Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients
Neutrophils play a pathogenic role in COVID-19 by releasing Neutrophils Extracellular Traps (NETs) or human neutrophil elastase (HNE). Given that HNE is inhibited by α1-antitrypsin (AAT), we aimed to assess the content of HNE, α1-antitrypsin (AAT) and HNE–AAT complexes (the AAT/HNE balance) in 33 br...
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MDPI AG
2022-05-01
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| Series: | Current Issues in Molecular Biology |
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| Online Access: | https://www.mdpi.com/1467-3045/44/5/143 |
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| author | Maura D’Amato Valentina Vertui Laura Pandolfi Sara Bozzini Tommaso Fossali Riccardo Colombo Anna Aliberti Marco Fumagalli Paolo Iadarola Camilla Didò Simona Viglio Federica Meloni |
| author_facet | Maura D’Amato Valentina Vertui Laura Pandolfi Sara Bozzini Tommaso Fossali Riccardo Colombo Anna Aliberti Marco Fumagalli Paolo Iadarola Camilla Didò Simona Viglio Federica Meloni |
| author_sort | Maura D’Amato |
| collection | DOAJ |
| description | Neutrophils play a pathogenic role in COVID-19 by releasing Neutrophils Extracellular Traps (NETs) or human neutrophil elastase (HNE). Given that HNE is inhibited by α1-antitrypsin (AAT), we aimed to assess the content of HNE, α1-antitrypsin (AAT) and HNE–AAT complexes (the AAT/HNE balance) in 33 bronchoalveolar lavage fluid (BALf) samples from COVID-19 patients. These samples were submitted for Gel-Electrophoresis, Western Blot and ELISA, and proteins (bound to AAT or HNE) were identified by Liquid Chromatography-Mass Spectrometry. NETs’ release was analyzed by confocal microscopy. Both HNE and AAT were clearly detectable in BALf at high levels. Contrary to what was previously observed in other settings, the formation of HNE–AAT complex was not detected in COVID-19. Rather, HNE was found to be bound to acute phase proteins, histones and C3. Due to the relevant role of NETs, we assessed the ability of free AAT to bind to histones. While confirming this binding, AAT was not able to inhibit NET formation. In conclusion, despite the finding of a high burden of free and bound HNE, the lack of the HNE–AAT inhibitory complex in COVID-19 BALf demonstrates that AAT is not able to block HNE activity. Furthermore, while binding to histones, AAT does not prevent NET formation nor their noxious activity. |
| first_indexed | 2024-03-10T03:05:45Z |
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| language | English |
| last_indexed | 2024-03-10T03:05:45Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Current Issues in Molecular Biology |
| spelling | doaj.art-66bf402ec7be4215840296963b79cb362023-11-23T10:32:20ZengMDPI AGCurrent Issues in Molecular Biology1467-30371467-30452022-05-014452122213810.3390/cimb44050143Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 PatientsMaura D’Amato0Valentina Vertui1Laura Pandolfi2Sara Bozzini3Tommaso Fossali4Riccardo Colombo5Anna Aliberti6Marco Fumagalli7Paolo Iadarola8Camilla Didò9Simona Viglio10Federica Meloni11Department of Molecular Medicine, University of Pavia, 27100 Pavia, ItalyDepartment of Internal Medicine and Medical Therapeutics, University of Pavia, 27100 Pavia, ItalyDepartment of Internal Medicine and Medical Therapeutics, University of Pavia, 27100 Pavia, ItalyLaboratory of Respiratory Disease, Cell Biology Section, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, ItalyDepartment of Anesthesiology and Intensive Care, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, University of Milan, 20121 Milan, ItalyDepartment of Anesthesiology and Intensive Care, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, University of Milan, 20121 Milan, ItalyDivision of Anesthesiology and Intensive Care 1, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, ItalyDepartment of Biology and Biotechnologies “L. Spallanzani”, University of Pavia, 27100 Pavia, ItalyDepartment of Biology and Biotechnologies “L. Spallanzani”, University of Pavia, 27100 Pavia, ItalyDepartment of Internal Medicine and Medical Therapeutics, University of Pavia, 27100 Pavia, ItalyDepartment of Molecular Medicine, University of Pavia, 27100 Pavia, ItalyDepartment of Internal Medicine and Medical Therapeutics, University of Pavia, 27100 Pavia, ItalyNeutrophils play a pathogenic role in COVID-19 by releasing Neutrophils Extracellular Traps (NETs) or human neutrophil elastase (HNE). Given that HNE is inhibited by α1-antitrypsin (AAT), we aimed to assess the content of HNE, α1-antitrypsin (AAT) and HNE–AAT complexes (the AAT/HNE balance) in 33 bronchoalveolar lavage fluid (BALf) samples from COVID-19 patients. These samples were submitted for Gel-Electrophoresis, Western Blot and ELISA, and proteins (bound to AAT or HNE) were identified by Liquid Chromatography-Mass Spectrometry. NETs’ release was analyzed by confocal microscopy. Both HNE and AAT were clearly detectable in BALf at high levels. Contrary to what was previously observed in other settings, the formation of HNE–AAT complex was not detected in COVID-19. Rather, HNE was found to be bound to acute phase proteins, histones and C3. Due to the relevant role of NETs, we assessed the ability of free AAT to bind to histones. While confirming this binding, AAT was not able to inhibit NET formation. In conclusion, despite the finding of a high burden of free and bound HNE, the lack of the HNE–AAT inhibitory complex in COVID-19 BALf demonstrates that AAT is not able to block HNE activity. Furthermore, while binding to histones, AAT does not prevent NET formation nor their noxious activity.https://www.mdpi.com/1467-3045/44/5/143lungalpha-1-antitrypsin (AAT)human neutrophil elastase (HNE)COVID-19broncho-alveolar lavage (BAL)Neutrophils Extracellular Traps (NETs) |
| spellingShingle | Maura D’Amato Valentina Vertui Laura Pandolfi Sara Bozzini Tommaso Fossali Riccardo Colombo Anna Aliberti Marco Fumagalli Paolo Iadarola Camilla Didò Simona Viglio Federica Meloni Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients Current Issues in Molecular Biology lung alpha-1-antitrypsin (AAT) human neutrophil elastase (HNE) COVID-19 broncho-alveolar lavage (BAL) Neutrophils Extracellular Traps (NETs) |
| title | Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients |
| title_full | Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients |
| title_fullStr | Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients |
| title_full_unstemmed | Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients |
| title_short | Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients |
| title_sort | investigating the link between alpha 1 antitrypsin and human neutrophil elastase in bronchoalveolar lavage fluid of covid 19 patients |
| topic | lung alpha-1-antitrypsin (AAT) human neutrophil elastase (HNE) COVID-19 broncho-alveolar lavage (BAL) Neutrophils Extracellular Traps (NETs) |
| url | https://www.mdpi.com/1467-3045/44/5/143 |
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