SCIENTISTS at Hannover Medical School (MHH) have developed the first-ever blood-generating heart organoid, a breakthrough enabling the replication of early human heart and blood cell development in laboratory conditions. This innovation provides new insights into human development and creates avenues for disease modelling and drug testing.
The organoid was created by modifying heart-forming organoids (HFOs), which simulate the early stages of heart development using human pluripotent stem cells (hPSCs). By introducing additional growth factors and a dense endothelial layer, researchers achieved the development of a blood-generating heart organoid (BG-HFO). These organoids resemble embryonic structures, featuring three distinct layers that include precursors for the heart, liver, lungs, and blood vessels. Importantly, the endothelial layer gives rise to blood-forming cells and progenitors, replicating the close relationship between cardiac and haematopoietic systems observed in natural embryonic development. The study reported haematopoietic progenitor cells with potential for erythro-myeloid and lymphoid differentiation, recapitulating primitive and definitive haematopoiesis. The organoids were developed over 10–14 days and contained at least seven distinct tissue types, showcasing remarkable structural complexity.
This breakthrough offers numerous implications for clinical research and practice. Blood-generating heart organoids provide a reliable platform to study cross-tissue interactions in blood formation, offering insights into congenital heart and blood disorders. The organoid model has potential applications in understanding cardiovascular complications caused by diseases such as COVID-19, as well as genetic or infection-induced malformations. Additionally, its flexibility enables researchers to study disease mechanisms and test pharmaceutical agents more accurately than in animal models, given the physiological differences between species. The production protocol, akin to a modular construction system, could also be adapted for developing multi-tissue organoid models of other organs, promising advancements in medical research.
This research not only advances knowledge of human development but also paves the way for innovative approaches in regenerative medicine and personalised treatments. Future studies may expand these organoid systems further, enabling the investigation of complex multi-organ interactions and the development of more precise therapeutic interventions.
Katrina Thornber, EMJ
Reference
Dardano M et al. Blood-generating heart-forming organoids recapitulate co-development of the human haematopoietic system and the embryonic heart. Nat Cell Biol. 2024;26:1984-96.
