The results, published in Nature, have far-reaching implications for how we understand the ageing process, and how we might develop much-needed treatments for age-related brain diseases.
As our bodies age, our muscles and joints can become stiff, making everyday movements more difficult. This study shows the same is true in our brains, and 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 at the 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 – the fatty sheath that surrounds our nerves, which is damaged in multiple sclerosis (MS). The effects of age on these cells contributes 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.
To study this further, 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.
Image: Aged rat brain stem cells grown on a soft surface (right) show more healthy, vigorous growth than similar aged brain stem cells grown on a stiff surface (left). The red marker shows brain stem cells, and the green marker indicates cell proliferation.
Credit: Mikey Segel
Reproduced courtesy of the University of Cambridge