Abstract
A wide variety of cell types exhibit substrate topography-based behavior, also known as contact guidance. However, the precise cellular mechanisms underlying this process are still unknown. In this study, we investigated contact guidance by studying the reaction of human endothelial cells (ECs) to well-defined microgroove topographies, both during and after initial cell spreading. As the cytoskeleton plays a major role in cellular adaptation to topographical features, two methods were used to perturb cytoskeletal structures. Inhibition of actomyosin contractility with the chemical inhibitor blebbistatatin demonstrated that initial contact guidance events are independent of traction force generation. However, cell alignment to the grooved substrate was altered at later time points, suggesting an initial 'passive' phase of contact guidance, followed by a contractility-dependent 'active' phase that relies on mechanosensitive feedback. The actin cytoskeleton was also perturbed in an indirect manner by culturing cells upside down, resulting in decreased levels of contact guidance and suggesting that a possible loss of contact between the actin cytoskeleton and the substrate could lead to cytoskeleton impairment. The process of contact guidance at the microscale was found to be primarily lamellipodia driven, as no bias in filopodia extension was observed on micron-scale grooves.
Highlights
IntroductionCells are generally capable of being oriented and directed, both in vivo and in vitro, by the micro- and nanotopography of their substrate in a complex feedback process known as contact guidance.[1,2,3,4,5] This phenomenon has been observed in a wide variety of settings, including organ and tissue generation and regeneration,[6] wound healing,[7,8] and axon pathfinding.[9,10] Contact guidance is an important parameter in the design of medical implant surfaces, as tailored topography can provide a level of cellular control in vivo.[11,12]One particular aspect of contact guidance that remains unclear is the role of actomyosin contractility during initial cell spreading
We have investigated the morphology and orientation of human endothelial cells (ECs) on microstructured poly(dimethylsiloxane) (PDMS) substrates consisting of parallel microgrooves
Even at early time points, contact guidance was observed in the periphery of the cells, as portions of the membrane preferentially aligned along the grooves (Fig. 1 zoom C1–E1)
Summary
Cells are generally capable of being oriented and directed, both in vivo and in vitro, by the micro- and nanotopography of their substrate in a complex feedback process known as contact guidance.[1,2,3,4,5] This phenomenon has been observed in a wide variety of settings, including organ and tissue generation and regeneration,[6] wound healing,[7,8] and axon pathfinding.[9,10] Contact guidance is an important parameter in the design of medical implant surfaces, as tailored topography can provide a level of cellular control in vivo.[11,12]One particular aspect of contact guidance that remains unclear is the role of actomyosin contractility during initial cell spreading. After injury or damage (e.g. stent insertion), ECs undergo the process of endothelialization, in which cells migrate to the injured area and proliferate in order to heal the damage. This process is not always effective and can lead to fatal consequences.[36,37] One possible method for improving the endothelialization process is microstructuring implant surfaces that come into contact with the vessel, with the goal of enhancing directional cell migration towards the injured area and controlling cell proliferation. Specific surface topographies can favor cell polarization, an important aspect of healthy endothelium function.[38]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
