Washington: A recent study has revealed that our brain stem cell becomes less productive as we age because of the increased brain stiffness. The research also found different ways to reverse the aged and unhealthy brain cells with a healthier one.
The study conducted at the University of Cambridge was published in the journal 'Nature'.
As our bodies age, muscles, and joints can become stiff, making everyday movement more difficult. The study emphasises the same for our brains, that age-related brain stiffening has a significant impact on the function of brain stem cells.
A multi-disciplinary research team, based at the Wellcome-MRC Cambridge Stem Cell Institute (University of Cambridge), studied young and old rat brains to understand the impact of age-related brain stiffening on the function of oligodendrocyte progenitor cells (OPCs).
These cells are a type of brain stem cell important for maintaining normal brain function, and for the regeneration of myelin a fatty sheath that surrounds our nerves, which is damaged in multiple sclerosis (MS). The effects of age on these cells contribute to MS, but their function also declines with age in healthy people.
To determine whether the loss of function in aged OPCs was reversible, the researchers transplanted older OPCs from aged rats into the soft, spongy brains of younger animals. Remarkably, the older brain cells were rejuvenated and began to behave like the younger, more vigorous cells.
The researchers developed new materials in the lab with varying degrees of stiffness and used these to grow and study the rat brain stem cells in a controlled environment. The materials were engineered to have a similar softness to either young or old brains.
To fully understand how brain softness and stiffness influences cell behaviour, the researchers investigated Piezo1 -- a protein found on the cell surface, which informs the cell whether the surrounding environment is soft or stiff.
"We were fascinated to see that when we grew young, functioning rat brain stem cells on the stiff material, the cells became dysfunctional and lost their ability to regenerate, and in fact began to function like aged cells. What was especially interesting, however, was that when the old brain cells were grown on the soft material, they began to function like young cells, in other words, they were rejuvenated," said Dr. Kevin Chalut, one of the researchers who carried out the study.
"When we removed Piezo1 from the surface of aged brain stem cells, we were able to trick the cells into perceiving a soft surrounding environment, even when they were growing on the stiff material," explained co-author Robin Franklin
"What's more, we were able to delete Piezo1 in the OPCs within the aged rat brains, which lead to the cells becoming rejuvenated and once again able to assume their normal regenerative function," added Franklin.
This research was supported by the European Research Council, MS Society, Biotechnology and Biological Sciences Research Council, The Adelson Medical Research Foundation, Medical Research Council and Wellcome.
