Organoids mimic the early development of the heart in mouse embryos

Organoids can be used to study early stages of heart development in mouse embryos, a new study shows.

Researchers from the École Polytechnique Fédérale de Lausanne, Switzerland, have reported that they were able to produce a mouse heart organoid from embryonic stem cells, which displayed essential features of an early developing heart. They suggested that this reveals a novel application of organoids for studying early embryonic stages of development.

'One of the advantages of embryonic organoids is that, through the co-development of multiple tissues, they preserve crucial interactions that are necessary for embryonic organogenesis,' said Dr Giuliana Rossi, lead author of the study. 'The emerging cardiac cells are thus exposed to a context similar to the one that they encounter in the embryo.'

In their study, published in Cell Stem Cell, the team exposed mouse embryonic stem cells to a mix of three factors involved in promoting heart growth. One week later, the stem cells self-organised into so-called gastruloids: organoids with an embryo-like organisation, which displayed signs of early heart development. The cell aggregates not only expressed several genes known to regulate cardiovascular development, but also generated a structure resembling a vascular network. Furthermore, the researchers found an 'anterior cardiac crescent-like domain' in the gastruloids, which even produced a beating heart tissue. Similar to the muscle cells of the embryonic heart, this area was also sensitive to calcium ions.

Organoids have been mostly the focus of research into the generation of adult tissues and organs for pharmaceutical and medical research. In their new publication, Professor Matthias Lütolf and his team suggested that they can also provide a system to study early embryonic stages of the developing heart and other organs, as they preserve important tissue-tissue interactions.