Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm

Abstract Circulating cell-free (cf) DNA in blood plasma is considered a diagnostic and prognostic biomarker of tissue damage and could be a driver of chronic inflammation by stimulating the innate immune response via activation of inflammasomes. Increased AIM2-inflammasome activity in the aortic wal...

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Main Authors: Susanne Dihlmann, Carolin Kaduk, Karola H. Passek, Anja Spieler, Dittmar Böckler, Andreas S. Peters
Format: Article
Language:English
Published: Nature Portfolio 2025-06-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-06220-5
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author Susanne Dihlmann
Carolin Kaduk
Karola H. Passek
Anja Spieler
Dittmar Böckler
Andreas S. Peters
author_facet Susanne Dihlmann
Carolin Kaduk
Karola H. Passek
Anja Spieler
Dittmar Böckler
Andreas S. Peters
author_sort Susanne Dihlmann
collection DOAJ
description Abstract Circulating cell-free (cf) DNA in blood plasma is considered a diagnostic and prognostic biomarker of tissue damage and could be a driver of chronic inflammation by stimulating the innate immune response via activation of inflammasomes. Increased AIM2-inflammasome activity in the aortic wall is associated with abdominal aortic aneurysm (AAA). We here hypothesized that cfDNAs are elevated in the plasma of AAA patients and are associated with chronic inflammation. Single strand (ss)DNA, double strand (ds)DNA and mitochondrial (mt)DNA levels were explored in plasma and leucocytes from 93 AAA patients, 89 controls (non-AAA patients) and 10 healthy subjects, using fluorescence-based quantification and real-time qPCR, respectively. To analyse inflammasome activation by cfDNA, differentiated THP-1 macrophages were primed with lipopolysaccharide (LPS) and then stimulated for one, six or 24 h with DNA extracted from peripheral blood mononuclear cells (PBMC) of AAA patients. Our analysis revealed significantly increased levels of ssDNA, dsDNA and mtDNA levels in plasma from AAA patients compared with non-AAA patients and healthy subjects. In addition, the mtDNA copy number was significantly higher in PBMC from AAA patients. Stimulation of THP-1 cells with PBMC-DNA resulted in increased expression of inflammasome genes, especially the DNA sensors AIM2 and IFI16. At early time points, PBMC-DNA stimulated THP-1 showed significantly increased apoptosis-associated speck-like protein with a CARD (ASC) and Pro-Interleukin-1β protein levels compared to untreated or only LPS-primed cells, resulting in the formation of significantly more ASC specks after 24 h, a sign of inflammasome activation. We conclude from our data that cfDNA of AAA patients triggers a proinflammatory response in macrophages by activating the AIM2 inflammasome and thus could be a driving force for the chronic inflammation observed in these patients.
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spelling doaj-art-6ec61926040a4fb8b3824e5a97745e002025-08-20T03:47:14ZengNature PortfolioScientific Reports2045-23222025-06-0115111710.1038/s41598-025-06220-5Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysmSusanne Dihlmann0Carolin Kaduk1Karola H. Passek2Anja Spieler3Dittmar Böckler4Andreas S. Peters5Department of Vascular and Endovascular Surgery, University Hospital HeidelbergDepartment of Vascular and Endovascular Surgery, University Hospital HeidelbergDepartment of Vascular and Endovascular Surgery, University Hospital HeidelbergDepartment of Vascular and Endovascular Surgery, University Hospital HeidelbergDepartment of Vascular and Endovascular Surgery, University Hospital HeidelbergDepartment of Vascular and Endovascular Surgery, University Hospital HeidelbergAbstract Circulating cell-free (cf) DNA in blood plasma is considered a diagnostic and prognostic biomarker of tissue damage and could be a driver of chronic inflammation by stimulating the innate immune response via activation of inflammasomes. Increased AIM2-inflammasome activity in the aortic wall is associated with abdominal aortic aneurysm (AAA). We here hypothesized that cfDNAs are elevated in the plasma of AAA patients and are associated with chronic inflammation. Single strand (ss)DNA, double strand (ds)DNA and mitochondrial (mt)DNA levels were explored in plasma and leucocytes from 93 AAA patients, 89 controls (non-AAA patients) and 10 healthy subjects, using fluorescence-based quantification and real-time qPCR, respectively. To analyse inflammasome activation by cfDNA, differentiated THP-1 macrophages were primed with lipopolysaccharide (LPS) and then stimulated for one, six or 24 h with DNA extracted from peripheral blood mononuclear cells (PBMC) of AAA patients. Our analysis revealed significantly increased levels of ssDNA, dsDNA and mtDNA levels in plasma from AAA patients compared with non-AAA patients and healthy subjects. In addition, the mtDNA copy number was significantly higher in PBMC from AAA patients. Stimulation of THP-1 cells with PBMC-DNA resulted in increased expression of inflammasome genes, especially the DNA sensors AIM2 and IFI16. At early time points, PBMC-DNA stimulated THP-1 showed significantly increased apoptosis-associated speck-like protein with a CARD (ASC) and Pro-Interleukin-1β protein levels compared to untreated or only LPS-primed cells, resulting in the formation of significantly more ASC specks after 24 h, a sign of inflammasome activation. We conclude from our data that cfDNA of AAA patients triggers a proinflammatory response in macrophages by activating the AIM2 inflammasome and thus could be a driving force for the chronic inflammation observed in these patients.https://doi.org/10.1038/s41598-025-06220-5Cell free DNAmtDNAAbdominal aortic aneurysmAIM2InflammasomeBiomarker
spellingShingle Susanne Dihlmann
Carolin Kaduk
Karola H. Passek
Anja Spieler
Dittmar Böckler
Andreas S. Peters
Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm
Scientific Reports
Cell free DNA
mtDNA
Abdominal aortic aneurysm
AIM2
Inflammasome
Biomarker
title Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm
title_full Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm
title_fullStr Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm
title_full_unstemmed Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm
title_short Exploring circulating cell-free DNA as a biomarker and as an inducer of AIM2-inflammasome-mediated inflammation in patients with abdominal aortic aneurysm
title_sort exploring circulating cell free dna as a biomarker and as an inducer of aim2 inflammasome mediated inflammation in patients with abdominal aortic aneurysm
topic Cell free DNA
mtDNA
Abdominal aortic aneurysm
AIM2
Inflammasome
Biomarker
url https://doi.org/10.1038/s41598-025-06220-5
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