Breaking Bones

Reshaping a bone, like renovating a building, makes a lot of mess. Old cells and debris must be cleared to make space for new, fresh growth. Researchers know that osteoclast cells break down old bone, but what about the spongy cartilage often found where bones meet? This three-week old mouse femur, scanned under a confocal microscope, highlights patterns of blood vessels (red) and cell nuclei (blue), but also elusive cells known as septoclasts (green). They lurk near the growth plate (top) – where cartilage is gradually replaced by hardened bone in early life. Researchers find chemical signals that call septoclasts to action, helping with this ossification. They help during healing too, but as fractures heal slowly in later life, the next challenge is to find ways to boost septoclasts in their vital cartilage clearing.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

Website

• Image from work by Kishor K. Sivaraj and colleagues
• Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Münster, Faculty of Medicine, Münster, Germany
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Nature Communications, January 2022