Neuronal PAS Domain 2 (Npas2)-Deficient Fibroblasts Accelerate Skin Wound Healing and Dermal Collagen Reconstruction

Anat Rec (Hoboken). 2020 Jun;303(6):1630-1641. doi: 10.1002/ar.24109. Epub 2019 Mar 27.

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.

Keywords: Npas2; circadian rhythm; collagen; fibroblast; wound healing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cell Movement / physiology
  • Cell Proliferation / physiology
  • Collagen / metabolism*
  • Fibroblasts / metabolism*
  • Mice
  • Mice, Knockout
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Skin / metabolism*
  • Wound Healing / physiology*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Nerve Tissue Proteins
  • Npas2 protein, mouse
  • Collagen