by Charité - Universitätsmedizin Berlin
When
cells exchange metabolic products with other cells, they live longer.
This new finding comes from a research team at
Charité–Universitätsmedizin Berlin, which made the discovery in a study
using yeast cells. The fact that these exchanges directly impact cell
lifespans could play a significant role in future research into human
aging processes and age-related diseases. The study appears in the
latest issue of Cell.
Metabolism
is inextricably linked to aging. While it helps maintain vital
processes, makes us grow, and triggers cellular repairs, it also
produces substances that damage our cells and cause us to age. "The metabolic processes that
occur within cells are highly complex," says Prof. Markus Ralser,
Director of Charité's Department of Biochemistry and Einstein Professor
of Biochemistry on Charité's medical faculty. "The exchange of
substances between cells in a community is one important factor, because
it has a substantial impact on the metabolism occurring inside a cell."
Cells
are in constant contact with neighboring cells—within tissues, for
instance. They release some substances and consume others from their
surrounding environment. In a recent study, the team led by Prof.
Ralser, a renowned expert in metabolism, investigated whether the
exchange of metabolic products (known as metabolites) affects the lifespan of cells.
The researchers used yeast cells and
performed experiments to establish their lifespan. Yeast cells are a
key model in basic research, a dominant microorganism in biotechnology,
and important in medicine because they can cause fungal infections. "We
showed that the cells lived around 25% longer when they exchanged more
metabolites with each other," says lead author Dr. Clara Correia-Melo,
who also works in the Department of Biochemistry at Charité. "So then we
obviously wanted to identify the substances and exchange processes that
are behind this life-prolonging effect."
To do so, the researchers employed a special analytical system supported by mass spectrometry that
allowed them to precisely track the exchange of metabolites between
cells. They found that young cells, which were still able to divide well
and often, released amino acids that were consumed by older cells.
Amino acids are the building blocks that
make up proteins. The research team discovered that the exchange of the
amino acid methionine extended the lives of the cells involved.
Methionine occurs in all organisms and plays a key role in protein
synthesis, as well as many other cellular processes. "Interestingly, it
was the young cells' metabolism that prolonged the lives of the old
cells," says Prof. Ralser.
The
cells which within the community consumed methionine, released
glycerol. In turn, the presence of glycerol affected methionine
producing cells, causing them to live longer. Glycerol is needed for
building cell membranes and plays a part in protecting cells. "It's a
win-win situation," explains Dr. Correia-Melo. "As cells engage in this
collaborative exchange, they prolong the lifespan of their community as a
whole."
This
study of yeast cell communities is the first to show that metabolite
exchange directly impacts the lifespan and aging process of the cells.
The researchers suspect this also applies to other types of cells, such
as those in the human body, and are aiming to investigate this in further studies.
"A
better understanding of the complex metabolic pathways both within and
between cells will help with investigations into how age-related
diseases like diabetes, cancer, and neurodegenerative conditions
develop," says Prof. Ralser. "Metabolite exchange between cells has been
overlooked in the past, but it's clearly a very important factor in the
cellular aging process. We hope our study will help make the exchange
of metabolic products between cells an area of greater focus in future
research."
For his part, Prof. Ralser is now planning to investigate the precise mechanisms that allow glycerol to protect cells and extend their lives.
More information: Clara Correia-Melo et al, Cell-cell metabolite exchange creates a pro-survival metabolic environment that extends lifespan, Cell (2023). DOI: 10.1016/j.cell.2022.12.007
Journal information: Cell
Provided by Charité - Universitätsmedizin Berlin