Longevity Briefs: Could We Rejuvenate Fragile Bones Using Extracellular Vesicles?

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

Osteoporosis is a disease of ageing in which bones become weaker and more fragile. This happens because the body’s normal process of breaking down old bone and building new bone gets out of balance. The activity of cells called osteoblasts, responsible for forming new bone, is outstripped by the activity of osteoclasts, the cells that remove bone tissue in a process called resorption. Most treatments today try to slow down the bone breakdown by targeting osteoclasts, but many people find it hard to stick to these treatments due to a variety of factors including side effects.

The discovery:

In this study, researchers found that the expression of a gene called WIF1 increased significantly during the last stage of the development of new osteoblasts from precursor cells. Suspecting that WIF1 might regulate bone formation, they used genetic techniques to shut down WIF1 activity, and found that the ability of these cells to produce new bone tissue was reduced, while boosting the activity of WIF1 had the opposite effect.

Next, they took cells overexpressing WIF1 and collected their extracellular vesicles (EVs). EVs are tiny packages of cell membranes released by cells. They contain many components including signalling molecules, proteins and genetic material, and can be absorbed by other cells, within which they can activate signalling pathways and regulate gene activity. Researchers found that when they injected these extracellular vesicles into mice with osteoporosis, their condition improved significantly with a reversal of bone loss. 

The implications:

These findings suggest that WIF1 is important for bone health and could be a target for treating osteoporosis. It also reminds us of the potential of EVs for treating diseases in humans. EVs that are harvested from our own cells are unlikely to be dangerous, and have many advantages over conventional drugs such as the ability to target them to a particular tissue, meaning fewer side effects.