1. Academic Validation
  2. Knockdown of HIF-1α inhibits the proliferation and migration of outer root sheath cells exposed to hypoxia in vitro: An involvement of Shh pathway

Knockdown of HIF-1α inhibits the proliferation and migration of outer root sheath cells exposed to hypoxia in vitro: An involvement of Shh pathway

  • Life Sci. 2017 Dec 15;191:82-89. doi: 10.1016/j.lfs.2017.10.011.
Haihua Zhang 1 Weixiao Nan 2 Xingchao Song 1 Shiyong Wang 1 Huazhe Si 1 Guangyu Li 3
Affiliations

Affiliations

  • 1 State Key Laboratory of Special Economic Animal Molecular Biology, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun 130112, People's Republic of China.
  • 2 College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, People's Republic of China.
  • 3 State Key Laboratory of Special Economic Animal Molecular Biology, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun 130112, People's Republic of China. Electronic address: liguangyu@caas.cn.
Abstract

Aims: Outer root sheath (ORS) is a highly proliferative component of a hair follicle. This study is performed to investigate whether hypoxia-induced elevation of hypoxia-inducible factor (HIF)-1α, a transcriptional activator, contributes to the outgrowth of ORS cells in vitro.

Main methods: Hair follicles with intact ORS collected from 4-month old male American minks were cultured in normoxic or hypoxic condition (3% oxygen) for 7days. Primary ORS cells isolated from the mink hair follicles were exposed to hypoxia for 12, 24 or 48h, and their proliferation was analyzed with immunofluorescence assay using anti-proliferating cell nuclear antigen (PCNA) antibody. The migratory ability of ORS cells was detected via the transwell chamber. The endogenous HIF-1α was knocked down with its specific siRNA in ORS cells.

Key findings: Hypoxic exposure induced an elevation of HIF-1α in ex vivo cultured hair follicles. The mRNA and protein levels of sonic Hedgehog (Shh), Shh receptor Patched 1, Smoothened and glioma-associated oncogene homologue 1 were upregulated. In vitro, hypoxia induced an increase in HIF-1α in ORS cells. Further, under hypoxic condition, the number of PCNA-positive cells was increased, and more cells migrated towards high serum media. Hypoxia-enhanced proliferation and migration of ORS cells were suppressed either by HIF-1α siRNA or by pharmacological inhibitors of Shh pathway, cyclopamine and GANT61. The activation of Shh pathway was attenuated in HIF-1α-silenced ORS cells under hypoxic condition.

Significance: Our work demonstrates a direct role of activated HIF-1/Shh biological axis in sustaining the development of ORS in vitro.

Keywords

HIF-1α; Hair follicle; Migration; ORS cells; Proliferation; Shh signaling pathway.

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