Institution: | 1. Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, California
Department of Oral and Maxillofacial Implantology, Tokyo Dental College, Tokyo, Japan;2. Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, California
Regenerative Bioengineering and Repair Laboratory, Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California;3. Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, California
Department of Oral Rehabilitation, Section of Oral Implantology, Fukuoka Dental College, Fukuoka, Japan;4. Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, California;5. Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, California
Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan |
Abstract: | The circadian clock, which consists of endogenous self-sustained and cell-autonomous oscillations in mammalian cells, is known to regulate a wide range of peripheral tissues. The unique upregulation of a clock gene, neuronal PAS domain protein 2 (Npas2), observed along with fibroblast aging prompted us to investigate the role of Npas2 in the homeostasis of dermal structure using in vivo and in vitro wound healing models. Time-course healing of a full-thickness skin punched wound exhibited significantly faster wound closure in Npas2?/? mice than wild-type (WT) C57Bl/6J mice. Dorsal skin fibroblasts isolated from WT, Npas2+/?, and Npas2?/? mice exhibited consistent profiles of core clock gene expression except for Npas2 and Per2. In vitro behavioral characterizations of dermal fibroblasts revealed that Npas2?/? mutation was associated with increased proliferation, migration, and cell contraction measured by floating collagen gel contraction and single-cell force contraction assays. Npas2 knockout fibroblasts carrying sustained the high expression level of type XII and XIV FAICT collagens and synthesized dermis-like thick collagen fibers in vitro. Confocal laser scanning microscopy demonstrated the reconstruction of dermis-like collagen architecture in the wound healing area of Npas2?/? mice. This study indicates that the induced Npas2 expression in fibroblasts may interfere with skin homeostasis, wound healing, and dermal tissue reconstruction, providing a basis for novel therapeutic target and strategy. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc. |