A new study published in the journal Nature on August 14, 2019, shows how the increasing brain stiffness that comes with age leads to dysfunction of brain stem cells and shows new ways to restore older stem cells to a younger and healthier state.
The results have a profound impact on how we understand the aging process and how we can develop essential treatments for age-related brain diseases.
With age, muscles and joints can become stiff, making daily movements more difficult. This study shows that the same is true for our brain and that age-related brain stiffness has a significant impact on the functioning of brain stem cells.
A multidisciplinary research team at the Cambridge Stem Cell Institute (University of Cambridge) studied the effects of age-related brain rigidity on the functioning of oligodendrocyte progenitor cells (OPCs) in young and elderly rats.
These cells are one of the types of brain stem cells that play an important role in maintaining normal brain function and regenerating myelin, the fatty membrane that surrounds our nerves and is damaged by multiple sclerosis. The effect of age on these cells contributes to the development of MS, but also in healthy individuals, their function decreases with age.
To determine if the loss of function of the old OPCs is reversible, researchers transferred old OPCs from old rats to the spongy and soft brains of young animals. As a result the old brain cells have been rejuvenated and have begun to act like younger and more energetic cells.
To further this research, researchers created new materials with different stiffness in the laboratory and used them to culture and study rat brain’s stem cells in a lab controlled environment. The materials have been developed to be as soft as young or old brains.
To understand how the softness and rigidity of the brain affect cell behavior, researchers studied Piezo1, a protein on the cell surface that tells the cell whether the environment is soft or hard.
Dr. Kevin Chalut, co-director of the study, said that the research team was fascinated by the fact that when the young functional brain stem cells from rats became hard, they started to malfunction and also lost their ability to regenerate, and began to act like old cells. What is particularly interesting, however, is that the old brain cells that developed in soft material began to function as young cells, that is, they were rejuvenated.
When they removed Piezo1 from the surface of old brain stem cells, they were able to make the cells perceive a soft environment, even if they were growing on hard materials, explains Professor Robin Franklin, who led the research with Dr. Chalut. In addition, they were able to remove Piezo1 from the OPCs of the old rat brain, which resulted in cell rejuvenation and allowed them to regain their normal regenerative function.
Dr. Susan Kohlhaas, research director of the MS Society, who partly funded the study, said, MS is relentless, disabling and painful and treatment that can help over time is essential. The Cambridge team’s conclusions on the aging of brain stem cells and how this process can be reversed are important for future treatment, as they give us a new focus on solving the problems associated with aging and MS, and also how we can recover potentially lost functions in the brain.