Red Blood Cells Alter Shape From Disc to Bullet

Via Xinhua -

BEIJING, March 14 (Xinhuanet) -- A new study reveals how human red blood cells are able to change shape to squeeze through capillaries and could help scientists better understand blood disorders such as malaria and sickle cell anemia, U.S. media reported Wednesday.

Blood cells must squeeze through the body's smallest blood vessels to carry oxygen and carbon dioxide to and from organs. But capillaries often become narrower than the cells in their normal disc shape. So the cells must deform to fit through them.

To change shape, the cells rearrange protein components of their internal scaffolding, called the cytoskeleton.

The rearrangement occurs when the cell is squeezed as it tries to fit through a tiny capillary -- the bonds holding the proteins together break, allowing the blood cells to behave like a liquid and stretch into a bullet shape.

"Now we can study how molecular structure affects the shape, which affects the mechanical properties, and both of which affect mobility," said study author Subra Suresh of MIT.

Mobility is a key factor in diseases such as malaria, which makes red blood cells less deformable, and the genetic disorder sickle cell anemia, which gives red blood cells a sickle shape that prevents them from flowing through the blood vessels.

With this new discovery, published in the March 22 online edition of Proceedings of the National Academy of Sciences, scientists will be able to examine how these disorders affect the cells at the molecular level.