Soung-Hoon Lee,1,2 Mi-Yeon Kim,1,2 Hyun-Yi Kim,1,2 Young-Mi Lee,1,2 Heesu Kim,3 Kyoung Ae Nam,3 Mi Ryung Roh,3 Do Sik Min,1,4 Kee Yang Chung,3 and Kang-Yell Choi1,2
1Translational Research Center for Protein Function Control; 2Department of Biotechnology, College of Life Science and Biotechnology; and 3Department of Dermatology, Severance Hospital, Cutaneous Biology Research Institute, College of Medicine; Yonsei University, Seoul 120-749, South Korea
4Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 609-735, South Korea
CORRESPONDENCE Kang-Yell Choi
Abstract
Wnt/β-catenin signaling plays important roles in cutaneous wound healing and dermal fibrosis. However, its regulatory mechanism has not been fully elucidated, and a commercially available wound-healing agent targeting this pathway is desirable but currently unavailable. We found that CXXC-type zinc finger protein 5 (CXXC5) serves as a negative feedback regulator of the Wnt/β-catenin pathway by interacting with the Dishevelled (Dvl) protein. In humans, CXXC5 protein levels were reduced in epidermal keratinocytes and dermal fibroblasts of acute wounds. A differential regulation of β-catenin, α-smooth muscle actin (α-SMA), and collagen I by overexpression and silencing of CXXC5 in vitro indicated a critical role for this factor in myofibroblast differentiation and collagen production. In addition, CXXC5-/- mice exhibited accelerated cutaneous wound healing, as well as enhanced keratin 14 and collagen synthesis. Protein transduction domain (PTD)-Dvl-binding motif (DBM), a competitor peptide blocking CXXC5-Dvl interactions, disrupted this negative feedback loop and activated β-catenin and collagen production in vitro. Co-treatment of skin wounds with PTD-DBM and valproic acid (VPA), a glycogen synthase kinase 3β (GSK3β) inhibitor which activates the Wnt/β-catenin pathway, synergistically accelerated cutaneous wound healing in mice. Together, these data suggest that CXXC5 would represent a potential target for future therapies aimed at improving wound healing.