Boning Up

To construct a building from scratch, you might first build a basic shell or scaffold, then replace that with the permanent structure. Building new bone is similar. An intermediate cartilage structure is established first, only to be converted to solid bone subsequently. This process is supported by a dense network of blood vessels, but exactly how they help is unclear. A new study has found that a particular type of these vessels, known as type H (yellow in the bone section pictured, with vessels stained green and red), help replace the cartilage when it’s time. Specifically, the vessels steer bone growth direction, and endothelial cells lining them lead the cartilage breakdown. Excessive cartilage damage is a hallmark of arthritis, and improving bone repair would benefit countless injured patients, so the next step is asking whether we can control and harness this important function of blood vessels.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Sara G. Romeo and colleagues
• MRC London Institute of Medical Sciences, London, UK
• Image copyright held by the original authors
• Research published in Nature Cell Biology, April 2019