Hemolytic stress leads to expansion of erythropoiesis in the spleen

In anemia-stressed mice, compensatory RBC production occurs primarily in the spleen. We have compared erythropoiesis across the three models with a multiplexed single cell-RNA sequencing experiment of formalin-fixed spleen cell suspensions of one spherocytosis (Spta), two sickle cell disease (Berk) and one thalassemia (Thal) spleen. After de-multiplexing, batch correction, and Leiden clustering, Ptprc (CD45) negative cells were extracted, and pseudotimes were calculated to establish the erythropoietic differentiation trajectory. Along this trajectory, three cell populations could be delineated representing (1) Kit+Runx3+ hematopoietic stem cells (2) highly proliferative Mki67+Gata1+ Klf1+ Epor+ Tfrc+ early-stage erythropoietic progenitors; and (3) Gypa+ Xpo+ late-stage erythropoietic progenitors with active heme synthesis (Alas2+). We performed a multiplex single cell-RNAsequencing analysis on spleen tissues of one spherocytosis (SPH), two sickle cell disease (SCD ) and one thalassemia (THAL) mouse.