Eternal Life: Cell Cooperation Prevents Aging

The university reported that the exchange of substances has a direct influence on the lifespan of cells, which could play an important role in research into aging processes and age-related diseases in humans.

The study was published in the current specialist journal Cell (doi: 10.1016/j.cell/2022.12.007). “The metabolic processes that take place within cells are highly complex,” said Markus Ralser, Director of the Institute of Biochemistry at the Charite. “Among other things, the exchange of substances between the cells of a cell community plays a central role, because it has a significant influence on the internal cell metabolism.”

Cells are in constant interaction with “neighbors” – for example in body tissues. They eject substances that are not required from their cell interior and absorb substances from their environment. In the current study, the biochemist’s team investigated whether the exchange of metabolic products (metabolites) has an impact on the lifespan of cells.

Cells lived 25 percent longer

For their investigations, the scientists worked with yeast cells and carried out experiments to determine their lifespan. “We were able to show that the life span of the cells was extended by around 25 percent if they were able to exchange metabolites with one another,” said Clara Correia-Melo from the Institute of Biochemistry at the Charite and first author of the study. “Now of course we wanted to know which substances and exchange processes are behind this life-prolonging effect.”

To find out, the scientists used a special examination system supported by mass spectrometry, with which the exchange of substances between the cells could be precisely tracked. They found that young cells, which were still dividing well and frequently, excreted amino acids and that these were taken up by the older cells. It turned out that replacing the amino acid methionine in particular extends the life of the cells involved. This amino acid occurs in all organisms and plays an important role in protein production and also in many cellular processes.

“The interesting thing is that the metabolism of the young cells was responsible for extending the life of the old cells,” explained Ralser. Some young cells released methionine, which other young cells took up. This changed their cell metabolism in such a way that they excreted metabolic products from which the methionine-producing cells benefited. This is about glycerol, which is required for the construction of cell membranes and has cell-protecting properties. “When long-lived methionine-taking cells release glycerol, they also prolong the life of methionine-producing cells – a win-win situation,” explained Clara Correia-Melo. “And this cooperative exchange of substances between the cells extends the lifespan of the entire cell community.”

With their study, the researchers were able to show for the first time, using yeast cell communities, that the exchange of substances has a direct influence on the lifespan and the aging process of cells. They suspect that this also applies to other cell types, such as human body cells, and want to test this in further studies.

“In order to research the development of age-related diseases such as diabetes, cancer or neurodegenerative diseases, the complex metabolic pathways within, but also between the cells, must be better understood,” said Ralser. “The exchange of substances between cells is a hitherto overlooked but obviously crucial factor in the cellular aging process.” In further research projects, the Berlin scientists want to examine the exact mechanisms of the cell-protecting and life-prolonging effect of glycerol in more detail.