Searching for just a few words should be enough to get started. If you need to make more complex queries, use the tips below to guide you.
Article type: Research Article
Authors: Hallows, Kenneth R.a | Frank, Robert S.b
Affiliations: [a] Department of Biophysics, University of Rochester Medical Center, Rochester, NY 14642 | [b] Department of Mechanical Engineering, University of Rochester Medical Center, Rochester, NY 14642
Note: [] Accepted by: Editor H.L. Goldsmith
Abstract: We measured changes in the deformability of human pro myelocytic leukemic (HL-60) cells induced to differentiate for 5–6 days along the granulocyte pathway by 1.25 % dimethylsulfoxide (DMSO). Differentiation resulted in an approximately 90 % reduction in the transit times of the cells through capillary-sized pores over a range of aspiration pressures. Cell volume, as measured by two methods, decreased by an average of 35 %. To account for the contribution of the volume decrease to the decrease in transit time, the liquid drop model, developed to describe neutrophil deformability, was used to calculate an apparent viscosity of the cells during this deformation. The apparent viscosity of both uninduced and induced HL-60 cells was a function of aspiration pressure, and an approximately 80 % reduction in viscosity occurred with induction, as determined by regression analysis. The deformation rate-dependent viscosities of the induced cells were between 65 and 240 Pa-sec, values similar to those measured for circulating neutrophils. To assess the role of polymerized actin in these viscosity changes, intracellular F-actin content was measured, and the effect of dihydrocytochalasin B (DHB), an agent that disrupts actin polymerization, was determined. Despite the significant decrease in cellular viscosity, F-actin content per cell volume did not change significantly after induced differentiation. Treatment with 3 and 30 μM DHB lowered cellular F-actin content in a dose-dependent manner in both uninduced and induced cells. Cellular viscosity of both uninduced and induced cells decreased sharply with 3 μM DHB treatment (85 % and 76 % respectively). 30 μM DHB treatment caused a further significant reduction in the viscosity of uninduced cells, but for induced cells the additional decrease in viscosity was not significant. These data indicate that reductions in both cell volume and intrinsic viscosity contribute to the increased deformability of HL-60 cells with DMSO-induced differentiation. However, changes in the concentration of F-actin cannot account for the decrease in cellular viscosity that occurs.
Keywords: HL-60 cells, deformability, differentiation, F-actin, cell volume, cytochalasins
DOI: 10.3233/BIR-1992-292-309
Journal: Biorheology, vol. 29, no. 2-3, pp. 295-309, 1992
IOS Press, Inc.
6751 Tepper Drive
Clifton, VA 20124
USA
Tel: +1 703 830 6300
Fax: +1 703 830 2300
sales@iospress.com
For editorial issues, like the status of your submitted paper or proposals, write to editorial@iospress.nl
IOS Press
Nieuwe Hemweg 6B
1013 BG Amsterdam
The Netherlands
Tel: +31 20 688 3355
Fax: +31 20 687 0091
info@iospress.nl
For editorial issues, permissions, book requests, submissions and proceedings, contact the Amsterdam office info@iospress.nl
Inspirees International (China Office)
Ciyunsi Beili 207(CapitaLand), Bld 1, 7-901
100025, Beijing
China
Free service line: 400 661 8717
Fax: +86 10 8446 7947
china@iospress.cn
For editorial issues, like the status of your submitted paper or proposals, write to editorial@iospress.nl
如果您在出版方面需要帮助或有任何建, 件至: editorial@iospress.nl