1471 A new proposal for skin wound healing: The combination of HMGB1 B-Box and non-equilibrium atmospheric pressure plasma

Background: High mobility group box 1 (HMGB1) is a multifunctional protein and it’s activity depends on the redox status. HMGB1 contains two homologous DNA-binding domains, A- and B-box. Generally, B-box is known to induce strong inflammation whereas A-box acts as anti-HMGB1. However, we could not see any of these effect in normal human keratinocytes, besides, although the effect was limited, we have previously shown that HMGB1 B-box promoted wound healing bothin vitro and in vivo. Therefore, we next focused on non-equilibrium atmospheric pressure discharge plasma (NEADP) to enhance this effect. NEADP can be applied to the living body without thermal effects, and has been found to have not only anti-bacterial effect but also anti-inflammatory effect which could promote wound healing. In this study, we evaluated the synergistic effect of NEADP on HMGB1 B-box in keratinocytes. Method: Monolayered cultured normal human keratinocytes was treated with either of the followings; NEADP with HMGB1 B-box, NEADP with HMGB1 A-box, NEADP alone, HMGB1 B-box alone, and HMGB1 A-box alone. NEAP was irradiated for 2 seconds followed by the addition of HMGB1 A-box or B-box in the culture medium. Then a scratch test was performed and was evaluated to compare the wound healing by measured reducing area after 24 hours. Result: Only keratinocytes treated with NEADP with HMGB1 B-box significantly accelerated wound healing compared with other arms. Surprisingly, NEADP with HMGB1 B-box arm showed better than the sum of each monotherapy. Conclusion: NEADP may act synergistically with HMGB1 B-box in wound-healing process.