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Mukhatayev Z, Adilbayeva A, Kunz J. CTHRC1: An Emerging Hallmark of Pathogenic Fibroblasts in Lung Fibrosis. Cells 2024; 13:946. [PMID: 38891078 PMCID: PMC11171484 DOI: 10.3390/cells13110946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/13/2024] [Accepted: 05/16/2024] [Indexed: 06/21/2024] Open
Abstract
Pulmonary fibrosis is a chronic, progressive, irreversible lung disease characterized by fibrotic scarring in the lung parenchyma. This condition involves the excessive accumulation of extracellular matrix (ECM) due to the aberrant activation of myofibroblasts in the alveolar environment. Transforming growth factor beta (TGF-β) signaling is a crucial driver of fibrogenesis because it promotes excessive ECM deposition, thereby leading to scar formation and lung damage. A primary target of TGF-β signaling in fibrosis is Collagen Triple Helix Repeat Containing 1 (CTHRC1), a secreted glycoprotein that plays a pivotal role in ECM deposition and wound repair. TGF-β transcriptionally regulates CTHRC1 in response to tissue injury and controls the wound healing response through functional activity. CTHRC1 may also play an essential role in re-establishing and maintaining tissue homeostasis after wound closure by modulating both the TGF-β and canonical Wnt signaling pathways. This dual function suggests that CTHRC1 regulates tissue remodeling and homeostasis. However, deregulated CTHRC1 expression in pathogenic fibroblasts has recently emerged as a hallmark of fibrosis in multiple organs and tissues. This review highlights recent studies suggesting that CTHRC1 can serve as a diagnostic and prognostic biomarker for fibrosis in idiopathic pulmonary fibrosis, systemic sclerosis, and post-COVID-19 lung fibrosis. Notably, CTHRC1 expression is responsive to antifibrotic drugs that target the TGF-β pathway, such as pirfenidone and bexotegrast, indicating its potential as a biomarker of treatment success. These findings suggest that CTHRC1 may present new opportunities for diagnosing and treating patients with lung fibrosis.
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Affiliation(s)
| | | | - Jeannette Kunz
- Department of Biomedical Sciences, School of Medicine, Nazarbayev University, 5/1 Kerey and Zhanibek Khans St., 020000 Astana, Kazakhstan; (Z.M.); (A.A.)
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Ishida Y, Kuninaka Y, Mukaida N, Kondo T. Immune Mechanisms of Pulmonary Fibrosis with Bleomycin. Int J Mol Sci 2023; 24:ijms24043149. [PMID: 36834561 PMCID: PMC9958859 DOI: 10.3390/ijms24043149] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/27/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial-mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.
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Elżbieta R, Iwona K, Joanna B, Karina JR, Piotr R. Role of fibrocytes and endothelial progenitor cells among low-differentiated CD34+ cells in the progression of lung sarcoidosis. BMC Pulm Med 2020; 20:306. [PMID: 33218322 PMCID: PMC7678043 DOI: 10.1186/s12890-020-01345-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 11/12/2020] [Indexed: 12/18/2022] Open
Abstract
Background Sarcoidosis is a multisystemic granulomatous disease with still unknown etiology. Our previous studies showed a significantly higher percentage of CD34 + cells in the peripheral blood in patients with sarcoidosis (SA) compared to the control group. The objective of the present study was to characterized of the CD34 + cell population in peripheral blood in patients with SA with reference to the control group. Moreover in patients with SA, fibrocytes and endothelial cells were analysed and their relationship to the fibrosis process based on assessment of diffusing capacity for carbon monoxide (DLCO). Methods Data from patients diagnosed with SA at Military Institute of Medicine (Warsaw, Poland) between January 2018 and December 2019 were collected and analysed ongoing basis. Peripheral blood was collected from 26 patients with newly diagnosed pulmonary SA and 16 healthy subjects. The immunomagnetic method and flow cytometry were used. Among the CD34+ progenitor cells were assessed: low-differentiated cells, hematopoietic progenitor cells and endothelial progenitor cells. The Statistica 12.0 software was used for a statistical analysis. Results We observed a significantly higher percentage of low-differentiated cells (13.8 vs. 2.3, P = 0.001) and endothelial cells (0.3 vs. 0.0, P = 0.001) in patients with SA compared to the control group. In the study group the median proportion of fibrocytes was 1.877% (0.983–2.340) in patients with DLCO< 80%, while in patients with DLCO> 80% was 0.795% (0.139–1.951) (P = 0.72). The median proportion of endothelial progenitor cells was higher in patients with DLCO< 80%: 0.889% (0.391–1.741), than in patients with DLCO> 80%: 0.451% (0.177–0.857) (P = 0.44). Conclusions In conclusion we demonstrated for the first time the immunophenotype of peripheral CD34 + cells with the degree of their differentiation. The study confirmed the involvement of low differentiated cells and endothelial cells in patients with SA.
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Affiliation(s)
- Rutkowska Elżbieta
- Department of Internal Medicine and Hematology, Laboratory of Hematology and Flow Cytometry, Military Institute of Medicine, Warsaw, Poland.
| | - Kwiecień Iwona
- Department of Internal Medicine and Hematology, Laboratory of Hematology and Flow Cytometry, Military Institute of Medicine, Warsaw, Poland
| | - Bednarek Joanna
- Department of Internal Medicine, Pulmonology, Allergology and Clinical Immunology, Military Institute of Medicine, Warsaw, Poland
| | - Jahnz-Różyk Karina
- Department of Internal Medicine, Pulmonology, Allergology and Clinical Immunology, Military Institute of Medicine, Warsaw, Poland
| | - Rzepecki Piotr
- Department of Internal Medicine and Hematology, Military Institute of Medicine, Warsaw, Poland
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Sun L, Hult EM, Cornell TT, Kim KK, Shanley TP, Wilke CA, Agarwal M, Gurczynski SJ, Moore BB, Dahmer MK. Loss of myeloid-specific protein phosphatase 2A enhances lung injury and fibrosis and results in IL-10-dependent sensitization of epithelial cell apoptosis. Am J Physiol Lung Cell Mol Physiol 2019; 316:L1035-L1048. [PMID: 30838865 DOI: 10.1152/ajplung.00299.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Protein phosphatase 2A (PP2A), a ubiquitously expressed Ser/Thr phosphatase is an important regulator of cytokine signaling and cell function. We previously showed that myeloid-specific deletion of PP2A (LysMcrePP2A-/-) increased mortality in a murine peritoneal sepsis model. In the current study, we assessed the role of myeloid PP2A in regulation of lung injury induced by lipopolysaccharide (LPS) or bleomycin delivered intratracheally. LysMcrePP2A-/- mice experienced increased lung injury in response to both LPS and bleomycin. LysMcrePP2A-/- mice developed more exuberant fibrosis in response to bleomycin, elevated cytokine responses, and chronic myeloid inflammation. Bone marrow-derived macrophages (BMDMs) from LysMcrePP2A-/- mice showed exaggerated inflammatory cytokine release under conditions of both M1 and M2 activation. Notably, secretion of IL-10 was elevated under all stimulation conditions, including activation of BMDMs by multiple Toll-like receptor ligands. Supernatants collected from LPS-stimulated LysMcrePP2A-/- BMDMs induced epithelial cell apoptosis in vitro but this effect was mitigated when IL-10 was also depleted from the BMDMs by crossing LysMcrePP2A-/- mice with systemic IL-10-/- mice (LysMcrePP2A-/- × IL-10-/-) or when IL-10 was neutralized. Despite these findings, IL-10 did not directly induce epithelial cell apoptosis but sensitized epithelial cells to other mediators from the BMDMs. Taken together our results demonstrate that myeloid PP2A regulates production of multiple cytokines but that its effect is most pronounced on IL-10 production. Furthermore, IL-10 sensitizes epithelial cells to apoptosis in response to myeloid-derived mediators, which likely contributes to the pathogenesis of lung injury and fibrosis in this model.
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Affiliation(s)
- Lei Sun
- Department of Pediatrics and Critical Care, University of Michigan , Ann Arbor, Michigan
| | - Elissa M Hult
- Molecular and Integrative Physiology Graduate Program, University of Michigan , Ann Arbor, Michigan
| | - Timothy T Cornell
- Department of Pediatrics and Critical Care, University of Michigan , Ann Arbor, Michigan
| | - Kevin K Kim
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan
| | - Thomas P Shanley
- Department of Pediatrics, Northwestern University Feinberg School of Medicine and Stanley Manne Children's Research Institute at Lurie Children's Hospital , Chicago, Illinois
| | - Carol A Wilke
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan
| | - Manisha Agarwal
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan
| | - Stephen J Gurczynski
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan
| | - Bethany B Moore
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan.,Department of Microbiology and Immunology, University of Michigan , Ann Arbor, Michigan
| | - Mary K Dahmer
- Department of Pediatrics and Critical Care, University of Michigan , Ann Arbor, Michigan
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Mohyi M, Smith TJ. IGF1 receptor and thyroid-associated ophthalmopathy. J Mol Endocrinol 2018; 61:T29-T43. [PMID: 29273685 PMCID: PMC6561656 DOI: 10.1530/jme-17-0276] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/22/2017] [Indexed: 12/13/2022]
Abstract
Thyroid-associated ophthalmopathy (TAO) is a vexing and poorly understood autoimmune process involving the upper face and tissues surrounding the eyes. In TAO, the orbit can become inflamed and undergo substantial remodeling that is disfiguring and can lead to loss of vision. There are currently no approved medical therapies for TAO, the consequence of its uncertain pathogenic nature. It usually presents as a component of the syndrome known as Graves' disease where loss of immune tolerance to the thyrotropin receptor (TSHR) results in the generation of activating antibodies against that protein and hyperthyroidism. The role for TSHR and these antibodies in the development of TAO is considerably less well established. We have reported over the past 2 decades evidence that the insulin-like growth factorI receptor (IGF1R) may also participate in the pathogenesis of TAO. Activating antibodies against IGF1R have been detected in patients with GD. The actions of these antibodies initiate signaling in orbital fibroblasts from patients with the disease. Further, we have identified a functional and physical interaction between TSHR and IGF1R. Importantly, it appears that signaling initiated from either receptor can be attenuated by inhibiting the activity of IGF1R. These findings underpin the rationale for therapeutically targeting IGF1R in active TAO. A recently completed therapeutic trial of teprotumumab, a human IGF1R inhibiting antibody, in patients with moderate to severe, active TAO, indicates the potential effectiveness and safety of the drug. It is possible that other autoimmune diseases might also benefit from this treatment strategy.
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Affiliation(s)
- Michelle Mohyi
- Department of Ophthalmology and Visual SciencesUniversity of Michigan, Ann Arbor, Michigan, USA
| | - Terry J Smith
- Department of Ophthalmology and Visual SciencesUniversity of Michigan, Ann Arbor, Michigan, USA
- Division of MetabolismEndocrine, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
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Marriott S, Baskir RS, Gaskill C, Menon S, Carrier EJ, Williams J, Talati M, Helm K, Alford CE, Kropski JA, Loyd J, Wheeler L, Johnson J, Austin E, Nozik-Grayck E, Meyrick B, West JD, Klemm DJ, Majka SM. ABCG2pos lung mesenchymal stem cells are a novel pericyte subpopulation that contributes to fibrotic remodeling. Am J Physiol Cell Physiol 2014; 307:C684-98. [PMID: 25122876 PMCID: PMC4200000 DOI: 10.1152/ajpcell.00114.2014] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 08/05/2014] [Indexed: 01/13/2023]
Abstract
Genesis of myofibroblasts is obligatory for the development of pathology in many adult lung diseases. Adult lung tissue contains a population of perivascular ABCG2(pos) mesenchymal stem cells (MSC) that are precursors of myofibroblasts and distinct from NG2 pericytes. We hypothesized that these MSC participate in deleterious remodeling associated with pulmonary fibrosis (PF) and associated hypertension (PH). To test this hypothesis, resident lung MSC were quantified in lung samples from control subjects and PF patients. ABCG2(pos) cell numbers were decreased in human PF and interstitial lung disease compared with control samples. Genetic labeling of lung MSC in mice enabled determination of terminal lineage and localization of ABCG2 cells following intratracheal administration of bleomycin to elicit fibrotic lung injury. Fourteen days following bleomycin injury enhanced green fluorescent protein (eGFP)-labeled lung MSC-derived cells were increased in number and localized to interstitial areas of fibrotic and microvessel remodeling. Finally, gene expression analysis was evaluated to define the response of MSC to bleomycin injury in vivo using ABCG2(pos) MSC isolated during the inflammatory phase postinjury and in vitro bleomycin or transforming growth factor-β1 (TGF-β1)-treated cells. MSC responded to bleomycin treatment in vivo with a profibrotic gene program that was not recapitulated in vitro with bleomycin treatment. However, TGF-β1 treatment induced the appearance of a profibrotic myofibroblast phenotype in vitro. Additionally, when exposed to the profibrotic stimulus, TGF-β1, ABCG2, and NG2 pericytes demonstrated distinct responses. Our data highlight ABCG2(pos) lung MSC as a novel cell population that contributes to detrimental myofibroblast-mediated remodeling during PF.
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Affiliation(s)
- Shennea Marriott
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - Rubin S Baskir
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennesse
| | - Christa Gaskill
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - Swapna Menon
- Pulmonary Vascular Research Institute Kochi and AnalyzeDat Consulting Services, Kerala, India
| | - Erica J Carrier
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - Janice Williams
- Vanderbilt Ingram Cancer Center, Electron Microscopy-Cell Imaging Shared Resource, Vanderbilt University, Nashville, Tennessee
| | - Megha Talati
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - Karen Helm
- Cancer Center Flow Cytometry Shared Resource, University of Colorado, Aurora, Colorado
| | - Catherine E Alford
- Department of Pathology and Laboratory Medicine, Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Jonathan A Kropski
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - James Loyd
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - Lisa Wheeler
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - Joyce Johnson
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee
| | - Eric Austin
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Eva Nozik-Grayck
- Department of Pediatrics or Medicine, Pulmonary and Critical Care Medicine, Gates Center for Regenerative Medicine and Stem Cell Biology, University of Colorado, Aurora, Colorado; and
| | - Barbara Meyrick
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse
| | - James D West
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse; Vanderbilt Pulmonary Circulation Center, Vanderbilt University, Nashville, Tennessee
| | - Dwight J Klemm
- Department of Pediatrics or Medicine, Pulmonary and Critical Care Medicine, Gates Center for Regenerative Medicine and Stem Cell Biology, University of Colorado, Aurora, Colorado; and
| | - Susan M Majka
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University, Nashville, Tennesse; Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee; Vanderbilt Pulmonary Circulation Center, Vanderbilt University, Nashville, Tennessee; Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennesse;
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Macedo-Silva RM, Santos CDLPD, Diniz VA, Carvalho JJD, Guerra C, Côrte-Real S. Peripheral blood fibrocytes: new information to explain the dynamics of Leishmania infection. Mem Inst Oswaldo Cruz 2013; 109:61-9. [PMID: 24626303 PMCID: PMC4005535 DOI: 10.1590/0074-0276130247] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 09/24/2013] [Indexed: 01/22/2023] Open
Abstract
Fibrocytes are important for understanding the progression of many diseases because
they are present in areas where pathogenic lesions are generated. However, the
morphology of fibrocytes and their interactions with parasites are poorly understood.
In this study, we examined the morphology of peripheral blood fibrocytes and their
interactions with Leishmania (L.) amazonensis . Through
ultrastructural analysis, we describe the details of fibrocyte morphology and how
fibrocytes rapidly internalise Leishmania promastigotes. The
parasites differentiated into amastigotes after 2 h in phagolysosomes and the
infection was completely resolved after 72 h. Early in the infection, we found
increased nitric oxide production and large lysosomes with electron-dense material.
These factors may regulate the proliferation and death of the parasites. Because
fibrocytes are present at the infection site and are directly involved in developing
cutaneous leishmaniasis, they are targets for effective, non-toxic cell-based
therapies that control and treat leishmaniasis.
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Affiliation(s)
| | | | - Vanessa Alvaro Diniz
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, Brasil
| | - Jorge José de Carvalho
- Departamento de Histologia e Embriologia, Universidade do Estado do Rio de Janeiro, Rio de JaneiroRJ, Brasil
| | - Camila Guerra
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, Brasil
| | - Suzana Côrte-Real
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, Brasil
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Loomis-King H, Moore BB. Fibrocytes in the Pathogenesis of Chronic Fibrotic Lung Disease. CURRENT RESPIRATORY MEDICINE REVIEWS 2013; 9:34-41. [PMID: 27512347 DOI: 10.2174/1573398x11309010005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fibrocytes were initially described in 1999 and since that time there has been a growing body of literature to suggest their importance in a number of chronic lung diseases. It is now well established that fibrocytes derive from the bone marrow and circulate within the peripheral blood. However, when injury occurs, fibrocytes can travel to the site of damage via chemokine-mediated recruitment. Recent studies suggest that fibrocyte numbers increase within the lung or circulation during numerous disease processes. Although fibrocytes readily differentiate into fibroblasts in vitro, whether they do so in vivo is still unknown. The variety of pro-fibrotic mediators that are secreted by fibrocytes makes it likely that they act via paracrine functions to influence the behavior of resident lung cells. This review summarizes recent insights regarding fibrocytes in asthma, scleroderma and IPF.
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Affiliation(s)
- Hillary Loomis-King
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-0642
| | - Bethany B Moore
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-0642
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Jun D, Garat C, West J, Thorn N, Chow K, Cleaver T, Sullivan T, Torchia EC, Childs C, Shade T, Tadjali M, Lara A, Nozik-Grayck E, Malkoski S, Sorrentino B, Meyrick B, Klemm D, Rojas M, Wagner DH, Majka SM. The pathology of bleomycin-induced fibrosis is associated with loss of resident lung mesenchymal stem cells that regulate effector T-cell proliferation. Stem Cells 2011; 29:725-35. [PMID: 21312316 PMCID: PMC3322548 DOI: 10.1002/stem.604] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tissue-resident mesenchymal stem cells (MSCs) are important regulators of tissue repair or regeneration, fibrosis, inflammation, angiogenesis, and tumor formation. Here, we define a population of resident lung MSCs (luMSCs) that function to regulate the severity of bleomycin injury via modulation of the T-cell response. Bleomycin-induced loss of these endogenous luMSCs and elicited fibrosis (pulmonary fibrosis), inflammation, and pulmonary arterial hypertension (PAH). Replacement of resident stem cells by administration of isolated luMSCs attenuated the bleomycin-associated pathology and mitigated the development of PAH. In addition, luMSC modulated a decrease in numbers of lymphocytes and granulocytes in bronchoalveolar fluid and demonstrated an inhibition of effector T-cell proliferation in vitro. Global gene expression analysis indicated that the luMSCs are a unique stromal population differing from lung fibroblasts in terms of proinflammatory mediators and profibrotic pathways. Our results demonstrate that luMSCs function to protect lung integrity after injury; however, when endogenous MSCs are lost, this function is compromised illustrating the importance of this novel population during lung injury. The definition of this population in vivo in both murine and human pulmonary tissue facilitates the development of a therapeutic strategy directed at the rescue of endogenous cells to facilitate lung repair during injury.
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Affiliation(s)
- Du Jun
- Charles C. Gates Center for Regenerative Medicine and Stem Cell Biology Program, University of Colorado Denver, Aurora, Colorado 80045, USA
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Moore BB. Fibrocytes as potential biomarkers in idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 2009; 179:524-5. [PMID: 19318541 DOI: 10.1164/rccm.200812-1847ed] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Moore BB, Murray L, Das A, Wilke CA, Herrygers AB, Toews GB. The role of CCL12 in the recruitment of fibrocytes and lung fibrosis. Am J Respir Cell Mol Biol 2006; 35:175-81. [PMID: 16543609 PMCID: PMC2643255 DOI: 10.1165/rcmb.2005-0239oc] [Citation(s) in RCA: 240] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We have previously shown that mice that are genetically deficient in the CCR2 gene (CCR2-/- mice) are protected from fluorescein isothiocyanate (FITC)-induced lung fibrosis. Protection from fibrosis correlated with impaired recruitment of fibrocytes (bone marrow-derived cells, which share both leukocyte and mesenchymal markers). There are three ligands for CCR2 in the mouse: CCL2, CCL7, and CCL12. CCL2 and CCL12 are both elevated in the lung after FITC injury, but with different kinetics. CCL2 is maximal at Day 1 and absent by Day 7 after FITC. In contrast, CCL12 peaks at Day 3, but remains elevated through Day 21 after FITC. We now demonstrate that while CCR2-/- mice are protected from FITC-induced fibrosis, CCL2-/- mice are not. CCL2-/- mice are able to recruit fibrocytes to FITC-injured airspaces, unlike CCR2-/- mice. Adoptive transfer of CCR2-expressing fibrocytes augments FITC-induced fibrosis in both wild-type and CCR2-/- mice, suggesting that these cells play a pathogenic role in the disease process. Both CCL2 and CCL12 are chemotactic for fibrocytes. However, neutralization of CCL12 in wild-type mice significantly protects from FITC-induced fibrosis, whereas neutralization of CCL2 was less effective. Thus, CCL12 is likely the CCR2 ligand responsible for driving fibroproliferation in the mouse. As murine CCL12 is homologous to human CCL2, we suggest that the pathobiology of murine CCL12 in fibroproliferation may correlate to human CCL2 biology.
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Affiliation(s)
- Bethany B Moore
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, 48109-0642, USA.
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