TY - JOUR
T1 - Hypoxia and TLR9 activation drive CXCL4 production in systemic sclerosis plasmacytoid dendritic cells via mtROS and HIF-2α
AU - Ottria, Andrea
AU - Zimmermann, Maili
AU - Paardekooper, Laurent M
AU - Carvalheiro, Tiago
AU - Vazirpanah, Nadia
AU - Silva-Cardoso, Sandra
AU - Affandi, Alsya J
AU - Chouri, Eleni
AU - V D Kroef, Maarten
AU - Tieland, Ralph G
AU - Bekker, Cornelis P J
AU - Wichers, Catharina G K
AU - Rossato, Marzia
AU - Mocholi-Gimeno, Enric
AU - Tekstra, Janneke
AU - Ton, Evelien
AU - van Laar, Jaap M
AU - Cossu, Marta
AU - Beretta, Lorenzo
AU - Garcia Perez, Samuel
AU - Pandit, Aridaman
AU - Bonte-Mineur, Femke
AU - Reedquist, Kris A
AU - van den Bogaart, Geert
AU - Radstake, Timothy R D J
AU - Marut, Wioleta
N1 - © The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: [email protected].
PY - 2022/5/30
Y1 - 2022/5/30
N2 - Objective: SSc is a complex disease characterized by vascular abnormalities and inflammation culminating in hypoxia and excessive fibrosis. Previously, we identified chemokine (C-X-C motif) ligand 4 (CXCL4) as a novel predictive biomarker in SSc. Although CXCL4 is well-studied, the mechanisms driving its production are unclear. The aim of this study was to elucidate the mechanisms leading to CXCL4 production. Methods: Plasmacytoid dendritic cells (pDCs) from 97 healthy controls and 70 SSc patients were cultured in the presence of hypoxia or atmospheric oxygen level and/or stimulated with several toll-like receptor (TLR) agonists. Further, pro-inflammatory cytokine production, CXCL4, hypoxia-inducible factor (HIF)-1α and HIF-2α gene and protein expression were assessed using ELISA, Luminex, qPCR, FACS and western blot assays. Results: CXCL4 release was potentiated only when pDCs were simultaneously exposed to hypoxia and TLR9 agonist (P < 0.0001). Here, we demonstrated that CXCL4 production is dependent on the overproduction of mitochondrial reactive oxygen species (mtROS) (P = 0.0079) leading to stabilization of HIF-2α (P = 0.029). In addition, we show that hypoxia is fundamental for CXCL4 production by umbilical cord CD34 derived pDCs. Conclusion: TLR-mediated activation of immune cells in the presence of hypoxia underpins the pathogenic production of CXCL4 in SSc. Blocking either mtROS or HIF-2α pathways may therapeutically attenuate the contribution of CXCL4 to SSc and other inflammatory diseases driven by CXCL4.
AB - Objective: SSc is a complex disease characterized by vascular abnormalities and inflammation culminating in hypoxia and excessive fibrosis. Previously, we identified chemokine (C-X-C motif) ligand 4 (CXCL4) as a novel predictive biomarker in SSc. Although CXCL4 is well-studied, the mechanisms driving its production are unclear. The aim of this study was to elucidate the mechanisms leading to CXCL4 production. Methods: Plasmacytoid dendritic cells (pDCs) from 97 healthy controls and 70 SSc patients were cultured in the presence of hypoxia or atmospheric oxygen level and/or stimulated with several toll-like receptor (TLR) agonists. Further, pro-inflammatory cytokine production, CXCL4, hypoxia-inducible factor (HIF)-1α and HIF-2α gene and protein expression were assessed using ELISA, Luminex, qPCR, FACS and western blot assays. Results: CXCL4 release was potentiated only when pDCs were simultaneously exposed to hypoxia and TLR9 agonist (P < 0.0001). Here, we demonstrated that CXCL4 production is dependent on the overproduction of mitochondrial reactive oxygen species (mtROS) (P = 0.0079) leading to stabilization of HIF-2α (P = 0.029). In addition, we show that hypoxia is fundamental for CXCL4 production by umbilical cord CD34 derived pDCs. Conclusion: TLR-mediated activation of immune cells in the presence of hypoxia underpins the pathogenic production of CXCL4 in SSc. Blocking either mtROS or HIF-2α pathways may therapeutically attenuate the contribution of CXCL4 to SSc and other inflammatory diseases driven by CXCL4.
KW - Basic Helix-Loop-Helix Transcription Factors/metabolism
KW - Dendritic Cells/metabolism
KW - Humans
KW - Hypoxia/metabolism
KW - Hypoxia-Inducible Factor 1, alpha Subunit
KW - Platelet Factor 4/metabolism
KW - Reactive Oxygen Species/metabolism
KW - Scleroderma, Systemic
KW - Toll-Like Receptor 9
KW - CXCL4
KW - HIF-2α
KW - TLRs
KW - hypoxia
KW - mtROS
KW - plasmacytoid dendritic cells
KW - systemic sclerosis
UR - https://www.mendeley.com/catalogue/5c3329cf-70f9-3b35-a924-61e3bb364dae/
U2 - 10.1093/rheumatology/keab532
DO - 10.1093/rheumatology/keab532
M3 - Article
C2 - 34559222
SN - 1462-0324
VL - 61
SP - 2682
EP - 2693
JO - Rheumatology (Oxford, England)
JF - Rheumatology (Oxford, England)
IS - 6
ER -