A building block for liver fitness in old age

Researchers discover a cell’s own protection against epigenetic changes

The liver can regenerate itself into old age and remains surprisingly efficient, even though the chromatin in its cells undergoes major changes due to epigenetic changes, according to researchers from the Max Planck Institute for Biology of Aging in Cologne. Found it now. Thus they have discovered a possible reason why the conversion has almost no results.

Changes in epigenetics are known to be the cause of aging processes. Epigenetics itself describes changes in genetic information that do not change the sequence of genes themselves, but affect their activity. This can be controlled, among other things, by the access of proteins to DNA.

In this study, researchers found in liver cells that the DNA of liver cells becomes less packed with age. This makes it more accessible to proteins that bind to DNA and make up the messenger molecule RNA. “If DNA is easily accessible, then we should also be making large amounts of RNA. But this was not the case at all,” explains the lead of the study, Peter Tessarz.

short break on DNA

The researchers directly provide a possible explanation for this. They found that RNA polymerase, a protein that binds to DNA and then forms RNA, degrades DNA faster in aged liver cells than in younger cells. This decreased stability means that despite increased DNA accessibility, no more RNA is purified and thus equilibrium is maintained within the cell.

“We think we have discovered a new pathway in cells that compensates for age-related epigenetic changes. This may be one reason for the liver’s prolongation. Could a similar mechanism be responsible for epigenetic changes in other tissues in the future? responds, remains to be explored. However, we also observe completely different epigenetic changes during aging,” says Tesserz.