Biophysical Society Thematic Meeting | Singapore

Mechanobiology of Disease

Poster Abstracts

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).

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