New findings about how the aging process works may pave the way to better treatments and revolutionary new medications that could immensely improve human health.
Recent research from USC Viterbi School of Engineering has focused on senescence, the natural process by which cells permanently cease creating new cells. Senescence is one of the major causes of age related declines in health.
Senescent cells are the complete opposite of stem cells. Stem cells have unlimited potential for division or self renewal. Senescent cells can never divide again. They are in a state of cell cycle arrest.
The team discovered that these aging senescent cells ceased producing a class of chemicals known as nucleotides which are DNA building blocks. When the team took these young cells and forced them to cease producing nucleotides, they then became aged or senescent.
This observation means the production of nucleotides is mandatory in keeping cells young. And it additionally means that if cells could be prevented from losing nucleotide synthesis, the cells could age more slowly.
The study team examined cells that were young which were proliferating robustly. They fed them molecules that were labeled with stable isotopes of carbon so that they could trace how the nutrients consumed by the cells were processed into a variety of biochemical pathways.
The team worked with a team to develop 3D imagery of the results. Unexpectedly, the images revealed the senescent cells often contain two nuclei and they do not synthesize DNA.
Previously, senescence had primarily been studied in cells which are known as fibroblasts which are the most common cells which comprise the connective tissue in animals. The team instead focused on how senescence occurs in epithelial cells which are cells that line the surfaces of organs and structures in the body.
The team’s goal was not to completely prevent senescence, however they wanted to find a way to remove senescent cells to promote better function and healthy aging.
The research has applications in the emerging field of senolytics which is the development of medications that might be able to eliminate aging cells. Human clinical trials are in early stages, however studies on mice have indicated that through eliminating senescent cells, mice do age better and have a more productive life span.
They can take mice that are aging and diminishing in function, treat them with senolytic drugs to eliminate the senescent cells and the mice are rejuvenated. The team refers to these drugs as the fountains of youth.
In order for successful senolytic drugs to be developed, it is important to identify exactly what is unique about senescent cells so that developed drugs don’t affect the normal non senescent cells. This is where the research team is at…studying the metabolism of senescent cells and then trying to figure out how senescent cells are unique so that targeted therapeutics around these metabolic pathways can be designed.
To view the original scientific study click below
Inhibition of nucleotide synthesis promotes replicative senescence of human mammary epithelial cells
