In JoVE (1)
Other Publications (1)
Articles by Yashar Bashirzadeh in JoVE
Stiffness Measurement of Soft Silicone Substrates for Mechanobiology Studies Using a Widefield Fluorescence Microscope Yashar Bashirzadeh*1, Siddharth Chatterji*1, Dakota Palmer*2, Sandeep Dumbali*1, Shizhi Qian1, Venkat Maruthamuthu1 1Department of Mechanical & Aerospace Engineering, Old Dominion University, 2Department of Biological Sciences, Old Dominion University Substrates with stiffness in the kilopascal-range are useful to study the response of cells to physiologically relevant micro-environment stiffness. Using just a widefield fluorescence microscope, the Young's modulus of soft silicone gels can be determined using an indentation with a suitable sphere.
Other articles by Yashar Bashirzadeh on PubMed
Effect of Pharmacological Modulation of Actin and Myosin on Collective Cell Electrotaxis Bioelectromagnetics. | Pubmed ID: 29663474 Electrotaxis-the directional migration of cells in response to an electric field-is most evident in multicellular collectives and plays an important role in physiological contexts. While most cell types respond to applied electric fields of the order of a Volt per centimeter, our knowledge of the factors influencing this response is limited. This is especially true for collective cell electrotaxis, in which the subcellular migration response within a cell has to be coordinated with coupled neighboring cells. Here, we investigated the effect of the level of actin cytoskeleton polymerization and myosin activity on collective cell electrotaxis of Madin-Darby Canine Kidney (MDCK) cells in response to a weak electric field of physiologically relevant magnitude. We modulated the polymerization state of the actin cytoskeleton using the depolymerizing agent cytochalasin D or the polymerizing agent jasplakinolide. We also modulated the contractility of the cell using the myosin motor inhibitor blebbistatin or the phosphatase inhibitor calyculin A. While all the above pharmacological treatments altered cell speed to various extents, we found that only increasing the contractility and a high level of increase/stabilization of polymerized actin had a strong inhibitory effect specifically on the directedness of collective cell electrotaxis. On the other hand, even as the effect of the actin modulators on collective cell migration was varied, most conditions of actin and myosin pharmacological modulation-except for high level of actin polymerization/stabilization-resulted in cell speeds that were similar in the absence or presence of the electric field. Our results led us to speculate that the applied electric field may largely impact the cellular apparatus specifying the polarity of collective cell migration, rather than the functioning of the migratory apparatus. Bioelectromagnetics. 39:289-298, 2018. © 2018 Wiley Periodicals, Inc.