Abstract
Fanconi Anemia (FA) is an inherited disorder of DNA-repair due to mutation in one of 20+ interrelated genes that repair intra-strand DNA crosslinks and rescue collapsed or stalled replication forks. The most common hematologic abnormality in FA is anemia, but progression to bone marrow failure (BMF), clonal hematopoiesis, or acute myeloid leukemia (AML) may also occur. In prior studies, we found that Fanconi DNA-repair is required for successful emergency granulopoiesis; the process for rapid neutrophil production during the innate immune response. Specifically, Fancc-/- mice did not develop neutrophilia in response to emergency granulopoiesis stimuli, but instead exhibited apoptosis of bone marrow hematopoietic stem cells (HSCs) and differentiating neutrophils. Repeated emergency granulopoiesis challenges induced BMF in most Fancc-/- mice, with AML in survivors. In contrast, we found equivalent neutrophilia during emergency granulopoiesis in Fancc-/-Tp53+/- mice and wild type (WT) mice, without BMF. Since termination of emergency granulopoiesis is triggered by accumulation of bone marrow neutrophils, we hypothesize neutrophilia protects Fancc-/-Tp53+/- bone marrow from the stress of a sustained inflammation that is experienced by Fancc-/- mice. In the current work, we found that blocking neutrophil accumulation during emergency granulopoiesis led to BMF in Fancc-/-Tp53+/- mice, consistent with this hypothesis. Blocking neutrophilia during emergency granulopoiesis in Fancc-/-Tp53+/- mice (but not WT) impaired cell cycle checkpoint activity, also found in Fancc-/- mice. Mechanisms for loss of cell cycle checkpoints during infections challenges may define molecular markers of FA progression, or suggest therapeutic targets for bone marrow protection in this disorder.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call