DNA changes shape after injury: scientists identify a mechanism essential for tissue regeneration

After tissue injury, DNA not only changes the activity of individual genes but also undergoes spatial reorganization within the cell nucleus. Scientists have discovered that the formation of special chromatin loops — regions that connect DNA segments located far apart from each other — is necessary for effective tissue repair after injury.

The findings were published in the journal Science Advances. The study was conducted by a team of scientists led by Professor Montserrat Corominas of the University of Barcelona and the Institute of Biomedicine of Barcelona. Researchers from the National Centre for Genomic Analysis, the Centre for Genomic Regulation, and the University of Lausanne also participated in the work.

Inside the cell nucleus, DNA associates with proteins to form chromatin. It has a complex three-dimensional structure that allows regions of the genome that are far apart in the linear DNA sequence to come into physical proximity. This influences which genes are activated and which remain inactive.

To investigate the role of this structure in regeneration, the researchers used wing imaginal discs of the fruit fly Drosophila melanogaster — a model that allows scientists to observe tissue repair after injury.

The scientists identified three DNA loops and experimentally demonstrated that they are necessary for effective regeneration. When the researchers altered genomic regions responsible for forming these loops, the tissues' ability to repair themselves was significantly reduced. At the same time, normal organismal development was largely unaffected.

According to the authors, the findings show that tissue repair depends not only on which genes are switched on or off after injury. The spatial organization of the genome itself is also important.

Thus, the three-dimensional architecture of DNA may represent an additional level of regulation of tissue regeneration. The researchers believe that further study of these changes could help improve our understanding of the mechanisms underlying tissue repair.