(Image: BHF/Dr Jana Koth)
The future of regenerative medicine is bright: in this case, literally. This image of a stained zebrafish heart glowing with multiple colours is one of the winners of the British Heart Foundation’s annual heart and blood vessel photography competition.
The green staining of the two-day-old heart highlights the cardiomyocytes, the cells of the heart muscle itself. The red and blue-stained areas represent the contractile apparatus, the muscles that keep the heart beating strong.
Zebrafish are useful experimental animals: their genome has been fully sequenced, their bodies are transparent, and their developing embryos are fairly robust. Even more impressively, their hearts have the ability to regenerate after damage. Zebrafish can lose up to 20 per cent of their heart muscle without long-term consequences, as they can repair the damage completely within eight weeks.
Adult mammals lack this superpower. Although some newborn mammals can regenerate damaged heart tissue, this ability vanishes as they mature. During a heart attack, heart muscle cells are deprived of oxygen and they die, leaving scar tissue. “Understanding how zebrafish regenerate [their heart] may one day help victims of heart attacks recover,” says Jana Koth of the BHF Centre of Research Excellence at Oxford University , who took the photograph.