Scientists Reverse Aging in Rat Stem Cells

Scientists who discovered aging appears to be related to the stiffness of the environment where cells live have reversed the process in rat brain stem cells.

Researchers studied oligodendrocyte progenitor cells (OPCs) in young and old rat brains, and found they were affected by stiffness in the organ caused by aging. These stem cells, meaning they can turn into other types of cell, are found in the central nervous system.

The team also found that a protein called Piezo1, which senses how stiff its surroundings are, could be harnessed to trick stem cells into thinking they were in a younger, softer environment. Deleting the protein from the OPCs in older rat brains appeared to make them behave younger. Taking OPCs from older rats and putting them in younger rodents was also found to rejuvenate the cells.

Kevin Chalut, a biophysicist at the University of Cambridge and co-author of the study published in the journal Nature told Newsweek: "The study tells us that aging, at least for stem cells we studied, is not driven by anything intrinsic to the cell. It is instead driven by the environment. This was already known to be a factor, but the true significance here is to show that it is the stiffness of the environment alone that drives the aging of the stem cells.

"This is rather remarkable because it suggests an entirely new way of thinking about what controls aging in stem cells, and furthermore, since stiffness is a single factor from the environment, it suggest a means to straightforwardly reverse aging in stem cells'" Chalut explained.

"It may be that this could be a key to aging in stem cells for all the tissues in the body, pointing to a means to aid regeneration of diseased or damaged tissue with age."

However, Chalut stressed the team has so far only demonstrated the findings in just one stem cell system in rodents, and this may not work in humans.

Asked whether the research could be used to reverse physical aging in humans, or treat age-related conditions such as Alzheimer's disease, Chalut told Newsweek: "The need to study other tissues, such as skin, is very pressing. We have every reason to believe that the mechanical properties of tissue could play a highly significant role in aging.

"It may well be that our findings could be applied to help rejuvenate other tissues. It is possible that our findings could help with multiple brain conditions, including Alzheimer's, but as of now the most obvious is multiple sclerosis (MS), which is driven in large part by loss of function in the stem cells we studied."

OPCs help to keep the brain healthy and are used by the body to make the myelin sheath which protects our central nervous system. This myelin is attacked by the immune system in those with MS.

Susan Kohlhaas, director of research at the MS Society which part funded the research, highlighted how the findings could one day help those with multiple sclerosis. She commented in a statement: "MS is relentless, painful, and disabling, and treatments that can slow and prevent the accumulation of disability over time are desperately needed.

"The Cambridge team's discoveries on how brain stem cells age and how this process might be reversed have important implications for future treatment, because it gives us a new target to address issues associated with aging and MS, including how to potentially regain lost function in the brain."

Joao Pedro De Magalhaes, senior lecturer in musculoskeletal biology at the University of Liverpool, who did not work on the study, told Newsweek the research is "really interesting and timely."

"The topic of how the tissue microenvironment influences aging of stem cells is a fascinating one that has been the focus of considerable research in recent years. Results from other labs, for example using parabiosis (i.e., joining the circulatory system to two animals), have demonstrated the role of the environment and circulatory factors in loss of function with age of stem cells. This study is quite interesting in showing the importance of tissue microenvironment for a particular type of stem cell found in the central nervous system."

Georgina Ellison-Hughes reader of physiology at King's College London, who was not involved in the work, told Newsweek she was surprised by the importance of the aged environment together with tissue mechanics on central nervous system progenitor cell function.

"It would be interesting to see if tissue mechanics affect progenitor cell function in other organs, especially where increased stiffness plays a big part in other age-related disease, such as cardiovascular disease," she said.