iPSC disease models to study and treat Diamond-Blackfan Anemia Syndrome (DBAS)
Disease mechanisms driving anemia in DBAS are not completely elucidated, and research is hampered by the scarce availability of patient samples and disease models. Recently, we have developed an induced pluripotent stem cell (iPSC) culture to RBC differentiation platform, providing a powerful tool to study erythroid development.
The TRACER-consortium aims to generate novel DBAS disease models, to genetically correct DBAS-iPSCs to produce cultured RBCs for transfusion, or corrected HSCs for autologous stem cell transplantation. Currently, DBAS treatment is limited to glucocorticoids, blood transfusions, or allogeneic SCT, associated with toxicity and risk.
Patients were selected from the Dutch Registry (DBAN; Fig.1B) and PBMC-derived cultured proerythroblasts (proEB) were reprogrammed using the non-integrative Cytotune-Sendai-IPS2.0-kit. The DBAS-iPSC pluripotency marker expression and differentiation potential is demonstrated. DBAS-iPSC derived embryoid bodies (EBs) give rise to ‘hematopoietic organoids’ (HO) that produce hematopoietic production cells (HPCs) which are characterized by flow cytometry, and further expanded to produce proEBs and enucleated cRBCs.
ProEBs of three DBAS patients were reprogrammed and these DBAS-iPSCs form EBs, HO, and HPCs, similar to healthy control iPSCs. However, the DBAS-HPCs display a slight bias to the myeloid lineage, and a reduced proEB expansion potential. Nonetheless, this platform allows the sustainable production of HPCs for further mechanistic studies.
In DBAS there is a clinical need for novel therapeutic strategies to treat severe anemia and reduce organ toxicity. DBAS-iPSC lines provide a sustainable source of DBAS models, in which erythropoiesis, novel therapeutics, including gene therapy, can be studied for clinical applications.