The damage caused by a heart attack leads to a permanent loss of cardiac tissue in adult mammals. The human heart cannot replenish these lost cells, instead forming a permanent cardiac scar, which will eventually lead to heart failure. In contrast, the zebrafish, a freshwater fish native to South Asia, has the ability to fully regenerate its heart after injury, even in the presence of scarring, because its cardiac scar is only temporary as new cardiac muscle cells are formed. In early 2020, a Riley group study led by Dr Filipa Simões revealed that macrophages are integral to both repair by scar formation and tissue regeneration. However, scientists so far have been unable to uncover the mechanisms behind the behaviour of macrophages that allows zebrafish to adjust the balance between a pro-fibrotic versus a pro-regenerative state.
According to Dr Simões: “What is clear is that the zebrafish post-cardiac injury environment is unique compared to mammals and, therefore, key in elucidating how the interplay between the cardiac niche and macrophages can dictate a successful regenerative response.”
Dr Simões has now been awarded a BHF Intermediate Basic Science Research Fellowship to pursue a project entitled “Niche-Dependent Programming of Macrophage Function in the Regenerating Heart” for the next five years. It will allow Dr Simões to establish her independent research programme as Principal Investigator at the IDRM in Spring 2022.