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Ostermann L, Maus R, Stolper J, Schütte L, Katsarou K, Tumpara S, Pich A, Mueller C, Janciauskiene S, Welte T, Maus UA. Alpha-1 antitrypsin deficiency impairs lung antibacterial immunity in mice. JCI Insight 2021; 6:140816. [PMID: 33554955 PMCID: PMC7934856 DOI: 10.1172/jci.insight.140816] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 12/17/2020] [Indexed: 01/05/2023] Open
Abstract
Alpha-1 antitrypsin (AAT) is a major inhibitor of serine proteases in mammals. Therefore, its deficiency leads to protease–antiprotease imbalance and a risk for developing lung emphysema. Although therapy with human plasma-purified AAT attenuates AAT deficiency–related emphysema, its impact on lung antibacterial immunity is poorly defined. Here, we examined the effect of AAT therapy on lung protective immunity in AAT-deficient (KO) mice challenged with Streptococcus pneumoniae. AAT-KO mice were highly susceptible to S. pneumoniae, as determined by severe lobar pneumonia and early mortality. Mechanistically, we found that neutrophil-derived elastase (NE) degraded the opsonophagocytically important collectins, surfactant protein A (SP-A) and D (SP-D), which was accompanied by significantly impaired lung bacterial clearance in S. pneumoniae–infected AAT-KO mice. Treatment of S. pneumoniae–infected AAT-KO mice with human AAT protected SP-A and SP-D from NE-mediated degradation and corrected the pulmonary pathology observed in these mice. Likewise, treatment with Sivelestat, a specific inhibitor of NE, also protected collectins from degradation and significantly decreased bacterial loads in S. pneumoniae–infected AAT-KO mice. Our findings show that NE is responsible for the degradation of lung SP-A and SP-D in AAT-KO mice affecting lung protective immunity in AAT deficiency.
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Affiliation(s)
| | | | | | | | | | | | - Andreas Pich
- Institute of Toxicology and Core Facility Proteomics, Hannover Medical School, Hannover, Germany
| | - Christian Mueller
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Sabina Janciauskiene
- Clinic for Pneumology, and.,German Center for Lung Research, partner site BREATH, Hannover, Germany
| | - Tobias Welte
- Clinic for Pneumology, and.,German Center for Lung Research, partner site BREATH, Hannover, Germany
| | - Ulrich A Maus
- Division of Experimental Pneumology.,German Center for Lung Research, partner site BREATH, Hannover, Germany
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2
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Kaur A, Riaz MS, Murugaiah V, Varghese PM, Singh SK, Kishore U. A Recombinant Fragment of Human Surfactant Protein D induces Apoptosis in Pancreatic Cancer Cell Lines via Fas-Mediated Pathway. Front Immunol 2018; 9:1126. [PMID: 29915574 PMCID: PMC5994421 DOI: 10.3389/fimmu.2018.01126] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 05/03/2018] [Indexed: 12/24/2022] Open
Abstract
Human surfactant protein D (SP-D) is a potent innate immune molecule, which is emerging as a key molecule in the recognition and clearance of altered and non-self targets. Previous studies have shown that a recombinant fragment of human SP-D (rfhSP-D) induced apoptosis via p53-mediated apoptosis pathway in an eosinophilic leukemic cell line, AML14.3D10. Here, we report the ability of rfhSP-D to induce apoptosis via TNF-α/Fas-mediated pathway regardless of the p53 status in human pancreatic adenocarcinoma using Panc-1 (p53mt), MiaPaCa-2 (p53mt), and Capan-2 (p53wt) cell lines. Treatment of these cell lines with rfhSP-D for 24 h caused growth arrest in G1 cell cycle phase and triggered transcriptional upregulation of pro-apoptotic factors such as TNF-α and NF-κB. Translocation of NF-κB from the cytoplasm into the nucleus of pancreatic cancer cell lines was observed via immunofluorescence microscopy following treatment with rfhSP-D as compared to the untreated cells. The rfhSP-D treatment caused upregulation of pro-apoptotic marker Fas, as analyzed via qPCR and western blot, which then triggered caspase cascade, as evident from cleavage of caspase 8 and 3 analyzed via western blot at 48 h. The cell number following the rfhSP-D treatment was reduced in the order of Panc-1 (~67%) > MiaPaCa-2 (~60%) > Capan-2 (~35%). This study appears to suggest that rfhSP-D can potentially be used to therapeutically target pancreatic cancer cells irrespective of their p53 phenotype.
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Affiliation(s)
- Anuvinder Kaur
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Muhammad Suleman Riaz
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Valarmathy Murugaiah
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Praveen Mathews Varghese
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Shiv K. Singh
- Department of Gastroenterology and Gastrointestinal Oncology, University Medical Center, Goettingen, Germany
| | - Uday Kishore
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
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Sorensen GL. Surfactant Protein D in Respiratory and Non-Respiratory Diseases. Front Med (Lausanne) 2018; 5:18. [PMID: 29473039 PMCID: PMC5809447 DOI: 10.3389/fmed.2018.00018] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/19/2018] [Indexed: 12/16/2022] Open
Abstract
Surfactant protein D (SP-D) is a multimeric collectin that is involved in innate immune defense and expressed in pulmonary, as well as non-pulmonary, epithelia. SP-D exerts antimicrobial effects and dampens inflammation through direct microbial interactions and modulation of host cell responses via a series of cellular receptors. However, low protein concentrations, genetic variation, biochemical modification, and proteolytic breakdown can induce decomposition of multimeric SP-D into low-molecular weight forms, which may induce pro-inflammatory SP-D signaling. Multimeric SP-D can decompose into trimeric SP-D, and this process, and total SP-D levels, are partly determined by variation within the SP-D gene, SFTPD. SP-D has been implicated in the development of respiratory diseases including respiratory distress syndrome, bronchopulmonary dysplasia, allergic asthma, and chronic obstructive pulmonary disease. Disease-induced breakdown or modifications of SP-D facilitate its systemic leakage from the lung, and circulatory SP-D is a promising biomarker for lung injury. Moreover, studies in preclinical animal models have demonstrated that local pulmonary treatment with recombinant SP-D is beneficial in these diseases. In recent years, SP-D has been shown to exert antimicrobial and anti-inflammatory effects in various non-pulmonary organs and to have effects on lipid metabolism and pro-inflammatory effects in vessel walls, which enhance the risk of atherosclerosis. A common SFTPD polymorphism is associated with atherosclerosis and diabetes, and SP-D has been associated with metabolic disorders because of its effects in the endothelium and adipocytes and its obesity-dampening properties. This review summarizes and discusses the reported genetic associations of SP-D with disease and the clinical utility of circulating SP-D for respiratory disease prognosis. Moreover, basic research on the mechanistic links between SP-D and respiratory, cardiovascular, and metabolic diseases is summarized. Perspectives on the development of SP-D therapy are addressed.
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Affiliation(s)
- Grith L Sorensen
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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5
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Lung epithelium and myeloid cells cooperate to clear acute pneumococcal infection. Mucosal Immunol 2016; 9:1288-302. [PMID: 26627460 PMCID: PMC4990776 DOI: 10.1038/mi.2015.128] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 11/01/2015] [Indexed: 02/04/2023]
Abstract
The Gram-positive bacterium Streptococcus pneumoniae causes life-threatening infections, especially among immunocompromised patients. The host's immune system senses S. pneumoniae via different families of pattern recognition receptors, in particular the Toll-like receptor (TLR) family that promotes immune cell activation. Yet, while single TLRs are dispensable for initiating inflammatory responses against S. pneumoniae, the central TLR adapter protein myeloid differentiation factor 88 (MyD88) is of vital importance, as MyD88-deficient mice succumb rapidly to infection. Since MyD88 is ubiquitously expressed in hematopoietic and non-hematopoietic cells, the extent to which MyD88 signaling is required in different cell types to control S. pneumoniae is unknown. Therefore, we used novel conditional knockin mice to investigate the necessity of MyD88 signaling in distinct lung-resident myeloid and epithelial cells for the initiation of a protective immune response against S. pneumoniae. Here, we show that MyD88 signaling in lysozyme M (LysM)- and CD11c-expressing myeloid cells, as well as in pulmonary epithelial cells, is critical to restore inflammatory cytokine and antimicrobial peptide production, leading to efficient neutrophil recruitment and enhanced bacterial clearance. Overall, we show a novel synergistic requirement of compartment-specific MyD88 signaling in S. pneumoniae immunity.
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Barrow AD, Palarasah Y, Bugatti M, Holehouse AS, Byers DE, Holtzman MJ, Vermi W, Skjødt K, Crouch E, Colonna M. OSCAR is a receptor for surfactant protein D that activates TNF-α release from human CCR2+ inflammatory monocytes. THE JOURNAL OF IMMUNOLOGY 2015; 194:3317-26. [PMID: 25716998 DOI: 10.4049/jimmunol.1402289] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Surfactant protein D (SP-D) is critical for maintenance of lung homeostasis and provides a first line of defense to pathogens at mucosal surfaces. Polymorphisms in the SP-D-encoding gene SFTPD have been associated with chronic obstructive pulmonary disease and ulcerative colitis. Identification of the immunoreceptors that bind SP-D is essential for understanding its contribution to lung homeostasis and mucosal defense. We located a putative binding motif for the osteoclast-associated receptor (OSCAR) within the SP-D collagenous domain. An OSCAR-Fc fusion protein specifically bound to the collagenous region of recombinant SP-D and captured native SP-D from human bronchoalveolar lavage. OSCAR localized in an intracellular compartment of alveolar macrophages together with SP-D. Moreover, we found OSCAR on the surface of interstitial lung and blood CCR2(+) inflammatory monocytes, which secreted TNF-α when exposed to SP-D in an OSCAR-dependent fashion. OSCAR and SP-D did not exclusively colocalize in lung, as they were also highly expressed in atherosclerotic plaques of human aorta, supporting a role for this interaction in atherosclerosis. Our results identify the OSCAR:SP-D interaction as a potential therapeutic target in chronic inflammatory diseases of the lung as well as other diseases involving tissue accumulation of SP-D, infiltration of inflammatory monocytes, and release of TNF-α.
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Affiliation(s)
- Alexander D Barrow
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Yaseelan Palarasah
- Department of Cancer and Inflammation, University of Southern Denmark, 5000 Odense, Denmark
| | - Mattia Bugatti
- Department of Molecular and Translational Medicine, Section of Pathology, School of Medicine, University of Brescia, Brescia 25123, Italy
| | - Alex S Holehouse
- Division of Biology and Biomedical Sciences, Washington University, St. Louis, MO 63110; Center for Biological Systems Engineering, Washington University, St. Louis, MO 63130; and
| | - Derek E Byers
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Michael J Holtzman
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - William Vermi
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110; Department of Molecular and Translational Medicine, Section of Pathology, School of Medicine, University of Brescia, Brescia 25123, Italy
| | - Karsten Skjødt
- Department of Cancer and Inflammation, University of Southern Denmark, 5000 Odense, Denmark
| | - Erika Crouch
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110;
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Key mediators in the immunopathogenesis of allergic asthma. Int Immunopharmacol 2014; 23:316-29. [PMID: 24933589 DOI: 10.1016/j.intimp.2014.05.034] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 12/20/2022]
Abstract
Asthma is described as a chronic inflammatory disorder of the conducting airways. It is characterized by reversible airway obstruction, eosinophil and Th2 infiltration, airway hyper-responsiveness and airway remodeling. Our findings to date have largely been dependent on work done using animal models, which have been instrumental in broadening our understanding of the mechanism of the disease. However, using animals to model a uniquely human disease is not without its drawbacks. This review aims to examine some of the key mediators and cells of allergic asthma learned from animal models and shed some light on emerging mediators in the pathogenesis allergic airway inflammation in acute and chronic asthma.
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Thacker S, Moran A, Lionakis M, Mastrangelo MAA, Halder T, del Pilar Huby M, Wu Y, Tweardy DJ. Restoration of lung surfactant protein D by IL-6 protects against secondary pneumonia following hemorrhagic shock. J Infect 2014; 68:231-41. [PMID: 24291043 PMCID: PMC4692462 DOI: 10.1016/j.jinf.2013.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 11/11/2013] [Accepted: 11/19/2013] [Indexed: 01/09/2023]
Abstract
OBJECTIVES To identify novel approaches to improve innate immunity in the lung following trauma complicated by hemorrhagic shock (T/HS) for prevention of nosocomial pneumonia. METHODS We developed a rat model of T/HS followed by Pseudomonas aeruginosa (PA) pneumonia to assess the effect of alveolar epithelial cell (AEC) apoptosis, and its prevention by IL-6, on lung surfactant protein (SP)-D protein levels, lung bacterial burden, and survival from PA pneumonia, as well as to determine whether AEC apoptosis is a consequence of the unfolded protein response (UPR). Lung UPR transcriptome analysis was performed on rats subjected to sham, T/HS, and T/HS plus IL-6 protocols. Group comparisons were performed via Kaplan-Meier or ANOVA. RESULTS T/HS decreased lung SP-D by 1.8-fold (p < 0.05), increased PA bacterial burden 9-fold (p < 0.05), and increased PA pneumonia mortality by 80% (p < 0.001). IL-6, when provided at resuscitation, normalized SP-D levels (p < 0.05), decreased PA bacterial burden by 4.8-fold (p < 0.05), and prevented all mortality from PA pneumonia (p < 0.001). The UPR transcriptome was significantly impacted by T/HS; IL-6 treatment normalized the T/HS-induced UPR transcriptome changes (p < 0.05). CONCLUSIONS Impaired innate lung defense occurs following T/HS and is mediated, in part, by reduction in SP-D protein levels, which, along with AEC apoptosis, may be mediated by the UPR, and prevented by use of IL-6 as a resuscitation adjuvant.
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Affiliation(s)
- Stephen Thacker
- Section of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Ana Moran
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Mihalis Lionakis
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Mary-Ann A Mastrangelo
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Tripti Halder
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Maria del Pilar Huby
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Yong Wu
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - David J Tweardy
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
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9
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Hamvas A, Deterding RR, Wert SE, White FV, Dishop MK, Alfano DN, Halbower AC, Planer B, Stephan MJ, Uchida DA, Williames LD, Rosenfeld JA, Lebel RR, Young LR, Cole FS, Nogee LM. Heterogeneous pulmonary phenotypes associated with mutations in the thyroid transcription factor gene NKX2-1. Chest 2014; 144:794-804. [PMID: 23430038 DOI: 10.1378/chest.12-2502] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Mutations in the gene encoding thyroid transcription factor, NKX2-1, result in neurologic abnormalities, hypothyroidism, and neonatal respiratory distress syndrome (RDS) that together are known as the brain-thyroid-lung syndrome. To characterize the spectrum of associated pulmonary phenotypes, we identified individuals with mutations in NKX2-1 whose primary manifestation was respiratory disease. METHODS Retrospective and prospective approaches identified infants and children with unexplained diffuse lung disease for NKX2-1 sequencing. Histopathologic results and electron micrographs were assessed, and immunohistochemical analysis for surfactant-associated proteins was performed in a subset of 10 children for whom lung tissue was available. RESULTS We identified 16 individuals with heterozygous missense, nonsense, and frameshift mutations and five individuals with heterozygous, whole-gene deletions of NKX2-1. Neonatal RDS was the presenting pulmonary phenotype in 16 individuals (76%), interstitial lung disease in four (19%), and pulmonary fibrosis in one adult family member. Altogether, 12 individuals (57%) had the full triad of neurologic, thyroid, and respiratory manifestations, but five (24%) had only pulmonary symptoms at the time of presentation. Recurrent respiratory infections were a prominent feature in nine subjects. Lung histopathology demonstrated evidence of disrupted surfactant homeostasis in the majority of cases, and at least five cases had evidence of disrupted lung growth. CONCLUSIONS Patients with mutations in NKX2-1 may present with pulmonary manifestations in the newborn period or during childhood when thyroid or neurologic abnormalities are not apparent. Surfactant dysfunction and, in more severe cases, disrupted lung development are likely mechanisms for the respiratory disease.
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Affiliation(s)
- Aaron Hamvas
- Edward Mallinckrodt Department of Pediatrics, Washington University, St. Louis, MO.
| | - Robin R Deterding
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | - Susan E Wert
- The Perinatal Institute, Divisions of Neonatology, Perinatal and Pulmonary Biology, Cincinnati Children's Hospital Medical Center and the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Frances V White
- Lauren Ackerman Department of Pathology and Immunology, Washington University, St. Louis, MO
| | - Megan K Dishop
- Department of Pathology and Laboratory Medicine, University of Colorado School of Medicine, Aurora, CO
| | - Danielle N Alfano
- Edward Mallinckrodt Department of Pediatrics, Washington University, St. Louis, MO
| | - Ann C Halbower
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | - Benjamin Planer
- Department of Pediatrics, Hackensack University Medical Center, Hackensack, NJ
| | - Mark J Stephan
- Department of Pediatrics, University of Washington, Seattle, WA
| | - Derek A Uchida
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
| | - Lee D Williames
- Department of Pediatrics, Madigan Healthcare System, Tacoma, WA
| | | | - Robert Roger Lebel
- Section of Medical Genetics, Department of Pediatrics, SUNY Upstate Medical University, Syracuse, NY
| | - Lisa R Young
- Departments of Pediatrics and Medicine, Vanderbilt University, Nashville, TN
| | - F Sessions Cole
- Edward Mallinckrodt Department of Pediatrics, Washington University, St. Louis, MO
| | - Lawrence M Nogee
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD
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Alexander DB, Iigo M, Yamauchi K, Suzui M, Tsuda H. Lactoferrin: an alternative view of its role in human biological fluids. Biochem Cell Biol 2012; 90:279-306. [PMID: 22553915 DOI: 10.1139/o2012-013] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Lactoferrin is a major component of biologically important mucosal fluids and of the specific granules of neutrophils. Understanding its biological function is essential for understanding neutrophil- and mucosal-mediated immunity. In this review, we reevaluate the in vivo functions of human lactoferrin (hLF) emphasizing in vivo studies and in vitro studies performed in biologically relevant fluids. We discuss the evidence in the literature that supports (or does not support) proposed roles for hLF in mucosal immunity and in neutrophil function. We argue that the current literature supports a microbiostatic role, but not a microbicidal role, for hLF in vivo. The literature also supports a role for hLF in inhibiting colonization and infection of epithelial surfaces by microorganisms and in protecting tissues from neutrophil-mediated damage. Using this information, we briefly discuss hLF in the context of the complex biological fluids in which it is found.
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Affiliation(s)
- David B Alexander
- Laboratory of Nanotoxicology Project, Nagoya City University, 3-1 Tanabedohri, Mizuho-ku, Nagoya 467-8603, Japan.
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Hu F, Liang W, Ren Z, Wang G, Ding G. Surfactant protein D inhibits lipopolysaccharide-induced monocyte chemoattractant protein-1 expression in human renal tubular epithelial cells: implication for tubulointerstitial fibrosis. Clin Exp Immunol 2012; 167:514-22. [PMID: 22288595 DOI: 10.1111/j.1365-2249.2011.04521.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Surfactant protein D (SP-D), a member of the C-type lectin (collectin) protein family, plays a critical role in innate host defence against various microbial pathogens and in the modulation of inflammatory responses in the lung. However, little is known about its expression and biological function in the kidney. In this work, we studied SP-D expression in human kidney and cultured human renal proximal tubular epithelial cells (HK-2), and examined the effect of SP-D on proinflammatory cytokine production after lipopolysaccharide (LPS) stimulus. We observed the expression of both SP-D mRNA and protein in human kidney and in-vitro HK-2 cells by immunohistochemistry, Western blot analysis, reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR. To explore the potential role of SP-D in the pathogenesis of tubulointerstitial fibrosis in kidney infection, we examined the production of monocyte chemoattractant protein-1 (MCP-1) in HK-2 cells after LPS treatment. Results showed that the level of MCP-1 in the conditioned medium increased significantly when HK-2 cells were cultured with LPS (>0·1 µg/ml) for 8 h. Of interest, LPS treatment inhibited SP-D expression in HK-2 cells. Furthermore, over-expression of SP-D reduced significantly the LPS-induced expression of MCP-1 in transfected cells. These findings suggest that SP-D in the kidney functions as an anti-inflammatory factor in renal tubular epithelial cells and may modulate tubulointerstitial fibrosis in kidney.
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Affiliation(s)
- F Hu
- Division of Nephrology, Department of Medicine, Renmin Hospital of Wuhan University, Wuhan, China
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12
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Atochina-Vasserman EN. S-nitrosylation of surfactant protein D as a modulator of pulmonary inflammation. Biochim Biophys Acta Gen Subj 2011; 1820:763-9. [PMID: 22183030 DOI: 10.1016/j.bbagen.2011.12.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 10/13/2011] [Accepted: 12/04/2011] [Indexed: 01/26/2023]
Abstract
BACKGROUND Surfactant protein D (SP-D) is a member of the family of proteins termed collagen-like lectins or "collectins" that play a role in non-antibody-mediated innate immune responses [1]. The primary function of SP-D is the modulation of host defense and inflammation [2]. SCOPE OF REVIEW This review will discuss recent findings on the physiological importance of SP-D S-nitrosylation in biological systems and potential mechanisms that govern SP-D mediated signaling. MAJOR CONCLUSIONS SP-D appears to have both pro- and anti-inflammatory signaling functions. SP-D multimerization is a critical feature of its function and plays an important role in efficient innate host defense. Under baseline conditions, SP-D forms a multimer in which the N-termini are hidden in the center and the C-termini are on the surface. This multimeric form of SP-D is limited in its ability to activate inflammation. However, NO can modify key cysteine residues in the hydrophobic tail domain of SP-D resulting in a dissociation of SP-D multimers into trimers, exposing the S-nitrosylated N-termini. The exposed S-nitrosylated tail domain binds to the calreticulin/CD91 receptor complex and initiates a pro-inflammatory response through phosphorylation of p38 and NF-κB activation [3,4]. In addition, the disassembled SP-D loses its ability to block TLR4, which also results in activation of NF-κB. GENERAL SIGNIFICANCE Recent studies have highlighted the capability of NO to modify SP-D through S-nitrosylation, causing the activation of a pro-inflammatory role for SP-D [3]. This represents a novel mechanism both for the regulation of SP-D function and NO's role in innate immunity, but also demonstrates that the S-nitrosylation can control protein function by regulating quaternary structure. This article is part of a Special Issue entitled Regulation of Cellular Processes by S-nitrosylation.
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Affiliation(s)
- Elena N Atochina-Vasserman
- Pulmonary, Allergy and Critical Care Division, Department of Medicine University of Pennsylvania, Vernon and Shirley Hill Pavilion, #H410C, 380 S. University Ave., Philadelphia, PA 19104-4539, USA.
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Recent advances in alveolar biology: evolution and function of alveolar proteins. Respir Physiol Neurobiol 2010; 173 Suppl:S43-54. [PMID: 20433956 DOI: 10.1016/j.resp.2010.04.023] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 04/21/2010] [Accepted: 04/21/2010] [Indexed: 12/25/2022]
Abstract
This review is focused on the evolution and function of alveolar proteins. The lung faces physical and environmental challenges, due to changing pressures/volumes and foreign pathogens, respectively. The pulmonary surfactant system is integral in protecting the lung from these challenges via two groups of surfactant proteins - the small molecular weight hydrophobic SPs, SP-B and -C, that regulate interfacial adsorption of the lipids, and the large hydrophilic SPs, SP-A and -D, which are surfactant collectins capable of inhibiting foreign pathogens. Further aiding pulmonary host defence are non-surfactant collectins and antimicrobial peptides that are expressed across the biological kingdoms. Linking to the first symposium session, which emphasised molecular structure and biophysical function of surfactant lipids and proteins, this review begins with a discussion of the role of temperature and hydrostatic pressure in shaping the evolution of SP-C in mammals. Transitioning to the role of the alveolus in innate host defence we discuss the structure, function and regulation of antimicrobial peptides, the defensins and cathelicidins. We describe the recent discovery of novel avian collectins and provide evidence for their role in preventing influenza infection. This is followed by discussions of the roles of SP-A and SP-D in mediating host defence at the alveolar surface and in mediating inflammation and the allergic response of the airways. Finally we discuss the use of animal models of lung disease including knockouts to develop an understanding of the role of these proteins in initiating and/or perpetuating disease with the aim of developing new therapeutic strategies.
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