Glycolytic enzyme PFKFB3 determines bone marrow endothelial progenitor cell damage post chemotherapy and irradiation

Bone marrow(BM) endothelial progenitor cell(EPC) damage with unknown mechanism delays the repair of endothelial cells(ECs) and hematopoiesis recovery after chemo-radiotherapy. Herein, enhanced glycolytic enzyme PFKFB3 was demonstrated in the damaged BM EPCs of patients with poor graft function(PGF), a clinical model of EPC damage-associated poor hematopoiesis after allogeneic hematopoietic stem cell transplantation(allo-HSCT). Moreover, glycolysis inhibitor 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one(3PO) alleviated the damaged BM EPCs of PGF patients in vitro. Consistently, PFKFB3 overexpression triggered BM EPC damage after 5FU treatment and impaired hematopoiesis-supporting ability in vitro. Mechanismly, PFKFB3 facilitated pro-apoptotic transcription factor FOXO3A and its downstream gene expressions, including p21, p27, FAS after 5FU treatment in vitro. Moreover, PFKFB3 induced NF-κB activation and its downstream adhesion molecule E-selectin expression, while reduced hematopoietic factor SDF-1 expression, which could be rescued by FOXO3A silence. Highly expressed PFKFB3 was found in damaged BM ECs of chemo-radiotherapy-induced myelosuppression murine models. Furthermore, the BM EC-specific PFKFB3 overexpression murine model demonstrated that PFKFB3 aggravated BM EC damage, and impaired hematopoiesis recovery after chemotherapy in vivo, which could be improved by 3PO, indicating a critical role of PFKFB3 in regulating BM EC damage. Clinically, PFKFB3-induced FOXO3A expression and NF-κB activation were confirmed to contribute to the damaged BM EPCs of patients with acute leukemia after chemotherapy. 3PO repaired the damaged BM EPCs by reducing FOXO3A expression and phospho-NF-κB p65 in patients after chemotherapy. In summary, our results reveal a critical role of PFKFB3 in triggering BM EPC damage and indicate that endothelial-PFKFB3 may be a potential therapeutic target for myelosuppressive injury.