Stressed Start

The force of running water shapes mountains and valleys over time, and it appears similar pressures sculpt your heart. Researchers investigating how valves form in the heart focussed on a signalling pathway called Notch, known to be key to how the heart chamber lining reforms during valve formation. They observed patterns of Notch expression (activity) (green in the mouse embryo heart section pictured) in heart lining cells (red), and found it unevenly distributed, concentrated where valves would ultimately form. They found that shear stress – the mechanical force of blood flowing – was sufficient to trigger a cascade of signals that activate the Notch pathway (and hence guide valve formation) even in the absence of other chemical signals. Understanding how mechanical signalling and the force of flowing blood write the blueprint for a healthy heart could help explain, or even prevent, congenital heart defects that often arise in these early moments of development.

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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• Still from video from work by Yunfei Mu and Shijia Hu, and colleagues
• Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China
• Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, February 2025