Blood grows when it flows

The physical forces exerted by a heart beat and the blood flow it produces trigger the formation of new blood cells, according to two studies published today (May 13) in Nature and Cell.

Cluster of blood cells developing after exposure to shear stress Image: Luigi Adamo, Ph.D. student in the García-Cardeña lab at Harvard

"It's very exciting work," said embryologist linkurl:Mary Dickinson;http://www.bcm.edu/db/db_fac-dickinson.html at Baylor College of Medicine in Houston, who was not involved in the research. "It's clear that mechanical forces can regulate pathways leading to differentiation that originally were only thought to be controlled by cell-to-cell signaling." Hematologist linkurl:Leonard Zon,;http://www.childrenshospital.org/cfapps/research/data_admin/Site228/mainpageS228P0.html director of the Stem Cell Program at Children's Hospital Boston, and colleagues screened a library of more than 2,500 chemicals for their effects on hematopoietic stem cell (HSC) production in thousands of zebrafish embryos. The group observed a direct correlation between a chemical's effect on blood flow and...