Effect of steady and oscillatory shear stress on F-actin content and distribution in neutrophils.
We investigated neutrophil activation, specifically F-actin content and distribution, in situations mimicking the in vivo environment using steady and oscillatory shear. Under low steady shear (<150 s(-1)) F-actin levels were decreased for both treated (n-formyl-L-methioryl-L-leucyl-L-phenylalanine (fMLP)) and untreated neutrophils. The F-actin content increased with a change to higher steady shear levels. Neutrophils show the same behavior of decreased F-actin content for oscillatory shear (26.7 s(-1)) as they did for steady shear. In both situations, the low shear levels caused a decrease in F-actin content. However, as the magnitude of the shear rate increased, cells showed a reversal to increasing F-actin content. Shear caused a decrease in F-actin in the cell cortex for both control and fMLP treated cells. Ctyochalasin B (CB), a common F-actin assembly blocker, significantly decreased F-actin content. The results indicate that neutrophils regulate their actin network based on the level and type of shear stress they encounter in the bloodstream.
Chen
Huai-Qing
HQ
Institute of Biomedical Engineering, West China Center of Medical Sciences, Sichuan University, Chengdu, Sichuan 610041, PR China.
Tian
Wei
W
Chen
Yun-Shuang
YS
Li
Liang
L
Raum
Jeffrey
J
Sung
K-L Paul
KL
D000199:Actins / Q000032:analysis*; D000704:Analysis of Variance; D005434:Flow Cytometry; D006801:Humans; D018375:Neutrophil Activation; D009504:Neutrophils / Q000502:physiology*; D013314:Stress, Mechanical
D000199:Actins