Ca2+ -regulated cell migration revealed by optogenetically engineered Ca2+ oscillations

Abstract

The ability of a single Ca²⁺ ion to play an important role in cell biology is highlighted by the need for cells to form Ca²⁺ signals in the dimensions of space, time, and amplitude. Thus, spatial and temporal changes in intracellular Ca²⁺ concentration are important for determining cell fate. Optogenetic technology has been developed to provide more precise and targeted stimulation of cells. Here, U2OS cells overexpressing Ca²⁺ translocating channelrhodopsin (CatCh) were used to mediate Ca²⁺ influx through blue light illumination with various parameters, such as intensity, frequency, duty cycle, and duration. We identified that several Ca²⁺ -dependent transcription factors and certain kinases can be activated by specific Ca²⁺ waves. Using a wound-healing assay, we found that low-frequency Ca²⁺ oscillations increased cell migration through the activation of NF-κB. This study explores the regulation of cell migration by Ca²⁺ signals. Thus, we can choose optical parameters to modulate Ca²⁺ waves and achieve activation of specific signaling pathways. This novel methodology can be applied to clarify related cell-signaling mechanisms in the future.

Keywords: Ca2+ translocating channelrhodopsin; Ca2+-dependent transcription factors; cell migration; channelrhodopsin-2; optogenetics.