α7-nAChR Activation Has an Opposite Effect on Healing of Covered and Uncovered Wounds
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The α7 nicotinic acetylcholine receptor (α7-nAChR) is associated with inflammation, re-epithelialization, and angiogenesis in wound healing process. A recent study demonstrated that PNU-282987, a selective agonist of α7-nAChR, accelerates the repair of diabetic excisional wounds. Whether α7-nAChR activation promotes non-diabetic wounds healing is unknown. The aim of this study was to evaluate the effects of α7-nAChR activation on non-diabetic wound healing. The effects were evaluated in two wound models. In the first model, the wound was covered with a semi-permeable transparent dressing. In the second model, the wound was left uncovered. In both models, the mice were randomly assigned to two treatment groups: saline or PNU282987 (25 mice in each group). In covered wounds, we found that α7-nAChR activation inhibited re-epithelialization, angiogenesis, and epithelial cells proliferation, promoted neo-epithelial detachment, and suppressed neutrophil infiltration and the expression of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF). However, in uncovered wounds, we observed that α7-nAChR activation promoted re-epithelialization and angiogenesis, inhibited neutrophil infiltration and the expression of high mobility group box (HMGB)-1, epidermal growth factor (EGF), and VEGF. In conclusion, this data demonstrated that α7-nAChR activation inhibited wound healing in covered wounds but played an opposite role in uncovered wounds. The opposite effect might be primarily due to inhibition of inflammation.
Key Wordsα7 nicotinic acetylcholine receptor wound healing dressing anti-inflammation re-epithelialization angiogenesis
This study was financially supported by grants from the National Natural Science Foundation of China (81273342, 81671862).
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