage to DNA and activated OGG1 signaling, resulting in the differential expression of 84 micro-RNAs (miRNAs), which then exacerbated antigen-driven allergic inflammation and histological changes in the lungs. The exogenous administration of the downregulated let-7b-p3 mimetic or inhibitors of upregulated miR-23a or miR-27a decreased eosinophil recruitment and mucus and collagen production via controlling the expression of IL-4, IL-5, and IL-13. Together, these data demonstrate the roles of OGG1 signaling in the regulation of antigen-driven allergic immune responses via differential expression of miRNAs upstream of Th2 cytokines and eosinophils.
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Affiliation(s)
| | - Wenging Hao
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Lang Pan
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Xiaoxue Li
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Alfredo Saavedra-Molina
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Attila Bacsi
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Zsolt Radak
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Sanjiv Sur
- Division of Endocrinology and Division of Allergy and Immunology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas; and
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Allan R Brasier
- Division of Endocrinology and Division of Allergy and Immunology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas; and
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Xueqing Ba
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas;
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas
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5
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Liu MW, Liu R, Wu HY, Chen M, Dong MN, Huang YQ, Zhang CH, Wang YZ, Xia J, Shi Y, Xie FM, Luo H, Zhao XY, Wei W, Su MX. Atorvastatin has a protective effect in a mouse model of bronchial asthma through regulating tissue transglutaminase and triggering receptor expressed on myeloid cells-1 expression. Exp Ther Med 2017; 14:917-930. [PMID: 28810543 PMCID: PMC5526119 DOI: 10.3892/etm.2017.4576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 01/26/2017] [Indexed: 02/07/2023] Open
Abstract
Airway remodeling in asthma contributes to airway hyperreactivity, loss of lung function and persistent symptoms. Current therapies do not adequately treat the structural airway changes associated with asthma. Statin drugs have improved respiratory health and their therapeutic potential in asthma has been tested in clinical trials. However, the mechanism of action of statins in this context has remained elusive. The present study hypothesized that atorvastatin treatment of ovalbumin-exposed mice attenuates early features of airway remodeling via a mevalonate-dependent mechanism. BALB/c mice were sensitized with ovalbumin and atorvastatin was delivered via oral gavage prior to each ovalbumin exposure. Reverse transcription-semi-quantitative polymerase chain reaction (RT-semi-qPCR), ELISA and western blot analysis were used to assess the expression of a number of relevant genes, including tissue transglutaminase (tTG), triggering receptor expressed on myeloid cells (TREM)-1, nuclear factor erythroid 2-related factor (Nrf) 2, hypoxia-inducible factor (HIF)-1α, transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-9 and tissue inhibitors of metalloproteinases (TIMP)-1 in lung tissue. α-Smooth muscle actin (α-SMA) activity was measured by immunohistochemistry. Airway hyperresponsiveness, lung collagen deposition, airway wall area, airway smooth muscle thickness and lung pathology were also assessed. Atorvastatin treatment led to downregulation of tTG and TREM-1 expression in lung tissue after ovalbumin sensitization, blocked the activity of MMP-9, vascular endothelial growth factor, nuclear factor-κB p65, α-SMA, HIF-α and TGF-β1 and up-regulated Nrf2 expression. Furthermore, the number of lymphocytes and eosinophils in the atorvastatin group was significantly lower than that in the control group. In addition, airway hyperresponsiveness, lung collagen deposition, airway wall area, airway smooth muscle thickness and pathological changes in the lung were significantly decreased in the atorvastatin group, and tumor necrosis factor-α, interleukin (IL)-8, IL-13 and IL-17 in serum were significantly decreased. Histological results demonstrated the attenuating effect of atorvastatin on ovalbumin-induced airway remodeling in asthma. In conclusion, the present study indicated that atorvastatin significantly alleviated ovalbumin-induced airway remodeling in asthma by downregulating tTG and TREM-1 expression. The marked protective effects of atorvastatin suggest its therapeutic potential in ovalbumin-induced airway remodeling in asthma treatment.
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Affiliation(s)
- Ming-Wei Liu
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Rong Liu
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Hai-Ying Wu
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Mei Chen
- Department of Respiratory Medicine, The Yan'An Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Min-Na Dong
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Yun-Qiao Huang
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Chun-Hai Zhang
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Yin-Zhong Wang
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Jing Xia
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Yang Shi
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Feng-Mei Xie
- Department of Gastroenterology, The Second Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650106, P.R. China
| | - Hua Luo
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Xin-Yuan Zhao
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Wei Wei
- Department of Emergency, The First Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Mei-Xian Su
- Department of Emergency, The Second Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650106, P.R. China
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6
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Abstract
Fibrosis is a major player in cardiovascular disease, both as a contributor to the development of disease, as well as a post-injury response that drives progression. Despite the identification of many mechanisms responsible for cardiovascular fibrosis, to date no treatments have emerged that have effectively reduced the excess deposition of extracellular matrix associated with fibrotic conditions. Novel treatments have recently been identified that hold promise as potential therapeutic agents for cardiovascular diseases associated with fibrosis, as well as other fibrotic conditions. The purpose of this review is to provide an overview of emerging antifibrotic agents that have shown encouraging results in preclinical or early clinical studies, but have not yet been approved for use in human disease. One of these agents is bone morphogenetic protein-7 (BMP7), which has beneficial effects in multiple models of fibrotic disease. Another approach discussed involves altering the levels of micro-RNA (miR) species, including miR-29 and miR-101, which regulate the expression of fibrosis-related gene targets. Further, the antifibrotic potential of agonists of the peroxisome proliferator-activated receptors will be discussed. Finally, evidence will be reviewed in support of the polypeptide hormone relaxin. Relaxin is long known for its extracellular remodeling properties in pregnancy, and is rapidly emerging as an effective antifibrotic agent in a number of organ systems. Moreover, relaxin has potent vascular and renal effects that make it a particularly attractive approach for the treatment of cardiovascular diseases. In each case, the mechanism of action and the applicability to various fibrotic diseases will be discussed.
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Affiliation(s)
- Benita L McVicker
- Research Service, VA Nebraska-Western Iowa Health Care System, OmahaNE, United States.,Division of Gastroenterology and Hepatology, University of Nebraska Medical Center, OmahaNE, United States
| | - Robert G Bennett
- Research Service, VA Nebraska-Western Iowa Health Care System, OmahaNE, United States.,The Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, OmahaNE, United States.,Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, OmahaNE, United States
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7
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Philpott H, Nandurkar S, Thien F, Gibson PR, Royce SG. Eosinophilic esophagitis: a clinicopathological review. Pharmacol Ther 2014; 146:12-22. [PMID: 25200122 DOI: 10.1016/j.pharmthera.2014.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 08/28/2014] [Indexed: 12/12/2022]
Abstract
Eosinophilic esophagitis (EoE) is considered to be a chronic antigen-driven disease whereby food and/or aeroallergens induce a chronic inflammatory infiltrate in the esophagus, resulting in pathological hyperplasia of the epithelia and muscular layers, and fibrosis of the lamina propria (referred to collectively as remodelling) and the symptoms of dysphagia and food impaction. EoE shares features with other atopic conditions of asthma and atopic dermatitis, such as a TH2 cytokine milieu and a mixed inflammatory infiltrate of eosinophils, mast cells and lymphocytes. Relatively distinct features include the strong male predominance amongst adult patients, and the expression of the eosinophil chemokine eotaxin 3. Current first line treatments such as strict dietary modification and corticosteroids fail many patients. Looking forward, clarification of distinct genotype/phenotype associations, determining the reversibility of remodelling following treatment, and the development of new pharmacotherapies that target fibrotic pathways (as opposed to eosinophilic inflammation per se) or specifically improve barrier integrity appear relevant.
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Affiliation(s)
- Hamish Philpott
- Department of Gastroenterology Eastern Health, Monash University Melbourne, Australia.
| | - Sanjay Nandurkar
- Department of Gastroenterology Eastern Health, Monash University Melbourne, Australia
| | - Francis Thien
- Department of Respiratory and Sleep Medicine Eastern Health, Monash University Melbourne, Australia
| | - Peter R Gibson
- Department of Gastroenterology The Alfred Hospital, Monash University Melbourne, Australia
| | - Simon G Royce
- Department of Pharmacology Clayton Campus, Monash University Melbourne, Australia
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8
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Clifton KB, Rodner C, Wolf JM. Detection of relaxin receptor in the dorsoradial ligament, synovium, and articular cartilage of the trapeziometacarpal joint. J Orthop Res 2014; 32:1061-7. [PMID: 24797570 DOI: 10.1002/jor.22640] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/09/2014] [Indexed: 02/04/2023]
Abstract
Basilar thumb osteoarthritis (OA) is postulated to occur due to ligament attenuation of the trapeziometacarpal (TM) joint. Relaxin is a peptide hormone, which loosens ligaments before childbirth, through remodeling of the extracellular matrix via upregulation of matrix metalloproteases (MMPs). We postulated that relaxin family peptide receptor 1 (RXFP-1), the receptor for circulating relaxin, was present in tissues of the TM joint. Ligaments and synovium were sampled from 15 patients during surgery for TM arthritis. We obtained trapezial cartilage from two autopsy donors and four patients. Tissues were fixed, paraffin embedded, and sectioned at 5 µm, then were immunostained for RXFP-1, as well as MMP-1, and MMP-13, using rabbit anti-human polyclonal antibodies. Eight DRL samples showed positive immunostaining for relaxin receptor, with 14/15 positively stained in synovium. Greater staining was seen in specimens obtained from women with more severe TM arthritis. Trapezial cartilage demonstrated receptor staining within chondrocytes in the middle and deep zones. Immunostaining for MMPs co-localized with relaxin receptor staining. Relaxin receptors are present at the ligament, cartilage, and synovium of the TM joint, indicating that it is a potential target for relaxin. This suggests that circulating relaxin may impact joint stability. The role of relaxin in cartilage and synovium may be related to its role in collagen regulation as a possible tissue response to OA.
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Affiliation(s)
- Kari B Clifton
- Department of Orthopaedic Surgery, University of Connecticut Health Center, Farmington, Connecticut
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9
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Royce SG, Li X, Tortorella S, Goodings L, Chow BSM, Giraud AS, Tang MLK, Samuel CS. Mechanistic insights into the contribution of epithelial damage to airway remodeling. Novel therapeutic targets for asthma. Am J Respir Cell Mol Biol 2014; 50:180-92. [PMID: 23980699 DOI: 10.1165/rcmb.2013-0008oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
It has been suggested that an inherent airway epithelial repair defect is the root cause of airway remodeling in asthma. However, the relationship between airway epithelial injury and repair, airway remodeling, and airway hyperresponsiveness (AHR) has not been directly examined. We investigated the contribution of epithelial damage and repair to the development of airway remodeling and AHR using a validated naphthalene (NA)-induced murine model of airway injury. In addition, we examined the endogenous versus exogenous role of the epithelial repair peptide trefoil factor 2 (TFF2) in disease pathogenesis. A single dose of NA (200 mg/kg in 10 ml/kg body weight corn oil [CO] vehicle, intraperitoneally) was administered to mice. Control mice were treated with CO (10 ml/kg body weight, intraperitoneally). At 12, 24, 48, and 72 hours after NA or CO injection, AHR and various measures of airway remodeling were examined by invasive plethysmography and morphometric analyses, respectively. TFF2-deficient mice and intranasal treatment were used to examine the role of the epithelial repair peptide. NA treatment induced denudation and apoptosis of airway epithelial cells, goblet cell metaplasia, elevated AHR, and increased levels of endogenous TFF2. Airway epithelial changes peaked at 12 hours after NA treatment, whereas airway remodeling changes were observed from 48 hours. TFF2 was protective against epithelial damage and induced remodeling and was found to mediate organ protection via a platelet-derived growth factor-associated mechanism. Our findings directly demonstrate the contribution of epithelial damage to airway remodeling and AHR and suggest that preventing airway epithelial damage and promoting epithelial repair may have therapeutic implications for asthma treatment.
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Affiliation(s)
- Simon G Royce
- 1 Department of Allergy and Immune Disorders, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
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10
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Glogowska A, Kunanuvat U, Stetefeld J, Patel TR, Thanasupawat T, Krcek J, Weber E, Wong GW, Del Bigio MR, Hoang-Vu C, Hombach-Klonisch S, Klonisch T. C1q-tumour necrosis factor-related protein 8 (CTRP8) is a novel interaction partner of relaxin receptor RXFP1 in human brain cancer cells. J Pathol 2013; 231:466-79. [DOI: 10.1002/path.4257] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 08/25/2013] [Accepted: 09/04/2013] [Indexed: 12/28/2022]
Affiliation(s)
- Aleksandra Glogowska
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Usakorn Kunanuvat
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Jörg Stetefeld
- Department of Chemistry, Faculty of Science; University of Manitoba; Winnipeg Manitoba Canada
- Department of Microbiology, Faculty of Science; University of Manitoba; Winnipeg Manitoba Canada
- Department of Biochemistry and Medical Genetics, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Trushar R Patel
- Department of Chemistry, Faculty of Science; University of Manitoba; Winnipeg Manitoba Canada
| | - Thatchawan Thanasupawat
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Jerry Krcek
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
- Department of Surgery, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Ekkehard Weber
- Institute of Physiological Chemistry; Martin Luther University Halle-Wittenberg; Halle/Saale Germany
| | - G William Wong
- Department of Physiology and Center for Metabolism and Obesity Research; Johns Hopkins School of Medicine; Baltimore MD USA
| | - Marc R Del Bigio
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
- Department of Pathology, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Cuong Hoang-Vu
- Clinics of General, Visceral and Vascular Surgery; Martin Luther University Halle-Wittenberg; Halle/Saale Germany
| | - Sabine Hombach-Klonisch
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
- Department of Obstetrics, Gynecology and Reproductive Medicine, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
| | - Thomas Klonisch
- Department of Human Anatomy and Cell Science, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
- Department of Surgery, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
- Department of Medical Microbiology and Infectious Diseases, Faculty of Medicine; University of Manitoba; Winnipeg Manitoba Canada
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11
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Royce SG, Moodley Y, Samuel CS. Novel therapeutic strategies for lung disorders associated with airway remodelling and fibrosis. Pharmacol Ther 2013; 141:250-60. [PMID: 24513131 DOI: 10.1016/j.pharmthera.2013.10.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/01/2013] [Indexed: 01/11/2023]
Abstract
Inflammatory cell infiltration, cytokine release, epithelial damage, airway/lung remodelling and fibrosis are central features of inflammatory lung disorders, which include asthma, chronic obstructive pulmonary disease, acute respiratory distress syndrome and idiopathic pulmonary fibrosis. Although the lung has some ability to repair itself from acute injury, in the presence of ongoing pathological stimuli and/or insults that lead to chronic disease, it no longer retains the capacity to heal, resulting in fibrosis, the final common pathway that causes an irreversible loss of lung function. Despite inflammation, genetic predisposition/factors, epithelial-mesenchymal transition and mechanotransduction being able to independently contribute to airway remodelling and fibrosis, current therapies for inflammatory lung diseases are limited by their ability to only target the inflammatory component of the disease without having any marked effects on remodelling (epithelial damage and fibrosis) that can cause lung dysfunction independently of inflammation. Furthermore, as subsets of patients suffering from these diseases are resistant to currently available therapies (such as corticosteroids), novel therapeutic approaches are required to combat all aspects of disease pathology. This review discusses emerging therapeutic approaches, such as trefoil factors, relaxin, histone deacetylase inhibitors and stem cells, amongst others that have been able to target airway inflammation and airway remodelling while improving related lung dysfunction. A better understanding of the mode of action of these therapies and their possible combined effects may lead to the identification of their clinical potential in the setting of lung disease, either as adjunct or alternative therapies to currently available treatments.
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Affiliation(s)
- Simon G Royce
- Fibrosis Laboratory, Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia; Departments of Pathology and Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Yuben Moodley
- Department of Respiratory and Sleep Medicine, School of Medicine and Pharmacology, Royal Perth Hospital, University of Western Australia, Perth 6000, Western Australia, Australia
| | - Chrishan S Samuel
- Fibrosis Laboratory, Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia; Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3010, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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12
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Bathgate RAD, Halls ML, van der Westhuizen ET, Callander GE, Kocan M, Summers RJ. Relaxin family peptides and their receptors. Physiol Rev 2013; 93:405-80. [PMID: 23303914 DOI: 10.1152/physrev.00001.2012] [Citation(s) in RCA: 379] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
There are seven relaxin family peptides that are all structurally related to insulin. Relaxin has many roles in female and male reproduction, as a neuropeptide in the central nervous system, as a vasodilator and cardiac stimulant in the cardiovascular system, and as an antifibrotic agent. Insulin-like peptide-3 (INSL3) has clearly defined specialist roles in male and female reproduction, relaxin-3 is primarily a neuropeptide involved in stress and metabolic control, and INSL5 is widely distributed particularly in the gastrointestinal tract. Although they are structurally related to insulin, the relaxin family peptides produce their physiological effects by activating a group of four G protein-coupled receptors (GPCRs), relaxin family peptide receptors 1-4 (RXFP1-4). Relaxin and INSL3 are the cognate ligands for RXFP1 and RXFP2, respectively, that are leucine-rich repeat containing GPCRs. RXFP1 activates a wide spectrum of signaling pathways to generate second messengers that include cAMP and nitric oxide, whereas RXFP2 activates a subset of these pathways. Relaxin-3 and INSL5 are the cognate ligands for RXFP3 and RXFP4 that are closely related to small peptide receptors that when activated inhibit cAMP production and activate MAP kinases. Although there are still many unanswered questions regarding the mode of action of relaxin family peptides, it is clear that they have important physiological roles that could be exploited for therapeutic benefit.
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Affiliation(s)
- R A D Bathgate
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology, Monash University, Victoria, Australia
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13
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A potential therapeutic strategy for malignant mesothelioma with gene medicine. BIOMED RESEARCH INTERNATIONAL 2013; 2013:572609. [PMID: 23484132 PMCID: PMC3581274 DOI: 10.1155/2013/572609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/25/2012] [Accepted: 12/25/2012] [Indexed: 12/29/2022]
Abstract
Malignant mesothelioma, closely linked with occupational asbestos exposure, is relatively rare in the frequency, but the patient numbers are going to increase in the next few decades all over the world. The current treatment modalities are not effective in terms of the overall survival and the quality of life. Mesothelioma mainly develops in the thoracic cavity and infrequently metastasizes to extrapleural organs. A local treatment can thereby be beneficial to the patients, and gene therapy with an intrapleural administration of vectors is one of the potential therapeutics. Preclinical studies demonstrated the efficacy of gene medicine for mesothelioma, and clinical trials with adenovirus vectors showed the safety of an intrapleural injection and a possible involvement of antitumor immune responses. Nevertheless, low transduction efficiency remains the main hurdle that hinders further clinical applications. Moreover, rapid generation of antivector antibody also inhibits transgene expressions. In this paper, we review the current status of preclinical and clinical gene therapy for malignant mesothelioma and discuss potential clinical directions of gene medicine in terms of a combinatory use with anticancer agents and with immunotherapy.
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14
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Combination therapy with relaxin and methylprednisolone augments the effects of either treatment alone in inhibiting subepithelial fibrosis in an experimental model of allergic airways disease. Clin Sci (Lond) 2012; 124:41-51. [PMID: 22817662 DOI: 10.1042/cs20120024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although CSs (corticosteroids) demonstrate potent effects in the control of airway inflammation in asthma, many patients continue to experience symptoms and AHR (airway hyper-responsiveness) despite optimal treatment with these agents, probably due to progressive airway remodelling. Identifying novel therapies that can target airway remodelling and/or airway reactivity may improve symptom control in these patients. We have demonstrated previously that the anti-fibrotic hormone RLN (relaxin) can reverse airway remodelling (epithelial thickening and subepithelial fibrosis) and AHR in a murine model of AAD (allergic airways disease). In the present study, we compared the effects of RLN with a CS (methylprednisolone) on airway remodelling and AHR when administered independently or in combination in the mouse AAD model. Female mice at 6-8 weeks of age were sensitized and challenged to OVA (ovalbumin) over a 9-week period and treated with methylprednisolone, RLN, a combination of both treatments or vehicle controls. Methylprednisolone was administered intraperitoneally on the same day as nebulization for 6 weeks, whereas recombinant human RLN-2 was administered via subcutaneously implanted osmotic mini-pumps from weeks 9-11. RLN or methylprednisolone alone were both able to significantly decrease subepithelial thickness and total lung collagen deposition; whereas RLN but not methylprednisolone significantly decreased epithelial thickness and AHR. Additionally, combination therapy with CS and RLN more effectively reduced subepithelial collagen thickness than either therapy alone. These findings demonstrate that RLN can modulate a broader range of airway remodelling changes and AHR than methylprednisolone and the combination of both treatments offers enhanced control of subepithelial fibrosis.
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15
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Cray JJ, Burrows AM, Vecchione L, Kinsella CR, Losee JE, Moursi AM, Siegel MI, Cooper GM, Mooney MP. Relaxin Does Not Rescue Coronal Suture Fusion in Craniosynostotic Rabbits. Cleft Palate Craniofac J 2012; 49:e46-54. [DOI: 10.1597/11-024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Objectives Craniosynostosis affects 1 in 2000 to 3000 live births and may result in craniofacial and neural growth disturbances. Histological data have shown that thick collagenous bundles are present in the sutural ligament, which may tether the osteogenic fronts, resulting in premature fusion. The hormone relaxin has been shown to disrupt collagen fiber organization, possibly preventing craniosynostosis by relaxing the sutural ligament and allowing osteogenic fronts to separate normally and stay patent. This study tested this hypothesis with a rabbit model of delayed-onset coronal suture synostosis. Methods A total of 18 New Zealand White rabbits with craniosynostosis were randomly assigned to one of three groups: sham control, protein control (BSA), relaxin treatment. After initial diagnosis, sham surgery, BSA, or relaxin was delivered to the fusing coronal suture in a slow-release (56-day) collagen vehicle. Longitudinal radiographs and body weights were collected at 10, 25, 42, and 84 days of age, and sutures were harvested for histology. Results Relaxin-treated animals had more disorganized intrasuture content than control groups. These specimens also appeared to have relatively wider sutures ectocranially. There were no significant differences in relaxin-treated animals for all craniofacial growth measures, or suture separation compared with controls. Conclusions These data do not support our initial hypothesis that the use of relaxin may rescue sutures destined to undergo premature suture fusion. These findings suggest that collagen fiber arrangement may not be important for suture fusion. This protein therapy would not be clinically useful for craniosynostosis.
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Affiliation(s)
- James J. Cray
- Department of Surgery, Division of Plastic Surgery, Pediatric Craniofacial Biology Laboratory, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anne M. Burrows
- Department of Physical Therapy, Duquesne University, Pittsburgh, Pennsylvania, and Department of Anthropology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Lisa Vecchione
- Pittsburgh Cleft–Craniofacial Research Center, Pittsburgh, Pennsylvania, and Assistant Clinical Professor of Surgery, Department of Surgery, Division of Plastic Surgery and Department of Orthodontics and Dentofacial Orthopedics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Christopher R. Kinsella
- Department of Surgery, Division of Plastic Surgery, Pediatric Craniofacial Biology Laboratory, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Joseph E. Losee
- Surgery and Pediatrics, Chief, Pediatric Plastic Surgery, and Director, Pittsburgh Cleft–Craniofacial Center Program, Pittsburgh, Pennslyvania, and Plastic Surgery Residency, Department of Surgery, Division of Plastic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Amr M. Moursi
- Department of Pediatric Dentistry, New York University, New York, New York
| | - Michael I. Siegel
- Departments of Anthropology and Orthodontics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Gregory M. Cooper
- Department of Surgery, Division of Plastic Surgery, Department of Orthopedic Surgery, and Department of Oral Biology, and Children's Hospital of Pittsburgh University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mark P. Mooney
- Departments of Anthropology, Surgery–Division of Plastic Surgery, and Orthodontics
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Halls ML. Constitutive formation of an RXFP1-signalosome: a novel paradigm in GPCR function and regulation. Br J Pharmacol 2012; 165:1644-1658. [PMID: 21557732 DOI: 10.1111/j.1476-5381.2011.01470.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The classical second messenger cAMP is important in diverse physiological processes, where its spatial and temporal compartmentalization allows precise control over multiple cellular events. Within this context, G-protein-coupled receptors (GPCRs) govern specialized pools of cAMP, which are functionally specific for the unique cellular effects attributed to a particular system. The relaxin receptor, RXFP1, is a GPCR that exerts pleiotropic physiological effects including a potent anti-fibrotic response, increased cancer metastases, and has efficacy as a vasodilator in heart failure. On a cellular level, relaxin stimulation of RXFP1 results in the activation of multiple G-protein pathways affecting cAMP accumulation. Specificity and diversity in the cAMP signal generated by RXFP1 is controlled by differential G-protein coupling dependent upon the background of cellular expression, and cAMP compartmentalization. Further complexity in cAMP signalling results from the constitutive assembly of an RXFP1-signalosome, which specifically responds to low concentrations of relaxin, and activates a distinct cAMP pathway. The RXFP1-signalosome is a higher-order protein complex that facilitates receptor sensitivity to attomolar concentration of peptide, exhibits constitutive activity and dual coupling to G-proteins and β-arrestins and reveals a concentration-biased agonism mediated by relaxin. The specific and directed formation of GPCR-centered signalosomes allows an even greater spatial and temporal control of cAMP, thus rationalizing the considerable physiological scope of this ubiquitous second messenger.
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Affiliation(s)
- Michelle L Halls
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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17
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Royce SG, Dang W, Yuan G, Tran J, El-Osta A, Karagiannis TC, Tang MLK. Effects of the histone deacetylase inhibitor, trichostatin A, in a chronic allergic airways disease model in mice. Arch Immunol Ther Exp (Warsz) 2012; 60:295-306. [PMID: 22684086 DOI: 10.1007/s00005-012-0180-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Accepted: 02/20/2012] [Indexed: 01/26/2023]
Abstract
There is a need for new asthma therapies that can concurrently address airway remodeling, airway hyperresponsiveness and progressive irreversible loss of lung function, in addition to inhibiting inflammation. Histone deacetylase inhibitors (HDACi) alter gene expression by interfering with the removal of acetyl groups from histones. The HDACi trichostatin A (TSA) has pleiotropic effects targeting key pathological processes in asthma including inflammation, proliferation, angiogenesis and fibrosis. The aim was to evaluate the effects of TSA treatment in a mouse model of chronic allergic airways disease (AAD). Wild-type BALB/c mice with AAD were treated intraperitoneally with 5 mg/kg TSA or vehicle control. Airway inflammation was assessed by bronchoalveolar lavage fluid (BALF) cell counts and histological examination of lung tissue sections. Remodeling was assessed by morphometric analysis and airway hyperresponsiveness was assessed by invasive plethysmography. TSA-treated mice had a reduced number of total inflammatory cells and eosinophils within the BALF as compared to vehicle-treated mice (both p < 0.05). Furthermore, airway remodeling changes were significantly reduced with TSA compared to vehicle-treated mice, with fewer goblet cells (p < 0.05), less subepithelial collagen deposition (p < 0.05) and attenuated airway hyperresponsiveness at the highest methacholine dose. These findings demonstrate that treatment with an HDACi can concurrently reduce structural airway remodeling changes and airway hyperresponsiveness, in addition to attenuating airway inflammation in a chronic AAD model. This has important implications for the development of novel treatments for severe asthma.
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Affiliation(s)
- Simon G Royce
- Allergy and Immune Disorders, Murdoch Children's Research Institute, Melbourne, VIC, Australia.
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Royce SG, Lim C, Muljadi RC, Samuel CS, Ververis K, Karagiannis TC, Giraud AS, Tang MLK. Trefoil factor-2 reverses airway remodeling changes in allergic airways disease. Am J Respir Cell Mol Biol 2012; 48:135-44. [PMID: 22652198 DOI: 10.1165/rcmb.2011-0320oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Trefoil factor 2 (TFF2) is a small peptide with an important role in mucosal repair. TFF2 is up-regulated in asthma, suggesting a role in asthma pathogenesis. Given its known biological role in promoting epithelial repair, TFF2 might be expected to exert a protective function in limiting the progression of airway remodeling in asthma. The contribution of TFF2 to airway remodeling in asthma was investigated by examining the expression of TFF2 in the airway and lung, and evaluating the effects of recombinant TFF2 treatment on established airway remodeling in a murine model of chronic allergic airways disease (AAD). BALB/c mice were sensitized and challenged with ovalbumin (OVA) or saline for 9 weeks, whereas mice with established OVA-induced AAD were treated with TFF2 or vehicle control (intranasally for 14 d). Effects on airway remodeling, airway inflammation, and airway hyperresponsiveness were then assessed, whereas TFF2 expression was determined by immunohistochemistry. TFF2 expression was significantly increased in the airways of mice with AAD, compared with expression levels in control mice. TFF2 treatment resulted in reduced epithelial thickening, subepithelial collagen deposition, goblet-cell metaplasia, bronchial epithelium apoptosis, and airway hyperresponsiveness (all P < 0.05, versus vehicle control), but TFF2 treatment did not influence airway inflammation. The increased expression of endogenous TFF2 in response to chronic allergic inflammation is insufficient to prevent the progression of airway inflammation and remodeling in a murine model of chronic AAD. However, exogenous TFF2 treatment is effective in reversing aspects of established airway remodeling. TFF2 has potential as a novel treatment for airway remodeling in asthma.
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Affiliation(s)
- Simon G Royce
- Department of Allergy and Immune Disorders, Murdoch Children's Research Institute Melbourne, Victoria, Australia
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19
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Royce SG, Cheng V, Samuel CS, Tang MLK. The regulation of fibrosis in airway remodeling in asthma. Mol Cell Endocrinol 2012; 351:167-75. [PMID: 22266540 DOI: 10.1016/j.mce.2012.01.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 01/04/2012] [Indexed: 01/12/2023]
Abstract
Fibrosis is one of the key pathological features of airway remodeling in asthma. In the normal airway the amount of collagen and other extracellular matrix components is kept in equilibrium by regulation of synthesis and degradation. In asthma this homeostasis is disrupted due to genetic and environmental factors. In the airways of patients with the disease there is increased extracellular matrix deposition, particularly in the reticular basement membrane region, lamina propria and submucosa. Fibrosis is important as it can occur early in the pathogenesis of asthma, be associated with severity and resistant to therapy. In this review we will discuss current knowledge of relaxin and other key regulators of fibrosis in the airway including TGFβ, Smad2/3 and matrix metalloproteinases. As fibrosis is not directly targeted or effectively treated by current asthma drugs including corticosteroids, characterization of airway fibrosis and how it is regulated will be essential for the development of novel therapies for asthma.
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Affiliation(s)
- Simon G Royce
- Department of Allergy and Immunology, Murdoch Children's Research Institute, The Royal Children's Hospital, Melbourne 3052, Australia
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Shabanpoor F, Bathgate RA, Belgi A, Chan LJ, Nair VB, Wade JD, Hossain MA. Site-specific conjugation of a lanthanide chelator and its effects on the chemical synthesis and receptor binding affinity of human relaxin-2 hormone. Biochem Biophys Res Commun 2012; 420:253-6. [DOI: 10.1016/j.bbrc.2012.02.141] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 02/24/2012] [Indexed: 12/24/2022]
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Royce SG, Lim C, Muljadi RC, Tang MLK. Trefoil factor 2 regulates airway remodeling in animal models of asthma. J Asthma 2011; 48:653-9. [PMID: 21793772 DOI: 10.3109/02770903.2011.599906] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Epithelial denudation and metaplasia are important in the pathogenesis of airway remodeling and asthma. Trefoil factor 2 (TFF2) is a member of a family of peptides involved in protection and healing of the gastrointestinal epithelium but which are also secreted in the airway mucosa. METHODS We investigated the role of TFF2 in airway remodeling by histological and morphometric analysis of lung tissue from TFF2-deficient mice subjected to two relevant animal models of asthma: an ovalbumin model of allergic airways disease and an Aspergillus fumigatus antigen sensitization model. RESULTS In the ovalbumin model TFF2-deficient mice had increased goblet cell hyperplasia, but not epithelial thickening compared to wild-type (WT) counterparts. In the Aspergillus model TFF2-deficient mice also had increased goblet cell hyperplasia, and epithelial thickness was also increased in the Aspergillus-sensitized mice compared to WT controls. TFF2 deficiency was also associated with increased subepithelial collagen layer thickness. DISCUSSION The current study demonstrates a role of TFF2 in airway remodeling in mouse models of airway disease. Further studies into the mechanisms of action of TFF2 and its role in asthma are warranted.
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Affiliation(s)
- Simon G Royce
- Allergy and Immune Disorders, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Australia
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22
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Royce SG, Dang W, Yuan G, Tran J, El Osta A, Karagiannis TC, Tang MLK. Resveratrol has protective effects against airway remodeling and airway hyperreactivity in a murine model of allergic airways disease. PATHOBIOLOGY OF AGING & AGE RELATED DISEASES 2011; 1:PBA-1-7134. [PMID: 22953028 PMCID: PMC3417665 DOI: 10.3402/pba.v1i0.7134] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 04/19/2011] [Accepted: 04/20/2011] [Indexed: 12/14/2022]
Abstract
Background New therapies for asthma which can address three main interrelated features of the disease, airway inflammation, airway remodeling and airway hyperreactivity, are urgently required. Resveratrol, a well known red wine polyphenol has received much attention due to its potential anti-aging properties. This compound is an agonist of silent information regulator two histone deacetylases and has many effects that are relevant to key aspects of the pathophysiology of asthma including inflammation, cell proliferation and fibrosis. Therefore, resveratrol may offer a novel asthma therapy that simultaneously inhibits airway inflammation, and airway remodeling which are the main contributors to airway hyperreactivity and irreversible lung function loss. Methods We evaluated the effects of systemic resveratrol treatment in a murine model of chronic allergic airways disease which displays most of the clinicopathological features of severe human asthma. Wild-type Balb/c mice with allergic airways disease were treated with 12.5 mg/kg resveratrol or vehicle control. Airway inflammation was assessed by bronchoalveolar lavage fluid cell counts and histological examination of lung tissue sections. Further, remodeling was assessed by morphometric analysis and lung function was assessed by invasive plethysmography measurement of airway resistance and dynamic compliance. Results Mice treated with resveratrol exhibited reduced tissue inflammation as compared to vehicle treated mice (p<0.05). Additionally, resveratrol treatment resulted in reduced subepithelial collagen deposition as compared to vehicle treated mice (p<0.05) and attenuated airway hyperreactivity (p<0.05). Conclusions These novel findings demonstrate that treatment with resveratrol can reduce structural airway remodeling changes and hyperreactivity. This has important implications for the development of new therapeutic approaches to asthma.
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Affiliation(s)
- Simon G Royce
- Allergy and Immune Disorders, Murdoch Children's Research Institute, Melbourne, Vic., Australia
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23
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Karagiannis TC, Li X, Tang MM, Orlowski C, El-Osta A, Tang MLK, Royce SG. Molecular model of naphthalene-induced DNA damage in the murine lung. Hum Exp Toxicol 2011; 31:42-50. [PMID: 21508073 DOI: 10.1177/0960327111407228] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Airway epithelial damage and repair represents a novel therapeutic target in asthma and chronic obstructive pulmonary disease. An established mouse model of airway epithelial damage involves the Clara cell cytotoxicity of parenterally administered naphthalene, an important environmental toxicant with genotoxic and carcinogenic potential. The objective of the current study was to investigate naphthalene-induced toxicity and to identify and quantify DNA double-strand breaks in a murine naphthalene model of airway epithelial damage. Male C57/BL6 mice were injected with 200 mg/kg naphthalene and culled at 12-, 24-, 48- and 72-h time points. Lung function and bronchoalveolar lavage was performed and the lungs were dissected for histological analysis and for quantitation of DNA double-strand breaks using γH2AX as a molecular marker. Mice injected with naphthalene had increased epithelial denudation, bronchoalveolar lavage fluid cellularity and reactivity to nebulized methacholine chloride as compared to corn oil vehicle controls. Histological changes were most pronounced at the 12- and 24-h time points. DNA double-strand breaks, quantitated as the number of γH2AX foci per cell, were highest at the 24- and 48-h time points. All parameters had decreased at the 72-h time point, consistent with airway re-epithelization and cellular repair. Our findings indicate a time-dependent accumulation of γH2AX foci in mouse airway epithelial cells following administration of naphthalene. Naphthalene airway epithelial injury constitutes a model of DNA double-strand breaks in mice, which can be adapted as a suitable model for further investigation of genotoxic damage for evaluating the efficacy of potential therapeutics.
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Affiliation(s)
- Tom C Karagiannis
- Epigenomic Medicine, Baker IDI Heart and Diabetes Institute, Melbourne, VIC, Australia
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Munroe ME, Businga TR, Kline JN, Bishop GA. Anti-inflammatory effects of the neurotransmitter agonist Honokiol in a mouse model of allergic asthma. THE JOURNAL OF IMMUNOLOGY 2010; 185:5586-97. [PMID: 20889543 DOI: 10.4049/jimmunol.1000630] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chronic airway inflammation is a hallmark of asthma, an immune-based disease with great societal impact. Honokiol (HNK), a phenolic neurotransmitter receptor (γ-aminobutyric acid type A) agonist purified from magnolia, has anti-inflammatory properties, including stabilization of inflammation in experimentally induced arthritis. The present study tested the prediction that HNK could inhibit the chronic inflammatory component of allergic asthma. C57BL/6 mice sensitized to and challenged with OVA had increased airway hyperresponsiveness to methacholine challenge and eosinophilia compared with naive controls. HNK-treated mice showed a reduction in airway hyperresponsiveness as well as a significant decrease in lung eosinophilia. Histopathology studies revealed a marked drop in lung inflammation, goblet cell hyperplasia, and collagen deposition with HNK treatment. Ag recall responses from HNK-treated mice showed decreased proinflammatory cytokines in response to OVA, including TNF-α-, IL-6-, Th1-, and Th17-type cytokines, despite an increase in Th2-type cytokines. Regulatory cytokines IL-10 and TGF-β were also increased. Assessment of lung homogenates revealed a similar pattern of cytokines, with a noted increase in the number of FoxP3(+) cells in the lung. HNK was able to alter B and T lymphocyte cytokine secretion in a γ-aminobutyric acid type A-dependent manner. These results indicate that symptoms and pathology of asthma can be alleviated even in the presence of increased Th2 cytokines and that neurotransmitter agonists such as HNK have promise as a novel class of anti-inflammatory agents in the treatment of chronic asthma.
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Affiliation(s)
- Melissa E Munroe
- Department of Microbiology, University of Iowa, Iowa City, IA 52242, USA
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Detection of RXFP1 receptors in skin biopsies from children with congenital adrenal hyperplasia: a preliminary report. J Pediatr Urol 2010; 6:389-95. [PMID: 19897422 DOI: 10.1016/j.jpurol.2009.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 10/05/2009] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Relaxin may potentiate the effect of topical estrogen treatment to eradicate post-incisional scarring in congenital adrenal hyperplasia (CAH) patients undergoing genitoplasty. The aim of this study was to determine whether CAH skin is capable of responding to relaxin. PATIENTS AND METHODS Skin biopsies were obtained from four female CAH patients (aged 2-9 years; Prader 4-5, salt-wasting, 21-hydroxylase deficiency, Caucasian) during routine genitoplasty surgery and screened for relaxin receptors. All received corticosteroid and mineralocorticoid replacement therapy. Specimens were sectioned, mounted and screened for the presence of the putative H2 relaxin receptor using conventional two-antibody immunohistochemistry. Tissue controls were processed concurrently. RESULTS Tissue controls evidenced appropriate staining. Biopsies from CAH patients stained positively for RXFP1 expression while some variation between specimens was evident. Staining occurred adjacent to the basement membrane of the epithelium, localized to germinative basal keratinocytes. CONCLUSION Based on a limited patient sample, germinative keratinocytes in CAH patients appear competent to respond to relaxin perhaps topically applied. Given that relaxin downregulates collagen accretion and upregulates collagenases, its use may potentiate the effects of estradiol and abrogate post-incisional wound scarring. More research is needed to confirm or refute this thesis.
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Royce SG, Lee M, Tang MLK. The contribution of L-selectin to airway hyperresponsiveness in chronic allergic airways disease. J Asthma Allergy 2010; 3:9-17. [PMID: 21437035 PMCID: PMC3047908 DOI: 10.2147/jaa.s9775] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Indexed: 11/23/2022] Open
Abstract
L-selectin is a cell adhesion molecule, which mediates leukocyte rolling on bronchopulmonary endothelium. Previous studies in a murine model of allergic airways disease have shown that L-selectin plays a role in the regulation of airway hyperresponsiveness in asthma via mechanisms independent of inflammation. Airway remodeling has been shown to modulate airway hyperresponsiveness independently of inflammation.
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Affiliation(s)
- Simon G Royce
- Department of Allergy and Immunology, Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, Victoria 3052, Australia
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Kong RCK, Shilling PJ, Lobb DK, Gooley PR, Bathgate RAD. Membrane receptors: structure and function of the relaxin family peptide receptors. Mol Cell Endocrinol 2010; 320:1-15. [PMID: 20138959 DOI: 10.1016/j.mce.2010.02.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 12/14/2009] [Accepted: 02/02/2010] [Indexed: 01/17/2023]
Abstract
The receptors for members of the relaxin peptide family have only recently been discovered and are G-protein-coupled receptors (GPCRs). Relaxin and insulin-like peptide 3 (INSL3) interact with the leucine-rich-repeat-containing GPCRs (LGRs) LGR7 and LGR8, respectively. These receptors show closest similarity to the glycoprotein hormone receptors and contain large ectodomains with 10 leucine-rich repeats (LRRs) but are unique members of the LGR family (class C) as they have an LDL class A (LDLa) module at their N-terminus. In contrast, relaxin-3 and INSL5 interact with another class of type I GPCRs which lack a large ectodomain, the peptide receptors GPCR135 and GPCR142, respectively. These receptors are now classified as relaxin family peptide (RXFP) receptors, RXFP1 (LGR7), RXFP2 (LGR8), RXFP3 (GPCR135) and RXFP4 (GPCR142). This review outlines the identification of the peptides and receptors, their expression profiles and physiological roles and the functional interactions of the peptides with their unique receptors.
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Affiliation(s)
- Roy C K Kong
- Florey Neuroscience Institutes, University of Melbourne, Victoria 3010, Australia
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Bennett RG. Relaxin and its role in the development and treatment of fibrosis. Transl Res 2009; 154:1-6. [PMID: 19524867 PMCID: PMC2697124 DOI: 10.1016/j.trsl.2009.03.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/20/2009] [Accepted: 03/23/2009] [Indexed: 10/20/2022]
Abstract
Relaxin, which is a peptide hormone of the insulin superfamily, is involved in the promotion of extracellular matrix remodeling. This property is responsible for many well-known reproductive functions of relaxin. Recent important findings, including the identification of the relaxin receptor and the development of the relaxin-null mouse, have identified new targets and mechanisms for relaxin's actions, which resulted in unprecedented advances in the field. Relaxin has emerged as a natural suppressor of age-related fibrosis in many tissues, which include the skin, lung, kidney, and heart. Furthermore, relaxin has shown efficacy in the prevention and treatment of a variety of models of experimentally induced fibrosis. The intention of this review is to present a summary of recent advances in relaxin research, with a focus on areas of potential translational research on fibrosis in nonreproductive organs.
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Affiliation(s)
- Robert G Bennett
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebr., USA.
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Royce SG, Miao YR, Lee M, Samuel CS, Tregear GW, Tang MLK. Relaxin reverses airway remodeling and airway dysfunction in allergic airways disease. Endocrinology 2009; 150:2692-9. [PMID: 19213838 DOI: 10.1210/en.2008-1457] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mice deficient in the antifibrotic hormone relaxin develop structural changes in the airway that resemble airway remodeling, and demonstrate exaggerated remodeling changes in models of allergic airways disease (AAD). Relaxin expression in asthma has not been previously studied. We evaluated the efficacy of relaxin in the treatment of established airway remodeling in a mouse model of AAD. Relaxin expression in mouse AAD was also examined by immunohistochemistry and real-time PCR. BALB/c mice with established AAD were treated with relaxin or vehicle control (sc for 14 d), and effects on airway remodeling, airway inflammation, and airway hyperresponsiveness (AHR) were assessed. Relaxin expression was significantly reduced in the airways of mice with AAD compared with controls. Recombinant relaxin treatment in a mouse model of AAD reversed collagen deposition and epithelial thickening, and significantly improved AHR (all P < 0.05 vs. vehicle control), but did not influence airway inflammation or goblet cell hyperplasia. Relaxin treatment was associated with increased matrix metalloproteinase-2 levels, suggesting a possible mechanism for its antifibrotic effects. Endogenous relaxin expression is decreased in murine AAD, whereas exogenous relaxin represents a novel treatment capable of reversing established airway remodeling and AHR.
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Affiliation(s)
- Simon G Royce
- Departments of Allergy and Immunology, The Royal Children's Hospital, Parkville, Victoria, Australia
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30
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Cooney TE, Schober JM, Lubahn JD, Konieczko EM. Relaxin's involvement in extracellular matrix homeostasis. Ann N Y Acad Sci 2009; 1160:329-35. [PMID: 19416214 DOI: 10.1111/j.1749-6632.2008.03801.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Burgeoning evidence suggests that the hormone relaxin modulates collagen in the extracellular matrix of diverse tissues. In separate lines of study, we provide further substantiation of this hypothesis. Immunofluorescence was used to probe isolated fibroblasts derived from volar oblique ligament explant culture for vimentin, actin, RXFP1, and estrogen receptor beta. Ligaments were obtained as surgical waste from thumb reconstruction patients. Four specimens have been examined to date. Cells derived from these patients expressed vimentin and actin, consistent with fibroblast morphology. Putative fibroblasts derived from two of three female patients expressed RXFP1 receptors; the solitary male was negative. Given the small sample, however, the data are considered preliminary. Immunohistochemistry was used on frozen sections from 26 skin biopsies obtained from children undergoing genitoplasty. A subset of samples was also probed for transforming growth factor (TGF-beta1) and TGF-beta3. Appropriate controls were used. Finally, a subset of patient blood was assayed for relaxin by using an enzyme-linked immunosorbent assay-based method. The results showed RXFP1 receptor expression in the cells that populate the basement membrane in 96% of patients, regardless of gender. Most tissue expressed TGF-beta. Finally, serology suggested that relaxin was detectable in these children. Our two lines of research provide additional evidence for the diverse tissue tropism of relaxin. In particular, connective tissues as diverse as ligaments and basal lamina keratinocytes express RXFP1. These data lend support to our contention that relaxin affects ligament integrity and wound healing.
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Affiliation(s)
- Timothy E Cooney
- Department of Orthopaedics and Orthopaedic Research, Hamot Medical Center, Erie, Pennsylvania 16550, USA.
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31
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Tang MLK, Samuel CS, Royce SG. Role of relaxin in regulation of fibrosis in the lung. Ann N Y Acad Sci 2009; 1160:342-7. [PMID: 19416216 DOI: 10.1111/j.1749-6632.2008.03825.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Airway remodeling changes are a key pathological feature of asthma. They are associated with airway hyperresponsiveness and fixed airway obstruction. Aged, relaxin-deficient mice display structural changes resembling airway remodeling in asthma, including thickening of the bronchial epithelium and extracellular matrix (ECM) deposition in the subepithelial region. Relaxin-deficient mice also have exaggerated airway remodeling in models of allergic airway disease compared to wild-type controls. Both in vitro and in vivo studies have suggested that airway fibrosis may drive other changes of airway remodeling, including epithelial changes. A suggested paradigm is that subepithelial fibrosis (deposition of ECM in the basement membrane region) may lead to increased epithelial cell proliferation and transforming growth factor-beta1 production, which in turn may lead to further fibrosis. Relaxin may therefore prevent or reverse activation of the epithelial and fibroblast remodeling in asthma. Control of epithelial remodeling and ECM production in the airway wall may play an important role in maintaining normal lung function. Understanding how relaxin protects against airway remodeling changes may have important implications in developing new therapies to treat airway remodeling in asthma.
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Affiliation(s)
- Mimi L K Tang
- Allergy and Immune Disorders, Murdoch Children's Research Institute, Melbourne, Australia.
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32
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Kern A, Bryant-Greenwood GD. Characterization of relaxin receptor (RXFP1) desensitization and internalization in primary human decidual cells and RXFP1-transfected HEK293 cells. Endocrinology 2009; 150:2419-28. [PMID: 19116340 PMCID: PMC2671891 DOI: 10.1210/en.2008-1385] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We report here the desensitization and internalization of the relaxin receptor (RXFP1) after agonist activation in both primary human decidual cells and HEK293 cells stably transfected with RXFP1. The importance of beta-arrestin 2 in these processes has also been demonstrated. Thus, in HEK-RXFP1 cells the desensitization of RXFP1 was significantly increased when beta-arrestin 2 was overexpressed. After relaxin activation, beta-arrestin 2 was translocated to the cell membrane and RXFP1 underwent rapid internalization. We have previously shown that RXFP1 forms dimers/oligomers during its biosynthesis and trafficking to the plasma membrane, we now show that internalization of RXFP1 occurs through this dimerization/oligomerization. In nonagonist stimulated cells, it is known that the majority of the RXFP1 is located intracellularly and was confirmed in the cells used here. Constitutive internalization of RXFP1 could account for this and indeed, slow but robust constitutive internalization, which was increased after agonist stimulation was demonstrated. A carboxyl-terminal deleted RXFP1 variant had a similar level of constitutive agonist-independent internalization as the wild-type RXFP1 but lost sensitivity to agonist stimulation. This demonstrated the importance of the carboxyl terminus in agonist-stimulated receptor internalization. These data suggest that the autocrine/paracrine actions of relaxin in the decidua are under additional controls at the level of expression of its receptor on the surface of its target cells.
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MESH Headings
- Arrestins/pharmacology
- Autocrine Communication/genetics
- Autocrine Communication/physiology
- Cell Culture Techniques
- Cell Line/drug effects
- Cell Line/metabolism
- Cells, Cultured
- Decidua/drug effects
- Decidua/metabolism
- Dimerization
- Female
- Gene Expression/physiology
- Humans
- Models, Biological
- Paracrine Communication/genetics
- Paracrine Communication/physiology
- Protein Structure, Tertiary/physiology
- Protein Transport/drug effects
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Peptide/agonists
- Receptors, Peptide/chemistry
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Relaxin/pharmacology
- Transfection
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Affiliation(s)
- András Kern
- The Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii 96822, USA.
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33
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Samuel CS, Royce SG, Chen B, Cao H, Gossen JA, Tregear GW, Tang MLK. Relaxin family peptide receptor-1 protects against airway fibrosis during homeostasis but not against fibrosis associated with chronic allergic airways disease. Endocrinology 2009; 150:1495-502. [PMID: 18974264 DOI: 10.1210/en.2008-1062] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Endogenous relaxin has recently been demonstrated to protect the airway/lung against age-related fibrosis and against inflammation-associated airway fibrosis in animal models of allergic airways disease (AAD). In the current study, we examined the contribution of the primary relaxin receptor, relaxin family peptide receptor-1 (RXFP1), in mediating these effects of relaxin. Lung tissues from healthy aging RXFP1 gene-knockout (Rxfp1(-/-)) and wild-type (Rxfp1(+/+)) mice and from 8- to 10-wk-old Rxfp1(-/-) and Rxfp1(+/+) mice subjected to a mouse model of AAD were assessed for various markers of airway fibrosis and remodeling. Male and female Rxfp1(-/-) mice demonstrated an age-related progression of airway/lung fibrosis. Saline-treated Rxfp1(-/-) mice had significantly increased myofibroblast differentiation and lung collagen deposition (both P < 0.05), decreased matrix metalloproteinase (MMP)-9 expression and activity (P < 0.05), but equivalent levels of MMP-2 and tissue inhibitor of metalloproteinases (TIMPs) to that measured in saline-treated Rxfp1(+/+) mice. As expected, ovalbumin (OVA)-treated Rxfp1(+/+) mice developed markedly increased lung myofibroblast differentiation and collagen deposition (both P < 0.01 vs saline-treated Rxfp1(+/+) mice), significantly decreased lung MMP-2 and MMP-9 expression and activity and increased TIMP-1 expression (all P < 0.05 vs. respective measurements from saline-treated Rxfp1(+/+) mice). Surprisingly, however, OVA-treated Rxfp1(-/-) animals had equivalent levels of airway fibrosis and gelatinase activity but increased TIMP-1 expression (P < 0.05) compared with OVA-treated Rxfp1(+/+) mice. These combined findings demonstrate that RXFP1 is involved in mediating relaxin's effects on airway fibrosis during homeostasis but not during inflammation-induced fibrosis associated with chronic AAD.
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Affiliation(s)
- Chrishan S Samuel
- Department of Biochemistry and Molecular Biology, Howard Florey Institute , University of Melbourne, Victoria, Australia.
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34
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Ganesan A, Klonisch T, McGuane JT, Feng S, Agoulnik AI, Parry LJ. Normal prostate morphology in relaxin-mutant mice. Reprod Fertil Dev 2009; 21:440-50. [DOI: 10.1071/rd08133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 10/20/2008] [Indexed: 11/23/2022] Open
Abstract
The peptide hormone relaxin is expressed in the prostate gland and secreted into the seminal plasma; however, its function within the prostate has not been established. Relaxin-mutant mice (Rln–/–) were reported to have abnormal prostate morphology, but there was no prostate phenotype in relaxin receptor-mutant (Rxfp1–/–) mice. The present study aimed to verify the phenotypes in the anterior, dorsal and lateral lobes of the prostate gland of Rln–/– and Rxfp1–/– mice at different adult ages. Rln–/– mice were also treated with relaxin to evaluate the effects of exogenously administered hormone on prostate morphology. Comparisons between these three lobes of the prostate demonstrated no obvious differences in duct morphology, epithelial height or collagen density between Rln+/+ and Rln–/– mice at 2, 4, 6, 8 and 12 months of age. This was similar in Rxfp1–/– mice. Relaxin treatment did not affect morphology or epithelial cell height in the different lobes. Furthermore, prostate lobe morphology in transgenic mice overexpressing relaxin Tg(Rln) was not different from the wild-type controls. Rxfp1 was detected in the prostate throughout adult life, but there was no consistent expression of relaxin. In summary, the present study found no evidence to support a prostate phenotype in adult Rln- or Rxfp1-mutant mice.
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35
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Mookerjee I, Hewitson TD, Halls ML, Summers RJ, Mathai ML, Bathgate RAD, Tregear GW, Samuel CS. Relaxin inhibits renal myofibroblast differentiation via RXFP1, the nitric oxide pathway, and Smad2. FASEB J 2008; 23:1219-29. [PMID: 19073841 DOI: 10.1096/fj.08-120857] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The hormone relaxin inhibits renal myofibroblast differentiation by interfering with TGF-beta1/Smad2 signaling. However, the pathways involved in the relaxin-TGF-beta1/Smad2 interaction remain unknown. This study investigated the signaling mechanisms by which human gene-2 (H2) relaxin regulates myofibroblast differentiation in vitro by examining its effects on mixed populations of fibroblasts and myofibroblasts propagated from injured rat kidneys. Cultures containing approximately 60-70% myofibroblasts were used to determine which relaxin receptors, G-proteins, and signaling pathways were involved in the H2 relaxin-mediated regulation of alpha-smooth muscle actin (alpha-SMA; a marker of myofibroblast differentiation). H2 relaxin only inhibited alpha-SMA immunostaining and collagen concentration in the presence of relaxin family peptide receptor 1 (RXFP1). H2 relaxin also induced a transient rise in cAMP in the presence of G(i/o) inhibition, and a sustained increase in extracellular signal-regulated kinase (ERK)-1/2 phosphorylation. Furthermore, inhibition of neuronal nitric oxide synthase (nNOS), NO, and cGMP significantly blocked the inhibitory effects of relaxin on alpha-SMA and Smad2 phosphorylation, while the NO inhibitor, L-nitroarginine methyl ester (hydrochloride) (L-NAME) significantly blocked the inhibitory actions of relaxin on collagen concentration in vivo. These findings suggest that relaxin signals through RXFP1, and a nNOS-NO-cGMP-dependent pathway to inhibit Smad2 phosphorylation and interfere with TGF-beta1-mediated renal myofibroblast differentiation and collagen production.
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Affiliation(s)
- Ishanee Mookerjee
- Howard Florey Institute, University of Melbourne, Victoria, Australia
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36
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van der Westhuizen ET, Halls ML, Samuel CS, Bathgate RA, Unemori EN, Sutton SW, Summers RJ. Relaxin family peptide receptors – from orphans to therapeutic targets. Drug Discov Today 2008; 13:640-51. [DOI: 10.1016/j.drudis.2008.04.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 03/04/2008] [Accepted: 04/04/2008] [Indexed: 01/11/2023]
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37
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Xu Q, Lekgabe ED, Gao XM, Ming Z, Tregear GW, Dart AM, Bathgate RAD, Samuel CS, Du XJ. Endogenous relaxin does not affect chronic pressure overload-induced cardiac hypertrophy and fibrosis. Endocrinology 2008; 149:476-82. [PMID: 17991721 DOI: 10.1210/en.2007-1220] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of endogenous relaxin on the development of cardiac hypertrophy, dysfunction, and fibrosis remains completely unknown. We addressed this question by subjecting relaxin-1 deficient (Rln1-/-) and littermate control (Rln1+/+) mice of both genders to chronic transverse aortic constriction (TAC). The extent of left ventricular (LV) remodeling and dysfunction were studied by serial echocardiography over an 8-wk period and by micromanometry. The degree of hypertrophy was estimated by LV weight, cardiomyocyte size, and expression of relevant genes. Cardiac fibrosis was determined by hydroxyproline assay and quantitative histology. Expression of endogenous relaxin during the course of TAC was also examined. In response to an 8-wk period of pressure overload, TAC mice of both genotypes developed significant LV hypertrophy, fibrosis, hypertrophy related gene profile, and signs indicating congestive heart failure when compared with respective sham controls. The severity of these alterations was not statistically different between the two genotypes of either gender. Relaxin mRNA expression was up-regulated, whereas that of its receptor was unchanged in the hypertrophic myocardium of wild-type mice. Collectively, the extent of pressure overload-induced LV hypertrophy, fibrosis, and dysfunction were comparable between Rln1+/+ and Rln1-/- mice. Thus, although up-regulated in its expression, endogenous relaxin had no significant effect on the progression of cardiac maladaptation and dysfunction in the setting of chronic pressure overload.
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MESH Headings
- Animals
- Blood Pressure/physiology
- Cardiomegaly/etiology
- Cardiomegaly/metabolism
- Cardiomegaly/pathology
- Chronic Disease
- Collagen/metabolism
- Disease Models, Animal
- Female
- Fibrosis
- Gene Expression/physiology
- Hypertension/complications
- Hypertension/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Myocardium/metabolism
- Myocardium/pathology
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Relaxin/genetics
- Relaxin/metabolism
- Ventricular Dysfunction, Left/etiology
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/pathology
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Affiliation(s)
- Qi Xu
- Baker Heart Research Institute, Melbourne, VIC, Australia
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38
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Samuel CS, Lekgabe ED, Mookerjee I. The effects of relaxin on extracellular matrix remodeling in health and fibrotic disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 612:88-103. [PMID: 18161483 DOI: 10.1007/978-0-387-74672-2_7] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Since its discovery as a reproductive hormone 80 years ago, relaxin has been implicated in a number of pregnancy-related functions involving extracellular matrix (ECM) turnover and collagen degradation. It is now becoming evident that relaxin's ability to reduce matrix synthesis and increase ECM degradation has important implications in several nonreproductive organs, including the heart, lung, kidney, liver and skin. The identification of relaxin and RXFP1 (Relaxin family peptide receptor-1) mRNA and/or binding sites in cells or vessels of these nonreproductive tissues, has confirmed them as targets for relaxin binding and activity. Recent studies on Rln1 and Rxfp1 gene-knockout mice have established relaxin as an important naturally occurring and protective moderator of collagen turnover, leading to improved organ structure and function. Furthermore, through its ability to regulate the ECM and in particular, collagen at multiple levels, relaxin has emerged as a potent anti-fibrotic therapy, with rapid-occurring efficacy. It not only prevents fibrogenesis, but also reduces established scarring (fibrosis), which is a leading cause of organ failure and affects several tissues regardless of etiology. This chapter will summarize these coherent findings as a means of highlighting the significance and therapeutic potential of relaxin.
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Affiliation(s)
- Chrishan S Samuel
- Howard Florey Institute, University of Melbourne, Parkville, Victoria 3010, Australia.
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39
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Tran T, Halayko AJ. Extracellular matrix and airway smooth muscle interactions: a target for modulating airway wall remodelling and hyperresponsiveness? Can J Physiol Pharmacol 2007; 85:666-71. [PMID: 17823630 DOI: 10.1139/y07-050] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The airway smooth muscle from asthmatic airways produces increased amounts and an altered composition of extracellular matrix proteins. The extracellular matrix can in turn influence the phenotype and function of airway smooth muscle cells, affecting the biochemical, geometric, and mechanical properties of the airway wall. This review provides a brief overview of the current understanding of the biology associated with airway smooth muscle interactions with the extracellular matrix. We present future directions needed for the study of cellular and molecular mechanisms that determine the outcomes of extracellular matrix - airway smooth muscle interactions, and discuss their possible importance as determinants of airway function in asthma.
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Affiliation(s)
- Thai Tran
- Department of Physiology, University of Manitoba, Winnipeg, MB, Canada
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40
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Ganguly K, Stoeger T, Wesselkamper SC, Reinhard C, Sartor MA, Medvedovic M, Tomlinson CR, Bolle I, Mason JM, Leikauf GD, Schulz H. Candidate genes controlling pulmonary function in mice: transcript profiling and predicted protein structure. Physiol Genomics 2007; 31:410-21. [PMID: 17804602 DOI: 10.1152/physiolgenomics.00260.2006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Impaired development and reduced lung capacity are risk factors of asthma and chronic obstructive pulmonary disease. Previously, our genomewide linkage analysis of C3H/HeJ (C3H) and JF1/Msf (JF1) mouse strains identified quantitative trait loci (QTLs) associated with the complex traits of dead space volume (Vd), total lung capacity (TLC), lung compliance (CL), and diffusing capacity for CO (D(CO)). We assessed positional candidate genes by comparing C3H with JF1 lung transcript levels by microarray and by comparing C3H, BALB/cByJ, C57BL/6J, A/J, PWD/PhJ, and JF1 strains, using exon sequencing to predict protein structure. Microarray identified >900 transcripts differing in C3H and JF1 lungs related to lung development, function, and remodeling. Of these, three genes localized to QTLs associated with differences in lung function. C3H and JF1 strains differed in transcript and protein levels of superoxide dismutase 3, extracellular [SOD3; mouse chromosome (mCh) 5: VD] and transcript of trefoil factor 2 (TFF2; mCh 17: TLC and D(CO)), and ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2; mCh 15: TLC and CL). Nucleotide sequencing of Sod3, Tff2, and previously identified Relaxin 1 (Rln1; mCh 19: CL) uncovered polymorphisms that could lead to nonsynonymous amino acid changes and altered predicted protein structure. Gene-targeted Sod3(-/-) mice had increased conducting airway volume (Vd/TLC) compared with strain-matched control Sod3(+/+) mice, consistent with the QTL on mCh 5. Two novel genes (Tff2 and Enpp2) have been identified and two suspected genes (Sod3 and Rln1) have been supported as determinants of lung function in mice. Findings with gene-targeted mice suggest that SOD3 is a contributing factor defining the complex trait of conducting airway volume.
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Affiliation(s)
- Koustav Ganguly
- National Research Center for Environment and Health (GSF), Institute for Inhalation Biology, Neuherberg, Germany
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41
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Samuel CS, Royce SG, Burton MD, Zhao C, Tregear GW, Tang MLK. Relaxin plays an important role in the regulation of airway structure and function. Endocrinology 2007; 148:4259-66. [PMID: 17584966 DOI: 10.1210/en.2007-0577] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Relaxin is a reproductive hormone with pleiotropic actions. In addition to airway fibrosis, relaxin deficiency results in airway structural changes (epithelial thickening) and increased lung recoil, suggesting that relaxin may impact other aspects of airway/lung structure and function beyond its ability to regulate collagen turnover. Furthermore, these structural changes associated with relaxin deficiency show marked similarity to the structural changes seen in asthma. The current study investigated the broader role of relaxin in regulating airway structure and function and examined the relationship between airway inflammation, structural changes, and airway hyperresponsiveness (AHR) using an ovalbumin (OVA)-induced model of allergic airways disease (AAD). The model of AAD was applied to 12-month-old relaxin-deficient (Rln(-/-)) mice with established airway fibrosis and age-matched wild-type (Rln(+/+)) controls. OVA-treated Rln(+/+) mice (induced inflammation) developed increased epithelial thickening (P < 0.05) and AHR (P < 0.05) but not airway fibrosis, compared with saline-treated Rln(+/+) controls. Saline-treated Rln(-/-) mice had significantly increased lung collagen deposition (existing fibrosis) and epithelial thickening and remarkably were found to have increased AHR that was equivalent to that in OVA-treated Rln(+/+) mice (all P < 0.05 vs. saline-treated Rln(+/+) controls). OVA-treated Rln(-/-) mice (existing fibrosis and induced inflammation) had increased airway/lung fibrosis (P < 0.05) but equivalent airway inflammation and AHR compared with OVA-treated Rln(+/+) animals. These findings demonstrate for the first time a role for relaxin in the regulation of airway responses using Rln(-/-) mice and suggest that airway fibrosis and/or epithelial thickening can result in increased AHR equivalent to that induced by airway inflammation in AAD.
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Affiliation(s)
- Chrishan S Samuel
- Howard Florey Institute of Experimental Physiology and Medicine, Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
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42
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Kern A, Agoulnik AI, Bryant-Greenwood GD. The low-density lipoprotein class A module of the relaxin receptor (leucine-rich repeat containing G-protein coupled receptor 7): its role in signaling and trafficking to the cell membrane. Endocrinology 2007; 148:1181-94. [PMID: 17158203 DOI: 10.1210/en.2006-1086] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The relaxin receptor (LGR7, relaxin family peptide receptor 1) is a member of the leucine-rich repeat containing G protein-coupled receptors subgroup C. This and the LGR8 (relaxin family peptide receptor 2) receptor are unique in having a low-density lipoprotein class A (LDL-A) module at their N termini. This study was designed to show the role of the LDL-A in LGR7 expression and function. Point mutants for the conserved cysteines (Cys(47) and Cys(53)) and for calcium binding asparagine (Asp(58)), a mutant with deleted LDL-A domain and chimeric LGR7 receptor with LGR8 LDL-A all showed no cAMP response to human relaxins H1 or H2. We have shown that their cell surface delivery was uncompromised. The mutation of the putative N-linked glycosylation site (Asn(36)) decreased cAMP production and reduced cell surface expression to 37% of the wild-type LGR7. All point mutant, chimeric, and wild-type receptor proteins were expressed as the two forms. The immature or precursor form of the receptor was 80 kDa, whereas the mature receptor, delivered to the cell surface was 95 kDa. The glycosylation mutant was also expressed as two forms with appropriately smaller molecular masses. Deletion of the LDL-A module resulted in expression of the mature receptor only. These data suggest that the LDL-A module of LGR7 influences receptor maturation, cell surface expression, and relaxin-activated signal transduction.
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Affiliation(s)
- András Kern
- Pacific Biosciences Research Center, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813, USA.
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43
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Ho TY, Yan W, Bagnell CA. Relaxin-induced matrix metalloproteinase-9 expression is associated with activation of the NF-κB pathway in human THP-1 cells. J Leukoc Biol 2007; 81:1303-10. [PMID: 17289798 DOI: 10.1189/jlb.0906556] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Matrix metalloproteinases (MMPs) and relaxin (RLX) are reported to play an important role in tissue remodeling and wound repair. When macrophages populate wound sites, they secrete biologically active substances, including MMPs. The transcription factor NF-kappaB is important in MMP gene regulation in macrophage cells. Thus, a monocyte/macrophage cell line, THP-1, was used to study the molecular mechanism of RLX action on MMP-2 and MMP-9 expression. After 24 h incubation with porcine RLX (100 ng/ml), conditioned media (CM) and THP-1 cells were collected. Gelatin zymography demonstrated an increase in pro-MMP-9 activity in response to RLX in CM, and no significant change in pro-MMP-2 expression was observed. Immunoblot analysis also revealed an increase in pro-MMP-9 in CM from RLX-treated THP-1 cells. Gel EMSA showed that NF-kappaB DNA-binding activity was elevated in THP-1 cells treated with RLX for 10 min and reached a peak at 30 min. The NF-kappaB DNA complex was supershifted using antibodies against NF-kappaB subunits p50 and p65. Increased expression of the p50 and p65 NF-kappaB subunits was also detected in THP-1 cells after RLX treatment. Incubation with RLX (90 min) reduced THP-1 expression of the NF-kappaB inhibitor protein, IkappaB-alpha. Using a specific NF-kappaB inhibitor, pyrrolidine dithiocarmate (PDTC) inhibited nuclear binding of NF-kappaB. Pre-exposure to PDTC suppressed pro-MMP-9 activity and protein levels in RLX-treated THP-1 cells. In conclusion, these data suggest that RLX-induced tissue remodeling through increasing MMP-9 expression is dependent on NF-kappaB activation.
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Affiliation(s)
- Teh-Yuan Ho
- Department of Animal Sciences, Rutgers University, New Brunswick, NJ 08901-8525, USA
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Silvertown JD, Walia JS, Summerlee AJ, Medin JA. Functional expression of mouse relaxin and mouse relaxin-3 in the lung from an Ebola virus glycoprotein-pseudotyped lentivirus via tracheal delivery. Endocrinology 2006; 147:3797-808. [PMID: 16709614 DOI: 10.1210/en.2006-0028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The peptide hormone relaxin is a known modulator of connective tissue and the extracellular matrix by virtue of its ability to regulate matrix metalloproteinases (MMPs). Relaxin knockout mice exhibit age-related pulmonary fibrosis, and delivery of recombinant human H2 relaxin ameliorates fibrotic-like conditions in the mouse lung. We investigated whether lentiviral vectors (LVs) engineering the expression of murine relaxins could induce MMP activity in the mouse lung. Mouse relaxin and mouse relaxin-3 peptides engineered by recombinant LVs were biologically active as shown by stimulation of cAMP from both THP-1 and 293T cells stably expressing relaxin receptor LGR7 and by up-regulation of MMP-2 activity from primary C57BL/6 lung cell cultures. To provide the virions with enhanced tropism for the lung, LVs were pseudotyped with the Zaire strain of the Ebola virus glycoprotein (EboZ GP) and delivered by endotracheal intubation. LVs engineering luciferase pseudotyped with EboZ GP, but not with vesicular stomatitis virus glycoprotein resulted in successful LV transduction and transgene expression in C57BL/6 mouse lung by as early as d 4. Mice treated via tracheal delivery with EboZ GP pseudotyped LVs that engineered expression of mouse relaxins exhibited increased MMP-2 and MMP-9 activity in lung tissue up until the end of our study at d 21. Taken together, this study provides proof-of- principle that relaxin gene expression targeted to the mouse lungs can result in enhanced MMP activity offering potential for alleviating disease conditions characterized by dysregulation of extracellular matrix protein accumulation.
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Affiliation(s)
- Josh D Silvertown
- Division of Stem Cell and Developmental Biology, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada M5G 2M1
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