In-situ monitoring of signal transduction between skin cells induced by UVB irradiation using scanning electrochemical microscopy

Skin is the first barrier of the immune system, protecting the body from various damages of the external environment, the signal transduction between skin cells plays an important role in skin healing and injury. Scanning electrochemical microscopy (SECM) combined with a Transwell co-culture device has been proposed to in-situ investigate the signal transduction between skin cells with UVB irradiation, in which, keratinocyte HaCaT cells and fibroblast HFF cells were used as signaling cells and signal-receiving cells, respectively. Extracellular ROS and pH, cell membrane permeability and cell height were in-situ monitored by multi-potential step waveform in SECM (SECM-MPSW), potentiometric mode, shear force mode and the probe approach curve (PAC) combined with COMSOL simulation, respectively. The results revealed that UVB irradiation stimulated HaCaT cells to release excess H⁺, which diffused to HFF cells and increased the ROS release and membrane permeability with unchanged cell height. Therefore, this work provides an effective way to in-situ investigate intercellular signal transduction.