Summary of the science
Immune cells, such as macrophages, are important for our bodies to fight off infection. Macrophages are like the "clean-up crew" of our body, as they surround and eat up harmful bacteria. However, for some animals, like the salamander, macrophages also play a role in regrowing body parts. The lab found that when macrophages stopped working, the regrowth failed, resulting in scars. Restoring macrophages enabled successful regrowth. Understanding how this occurs and the mechanisms involved may help scientists develop new ways to heal and regenerate damaged body parts, like the heart.
About the research
The lab led by Nadia Rosenthal investigates the interplay between immune cells and tissue regeneration. In adult mammals, the inability to replace damaged body parts is due to limited growth response and scarring. There are certain species like the salamander that have the ability to regrow certain body parts, but the signals, genes and mechanisms involved are not greatly understood. They studied immune signalling during limb regeneration in salamanders and discovered that macrophage infiltration at specific times is crucial for successful regeneration. Disrupting this process led to permanent failure, fibrosis, and abnormal gene expression. Restoring macrophages enabled limb regeneration, suggesting potential therapeutic approaches for regenerative medicine, such as regeneration of the cardiac tissue.
About the illustration
We wanted to emphasise that macrophage infiltration at specific times is crucial for successful regeneration of body parts. The thin layer of cells represents the tissue and the macrophages (round cells) are shown to aid tissue regeneration in the damaged areas, highlighted in white for clarity.