Wound healing is a complex and dynamic process that helps the skin or other tissue of the
body repair after injury. Some chronic skin wounds such as diabetic ulcers and bedsores are
difficult to heal. Photodynamic therapy (PDT) composes of photoactivation of a photosensitizer
with a specific wavelength of light. In clinic, low dose PDT enhances chronic ulcers to heal but
the mechanism remains unknown. Cystic fibrosis transmembrane conductance regulator (CFTR)
is an ion channel expresses in the multiple layers of keratinocytes. Recently, the role of CFTR
in wound healing has been explored. The CFTR expression levels are related to keratinocyte
migration, proliferation, and differentiation. In this study, we hypothesize that CFTR plays an
important role in PDT enhancement of skin wound healing.
PDT effects on wound healing were examined in C57BL/6 mice and the mechanism was
explored in vitro. The spatial and temporal expression levels of CFTR and proteins in focal
adhesion complex including focal adhesion kinase (FAK), and paxillin were studied during
wound healing.
HaCaT cells migrated faster after incubation with a low dose PDT conditioned medium (5
J/cm2 and 100 μg/mL indocyanine green (ICG)) than a high dose PDT conditioned medium (15
J/cm2 with the same ICG concentration). Curcumin, activator of CFTR increased cell migration
while inhibition of CFTR and FAK delayed PDT treated wound healing. The expressions of
phosphorylated FAK Y861 and phosphorylated paxillin in focal adhesion complex were spatial
and temporal regulated in parallel by PDT conditioned medium.
In conclusion, the results suggested that PDT enhancing cell migration at least partly
related to CFTR regulated FAK pathway

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