Judith Sluimer (Netherlands)
Maastricht University Medical Center PathologyAuthor Of 1 Presentation
O034 - Deficiency of myeloid phd proteins aggravates atherogenesis via macrophage apoptosis and paracrine fibrotic signaling (ID 1187)
Abstract
Background and Aims
Atherosclerotic plaque hypoxia is detrimental for macrophage function. Prolyl hydroxylases (PHDs) initiate cellular hypoxic responses, possibly influencing macrophage function in plaque hypoxia. Thus, we elucidated the role of myeloid PHDs in atherosclerosis.
Methods
Myeloid specific PHD knockout (PHDko) mice were fed high cholesterol diet for 6-12 weeks to induce atherosclerosis. Plaque parameters, e.g. plaque size and macrophage content, were analyzed. Bulk and single cell RNA sequencing was performed on PHD2 BMDMs and plaque macrophages, respectively.
Results
Aortic root plaque size was augmented 2.6fold in PHD2cko, and 1.4-fold in PHD3ko, but not in PHD1ko mice compared to controls. Macrophage apoptosis was promoted in PHD2cko and PHD3ko mice in vitro and in vivo, via the HIF1α/BNIP3 axis. Bulk and single cell RNA data of PHD2cko bone-marrow-derived macrophages (BMDM) and plaque macrophages, respectively, confirmed these findings and were validated by siRNA silencing. Human plaque BNIP3 mRNA associated with plaque necrotic core, suggesting similar adverse effects. Further, PHD2cko plaques displayed enhanced fibrosis, independent of macrophage and SMC function. PHD2cko BMDMs enhanced fibroblast collagen secretion in a paracrine manner and in silico analysis of macrophage-fibroblast communication predicted SPP1 signaling as regulator, in line with enhanced plaque SPP1 protein content, and SPP1mRNA in TREM2-foamy plaque macrophages, but not in neutrophils.
Conclusions
Myeloid PHD2cko and PHD3ko enhanced plaque growth, macrophage apoptosis, and PHD2cko activated paracrine collagen secretion by fibroblasts. PHD1 did not seem paramount in myeloid cells in atherogenesis.
Presenter of 1 Presentation
O034 - Deficiency of myeloid phd proteins aggravates atherogenesis via macrophage apoptosis and paracrine fibrotic signaling (ID 1187)
Abstract
Background and Aims
Atherosclerotic plaque hypoxia is detrimental for macrophage function. Prolyl hydroxylases (PHDs) initiate cellular hypoxic responses, possibly influencing macrophage function in plaque hypoxia. Thus, we elucidated the role of myeloid PHDs in atherosclerosis.
Methods
Myeloid specific PHD knockout (PHDko) mice were fed high cholesterol diet for 6-12 weeks to induce atherosclerosis. Plaque parameters, e.g. plaque size and macrophage content, were analyzed. Bulk and single cell RNA sequencing was performed on PHD2 BMDMs and plaque macrophages, respectively.
Results
Aortic root plaque size was augmented 2.6fold in PHD2cko, and 1.4-fold in PHD3ko, but not in PHD1ko mice compared to controls. Macrophage apoptosis was promoted in PHD2cko and PHD3ko mice in vitro and in vivo, via the HIF1α/BNIP3 axis. Bulk and single cell RNA data of PHD2cko bone-marrow-derived macrophages (BMDM) and plaque macrophages, respectively, confirmed these findings and were validated by siRNA silencing. Human plaque BNIP3 mRNA associated with plaque necrotic core, suggesting similar adverse effects. Further, PHD2cko plaques displayed enhanced fibrosis, independent of macrophage and SMC function. PHD2cko BMDMs enhanced fibroblast collagen secretion in a paracrine manner and in silico analysis of macrophage-fibroblast communication predicted SPP1 signaling as regulator, in line with enhanced plaque SPP1 protein content, and SPP1mRNA in TREM2-foamy plaque macrophages, but not in neutrophils.
Conclusions
Myeloid PHD2cko and PHD3ko enhanced plaque growth, macrophage apoptosis, and PHD2cko activated paracrine collagen secretion by fibroblasts. PHD1 did not seem paramount in myeloid cells in atherogenesis.