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Mechanobiology of Disease
Poster Abstracts
91
59-POS
Board 59
Actomyosin Driven Oscillatory Behavior in Microglial Cells
Eunyoung Park
, Young Bin Cho, Unghyun Ko, Jin-Sung Park, Sukyung Park, Jennifer H. Shin.
Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
Dynamics of cytoskeletal proteins are critically involved in many cellular processes including
polarity establishment, movement, and force generation. Despite the importance of cytoskeletal
proteins, identifying their roles in cellular processes is difficult due to the complexities in the
combinatorial effects of the involved proteins. In this study, we present microglia, a type of
immune cells in the central nervous system, which are known to alter their phenotypes by
rearranging the cytoskeletons depending on the microenvironment. Especially, microglia
featured oscillatory migration by forming a large lamellipodium at each end. From the physical
force measurement with traction force microscopy (TFM), we observed the localized stresses at
the both ends and their fluctuations, which are followed by the morphological oscillation. By the
correlation analysis, we identified two lagged motion: that the protruding of the lamellipodium
was prior to the traction development and nuclear translocation. Based on our observations, we
proposed a simple viscoelastic lumped model for oscillating microglia by comprising two
masses, two springs and two dampers, which represent the contractility and adhesive drag
induced by cytoskeletal proteins. By comparing the obtained coefficients of spring and damping
with the previously reported values, we could suggest that our simplistic model is able to capture
the dynamic behavior of complex cytoskeletal elements in the oscillating microglia. Moreover,
we also investigated the direct role of the cytoskeletal proteins by the inhibition assays, in which
the oscillations were shown to be regulated by actomyosin contractility. This work was
supported by the National Research Foundation of Korea Grant funded by the Korean
government (NRF-2015M3A9B3028685).