1. Deficiency of Antioxidative Paraoxonase 2 (Pon2) Leads to Increased Number of Phenotypic LT-HSCs and Disturbed Erythropoiesis
- Author
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Lisa Spiecker, Daniel Sasca, Andrea Schüler, Piyush More, Ines Witte, Victoria Petermann, Markus Meyerhöfer, Julia Mehlig, Viral N. Shah, Nina Cabezas-Wallscheid, Thomas Kindler, Andreas Daiber, Sven Horke, Andrea Pautz, Hartmut Kleinert, and Patricia S. Haehnel
- Subjects
Premature aging ,Aging ,Myeloid ,Article Subject ,Biology ,Biochemistry ,CXCR4 ,Antioxidants ,Cell Line ,Mice ,medicine ,Animals ,Erythropoiesis ,Progenitor cell ,QH573-671 ,Aryldialkylphosphatase ,Cell Differentiation ,Cell Biology ,General Medicine ,Hematopoietic Stem Cells ,Cell biology ,Haematopoiesis ,Phenotype ,medicine.anatomical_structure ,Bone marrow ,Stem cell ,Reactive Oxygen Species ,Cytology ,Research Article - Abstract
Background. Long-term hematopoietic stem cells (LT-HSCs) reside in bone marrow niches with tightly controlled reactive oxygen species (ROS) levels. ROS increase results into LT-HSC differentiation and stem cell exhaustion. Paraoxonase 2 (PON2) has been shown to be important for ROS control. Objectives. We investigate the effects of inactivation of the PON2 gene on hematopoietic cell differentiation and activity. Methods and Results. In young mice with inactivated Pon2 gene (Pon2-/-, -/- BM outcompeted WT BM at early time points. ROS levels were significantly increased in Pon2-/- whole BM, but not in Pon2-/- LT-HSCs. In more differentiated stages of hematopoiesis, Pon2 deficiency led to a misbalanced erythropoiesis both in physiologic and stress conditions. In older mice (>9 months), Pon2 depletion caused an increase in LT-HSCs as well as increased levels of granulocyte/macrophage progenitors (GMPs) and myeloid skewing, indicating a premature aging phenotype. No significant changes in ROS levels in old Pon2-/- LT- and short-term (ST-) HSCs were observed, but a significant reduction of spontaneous apoptotic cell death was measured. RNA-seq analysis in Pon2-/- LT-HSCs identified overrepresentation of genes involved in the C-X-C chemokine receptor type 4 (Cxcr4) signaling, suggesting compensatory mechanisms to overcome ROS-mediated accelerated aging in hematopoietic progenitor cells. Conclusions. In summary, our current data indicate that PON2 is involved in the regulation of HSC functions.
- Published
- 2021
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