Direct Cytoskeleton Forces Cause Membrane Softening in Red Blood Cells

作者:Rodriguez Garcia Ruddi; Lopez Montero Ivan; Mell Michael; Egea Gustavo; Gov Nir S; Monroy Francisco*
来源:Biophysical Journal, 2015, 108(12): 2794-2806.
DOI:10.1016/j.bpj.2015.05.005

摘要

Erythrocytes are flexible cells specialized in the systemic transport of oxygen in vertebrates. This physiological function is connected to their outstanding ability to deform in passing through narrow capillaries. In recent years, there has been an influx of experimental evidence of enhanced cell-shape fluctuations related to metabolically driven activity of the erythroid membrane skeleton. However, no direct observation of the active cytoskeleton forces has yet been reported to our knowledge. Here, we show experimental evidence of the presence of temporally correlated forces superposed over the thermal fluctuations of the erythrocyte membrane. These forces are ATP-dependent and drive enhanced flickering motions in human erythrocytes. Theoretical analyses provide support for a direct force exerted on the membrane by the cytoskeleton nodes as pulses of well-defined average duration. In addition, such metabolically regulated active forces cause global membrane softening, a mechanical attribute related to the functional erythroid deformability.

  • 出版日期2015-6-16