1
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Balczon R, Lin MT, Voth S, Nelson AR, Schupp JC, Wagener BM, Pittet JF, Stevens T. Lung endothelium, tau, and amyloids in health and disease. Physiol Rev 2024; 104:533-587. [PMID: 37561137 PMCID: PMC11281824 DOI: 10.1152/physrev.00006.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 06/26/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023] Open
Abstract
Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Mike T Lin
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Sarah Voth
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Monroe, Louisiana, United States
| | - Amy R Nelson
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Jonas C Schupp
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University, New Haven, Connecticut, United States
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- German Center for Lung Research (DZL), Hannover, Germany
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
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2
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Wormwood KL, Charette L, Ryan JP, Darie CC, Woods AG. A Proteomics Investigation of Salivary Profiles as Potential Biomarkers for Autism Spectrum Disorder (ASD). Protein J 2023; 42:607-620. [PMID: 37566278 DOI: 10.1007/s10930-023-10146-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2023] [Indexed: 08/12/2023]
Abstract
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects approximately 1/68 children, with a more recent study suggesting numbers as high as 1/36. According to Diagnostic and Statistical Manual of Mental Disorders, the etiology of ASD is unknown and diagnosis of this disorder is behavioral. There is currently no biomarker signature for ASD, however, identifying a biomarker signature is crucial as it would aid in diagnosis, identifying treatment targets, monitoring treatments, and identifying the etiology of the disorder. Here we used nanoliquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) to investigate the saliva from individuals with ASD and matched controls in a 14 vs 14 study. We found numerous proteins to have statistically significant dysregulations, including lactotransferrin, transferrin, polymeric immunoglobulin receptor, Ig A L, Ig J chain, mucin 5 AC, and lipocalin 1 isoform X1. These findings are consistent with previous studies by our lab, and others, and point to dysregulations in the immune system, lipid metabolism and/or transport, and gastrointestinal disturbances, which are common and reoccurring topics in ASD research.
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Affiliation(s)
- Kelly L Wormwood
- Biochemistry & Proteomics Laboratories, Department of Chemistry & Biomolecular Science, Clarkson University, 8 Clarkson Ave, Box 5810, Potsdam, NY, 13699, USA
| | - Laci Charette
- Center for Neurobehavioral Health and Department of Psychology, SUNY Plattsburgh, Plattsburgh, NY, USA
| | - Jeanne P Ryan
- Center for Neurobehavioral Health and Department of Psychology, SUNY Plattsburgh, Plattsburgh, NY, USA
| | - Costel C Darie
- Biochemistry & Proteomics Laboratories, Department of Chemistry & Biomolecular Science, Clarkson University, 8 Clarkson Ave, Box 5810, Potsdam, NY, 13699, USA.
| | - Alisa G Woods
- Biochemistry & Proteomics Laboratories, Department of Chemistry & Biomolecular Science, Clarkson University, 8 Clarkson Ave, Box 5810, Potsdam, NY, 13699, USA
- Center for Neurobehavioral Health and Department of Psychology, SUNY Plattsburgh, Plattsburgh, NY, USA
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3
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Nunzi E, Mezzasoma L, Bellezza I, Zelante T, Orvietani P, Coata G, Giardina I, Sagini K, Manni G, Di Michele A, Gargaro M, Talesa VN, Di Renzo GC, Fallarino F, Romani R. Microbiota-Associated HAF-EVs Regulate Monocytes by Triggering or Inhibiting Inflammasome Activation. Int J Mol Sci 2023; 24:ijms24032527. [PMID: 36768851 PMCID: PMC9916438 DOI: 10.3390/ijms24032527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/21/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
In pregnancy, human amniotic fluid extracellular vesicles (HAF-EVs) exert anti-inflammatory effects on T cells and on monocytes, supporting their immunoregulatory roles. The specific mechanisms are still not completely defined. The aim of this study was to investigate the ability of HAF-EVs, isolated from pregnant women who underwent amniocentesis and purified by gradient ultracentrifugation, to affect inflammasome activation in the human monocytes. Proteomic studies revealed that HAF-EV samples expressed several immunoregulatory molecules as well as small amounts of endotoxin. Surprisingly, metagenomic analysis shows the presence of specific bacterial strain variants associated with HAF-EVs as potential sources of the endotoxin. Remarkably, we showed that a single treatment of THP-1 cells with HAF-EVs triggered inflammasome activation, whereas the same treatment followed by LPS and ATP sensitization prevented inflammasome activation, a pathway resembling monocyte refractories. A bioinformatics analysis of microbiota-HAF-EVs functional pathways confirmed the presence of enzymes for endotoxin biosynthesis as well as others associated with immunoregulatory functions. Overall, these data suggest that HAF-EVs could serve as a source of the isolation of a specific microbiota during early pregnancy. Moreover, HAF-EVs could act as a novel system to balance immune training and tolerance by modulating the inflammasome in monocytes or other cells.
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Affiliation(s)
- Emilia Nunzi
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Letizia Mezzasoma
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Ilaria Bellezza
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Teresa Zelante
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Pierluigi Orvietani
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Giuliana Coata
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Irene Giardina
- Department of Obstetrics and Gynecology, University Hospital of Perugia, Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Krizia Sagini
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379 Oslo, Norway
| | - Giorgia Manni
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Alessandro Di Michele
- Department of Physics and Geology, University of Perugia, Via Pascoli, 06123 Perugia, Italy
| | - Marco Gargaro
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Vincenzo N. Talesa
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
| | - Gian Carlo Di Renzo
- Department of Obstetrics, Gynecology and Perinatology IM Sechenov First State University, 117997 Moscow, Russia
| | - Francesca Fallarino
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
- Correspondence: (F.F.); (R.R.)
| | - Rita Romani
- Department of Medicine and Surgery, University of Perugia, Polo Unico Sant’Andrea delle Fratte, P.e Lucio Severi 1, 06132 Perugia, Italy
- Correspondence: (F.F.); (R.R.)
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4
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Mihalj H, Butković J, Tokić S, Štefanić M, Kizivat T, Bujak M, Baus Lončar M, Mihalj M. Expression of Oxidative Stress and Inflammation-Related Genes in Nasal Mucosa and Nasal Polyps from Patients with Chronic Rhinosinusitis. Int J Mol Sci 2022; 23:5521. [PMID: 35628331 PMCID: PMC9145877 DOI: 10.3390/ijms23105521] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/09/2022] [Accepted: 05/12/2022] [Indexed: 12/10/2022] Open
Abstract
Chronic rhinosinusitis (CRS) is a prevalent, multifaceted inflammatory condition affecting the nasal cavity and the paranasal sinuses, frequently accompanied by formation of nasal polyps (CRSwNP). This apparently uniform clinical entity is preceded by heterogeneous changes in cellular and molecular patterns, suggesting the presence of multiple CRS endotypes and a diverse etiology. Alterations of the upper airway innate defense mechanisms, including antimicrobial and antioxidant capacity, have been implicated in CRSwNP etiology. The aim of this study was to investigate mRNA expression patterns of antioxidative enzymes, including superoxide dismutase (SOD) and peroxiredoxin-2 (PRDX2), and innate immune system defense players, namely the bactericidal/permeability-increasing fold-containing family A, member 1 (BPIFA1) and PACAP family members, particularly adenylate-cyclase-activating polypeptide receptor 1 (ADCYAP1) in nasal mucosa and nasal polyps from CRSwNP patients. Additional stratification based on age, sex, allergic comorbidity, and disease severity was applied. The results showed that ADCYAP1, BPIFA1, and PRDX2 transcripts are differentially expressed in nasal mucosa and scale with radiologically assessed disease severity in CRSwNP patients. Sinonasal transcriptome is not associated with age, sex, and smoking in CRSwNP. Surgical and postoperative corticosteroid (CS) therapy improves endoscopic appearance of the mucosa, but variably reverses target gene expression patterns in the nasal cavity of CRSwNP patients. Transcriptional cross-correlations analysis revealed an increased level of connectedness among differentially expressed genes under inflammatory conditions and restoration of basic network following CS treatment. Although results of the present study imply a possible engagement of ADCYAP1 and BPIFA1 as biomarkers for CRSwNP, a more profound study taking into account disease severity and CRSwNP endotypes prior to the treatment would provide additional information on their sensitivity.
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Affiliation(s)
- Hrvoje Mihalj
- Clinical Department of Otorhinolaryngology, Head and Neck Surgery University Hospital Osijek, HR-31000 Osijek, Croatia;
- Department of Otorhinolaryngology, Maxillofacial Surgery Faculty of Medicine University of Osijek, HR-31000 Osijek, Croatia;
| | - Josip Butković
- Department of Otorhinolaryngology, Maxillofacial Surgery Faculty of Medicine University of Osijek, HR-31000 Osijek, Croatia;
- Department of Oral and Maxillofacial Surgery, University Hospital Osijek, HR-31000 Osijek, Croatia
| | - Stana Tokić
- Department of Laboratory Medicine and Pharmacy, Faculty of Medicine, University of Osijek, HR-31000 Osijek, Croatia;
| | - Mario Štefanić
- Department of Nuclear Medicine and Oncology, Faculty of Medicine, University of Osijek, HR-31000 Osijek, Croatia; (M.Š.); (T.K.)
| | - Tomislav Kizivat
- Department of Nuclear Medicine and Oncology, Faculty of Medicine, University of Osijek, HR-31000 Osijek, Croatia; (M.Š.); (T.K.)
- Clinical Institute of Nuclear Medicine and Radiation Protection, University Hospital Osijek, HR-31000 Osijek, Croatia
| | - Maro Bujak
- Department of Materials Chemistry, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia;
| | - Mirela Baus Lončar
- Department of Molecular Medicine, Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
| | - Martina Mihalj
- Department of Dermatology and Venereology, University Hospital Osijek, HR-31000 Osijek, Croatia
- Department of Physiology and Immunology, Faculty of Medicine University of Osijek, HR-31000 Osijek, Croatia
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5
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Escobar‐Salom M, Torrens G, Jordana‐Lluch E, Oliver A, Juan C. Mammals' humoral immune proteins and peptides targeting the bacterial envelope: from natural protection to therapeutic applications against multidrug‐resistant
Gram
‐negatives. Biol Rev Camb Philos Soc 2022; 97:1005-1037. [PMID: 35043558 PMCID: PMC9304279 DOI: 10.1111/brv.12830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
Abstract
Mammalian innate immunity employs several humoral ‘weapons’ that target the bacterial envelope. The threats posed by the multidrug‐resistant ‘ESKAPE’ Gram‐negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are forcing researchers to explore new therapeutic options, including the use of these immune elements. Here we review bacterial envelope‐targeting (peptidoglycan and/or membrane‐targeting) proteins/peptides of the mammalian immune system that are most likely to have therapeutic applications. Firstly we discuss their general features and protective activity against ESKAPE Gram‐negatives in the host. We then gather, integrate, and discuss recent research on experimental therapeutics harnessing their bactericidal power, based on their exogenous administration and also on the discovery of bacterial and/or host targets that improve the performance of this endogenous immunity, as a novel therapeutic concept. We identify weak points and knowledge gaps in current research in this field and suggest areas for future work to obtain successful envelope‐targeting therapeutic options to tackle the challenge of antimicrobial resistance.
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Affiliation(s)
- María Escobar‐Salom
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Gabriel Torrens
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Elena Jordana‐Lluch
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Antonio Oliver
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Carlos Juan
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
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6
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Zhang R, Trower J, Wu T. Degradation of bacterial permeability family member A1 (BPIFA1) by house dust mite (HDM) cysteine protease Der p 1 abrogates immune modulator function. Int J Biol Macromol 2020; 164:4022-4031. [PMID: 32890564 PMCID: PMC7467078 DOI: 10.1016/j.ijbiomac.2020.08.214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/19/2020] [Accepted: 08/28/2020] [Indexed: 01/01/2023]
Abstract
Bacterial permeability family member A1 (BPIFA1) is one of the most abundant proteins present in normal airway surface liquid (ASL). It is known to be diminished in asthmatic patients' sputum, which causes airway hyperresponsiveness (AHR). What is currently unclear is how environmental factors, such as allergens' impact on BPIFA1's abundance and functions in the context of allergic asthma. House dust mite (HDM) is a predominant domestic source of aeroallergens. The group of proteases found in HDM is thought to cleave multiple cellular protective mechanisms, and therefore foster the development of allergic asthma. Here, we show that BPIFA1 is cleaved by HDM proteases in a time-, dose-, and temperature-dependent manner. We have also shown the main component in HDM that is responsible for BPIFA1's degradation is Der p1. Fragmented BPIFA1 failed to bind E. coli lipopolysaccharide (LPS), and hence elevated TNFα and IL-6 secretion in human whole blood. BPIFA1 degradation is also observed in vivo in bronchoalveolar fluid (BALF) of mice which are intranasally instilled with HDM. These data suggest that proteases associated with environmental allergens such as HDM cleave BPIFA1 and therefore impair its immune modulator function.
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Affiliation(s)
- Rui Zhang
- Department of Respiratory and Critical Care Medicine, General Hospital of Ningxia Medical University, Ningxia Medical University, Yinchuan, PR China
| | - Jessika Trower
- Department of Pharmaceutical Sciences, 302 East Lawson Street, North Carolina Central University, Durham, NC 27707, USA
| | - Tongde Wu
- Department of Pharmaceutical Sciences, 302 East Lawson Street, North Carolina Central University, Durham, NC 27707, USA; Biomanufacturing Research Institute & Technology Enterprise (BRITE), 302 East Lawson Street, North Carolina Central University, Durham, NC 27707, USA.
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7
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Akutsu T, Watanabe K. A Proposed Procedure for Discriminating between Nasal Secretion and Saliva by RT-qPCR. Diagnostics (Basel) 2020; 10:E519. [PMID: 32722656 PMCID: PMC7460356 DOI: 10.3390/diagnostics10080519] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 11/16/2022] Open
Abstract
In forensic casework, nasal secretion can be a good source of DNA. Moreover, saliva can prove useful in cases of sexual assault. However, discriminating between these body fluids is often difficult because of cross-reactivity between them on presumptive and confirmatory tests. Therefore, an RT-qPCR procedure was developed to discriminate between nasal secretion and saliva. Characteristic genes in nasal secretion and/or saliva (BPIFA1, STATH, HTN3, and PRH2) were selected as candidates. Discrimination criteria were established based on the expression levels of these markers in various body fluids. In addition, a flowchart was proposed and used to discriminate among nasal secretion, saliva, and other body fluids in various forensic samples. BPIFA1 was highly expressed in nasal secretion but was also expressed in saliva, semen, and vaginal fluid at trace levels. STATH was expressed in nasal secretion and saliva but not in other body fluids. HTN3 was specifically expressed in most of the saliva samples, as reported previously. Unexpectedly, PRH2 was expressed in only a few saliva samples. Using the proposed criteria and flowchart, nasal secretion and saliva were successfully discriminated among the various body fluids tested. The developed procedure could be useful in forensic casework.
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Affiliation(s)
- Tomoko Akutsu
- National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa-shi, Chiba 277-0882, Japan;
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8
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Ahmad S, Kim CSK, Tarran R. The SPLUNC1-βENaC complex prevents Burkholderia cenocepacia invasion in normal airway epithelia. Respir Res 2020; 21:190. [PMID: 32680508 PMCID: PMC7368771 DOI: 10.1186/s12931-020-01454-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022] Open
Abstract
Cystic fibrosis (CF) patients are extremely vulnerable to Burkholderia cepacia complex (Bcc) infections. However, the underlying etiology is poorly understood. We tested the hypothesis that short palate lung and nasal epithelial clone 1 (SPLUNC1)-epithelial sodium channel (ENaC) interactions at the plasma membrane are required to reduce Bcc burden in normal airways. To determine if SPLUNC1 was needed to reduce Bcc burden in the airways, SPLUNC1 knockout mice and their wild-type littermates were infected with B. cenocepacia strain J2315. SPLUNC1 knockout mice had increased bacterial burden in the lungs compared to wild-type littermate mice. SPLUNC1-knockdown primary human bronchial epithelia (HBECs) were incubated with J2315, which resulted in increased bacterial burden compared to non-transduced HBECs. We next determined the interaction of the SPLUNC1-ENaC complex during J2315 infection. SPLUNC1 remained at the apical plasma membrane of normal HBECs but less was present at the apical plasma membrane of CF HBECs. Additionally, SPLUNC1-βENaC complexes reduced intracellular J2315 burden. Our data indicate that (i) secreted SPLUNC1 is required to reduce J2315 burden in the airways and (ii) its interaction with ENaC prevents cellular invasion of J2315.
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Affiliation(s)
- Saira Ahmad
- Department of Cell Biology and Physiology, The University of North Carolina, Marsico Lung Insitute, 115 Mason Farm Rd CB 7545, UNC, Chapel Hill, NC, 27599, USA
| | - Christine Seul Ki Kim
- Department of Cell Biology and Physiology, The University of North Carolina, Marsico Lung Insitute, 115 Mason Farm Rd CB 7545, UNC, Chapel Hill, NC, 27599, USA
- Present address: Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Robert Tarran
- Department of Cell Biology and Physiology, The University of North Carolina, Marsico Lung Insitute, 115 Mason Farm Rd CB 7545, UNC, Chapel Hill, NC, 27599, USA.
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9
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Mashbat B, Bellos E, Hodeib S, Bidmos F, Thwaites RS, Lu Y, Wright VJ, Herberg JA, Klobassa DS, Walton WG, Zenz W, Hansel TT, Nadel S, Langford PR, Schlapbach LJ, Li MS, Redinbo MR, Di YP, Levin M, Sancho-Shimizu V. A Rare Mutation in SPLUNC1 Affects Bacterial Adherence and Invasion in Meningococcal Disease. Clin Infect Dis 2020; 70:2045-2053. [PMID: 31504285 PMCID: PMC7201419 DOI: 10.1093/cid/ciz600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 06/28/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Neisseria meningitidis (Nm) is a nasopharyngeal commensal carried by healthy individuals. However, invasive infections occurs in a minority of individuals, with devastating consequences. There is evidence that common polymorphisms are associated with invasive meningococcal disease (IMD), but the contributions of rare variants other than those in the complement system have not been determined. METHODS We identified familial cases of IMD in the UK meningococcal disease study and the European Union Life-Threatening Infectious Disease Study. Candidate genetic variants were identified by whole-exome sequencing of 2 patients with familial IMD. Candidate variants were further validated by in vitro assays. RESULTS Exomes of 2 siblings with IMD identified a novel heterozygous missense mutation in BPIFA1/SPLUNC1. Sequencing of 186 other nonfamilial cases identified another unrelated IMD patient with the same mutation. SPLUNC1 is an innate immune defense protein expressed in the nasopharyngeal epithelia; however, its role in invasive infections is unknown. In vitro assays demonstrated that recombinant SPLUNC1 protein inhibits biofilm formation by Nm, and impedes Nm adhesion and invasion of human airway cells. The dominant negative mutant recombinant SPLUNC1 (p.G22E) showed reduced antibiofilm activity, increased meningococcal adhesion, and increased invasion of cells, compared with wild-type SPLUNC1. CONCLUSIONS A mutation in SPLUNC1 affecting mucosal attachment, biofilm formation, and invasion of mucosal epithelial cells is a new genetic cause of meningococcal disease.
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Affiliation(s)
- Bayarchimeg Mashbat
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Evangelos Bellos
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Stephanie Hodeib
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Fadil Bidmos
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Ryan S Thwaites
- National Heart and Lung Institute, Imperial College London, United Kingdom
| | - Yaxuan Lu
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Victoria J Wright
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Jethro A Herberg
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Daniela S Klobassa
- Department of Pediatric and Adolescence Surgery, Division of General Pediatric Surgery, Medical University Graz, Austria
| | - William G Walton
- Paediatric Intensive Care Unit, St. Mary’s Hospital, Imperial College Healthcare Trust, London, United Kingdom
| | - Werner Zenz
- Department of Pediatric and Adolescence Surgery, Division of General Pediatric Surgery, Medical University Graz, Austria
| | - Trevor T Hansel
- National Heart and Lung Institute, Imperial College London, United Kingdom
| | - Simon Nadel
- Paediatric Intensive Care Unit, St. Mary’s Hospital, Imperial College Healthcare Trust, London, United Kingdom
| | - Paul R Langford
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Luregn J Schlapbach
- Faculty of Medicine Brisbane, The University of Queensland Brisbane, Australia
- Paediatric Critical Care Research Group, The University of Queensland Brisbane, Australia
- Paediatric Intensive Care Unit, Lady Cilento Children’s Hospital, Children’s Health Queensland, Brisbane, Australia
- Department of Pediatrics, Bern University Hospital, Inselspital, University of Bern, Switzerland
| | - Ming-Shi Li
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Matthew R Redinbo
- Department of Chemistry, University of North Carolina, Chapel Hill
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill
| | - Y Peter Di
- Department of Environmental and Occupational Health, University of Pittsburgh, Pennsylvania
| | - Michael Levin
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
| | - Vanessa Sancho-Shimizu
- Department of Paediatric Infectious Diseases, Division of Medicine, Imperial College London, Norfolk Place, United Kingdom
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10
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Geng R, Wang Q, Chen E, Zheng QY. Current Understanding of Host Genetics of Otitis Media. Front Genet 2020; 10:1395. [PMID: 32117425 PMCID: PMC7025460 DOI: 10.3389/fgene.2019.01395] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/20/2019] [Indexed: 12/13/2022] Open
Abstract
The pathogenesis of otitis media (OM), an inflammatory disease of the middle ear (ME), involves interplay between many different factors, including the pathogenicity of infectious pathogens, host immunological status, environmental factors, and genetic predisposition, which is known to be a key determinant of OM susceptibility. Animal models and human genetics studies have identified many genes and gene variants associated with OM susceptibility: genes that encode components of multiple signaling pathways involved in host immunity and inflammatory responses of the ME mucosa; genes involved in cellular function, such as mucociliary transport, mucin production, and mucous cell metaplasia; and genes that are essential for Eustachian tube (ET) development, ME cavitation, and homeostasis. Since our last review, several new mouse models with mutations in genes such as CCL3, IL-17A, and Nisch have been reported. Moreover, genetic variants and polymorphisms in several genes, including FNDC1, FUT2, A2ML1, TGIF1, CD44, and IL1-RA variable number tandem repeat (VNTR) allele 2, have been identified as being significantly associated with OM. In this review, we focus on the current understanding of the role of host genetics in OM, including recent discoveries and future research prospects. Further studies on the genes identified thus far and the discovery of new genes using advanced technologies such as gene editing, next generation sequencing, and genome-wide association studies, will advance our understanding of the molecular mechanism underlying the pathogenesis of OM and provide new avenues for early screening and developing effective preventative and therapeutic strategies to treat OM.
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Affiliation(s)
- Ruishuang Geng
- College of Special Education, Binzhou Medical University, Yantai, China
| | - Qingzhu Wang
- College of Special Education, Binzhou Medical University, Yantai, China.,Department of Otolaryngology, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Eileen Chen
- Department of Otolaryngology, Case Western Reserve University, Cleveland, OH, United States
| | - Qing Yin Zheng
- Department of Otolaryngology, Case Western Reserve University, Cleveland, OH, United States
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11
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Saferali A, Tang AC, Strug LJ, Quon BS, Zlosnik J, Sandford AJ, Turvey SE. Immunomodulatory function of the cystic fibrosis modifier gene BPIFA1. PLoS One 2020; 15:e0227067. [PMID: 31931521 PMCID: PMC6957340 DOI: 10.1371/journal.pone.0227067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Cystic fibrosis (CF) is characterized by a progressive decline in lung function due to airway obstruction, infection, and inflammation. CF patients are particularly susceptible to respiratory infection by a variety of pathogens, and the inflammatory response in CF is dysregulated and prolonged. BPI fold containing family A, member 1 (BPIFA1) and BPIFB1 are proteins expressed in the upper airways that may have innate immune activity. We previously identified polymorphisms in the BPIFA1/BPIFB1 region associated with CF lung disease severity. METHODS We evaluated whether the BPIFA1/BPIFB1 associations with lung disease severity replicated in individuals with CF participating in the International CF Gene Modifier Consortium (n = 6,365). Furthermore, we investigated mechanisms by which the BPIFA1 and BPIFB1 proteins may modify lung disease in CF. RESULTS The association of the G allele of rs1078761 with reduced lung function was replicated in an independent cohort of CF patients (p = 0.001, n = 2,921) and in a meta-analysis of the full consortium (p = 2.39x10-5, n = 6,365). Furthermore, we found that rs1078761G which is associated with reduced lung function was also associated with reduced BPIFA1, but not BPIFB1, protein levels in saliva from CF patients. Functional assays indicated that BPIFA1 and BPIFB1 do not have an anti-bacterial role against P. aeruginosa but may have an immunomodulatory function in CF airway epithelial cells. Gene expression profiling using RNAseq identified Rho GTPase signaling pathways to be altered in CF airway epithelial cells in response to treatment with recombinant BPIFA1 and BPIFB1 proteins. CONCLUSIONS BPIFA1 and BPIFB1 have immunomodulatory activity and genetic variation associated with low levels of these proteins may increase CF lung disease severity.
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Affiliation(s)
- Aabida Saferali
- Centre for Heart Lung Innovation, University of British Columbia and St Paul’s Hospital, Vancouver, British Columbia, Canada
- Department of Pediatrics, University of British Columbia and BC Children’s Hospital, Vancouver, British Columbia, Canada
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Anthony C. Tang
- Department of Pediatrics, University of British Columbia and BC Children’s Hospital, Vancouver, British Columbia, Canada
| | - Lisa J. Strug
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Bradley S. Quon
- Centre for Heart Lung Innovation, University of British Columbia and St Paul’s Hospital, Vancouver, British Columbia, Canada
| | - James Zlosnik
- Department of Pediatrics, University of British Columbia and BC Children’s Hospital, Vancouver, British Columbia, Canada
| | - Andrew J. Sandford
- Centre for Heart Lung Innovation, University of British Columbia and St Paul’s Hospital, Vancouver, British Columbia, Canada
| | - Stuart E. Turvey
- Department of Pediatrics, University of British Columbia and BC Children’s Hospital, Vancouver, British Columbia, Canada
- * E-mail:
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12
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Hong W, Khampang P, Kerschner AR, Mackinnon AC, Yan K, Simpson PM, Kerschner JE. Antibiotic modulation of mucins in otitis media; should this change our approach to watchful waiting? Int J Pediatr Otorhinolaryngol 2019; 125:134-140. [PMID: 31302575 PMCID: PMC6742428 DOI: 10.1016/j.ijporl.2019.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 06/05/2019] [Accepted: 07/02/2019] [Indexed: 01/16/2023]
Abstract
BACKGROUND Gel-forming mucins (GFMs) play important roles in otitis media (OM) pathogenesis. Increased mucin expression is activated by pathogens and proinflammatory cytokines. Bacterial biofilms influence inflammation and resolution of OM and may contribute to prolonged mucin production. The influence of specific pathogens on mucin expression and development of chronic OM with effusion (OME) remains an area of significant knowledge deficit. OBJECTIVES To assess the relationship between GFM expression, specific pathogens, middle ear mucosal (MEM) changes, biofilm formation, and antibiotic utilization. METHODS Mixed gender chinchillas were inoculated with nontypeable Haemophilus influenzae (NTHi) strain 86028NP or Streptococcus pneumoniae (SP) strain TIGR4 via transbulla injection. Antibiotic was administered on day 3-5 post inoculation. GFM expression was measured by quantitative PCR. Biofilm formation was identified and middle ear histologic changes were measured. RESULTS SP infection resulted in higher incidence of biofilm and ME effusion compared with NTHi infection. However, NTHi persisted in the ME longer than SP with no substantive bacterial clearance detected on day 10 compared with complete bacterial clearance on day 10 for 50-60% of the SP-infected chinchillas. Both infections increased MEM inflammatory cell infiltration and thickening. NTHi upregulated the Muc5AC, Muc5B and Muc19 expression on day 10 (p = 0.0004, 0.003, and 0.002 respectively). SP-induced GFM upregulations were trended toward significant. In both NTHi and SP infections, the degree of GFM upregulation had a direct relationship to increased MEM hypertrophy, inflammatory cell infiltration and biofilm formation. Antibiotic treatment reduced the incidence of ME effusion and biofilm, limited the MEM changes and reversed the GFM upregulation. In NTHi infection, the rate of returning to baseline level of GFMs in treated chinchillas was quicker than those without treatment. CONCLUSIONS In an animal model of OM, GFM genes are upregulated in conjunction with MEM hypertrophy and biofilm formation. This upregulation is less robust and more quickly ameliorated to a significant degree in the NTHi infection with appropriate antibiotic therapy. These findings contribute to the understanding of pathogen specific influences on mucin expression during OM pathogenesis and provide new data which may have implications in clinical approach for OM treatment.
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Affiliation(s)
- Wenzhou Hong
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, USA
| | - Pawjai Khampang
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, USA
| | - Abigail R Kerschner
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, USA
| | | | - Ke Yan
- Quantitative Health Sciences, Department of Pediatrics, Medical College of Wisconsin, USA
| | - Pippa M Simpson
- Quantitative Health Sciences, Department of Pediatrics, Medical College of Wisconsin, USA
| | - Joseph E Kerschner
- Division of Pediatric Otolaryngology, Medical College of Wisconsin, USA; Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, USA.
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13
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Moore PJ, Sesma J, Alexis NE, Tarran R. Tobacco exposure inhibits SPLUNC1-dependent antimicrobial activity. Respir Res 2019; 20:94. [PMID: 31113421 PMCID: PMC6530064 DOI: 10.1186/s12931-019-1066-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 05/06/2019] [Indexed: 11/24/2022] Open
Abstract
Background Tobacco smoke exposure impairs the lung’s innate immune response, leading to an increased risk of chronic infections. SPLUNC1 is a secreted, multifunctional innate defense protein that has antimicrobial activity against Gram negative organisms. We hypothesize that tobacco smoke-induced SPLUNC1 dysfunction contributes to the observed defect in innate immunity in tobacco smokers and that this dysfunction can be used as a potential biomarker of harm. Methods We collected sputum from never-smokers and otherwise healthy smokers. We performed Western blotting to determine SPLUNC1 levels and determined antimicrobial activity against nontypeable Haemophilus influenzae. An in vitro exposure model was utilized to measure the effect of tobacco exposure on human bronchial epithelial culture (HBEC) antimicrobial activity against H. influenzae. The direct effects of cigarette and little cigar smoke exposure on SPLUNC1 function was determined using 24 h growth measurements and LPS binding assays. Results H. influenzae growth in cigarette smoker’s sputum was significantly greater compared to never-smokers sputum over 24 h. HBEC supernatants and lysates contained significantly higher numbers of H. influenzae following chronic cigarette and little cigar smoke exposure compared to air-exposed controls. Furthermore, SPLUNC1’s antimicrobial activity and LPS-binding capability against both H. influenzae and P. aeruginosa was attenuated following cigarette and little cigar exposure. Conclusions These data suggest that cigarette and little cigar exposure impairs SPLUNC1’s antimicrobial ability and that this inhibition may serve as a novel biomarker of harm that can be used to assess the toxicity of commercial tobacco products.
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Affiliation(s)
- Patrick J Moore
- Marsico Lung Institute, University of North Carolina at Chapel Hill, 7118A Marsico Hall, 125 Mason Farm Road, Chapel Hill, NC, 27599, USA.
| | - Juliana Sesma
- CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Neil E Alexis
- Center for Environmental Medicine, Asthma and Lung Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina at Chapel Hill, 7118A Marsico Hall, 125 Mason Farm Road, Chapel Hill, NC, 27599, USA.,Department of Cell Biology & Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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14
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Fu XG, Huang Z, Zhou SJ, Yang J, Peng YJ, Cao LY, Guo H, Wu GH, Lin YH, Huang BY. Novel heterozygous BPIFC variant in a Chinese pedigree with hereditary trichilemmal cysts. Mol Genet Genomic Med 2019; 7:e697. [PMID: 31033252 PMCID: PMC6565563 DOI: 10.1002/mgg3.697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/15/2019] [Accepted: 04/08/2019] [Indexed: 12/30/2022] Open
Abstract
Background Trichilemmal cysts (TCs) are common intradermal or subcutaneous cysts, which are commonly sporadic and rarely autosomal dominantly inherited. However, little is known about the disease‐determining genes in families with TCs exhibiting Mendelian inheritance. Objective The aim of this study was to identify the causative gene in a family with TCs. Methods Whole‐exome sequencing was performed on a TCs family to identify the candidate gene. Sanger sequencing was conducted to validate the candidate variants and familial segregation. Results We identified the heterozygous variant c.3G>C (p.Met1?) within the BPIFC gene. Sanger sequencing confirmed the cosegregation of this variant with the TCs phenotype in the family by demonstrating the presence of the heterozygous variant in all the 12 affected and absence in all the seven unaffected individuals. This variant was found to be absent in dbSNP141, 1,000 Genomes database and 500 ethnicity matched controls. Conclusion Our results imply that BPIFC is a causative gene in this Chinese family with hereditary TCs. Further studies should be performed to validate the role of BPIFC in the pathogenesis of this disease.
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Affiliation(s)
- Xian-Guo Fu
- Department of Central Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China.,Department of Clinical Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Zhao Huang
- Department of Pathology, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Su-Juan Zhou
- Department of Pathology, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Jing Yang
- Department of Central Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Yun-Juan Peng
- Department of Clinical Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Luo-Yuan Cao
- Department of Central Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Hua Guo
- Department of Pathology, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Guang-Hui Wu
- Department of Neurosurgery, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Ying-Hua Lin
- Department of Central Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
| | - Bao-Ying Huang
- Department of Central Laboratory, Ningde Municipal Hospital, Fujian Medical University, Ningde, Fujian, China
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15
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Schaefer N, Li X, Seibold MA, Jarjour NN, Denlinger LC, Castro M, Coverstone AM, Teague WG, Boomer J, Bleecker ER, Meyers DA, Moore WC, Hawkins GA, Fahy J, Phillips BR, Mauger DT, Dakhama A, Gellatly S, Pavelka N, Berman R, Di YP, Wenzel SE, Chu HW. The effect of BPIFA1/SPLUNC1 genetic variation on its expression and function in asthmatic airway epithelium. JCI Insight 2019; 4:127237. [PMID: 30996135 DOI: 10.1172/jci.insight.127237] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/14/2019] [Indexed: 11/17/2022] Open
Abstract
Bacterial permeability family member A1 (BPIFA1), also known as short palate, lung, and nasal epithelium clone 1 (SPLUNC1), is a protein involved in the antiinflammatory response. The goal of this study was to determine whether BPIFA1 expression in asthmatic airways is regulated by genetic variations, altering epithelial responses to type 2 cytokines (e.g., IL-13). Nasal epithelial cells from patients with mild to severe asthma were collected from the National Heart, Lung, and Blood Institute Severe Asthma Research Program centers, genotyped for rs750064, and measured for BPIFA1. To determine the function of rs750064, cells were cultured at air-liquid interface and treated with IL-13 with or without recombinant human BPIFA1 (rhBPIFA1). Noncultured nasal cells with the rs750064 CC genotype had significantly less BPIFA1 mRNA expression than the CT and TT genotypes. Cultured CC versus CT and TT cells without stimulation maintained less BPIFA1 expression. With IL-13 treatment, CC genotype cells secreted more eotaxin-3 than CT and TT genotype cells. Also, rhBPIFA1 reduced IL-13-mediated eotaxin-3. BPIFA1 mRNA levels negatively correlated with serum IgE and fractional exhaled nitric oxide. Baseline FEV1% levels were lower in the asthma patients with the CC genotype (n = 1,016). Our data suggest that less BPIFA1 in asthma patients with the CC allele may predispose them to greater eosinophilic inflammation, which could be attenuated by rhBPIFA1 protein therapy.
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Affiliation(s)
| | - Xingnan Li
- University of Arizona, Tucson, Arizona, USA
| | | | | | | | - Mario Castro
- Washington University in St. Louis, St. Louis, Missouri, USA
| | | | | | - Jonathan Boomer
- Washington University in St. Louis, St. Louis, Missouri, USA
| | | | | | - Wendy C Moore
- Wake Forest University, Winston-Salem, North Carolina, USA
| | | | - John Fahy
- UCSF, San Francisco, California, USA
| | | | - David T Mauger
- Pennsylvania State University, Centre County, Pennsylvania, USA
| | | | | | | | | | - Y Peter Di
- University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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16
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Zhang H, Burrows J, Card GL, Attwood G, Wheeler TT, Arcus VL. The three dimensional structure of Bovine Salivary Protein 30b (BSP30b) and its interaction with specific rumen bacteria. PLoS One 2019; 14:e0206709. [PMID: 30978191 PMCID: PMC6461236 DOI: 10.1371/journal.pone.0206709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 03/26/2019] [Indexed: 11/18/2022] Open
Abstract
Bovine Salivary Protein 30b (BSP30b) is a member of the tubular lipid-binding (TULIP) superfamily that includes the human bactericidal/permeability-increasing proteins (BPI), lipopolysaccharide binding proteins (LBP) and palate, lung, and nasal epithelium carcinoma-associated proteins (PLUNC). BSP30b is most closely related to the PLUNC family and is predominantly found in bovine saliva. There are four BSP30 isoforms (BSP30a-d) and collectively, they are the most abundant protein component of bovine saliva. The PLUNC family members are proposed to be lipid binding proteins, although in most cases their lipid ligands are unknown. Here, we present the X-ray crystal structure of BSP30b at 2.0 Å resolution. We used a double methionine mutant and Se-Met SAD phasing to solve the structure. The structure adopts a curved cylindrical form with a hydrophobic channel formed by an α/β wrap, which is consistent with the TULIP superfamily. The structure of BSP30b in complex with oleic acid is also presented where the ligand is accommodated within the hydrophobic channel. The electron density for oleic acid suggests that the ligand is only partially occupied in the binding site implying that oleic acid may not be the preferred ligand. GFP-tagged BSP30b binds to the surface of olive oil droplets, as observed under fluorescent microscopy, and acts as a surfactant consistent with its association with decreased susceptibility to bloat in cattle. Bacteria extracted directly from bovine rumen contents indicate that the GFP_BSP30b fusion protein binds to a small number of selected bacterial species in vivo. These results suggest that BSP30b may bind to bacterial lipids from specific species and that this abundant protein may have important biological roles via interacting with rumen bacteria during feeding and rumination.
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Affiliation(s)
- Heng Zhang
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Judith Burrows
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Graeme L. Card
- Stanford Synchrotron Radiation Lightsource, Menlo Park, California, United States of America
| | - Graeme Attwood
- AgResearch Grasslands, Tennent Drive, Palmerston North, New Zealand
| | - Tom T. Wheeler
- Cawthron Research Institute, The Wood, Nelson, New Zealand
| | - Vickery L. Arcus
- School of Science, University of Waikato, Hamilton, New Zealand
- * E-mail:
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17
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Antibacterial Properties and Efficacy of a Novel SPLUNC1-Derived Antimicrobial Peptide, α4-Short, in a Murine Model of Respiratory Infection. mBio 2019; 10:mBio.00226-19. [PMID: 30967458 PMCID: PMC6456746 DOI: 10.1128/mbio.00226-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The rise of superbugs underscores the urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs) have the ability to kill superbugs regardless of resistance to traditional antibiotics. However, AMPs often display a lack of efficacy in vivo. Sequence optimization and engineering are promising but may result in increased host toxicity. We report here the optimization of a novel AMP (α4-short) derived from the multifunctional respiratory protein SPLUNC1. The AMP α4-short demonstrated broad-spectrum activity against superbugs as well as in vivo efficacy in the P. aeruginosa pneumonia model. Further exploration for clinical development is warranted. Multidrug resistance (MDR) by bacterial pathogens constitutes a global health crisis, and resistance to treatment displayed by biofilm-associated infections (e.g., cystic fibrosis, surgical sites, and medical implants) only exacerbates a problem that is already difficult to overcome. Antimicrobial peptides (AMPs) are a promising class of therapeutics that may be useful in the battle against antibiotic resistance, although certain limitations have hindered their clinical development. The goal of this study was to examine the therapeutic potential of novel AMPs derived from the multifunctional respiratory host defense protein SPLUNC1. Using standard growth inhibition and antibiofilm assays, we demonstrated that a novel structurally optimized AMP, α4-short, was highly effective against the most common group of MDR bacteria while showing broad-spectrum bactericidal and antibiofilm activities. With negligible hemolysis and toxicity to white blood cells, the new peptide also demonstrated in vivo efficacy when delivered directly into the airway in a murine model of Pseudomonas aeruginosa-induced respiratory infection. The data warrant further exploration of SPLUNC1-derived AMPs with optimized structures to assess the potential application to difficult-to-cure biofilm-associated infections.
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18
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Woods AG, Wormwood KL, Iosifescu DV, Murrough J, Darie CC. Protein Biomarkers in Major Depressive Disorder: An Update. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1140:585-600. [DOI: 10.1007/978-3-030-15950-4_35] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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19
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Britto CJ, Niu N, Khanal S, Huleihel L, Herazo-Maya JD, Thompson A, Sauler M, Slade MD, Sharma L, Dela Cruz CS, Kaminski N, Cohn LE. BPIFA1 regulates lung neutrophil recruitment and interferon signaling during acute inflammation. Am J Physiol Lung Cell Mol Physiol 2018; 316:L321-L333. [PMID: 30461288 DOI: 10.1152/ajplung.00056.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Bpifa1 (BPI fold-containing group A member 1) is an airway host-protective protein with immunomodulatory properties that binds to LPS and is regulated by infectious and inflammatory signals. Differential expression of Bpifa1 has been widely reported in lung disease, yet the biological significance of this observation is unclear. We sought to understand the role of Bpifa1 fluctuations in modulating lung inflammation. We treated wild-type (WT) and Bpifa1-/- mice with intranasal LPS and performed immunological and transcriptomic analyses of lung tissue to determine the immune effects of Bpifa1 deficiency. We show that neutrophil (polymorphonuclear cells, PMNs) lung recruitment and transmigration to the airways in response to LPS is impaired in Bpifa1-/- mice. Transcriptomic analysis revealed a signature of 379 genes that differentiated Bpifa1-/- from WT mice. During acute lung inflammation, the most downregulated genes in Bpifa1-/- mice were Cxcl9 and Cxcl10. Bpifa1-/- mice had lower bronchoalveolar lavage concentrations of C-X-C motif chemokine ligand 10 (Cxcl10) and Cxcl9, interferon-inducible PMN chemokines. This was consistent with lower expression of IFNγ, IFNλ, downstream IFN-stimulated genes, and IFN-regulatory factors, which are important for the innate immune response. Administration of Cxcl10 before LPS treatment restored the inflammatory response in Bpifa1-/- mice. Our results identify a novel role for Bpifa1 in the regulation of Cxcl10-mediated PMN recruitment to the lungs via IFNγ and -λ signaling during acute inflammation.
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Affiliation(s)
- Clemente J Britto
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Naiqian Niu
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Sara Khanal
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Luai Huleihel
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Jose D Herazo-Maya
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Alison Thompson
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Maor Sauler
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Martin D Slade
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut.,Yale University School of Public Health, Department of Environmental Health Sciences , New Haven, Connecticut
| | - Lokesh Sharma
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Charles S Dela Cruz
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Naftali Kaminski
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Lauren E Cohn
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine , New Haven, Connecticut
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20
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Yu Z, Deslouches B, Walton WG, Redinbo MR, Di YP. Enhanced biofilm prevention activity of a SPLUNC1-derived antimicrobial peptide against Staphylococcus aureus. PLoS One 2018; 13:e0203621. [PMID: 30216370 PMCID: PMC6138395 DOI: 10.1371/journal.pone.0203621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/23/2018] [Indexed: 11/18/2022] Open
Abstract
SPLUNC1 is a multifunctional protein of the airway with antimicrobial properties. We previously reported that it displayed antibiofilm activities against P. aeruginosa. The goal of this study was to determine whether (1) the antibiofilm property is broad (including S. aureus, another prevalent organism in cystic fibrosis); (2) the α4 region is responsible for such activity; and (3), if so, this motif could be structurally optimized as an antimicrobial peptide with enhanced activities. We used S. aureus biofilm-prevention assays to determine bacterial biomass in the presence of SPLUNC1 and SPLUNC1Δα4 recombinant proteins, or SPLUNC1-derived peptides (α4 and α4M1), using the well-established crystal-violet biofilm detection assay. The SPLUNC1Δα4 showed markedly reduced biofilm prevention compared to the parent protein. Surprisingly, the 30-residue long α4 motif alone demonstrated minimal biofilm prevention activities. However, structural optimization of the α4 motif resulted in a modified peptide (α4M1) with significantly enhanced antibiofilm properties against methicillin–sensitive (MSSA) and–resistant (MRSA) S. aureus, including six different clinical strains of MRSA and the well-known USA300. Hemolytic activity was undetectable at up to 100μM for the peptides. The data warrant further investigation of α4-derived AMPs to explore the potential application of antimicrobial peptides to combat bacterial biofilm-related infections.
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Affiliation(s)
- Zhongjie Yu
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Molecular Genetics, Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - Berthony Deslouches
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - William G. Walton
- Departments of Chemistry, Biochemistry, and Microbiology, University of North Carolina, Chapel Hill, NC, United States of America
| | - Matthew R. Redinbo
- Departments of Chemistry, Biochemistry, and Microbiology, University of North Carolina, Chapel Hill, NC, United States of America
| | - Y. Peter Di
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, United States of America
- * E-mail:
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21
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The Role of BPIFA1 in Upper Airway Microbial Infections and Correlated Diseases. BIOMED RESEARCH INTERNATIONAL 2018; 2018:2021890. [PMID: 30255091 PMCID: PMC6140130 DOI: 10.1155/2018/2021890] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/04/2018] [Accepted: 08/07/2018] [Indexed: 12/16/2022]
Abstract
The mucosa is part of the first line of immune defense against pathogen exposure in humans and prevents viral and bacterial infection of the soft palate, lungs, uvula, and nasal cavity that comprise the ear-nose-throat (ENT) region. Bactericidal/permeability-increasing fold containing family A, member 1 (BPIFA1) is a secretory protein found in human upper aerodigestive tract mucosa. This innate material is secreted in mucosal fluid or found in submucosal tissue in the human soft palate, lung, uvula, and nasal cavity. BPIFA1 is a critical component of the innate immune response that prevents upper airway diseases. This review will provide a brief introduction of the roles of BPIFA1 in the upper airway (with a focus on the nasal cavity, sinus, and middle ear), specifically its history, identification, distribution in various human tissues, function, and diagnostic value in various upper airway infectious diseases.
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22
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Terryah ST, Fellner RC, Ahmad S, Moore PJ, Reidel B, Sesma JI, Kim CS, Garland AL, Scott DW, Sabater JR, Carpenter J, Randell SH, Kesimer M, Abraham WM, Arendshorst WJ, Tarran R. Evaluation of a SPLUNC1-derived peptide for the treatment of cystic fibrosis lung disease. Am J Physiol Lung Cell Mol Physiol 2017; 314:L192-L205. [PMID: 28982737 DOI: 10.1152/ajplung.00546.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In cystic fibrosis (CF) lungs, epithelial Na+ channel (ENaC) hyperactivity causes a reduction in airway surface liquid volume, leading to decreased mucocilliary clearance, chronic bacterial infection, and lung damage. Inhibition of ENaC is an attractive therapeutic option. However, ENaC antagonists have failed clinically because of off-target effects in the kidney. The S18 peptide is a naturally occurring short palate lung and nasal epithelial clone 1 (SPLUNC1)-derived ENaC antagonist that restores airway surface liquid height for up to 24 h in CF human bronchial epithelial cultures. However, its efficacy and safety in vivo are unknown. To interrogate the potential clinical efficacy of S18, we assessed its safety and efficacy using human airway cultures and animal models. S18-mucus interactions were tested using superresolution microscopy, quartz crystal microbalance with dissipation, and confocal microscopy. Human and murine airway cultures were used to measure airway surface liquid height. Off-target effects were assessed in conscious mice and anesthetized rats. Morbidity and mortality were assessed in the β-ENaC-transgenic (Tg) mouse model. Restoration of normal mucus clearance was measured in cystic fibrosis transmembrane conductance regulator inhibitor 172 [CFTR(inh)-172]-challenged sheep. We found that S18 does not interact with mucus and rapidly penetrated dehydrated CF mucus. Compared with amiloride, an early generation ENaC antagonist, S18 displayed a superior ability to slow airway surface liquid absorption, reverse CFTR(inh)-172-induced reduction of mucus transport, and reduce morbidity and mortality in the β-ENaC-Tg mouse, all without inducing any detectable signs of renal toxicity. These data suggest that S18 is the first naturally occurring ENaC antagonist to show improved preclinical efficacy in animal models of CF with no signs of renal toxicity.
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Affiliation(s)
- Shawn T Terryah
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Robert C Fellner
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Saira Ahmad
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Patrick J Moore
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Boris Reidel
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | | | - Christine S Kim
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Alaina L Garland
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | | | - Juan R Sabater
- Department of Research, Mount Sinai Medical Center , Miami Beach, Florida
| | - Jerome Carpenter
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Scott H Randell
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Cell Biology and Physiology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Mehmet Kesimer
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - William M Abraham
- Department of Research, Mount Sinai Medical Center , Miami Beach, Florida
| | - William J Arendshorst
- Cell Biology and Physiology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Robert Tarran
- Cystic Fibrosis Center/Marsico Lung Institute, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,Cell Biology and Physiology, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
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23
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Wang H, Jiang D, Li W, Wang S. Increased expression of BPI fold-containing family A member 1 is associated with metastasis and poor prognosis in human colorectal carcinoma. Oncol Lett 2017; 14:4231-4236. [PMID: 28943932 DOI: 10.3892/ol.2017.6662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 05/26/2017] [Indexed: 12/13/2022] Open
Abstract
Bactericidal or permeability-increasing protein fold-containing family A member 1 (BPIFA1) has been demonstrated to be involved in inflammatory responses in the upper airway and the progression of non-small cell lung cancer. However, the expression levels of BPIFA1 and its clinical prognostic significance in colorectal carcinoma (CRC) has not yet been elucidated. Reverse transcription-polymerase chain reaction and immunohistochemistry were used to analyze the expression levels of BPIFA1 in CRC and normal mucosal tissues. The associations between BPIFA1 expression levels and clinicopathological characteristics, and its predictive value for prognosis in CRC, were statistically evaluated as appropriate. The expression levels of BPIFA1 were revealed to be upregulated at the transcriptional and translational levels in CRC tissues, compared with in normal mucosal tissues. A high expression level of BPIFA1 is significantly associated with invasion depth (P=0.040), lymph node metastasis (P=0.035) and distant metastasis (P=0.010). Furthermore, Kaplan-Meier analysis indicated that BIPFA1 overexpression is associated with short survival time, and the Cox proportional hazards model of risk analysis indicated that BPIFA1 is an independent prognostic factor for patients with CRC. The results of the present study suggested that BPIFA1 expression is upregulated in CRC tissues, and that an increased expression level of BPIFA1 is associated with tumor invasion, metastasis and poor prognosis, indicating that BPIFA1 may be a potential clinical prognostic predictor and therapeutic target for patients with CRC.
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Affiliation(s)
- Huanan Wang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Dongmei Jiang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Wenlu Li
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Shuang Wang
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
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24
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Tsou YA, Tung YT, Wu TF, Chang GRL, Chen HC, Lin CD, Lai CH, Chen HL, Chen CM. Lactoferrin interacts with SPLUNC1 to attenuate lipopolysaccharide-induced inflammation of human nasal epithelial cells via down-regulated MEK1/2-MAPK signaling. Biochem Cell Biol 2017; 95:394-399. [PMID: 28178421 DOI: 10.1139/bcb-2016-0047] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The short palate, lung, and nasal epithelium clone 1 (SPLUNC1) protein is an important innate material in the upper airway, and lactoferrin (LF) aids the innate functions in humans. In this study, a nasal epithelial model was used to investigate how LF modulates SPLUNC1 to reduce the inflammatory process mediated by lipopolysaccharide (LPS). The inflammation of human RPMI-2650 cells was induced with LPS to evaluate SPLUNC1 expression after treating the cells with bovine LF (bLF). The interaction pathway between LF and SPLUNC1 in LPS-induced inflammation was further investigated. Our study reveals that the addition of bLF results in the recovery of SPLUNC1 expression in nasal epithelial cells under LPS-induced inflammation. MAPK is involved in the main pathway for the SPLUNC1 and bLF interaction. Decreased SPLUNC1 function could be recovered by addition of bLF. The MEK1/2-MAPK signaling pathway is crucial for the SPLUNC1 and bLF interaction. Therefore, LF could support SPLUNC1 in the innate immunity recovery process.
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Affiliation(s)
- Yung-An Tsou
- a Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.,b Department of Otolaryngology-Head and Neck Surgery, China Medical University and Hospital, Taichung 40402, Taiwan.,c Graduate Institute of Biomedicine Sciences, China Medical University, Taichung 40402, Taiwan
| | - Yu-Tong Tung
- a Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Tsu-Fang Wu
- c Graduate Institute of Biomedicine Sciences, China Medical University, Taichung 40402, Taiwan
| | - Gary Ro-Lin Chang
- a Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Han-Chien Chen
- a Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chia-Der Lin
- b Department of Otolaryngology-Head and Neck Surgery, China Medical University and Hospital, Taichung 40402, Taiwan.,c Graduate Institute of Biomedicine Sciences, China Medical University, Taichung 40402, Taiwan
| | - Chih-Ho Lai
- d Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan 33302, Taiwan
| | - Hsiao-Ling Chen
- e Department of Bioresources, Da-Yeh University, Changhua 51591, Taiwan
| | - Chuan-Mu Chen
- a Department of Life Sciences, and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.,f Rong-Hsing Translational Medicine Center, iEGG Center, National Chung Hsing University, Taichung 40227, Taiwan
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25
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Sunde M, Pham CLL, Kwan AH. Molecular Characteristics and Biological Functions of Surface-Active and Surfactant Proteins. Annu Rev Biochem 2017; 86:585-608. [PMID: 28125290 DOI: 10.1146/annurev-biochem-061516-044847] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many critical biological processes take place at hydrophobic:hydrophilic interfaces, and a wide range of organisms produce surface-active proteins and peptides that reduce surface and interfacial tension and mediate growth and development at these boundaries. Microorganisms produce both small lipid-associated peptides and amphipathic proteins that allow growth across water:air boundaries, attachment to surfaces, predation, and improved bioavailability of hydrophobic substrates. Higher-order organisms produce surface-active proteins with a wide variety of functions, including the provision of protective foam environments for vulnerable reproductive stages, evaporative cooling, and gas exchange across airway membranes. In general, the biological functions supported by these diverse polypeptides require them to have an amphipathic nature, and this is achieved by a diverse range of molecular structures, with some proteins undergoing significant conformational change or intermolecular association to generate the structures that are surface active.
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Affiliation(s)
- Margaret Sunde
- Discipline of Pharmacology, School of Medical Sciences and Australian Institute for Nanoscale Science and Technology, University of Sydney, NSW 2006, Australia; ,
| | - Chi L L Pham
- Discipline of Pharmacology, School of Medical Sciences and Australian Institute for Nanoscale Science and Technology, University of Sydney, NSW 2006, Australia; ,
| | - Ann H Kwan
- School of Life and Environmental Sciences and Australian Institute for Nanoscale Science and Technology, University of Sydney, NSW 2006, Australia;
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26
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Shang YP, Lin L, Li CC. [Streptococcus pneumoniae induces SPLUNC1 and the regulatory effects of resveratrol]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2017; 19:111-116. [PMID: 28100333 PMCID: PMC7390127 DOI: 10.7499/j.issn.1008-8830.2017.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/24/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To investigate the host-defense role of short palate, lung, and nasal epithelium clone 1 (SPLUNC1) in Streptococcus pneumoniae (SP) infection and the effect of resveratrol (Res) on SPLUNC1 expression, and to provide new thoughts for the treatment of diseases caused by SP infection. METHODS According to the multiplicity of infection (MOI), BEAS-2B cells with SP infection were divided into control group, MOI20 SP group, and MOI50 SP group. According to the different concentrations of Res, the BEAS-2B cells with MOI20 SP infection pretreated by Res were divided into 12.5Res+SP group, 25Res+SP group, and 50Res+SP group (the final concentrations of Res were 12.5, 25, and 50 μmol/L, respectively). Cell Counting Kit-8 was used to measure cell activity and determine the optimal concentration and action time of SP and Res. In the formal experiment, the cells were divided into control group, Res group, SP group, and Res+SP group. Real-time PCR and ELISA were used to measure the mRNA and protein expression of SPLUNC1. RESULTS Over the time of SP infection, cell activity tended to decrease. Compared with the control group and the MOI20 SP group, the MOI50 SP group had a reduction in cell activity. Compared with the MOI20 SP group, the 25Res+SP group had increased cell activity and the 50Res+SP group had reduced cell activity (P<0.05). MOI20 SP bacterial suspension and 25 μmol/L Res were used for the formal experiment. Over the time of SP infection, the mRNA expression of SPLUNC1 in BEAS-2B cells firstly increased and then decreased in the SP group and the Res+SP group (P<0.05). Compared with the SP group, the Res+SP group had significant increases in the mRNA and protein expression of SPLUNC1 at all time points (P<0.05). Compared with the control group, the Res group had no significant changes in the mRNA and protein expression of SPLUNC1 (P>0.05). CONCLUSIONS SP infection can induce SPLUNC1 expression and the host-defense role of SPLUNC1. Res can upregulate SPLUNC1 expression during the development of infection and enhance cell protection in a concentration- and time-dependent manner.
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Affiliation(s)
- Yan-Ping Shang
- Department of Pediatric Pulmonology, Second Affiliated Hospital/Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.
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27
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Wåhlén K, Fornander L, Olausson P, Ydreborg K, Flodin U, Graff P, Lindahl M, Ghafouri B. Protein profiles of nasal lavage fluid from individuals with work-related upper airway symptoms associated with moldy and damp buildings. INDOOR AIR 2016; 26:743-754. [PMID: 26451694 DOI: 10.1111/ina.12257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 10/03/2015] [Indexed: 06/05/2023]
Abstract
Upper airway irritation is common among individuals working in moldy and damp buildings. The aim of this study was to investigate effects on the protein composition of the nasal lining fluid. The prevalence of symptoms in relation to work environment was examined in 37 individuals working in two damp buildings. Microbial growth was confirmed in one of the buildings. Nasal lavage fluid was collected from 29 of the exposed subjects and 13 controls, not working in a damp building. Protein profiles were investigated with a proteomic approach and evaluated by multivariate statistical models. Subjects from both workplaces reported upper airway and ocular symptoms. Based on protein profiles, symptomatic subjects in the two workplaces were discriminated from each other and separated from healthy controls. The groups differed in proteins involved in inflammation and host defense. Measurements of innate immunity proteins showed a significant increase in protein S100-A8 and decrease in SPLUNC1 in subjects from one workplace, while alpha-1-antitrypsin was elevated in subjects from the other workplace, compared with healthy controls. The results show that protein profiles in nasal lavage fluid can be used to monitor airway mucosal effects in personnel working in damp buildings and indicate that the profile may be separated when the dampness is associated with the presence of molds.
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Affiliation(s)
- K Wåhlén
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Pain and Rehabilitation Center, Anaesthetics, Operations and Speciality Surgery Center, Region Östergötland, Linkoping, Sweden
| | - L Fornander
- Occupational and Environmental Medicine, Div of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - P Olausson
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Pain and Rehabilitation Center, Anaesthetics, Operations and Speciality Surgery Center, Region Östergötland, Linkoping, Sweden
| | - K Ydreborg
- Clinic of Otorhinolaryngology, County Hospital Ryhov, Jönköping, Sweden
| | - U Flodin
- Division of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, Occupational and Environmental Medicine Center, Heart and Medicine Center, Region Östergötland, Linkoping, Sweden
| | - P Graff
- Department of Occupational and Environmental Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - M Lindahl
- Occupational and Environmental Medicine, Div of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - B Ghafouri
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Pain and Rehabilitation Center, Anaesthetics, Operations and Speciality Surgery Center, Region Östergötland, Linkoping, Sweden.
- Division of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University, Occupational and Environmental Medicine Center, Heart and Medicine Center, Region Östergötland, Linkoping, Sweden.
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28
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Short Palate, Lung, and Nasal Epithelial Clone 1 Has Antimicrobial and Antibiofilm Activities against the Burkholderia cepacia Complex. Antimicrob Agents Chemother 2016; 60:6003-12. [PMID: 27458217 DOI: 10.1128/aac.00975-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/17/2016] [Indexed: 02/07/2023] Open
Abstract
The opportunistic bacteria of the Burkholderia cepacia complex (Bcc) are extremely pathogenic to cystic fibrosis (CF) patients, and acquisition of Bcc bacteria is associated with a significant increase in mortality. Treatment of Bcc infections is difficult because the bacteria are multidrug resistant and able to survive in biofilms. Short palate, lung, and nasal epithelial clone 1 (SPLUNC1) is an innate defense protein that is secreted by the upper airways and pharynx. While SPLUNC1 is known to have antimicrobial functions, its effects on Bcc strains are unclear. We therefore tested the hypothesis that SPLUNC1 is able to impair Bcc growth and biofilm formation. We found that SPLUNC1 exerted bacteriostatic effects against several Bcc clinical isolates, including B. cenocepacia strain J2315 (50% inhibitory concentration [IC50] = 0.28 μM), and reduced biofilm formation and attachment (IC50 = 0.11 μM). We then determined which domains of SPLUNC1 are responsible for its antimicrobial activity. Deletions of SPLUNC1's N terminus and α6 helix did not affect its function. However, deletion of the α4 helix attenuated antimicrobial activity, while the corresponding α4 peptide displayed antimicrobial activity. Chronic neutrophilia is a hallmark of CF lung disease, and neutrophil elastase (NE) cleaves SPLUNC1. However, we found that the ability of SPLUNC1 to disrupt biofilm formation was significantly potentiated by NE pretreatment. While the impact of CF on SPLUNC1-Bcc interactions is not currently known, our data suggest that understanding this interaction may have important implications for CF lung disease.
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29
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Walton WG, Ahmad S, Little MR, Kim CS, Tyrrell J, Lin Q, Di YP, Tarran R, Redinbo MR. Structural Features Essential to the Antimicrobial Functions of Human SPLUNC1. Biochemistry 2016; 55:2979-91. [PMID: 27145151 PMCID: PMC4887393 DOI: 10.1021/acs.biochem.6b00271] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
SPLUNC1 is an abundantly secreted innate immune protein in the mammalian respiratory tract that exerts bacteriostatic and antibiofilm effects, binds to lipopolysaccharide (LPS), and acts as a fluid-spreading surfactant. Here, we unravel the structural elements essential for the surfactant and antimicrobial functions of human SPLUNC1 (short palate lung nasal epithelial clone 1). A unique α-helix (α4) that extends from the body of SPLUNC1 is required for the bacteriostatic, surfactant, and LPS binding activities of this protein. Indeed, we find that mutation of just four leucine residues within this helical motif to alanine is sufficient to significantly inhibit the fluid spreading abilities of SPLUNC1, as well as its bacteriostatic actions against Gram-negative pathogens Burkholderia cenocepacia and Pseudomonas aeruginosa. Conformational flexibility in the body of SPLUNC1 is also involved in the bacteriostatic, surfactant, and LPS binding functions of the protein as revealed by disulfide mutants introduced into SPLUNC1. In addition, SPLUNC1 exerts antibiofilm effects against Gram-negative bacteria, although α4 is not involved in this activity. Interestingly, though, the introduction of surface electrostatic mutations away from α4 based on the unique dolphin SPLUNC1 sequence, and confirmed by crystal structure, is shown to impart antibiofilm activity against Staphylococcus aureus, the first SPLUNC1-dependent effect against a Gram-positive bacterium reported to date. Together, these data pinpoint SPLUNC1 structural motifs required for the antimicrobial and surfactant actions of this protective human protein.
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Affiliation(s)
- William G. Walton
- Departments of Chemistry, Biochemistry and Microbiology, 4350 Genome Sciences Building, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Saira Ahmad
- Marsico Lung Institute, Cystic Fibrosis/Pulmonary Research and Treatment Center, 7102 Marsico Hall, University of North Carolina, Chapel Hill, NC 27599-7248, USA
| | - Michael R. Little
- Departments of Chemistry, Biochemistry and Microbiology, 4350 Genome Sciences Building, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Christine S.K. Kim
- Marsico Lung Institute, Cystic Fibrosis/Pulmonary Research and Treatment Center, 7102 Marsico Hall, University of North Carolina, Chapel Hill, NC 27599-7248, USA
| | - Jean Tyrrell
- Marsico Lung Institute, Cystic Fibrosis/Pulmonary Research and Treatment Center, 7102 Marsico Hall, University of North Carolina, Chapel Hill, NC 27599-7248, USA
| | - Qiao Lin
- Department of Environmental and Occupational Health, 331 Bridgeside Point Building, University of Pittsburgh, Pittsburgh, PA 15260
| | - Y. Peter Di
- Department of Environmental and Occupational Health, 331 Bridgeside Point Building, University of Pittsburgh, Pittsburgh, PA 15260
| | - Robert Tarran
- Marsico Lung Institute, Cystic Fibrosis/Pulmonary Research and Treatment Center, 7102 Marsico Hall, University of North Carolina, Chapel Hill, NC 27599-7248, USA
| | - Matthew R. Redinbo
- Departments of Chemistry, Biochemistry and Microbiology, 4350 Genome Sciences Building, University of North Carolina, Chapel Hill, NC 27599-3290, USA,Corresponding Author: 4350 Genome Sciences Building, University of North Carolina, Chapel Hill, NC 27599-3290, USA, 919-962-4581, 919-962-2388 fax,
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30
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Host-directed therapies for antimicrobial resistant respiratory tract infections. Curr Opin Pulm Med 2016; 22:203-11. [DOI: 10.1097/mcp.0000000000000271] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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31
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Interleukin-13 Inhibits Lipopolysaccharide-Induced BPIFA1 Expression in Nasal Epithelial Cells. PLoS One 2015; 10:e0143484. [PMID: 26646664 PMCID: PMC4672888 DOI: 10.1371/journal.pone.0143484] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 11/05/2015] [Indexed: 02/01/2023] Open
Abstract
Short palate, lung, and nasal epithelium clone 1 (SPLUNC1) protein is expressed in human nasopharyngeal and respiratory epithelium and has demonstrated antimicrobial activity. SPLUNC1 is now referred to as bactericidal/permeability-increasing fold containing family A, member 1 (BPIFA1). Reduced BPIFA1 expression is associated with bacterial colonization in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Interleukin 13 (IL-13), predominately secreted by T helper 2 (TH2) cells, has been found to contribute to airway allergies and suppress BPIFA1 expression in nasal epithelial cells. However, the molecular mechanism of IL-13 perturbation of bacterial infection and BPIFA1 expression in host airways remains unclear. In this study, we found that lipopolysaccharide (LPS)-induced BPIFA1 expression in nasal epithelial cells was mediated through the JNK/c-Jun signaling pathway and AP-1 activation. We further demonstrated that IL-13 downregulated the LPS-induced activation of phosphorylated JNK and c-Jun, followed by attenuation of BPIFA1 expression. Moreover, the immunohistochemical analysis showed that IL-13 prominently suppressed BPIFA1 expression in eosinophilic CRSwNP patients with bacterial infection. Taken together, these results suggest that IL-13 plays a critical role in attenuation of bacteria-induced BPIFA1 expression that may result in eosinophilic CRSwNP.
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32
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Zheng X, Tian Z, Wei H. Lung specific X protein as a novel therapeutic target for lung cancer. Oncoimmunology 2015; 4:e1052931. [PMID: 26587325 PMCID: PMC4635906 DOI: 10.1080/2162402x.2015.1052931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 10/31/2022] Open
Abstract
The identification of novel therapeutic targets in lung cancer is an urgent challenge. We found lung-specific X protein (LunX) is overexpressed in lung cancer and promotes primary tumor growth and metastatic colonization. The antibody against LunX appears to be potentially applicable for therapeutic use in the future, given its efficacy in preclinical models.
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Affiliation(s)
- Xiaohu Zheng
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease; School of Life Science and Medical Center; University of Science and Technology of China ; Hefei, China ; Hefei National Laboratory for Physical Sciences at Microscale; University of Science and Technology of China ; Hefei, China
| | - Zhigang Tian
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease; School of Life Science and Medical Center; University of Science and Technology of China ; Hefei, China ; Hefei National Laboratory for Physical Sciences at Microscale; University of Science and Technology of China ; Hefei, China
| | - Haiming Wei
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease; School of Life Science and Medical Center; University of Science and Technology of China ; Hefei, China ; Hefei National Laboratory for Physical Sciences at Microscale; University of Science and Technology of China ; Hefei, China
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33
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Britto CJ, Cohn L. Bactericidal/Permeability-increasing protein fold-containing family member A1 in airway host protection and respiratory disease. Am J Respir Cell Mol Biol 2015; 52:525-34. [PMID: 25265466 DOI: 10.1165/rcmb.2014-0297rt] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Bactericidal/permeability-increasing protein fold-containing family member A1 (BPIFA1), formerly known as SPLUNC1, is one of the most abundant proteins in respiratory secretions and has been identified with increasing frequency in studies of pulmonary disease. Its expression is largely restricted to the respiratory tract, being highly concentrated in the upper airways and proximal trachea. BPIFA1 is highly responsive to airborne pathogens, allergens, and irritants. BPIFA1 actively participates in host protection through antimicrobial, surfactant, airway surface liquid regulation, and immunomodulatory properties. Its expression is modulated in multiple lung diseases, including cystic fibrosis, chronic obstructive pulmonary disease, respiratory malignancies, and idiopathic pulmonary fibrosis. However, the role of BPIFA1 in pulmonary pathogenesis remains to be elucidated. This review highlights the versatile properties of BPIFA1 in antimicrobial protection and its roles as a sensor of environmental exposure and regulator of immune cell function. A greater understanding of the contribution of BPIFA1 to disease pathogenesis and activity may clarify if BPIFA1 is a biomarker and potential drug target in pulmonary disease.
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Affiliation(s)
- Clemente J Britto
- Section of Pulmonary, Critical Care and Sleep Medicine, Yale University School of Medicine, New Haven, Connecticut
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Lee B, Robinson KM, McHugh KJ, Scheller EV, Mandalapu S, Chen C, Di YP, Clay ME, Enelow RI, Dubin PJ, Alcorn JF. Influenza-induced type I interferon enhances susceptibility to gram-negative and gram-positive bacterial pneumonia in mice. Am J Physiol Lung Cell Mol Physiol 2015; 309:L158-67. [PMID: 26001778 DOI: 10.1152/ajplung.00338.2014] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 05/16/2015] [Indexed: 11/22/2022] Open
Abstract
Suppression of type 17 immunity by type I interferon (IFN) during influenza A infection has been shown to enhance susceptibility to secondary bacterial pneumonia. Although this mechanism has been described in coinfection with gram-positive bacteria, it is unclear whether similar mechanisms may impair lung defense against gram-negative infections. Furthermore, precise delineation of the duration of type I IFN-associated susceptibility to bacterial infection remains underexplored. Therefore, we investigated the effects of preceding influenza A virus infection on subsequent challenge with the gram-negative bacteria Escherichia coli or Pseudomonas aeruginosa and the temporal association between IFN expression with susceptibility to Staphylococcus aureus challenge in a mouse model of influenza and bacterial coinfection. Here we demonstrate that preceding influenza A virus led to increased lung E. coli and P. aeruginosa bacterial burden, which was associated with suppression of type 17 immunity and attenuation of antimicrobial peptide expression. Enhanced susceptibility to S. aureus coinfection ceased at day 14 of influenza infection, when influenza-associated type I IFN levels had returned to baseline levels, further suggesting a key role for type I IFN in coinfection pathogenesis. These findings further implicate type I IFN-associated suppression of type 17 immunity and antimicrobial peptide production as a conserved mechanism for enhanced susceptibility to both gram-positive and gram-negative bacterial coinfection during influenza infection.
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Affiliation(s)
- Benjamin Lee
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Keven M Robinson
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania; Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Kevin J McHugh
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Erich V Scheller
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Sivanarayana Mandalapu
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Chen Chen
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Y Peter Di
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Michelle E Clay
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Richard I Enelow
- Department of Medicine, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire
| | - Patricia J Dubin
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - John F Alcorn
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania;
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Bartlett JA, Meyerholz DK, Wohlford-Lenane CL, Naumann PW, Salzman NH, McCray PB. Increased susceptibility to otitis media in a Splunc1-deficient mouse model. Dis Model Mech 2015; 8:501-8. [PMID: 25765466 PMCID: PMC4415896 DOI: 10.1242/dmm.019646] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 03/07/2015] [Indexed: 12/15/2022] Open
Abstract
Otitis media (inflammation of the middle ear) is one of the most common diseases of early childhood. Susceptibility to otitis is influenced by a number of factors, including the actions of innate immune molecules secreted by the epithelia lining the nasopharynx, middle ear and Eustachian tube. The SPLUNC1 (short palate, lung, nasal epithelial clone 1) protein is a highly abundant secretory product of the mammalian nasal, oral and respiratory mucosa that is thought to play a multifunctional role in host defense. In this study we investigated Splunc1 expression in the ear of the mouse, and examined whether this protein contributes to overall host defense in the middle ear and/or Eustachian tube. We found that Splunc1 is highly expressed in both the surface epithelium and in submucosal glands in these regions in wild-type mice. In mice lacking Splunc1, we noted histologically an increased frequency of otitis media, characterized by the accumulation of leukocytes (neutrophils with scattered macrophages), proteinaceous fluid and mucus in the middle ear lumens. Furthermore, many of these mice had extensive remodeling of the middle ear wall, suggesting a chronic course of disease. From these observations, we conclude that loss of Splunc1 predisposes mice to the development of otitis media. The Splunc1−/− mouse model should help investigators to better understand both the biological role of Splunc1 as well as host defense mechanisms in the middle ear. Summary: We document expression of the innate immune factor Splunc1 in the murine middle ear and Eustachian tube, and describe spontaneous development of otitis media in mice lacking functional Splunc1.
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Affiliation(s)
- Jennifer A Bartlett
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - David K Meyerholz
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | | | - Paul W Naumann
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Nita H Salzman
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Paul B McCray
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Role of innate immunity in the pathogenesis of otitis media. Int J Infect Dis 2014; 29:259-67. [PMID: 25447732 DOI: 10.1016/j.ijid.2014.10.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/29/2014] [Accepted: 10/02/2014] [Indexed: 12/12/2022] Open
Abstract
Otitis media (OM) is a public health problem in both developed and developing countries. It is the leading cause of hearing loss and represents a significant healthcare burden. In some cases, acute OM progresses to chronic suppurative OM (CSOM), characterized by effusion and discharge, despite antimicrobial therapy. The emergence of antibiotic resistance and potential ototoxicity of antibiotics has created an urgent need to design non-conventional therapeutic strategies against OM based on modern insights into its pathophysiology. In this article, we review the role of innate immunity as it pertains to OM and discuss recent advances in understanding the role of innate immune cells in protecting the middle ear. We also discuss the mechanisms utilized by pathogens to subvert innate immunity and thereby overcome defensive responses. A better knowledge about bacterial virulence and host resistance promises to reveal novel targets to design effective treatment strategies against OM. The identification and characterization of small natural compounds that can boost innate immunity may provide new avenues for the treatment of OM. There is also a need to design novel methods for targeted delivery of these compounds into the middle ear, allowing higher therapeutic doses and minimizing systemic side effects.
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Zhang W, Zeng Z, Wei F, Chen P, Schmitt DC, Fan S, Guo X, Liang F, Shi L, Liu Z, Zhang Z, Xiang B, Zhou M, Huang D, Tang K, Li X, Xiong W, Tan M, Li G, Li X. SPLUNC1 is associated with nasopharyngeal carcinoma prognosis and plays an important role in all-trans-retinoic acid-induced growth inhibition and differentiation in nasopharyngeal cancer cells. FEBS J 2014; 281:4815-29. [PMID: 25161098 DOI: 10.1111/febs.13020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 06/19/2014] [Accepted: 08/22/2014] [Indexed: 12/13/2022]
Abstract
Human SPLUNC1 can suppress nasopharyngeal carcinoma (NPC) tumor formation; however, the correlation between SPLUNC1expression and NPC patient prognosis has not been reported. In the present study, we used a large-scale sample of 1015 tissue cores to detect SPLUNC1 expression and its association with patient prognosis. SPLUNC1 expression was reduced in NPC samples compared to nontumor nasopharyngeal epithelium tissues. Positive expression of SPLUNC1 in NPC predicted a better prognosis (disease-free survival, P = 0.034; overall survival, P = 0.048). Cox's proportional hazards model revealed that SPLUNC1 could be a significant prognostic factor affecting disease-free survival (P = 0.027). A cDNA micro-array analyzed by significant analysis of micro-array (SAM) and ingenuity pathway analysis (IPA) revealed that an indirect interaction existed between SPLUNC1 and retinoic acid (RA) in the cancer regulatory network. To further investigate the molecular mechanisms involved, we utilized several bioinformatics tools and identified 12 retinoid X receptors heterodimer binding sites in the promoter region of the SPLUNC1 gene. The transcriptional activity of the SPLUNC1 promoter was up-regulated significantly by all-trans-retinoic acid (ATRA). SPLUNC1 and retinoic acid receptor expression were induced significantly by ATRA, and removal of ATRA led to a progressive loss of SPLUNC1 and retinoic acid receptor expression. ATRA inhibited proliferation and induced the differentiation of NPC cells. Interestingly, over-expression of SPLUNC1 sensitized NPC cells to ATRA, whereas knockdown of SPLUNC1 in HNE1 cells increased cell viability. Under SPLUNC1 knockdown conditions, differentiation was reversed by ATRA treatment. We concluded that SPLUNC1 could potentially predict prognosis for NPC patients and play an important role in ATRA-induced growth inhibition and differentiation in NPC cells.
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Affiliation(s)
- Wenling Zhang
- Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China; Department of Medical Laboratory Science, Xiangya School of Medicine, Central South University, Changsha, China; Key Laboratory of Carcinogenesis of Ministry of Health and Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
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Electronic cigarette liquid increases inflammation and virus infection in primary human airway epithelial cells. PLoS One 2014; 9:e108342. [PMID: 25244293 PMCID: PMC4171526 DOI: 10.1371/journal.pone.0108342] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 08/27/2014] [Indexed: 11/19/2022] Open
Abstract
Background/Objective The use of electronic cigarettes (e-cigarettes) is rapidly increasing in the United States, especially among young people since e-cigarettes have been perceived as a safer alternative to conventional tobacco cigarettes. However, the scientific evidence regarding the human health effects of e-cigarettes on the lung is extremely limited. The major goal of our current study is to determine if e-cigarette use alters human young subject airway epithelial functions such as inflammatory response and innate immune defense against respiratory viral (i.e., human rhinovirus, HRV) infection. Methodology/Main Results We examined the effects of e-cigarette liquid (e-liquid) on pro-inflammatory cytokine (e.g., IL-6) production, HRV infection and host defense molecules (e.g., short palate, lung, and nasal epithelium clone 1, SPLUNC1) in primary human airway epithelial cells from young healthy non-smokers. Additionally, we examined the role of SPLUNC1 in lung defense against HRV infection using a SPLUNC1 knockout mouse model. We found that nicotine-free e-liquid promoted IL-6 production and HRV infection. Addition of nicotine into e-liquid further amplified the effects of nicotine-free e-liquid. Moreover, SPLUNC1 deficiency in mice significantly increased lung HRV loads. E-liquid inhibited SPLUNC1 expression in primary human airway epithelial cells. These findings strongly suggest the deleterious health effects of e-cigarettes in the airways of young people. Our data will guide future studies to evaluate the impact of e-cigarettes on lung health in human populations, and help inform the public about potential health risks of e-cigarettes.
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Ning F, Wang C, Berry KZ, Kandasamy P, Liu H, Murphy RC, Voelker DR, Nho CW, Pan CH, Dai S, Niu L, Chu HW, Zhang G. Structural characterization of the pulmonary innate immune protein SPLUNC1 and identification of lipid ligands. FASEB J 2014; 28:5349-60. [PMID: 25223608 DOI: 10.1096/fj.14-259291] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The short palate, lung and nasal epithelial clone 1 (SPLUNC1) protein is a member of the palate, lung, and nasal epithelium clone (PLUNC) family, also known as bactericidal/permeability-increasing (BPI) fold-containing protein, family A, member 1 (BPIFA1). SPLUNC1 is an abundant protein in human airways, but its function remains poorly understood. The lipid ligands of SPLUNC1 as well as other PLUNC family members are largely unknown, although some reports provide evidence that lipopolysaccharide (LPS) could be a lipid ligand. Unlike previous hypotheses, we found significant structural differences between SPLUNC1 and BPI. Recombinant SPLUNC1 produced in HEK 293 cells harbored several molecular species of sphingomyelin and phosphatidylcholine as its ligands. Significantly, in vitro lipid-binding studies failed to demonstrate interactions between SPLUNC1 and LPS, lipoteichoic acid, or polymyxin B. Instead, one of the major and most important pulmonary surfactant phospholipids, dipalmitoylphosphatidylcholine (DPPC), bound to SPLUNC1 with high affinity and specificity. We found that SPLUNC1 could be the first protein receptor for DPPC. These discoveries provide insight into the specific determinants governing the interaction between SPLUNC1 and lipids and also shed light on novel functions that SPLUNC1 and other PLUNC family members perform in host defense.
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Affiliation(s)
- Fangkun Ning
- School of Life Sciences, University of Science and Technology of China, Hefei, China; Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado, USA
| | - Chao Wang
- Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado, USA
| | - Karin Zemski Berry
- Department of Pharmacology, University of Colorado Denver, Aurora, Colorado, USA
| | | | - Haolin Liu
- Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado, USA
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, Colorado, USA
| | - Dennis R Voelker
- Department of Medicine, National Jewish Health, Denver, Colorado, USA; and
| | - Chu Won Nho
- Functional Food Center, Korea Institute of Science and Technology, GangNeung, Korea
| | - Choel-Ho Pan
- Functional Food Center, Korea Institute of Science and Technology, GangNeung, Korea
| | - Shaodong Dai
- Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado, USA
| | - Liwen Niu
- School of Life Sciences, University of Science and Technology of China, Hefei, China;
| | - Hong-Wei Chu
- Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado, USA; Department of Medicine, National Jewish Health, Denver, Colorado, USA; and
| | - Gongyi Zhang
- Integrated Department of Immunology, National Jewish Health and University of Colorado Denver, Denver, Colorado, USA
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Irander K, Borres MP, Ghafouri B. The effects of physical exercise and smoking habits on the expression of SPLUNC1 in nasal lavage fluids from allergic rhinitis subjects. Int J Pediatr Otorhinolaryngol 2014; 78:618-22. [PMID: 24512783 DOI: 10.1016/j.ijporl.2014.01.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/11/2014] [Accepted: 01/14/2014] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Palate lung nasal epithelial clone (PLUNC) is a family of proteins, which are proposed to participate in the innate immune defense against infections in the upper aero-digestive tract. The aim of this study was to investigate the expression of SPLUNC1 in allergic rhinitis subjects with considerations taken to the mucosal function and smoking habits. METHODS The participants, recruited from a cohort followed from infancy, were re-examined at the age of 18 years regarding allergy development. Based on medical histories and skin prick tests the participants were classified into groups with persistent allergic rhinitis (n=18), intermittent allergic rhinitis (n = 8) and healthy controls (n = 13). Seven subjects (3, 2 and 2 in each group, respectively) reported smoking habits. The SPLUNC1 levels in nasal lavage fluids were analyzed by Western blot. Changes in the volume of the proper nasal cavity before and after physical exercise (Vol2(increase)) were analyzed by acoustic rhinometry. RESULTS Compared to the control group the SPLUNC1 level was significantly lower in the persistent allergy group (3.8 ± 3.4 OD vs. 1.3 ± 1.5 OD; p = 0.02), but not in the intermittent allergy group without current exposure to allergens (3.6 ± 4.7 OD). No differences were found in Vol2(increase) between any of the allergy groups and controls. In smokers Vol2(increase) was significantly reduced (p < 0.01) and the SPLUNC1 levels were lower compared to non-smokers. A significant correlation was found between SPLUNC1 and Vol2(increase) (p < 0.01; r = 0.53) in non-smokers. CONCLUSIONS Current allergen exposure has an impact on SPLUNC1 expression in nasal lavage fluid, why allergy ought to be considered in study populations where analyses of SPLUNC1 levels are included in the reports. The normal nasal decongestion after exercise was not affected by allergy in contrast to smoking habits. The correlation between SPLUNC1 levels and Vol2(increase) in non-smokers may indicate involvement of SPLUNC1in the regulation of the normal function of the nasal mucosa. Complementary studies are needed to confirm the smoke-related reduction of SPLUNC1 expression and to analyze the possible participation of SPLUNC1 in the nasal mucosa regulation.
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Affiliation(s)
- K Irander
- Allergy Center, ENT Section, University Hospital, Linköping, Sweden
| | - M P Borres
- Department of Women's and Children's Health, Uppsala University, Sweden; Thermo Fisher Scientific, Uppsala, Sweden
| | - B Ghafouri
- Department of Medical and Health Sciences, Division of Community Medicine Rehabilitation Medicine, Faculty of Health Sciences, Linköping University, and Pain and Rehabilitation Centre, County Council of Östergötland, Linköping, Sweden; Occupational and Environmental Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, and Centre of Occupational and Environmental Medicine, County Council of Östergötland, Linköping, Sweden.
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High-quality 3D structures shine light on antibacterial, anti-biofilm and antiviral activities of human cathelicidin LL-37 and its fragments. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2160-72. [PMID: 24463069 DOI: 10.1016/j.bbamem.2014.01.016] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/26/2013] [Accepted: 01/10/2014] [Indexed: 01/07/2023]
Abstract
Host defense antimicrobial peptides are key components of human innate immunity that plays an indispensible role in human health. While there are multiple copies of cathelicidin genes in horses, cattle, pigs, and sheep, only one cathelicidin gene is found in humans. Interestingly, this single cathelicidin gene can be processed into different forms of antimicrobial peptides. LL-37, the most commonly studied form, is not only antimicrobial but also possesses other functional roles such as chemotaxis, apoptosis, wound healing, immune modulation, and cancer metastasis. This article reviews recent advances made in structural and biophysical studies of human LL-37 and its fragments, which serve as a basis to understand their antibacterial, anti-biofilm and antiviral activities. High-quality structures were made possible by using improved 2D NMR methods for peptide fragments and 3D NMR spectroscopy for intact LL-37. The two hydrophobic domains in the long amphipathic helix (residues 2-31) of LL-37 separated by a hydrophilic residue serine 9 explain its cooperative binding to bacterial lipopolysaccharides (LPS). Both aromatic rings (F5, F6, F17, and F27) and interfacial basic amino acids of LL-37 directly interact with anionic phosphatidylglycerols (PG). Although the peptide sequences reported in the literature vary slightly, there is a consensus that the central helix of LL-37 is essential for disrupting superbugs (e.g., MRSA), bacterial biofilms, and viruses such as human immunodeficiency virus 1 (HIV-1) and respiratory syncytial virus (RSV). In the central helix, the central arginine R23 is of particular importance in binding to bacterial membranes or DNA. Mapping the functional roles of the cationic amino acids of the major antimicrobial region of LL-37 provides a basis for designing antimicrobial peptides with desired properties. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.
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Cordeiro CMM, Esmaili H, Ansah G, Hincke MT. Ovocalyxin-36 is a pattern recognition protein in chicken eggshell membranes. PLoS One 2013; 8:e84112. [PMID: 24391897 PMCID: PMC3877205 DOI: 10.1371/journal.pone.0084112] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 11/12/2013] [Indexed: 12/15/2022] Open
Abstract
The avian eggshell membranes are essential elements in the fabrication of the calcified shell as a defense against bacterial penetration. Ovocalyxin-36 (OCX-36) is an abundant avian eggshell membrane protein, which shares protein sequence homology to bactericidal permeability-increasing protein (BPI), lipopolysaccharide-binding protein (LBP) and palate, lung and nasal epithelium clone (PLUNC) proteins. We have developed an efficient method to extract OCX-36 from chicken eggshell membranes for purification with cation and anion exchange chromatographies. Purified OCX-36 protein exhibited lipopolysaccharide (LPS) binding activity and bound lipopolysaccharide (LPS) from Escherichia coli O111:B4 in a dose-dependent manner. OCX-36 showed inhibitory activity against growth of Staphylococcus aureus ATCC 6538. OCX-36 single nucleotide polymorphisms (SNPs) were verified at cDNA 211 position and the corresponding proteins proline-71 (Pro-71) or serine-71 (Ser-71) were purified from eggs collected from genotyped hens. A significant difference between Pro-71 and Ser-71 OCX-36 for S. aureus lipoteichoic acid (LTA) binding activity was detected. The current study is a starting point to understand the innate immune role that OCX-36 may play in protection against bacterial invasion of both embryonated eggs (relevant to avian reproductive success) and unfertilized table eggs (relevant to food safety).
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Affiliation(s)
| | - Hamed Esmaili
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - George Ansah
- ISA North America, Division of Hendrix Genetics, Kitchener, Ontario, Canada
| | - Maxwell T. Hincke
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
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Di YP, Tkach AV, Yanamala N, Stanley S, Gao S, Shurin MR, Kisin ER, Kagan VE, Shvedova A. Dual acute proinflammatory and antifibrotic pulmonary effects of short palate, lung, and nasal epithelium clone-1 after exposure to carbon nanotubes. Am J Respir Cell Mol Biol 2013; 49:759-67. [PMID: 23721177 DOI: 10.1165/rcmb.2012-0435oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Carbon nanotubes (CNTs; allotropes of carbon with a cylindrical nanostructure) have emerged as one of the most commonly used types of nanomaterials, with numerous applications in industry and biomedicine. However, the inhalation of CNTs has been shown to elicit pulmonary toxicity, accompanied by a robust inflammatory response with an early-onset fibrotic phase. Epithelial host-defense proteins represent an important component of the pulmonary innate immune response to foreign inhalants such as particles and bacteria. The short palate, lung, and nasal epithelium clone-1 (SPLUNC1) protein, a member of the bactericidal/permeability-increasing-fold (BPIF)-containing protein family, is a 25-kD secretory protein that is expressed in nasal, oropharyngeal, and lung epithelia, and has been shown to have multiple functions, including antimicrobial and chemotactic activities, as well as surfactant properties. This study sought to assess the importance of SPLUNC1-mediated pulmonary responses in airway epithelial secretions, and to explore the biological relevance of SPLUNC1 to inhaled particles in a single-walled carbon nanotube (SWCNT) model. Using Scgb1a1-hSPLUNC1 transgenic mice, we observed that SPLUNC1 significantly modified host inflammatory responses by increasing leukocyte recruitment and enhancing phagocytic activity. Furthermore, we found that transgenic mice were more susceptible to SWCNT exposure at the acute phase, but showed resistance against lung fibrogenesis through pathological changes in the long term. The binding of SPLUNC1 also attenuated SWCNT-induced TNF-α secretion by RAW 264.7 macrophages. Taken together, our data indicate that SPLUNC1 is an important component of mucosal innate immune defense against pulmonary inhaled particles.
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Affiliation(s)
- Y Peter Di
- 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania
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Liu Y, Di ME, Chu HW, Liu X, Wang L, Wenzel S, Di YP. Increased susceptibility to pulmonary Pseudomonas infection in Splunc1 knockout mice. THE JOURNAL OF IMMUNOLOGY 2013; 191:4259-68. [PMID: 24048904 DOI: 10.4049/jimmunol.1202340] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The airway epithelium is the first line of host defense against pathogens. The short palate, lung, and nasal epithelium clone (SPLUNC)1 protein is secreted in respiratory tracts and is a member of the bacterial/permeability increasing (BPI) fold-containing protein family, which shares structural similarities with BPI-like proteins. On the basis of its homology with BPIs and restricted expression of SPLUNC1 in serous cells of submucosal glands and surface epithelial cells of the upper respiratory tract, SPLUNC1 is thought to possess antimicrobial activity in host defense. SPLUNC1 is also reported to have surfactant properties, which may contribute to anti-biofilm defenses. The objective of this study was to determine the in vivo functions of SPLUNC1 following Pseudomonas aeruginosa infection and to elucidate the underlying mechanism by using a knockout (KO) mouse model with a genetic ablation of Splunc1. Splunc1 KO mice showed accelerated mortality and increased susceptibility to P. aeruginosa infection with significantly decreased survival rates, increased bacterial burdens, exaggerated tissue injuries, and elevated proinflammatory cytokine levels as compared with those of their wild-type littermates. Increased neutrophil infiltration in Splunc1 KO mice was accompanied by elevated chemokine levels, including Cxcl1, Cxcl2, and Ccl20. Furthermore, the expression of several epithelial secretory proteins and antimicrobial molecules was considerably suppressed in the lungs of Splunc1 KO mice. The deficiency of Splunc1 in mouse airway epithelium also results in increased biofilm formation of P. aeruginosa. Taken together, our results support that the ablation of Splunc1 in mouse airways affects the mucociliary clearance, resulting in decreased innate immune response during Pseudomonas-induced respiratory infection.
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Affiliation(s)
- Yanyan Liu
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15260
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D-alanine modification of a protease-susceptible outer membrane component by the Bordetella pertussis dra locus promotes resistance to antimicrobial peptides and polymorphonuclear leukocyte-mediated killing. J Bacteriol 2013; 195:5102-11. [PMID: 24013634 DOI: 10.1128/jb.00510-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bordetella pertussis is the causative agent of pertussis, a highly contagious disease of the human respiratory tract. Despite very high vaccine coverage, pertussis has reemerged as a serious threat in the United States and many developing countries. Thus, it is important to pursue research to discover unknown pathogenic mechanisms of B. pertussis. We have investigated a previously uncharacterized locus in B. pertussis, the dra locus, which is homologous to the dlt operons of Gram-positive bacteria. The absence of the dra locus resulted in increased sensitivity to the killing action of antimicrobial peptides (AMPs) and human phagocytes. Compared to the wild-type cells, the mutant cells bound higher levels of cationic proteins and peptides, suggesting that dra contributes to AMP resistance by decreasing the electronegativity of the cell surface. The presence of dra led to the incorporation of d-alanine into an outer membrane component that is susceptible to proteinase K cleavage. We conclude that dra encodes a virulence-associated determinant and contributes to the immune resistance of B. pertussis. With these findings, we have identified a new mechanism of surface modification in B. pertussis which may also be relevant in other Gram-negative pathogens.
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Liu Y, Bartlett JA, Di ME, Bomberger JM, Chan YR, Gakhar L, Mallampalli RK, McCray PB, Di YP. SPLUNC1/BPIFA1 contributes to pulmonary host defense against Klebsiella pneumoniae respiratory infection. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:1519-31. [PMID: 23499554 DOI: 10.1016/j.ajpath.2013.01.050] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 01/10/2013] [Accepted: 01/14/2013] [Indexed: 12/12/2022]
Abstract
Epithelial host defense proteins comprise a critical component of the pulmonary innate immune response to infection. The short palate, lung, nasal epithelium clone (PLUNC) 1 (SPLUNC1) protein is a member of the bactericidal/permeability-increasing (BPI) fold-containing (BPIF) protein family, sharing structural similarities with BPI-like proteins. SPLUNC1 is a 25 kDa secretory protein that is expressed in nasal, oropharyngeal, and lung epithelia, and has been implicated in airway host defense against Pseudomonas aeruginosa and other organisms. SPLUNC1 is reported to have surfactant properties, which may contribute to anti-biofilm defenses. The objective of this study was to assess the importance of SPLUNC1 surfactant activity in airway epithelial secretions and to explore its biological relevance in the context of a bacterial infection model. Using cultured airway epithelia, we confirmed that SPLUNC1 is critically important for maintenance of low surface tension in airway fluids. Furthermore, we demonstrated that recombinant SPLUNC1 (rSPLUNC1) significantly inhibited Klebsiella pneumoniae biofilm formation on airway epithelia. We subsequently found that Splunc1(-/-) mice were significantly more susceptible to infection with K. pneumoniae, confirming the likely in vivo relevance of this anti-biofilm effect. Our data indicate that SPLUNC1 is a crucial component of mucosal innate immune defense against pulmonary infection by a relevant airway pathogen, and provide further support for the novel hypothesis that SPLUNC1 protein prevents bacterial biofilm formation through its ability to modulate surface tension of airway fluids.
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Affiliation(s)
- Yang Liu
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15260, USA
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