title: Oxygen tension affects terminal differentiation of corneal limbal epithelial cells.
abstract: Oxygen concentration has been shown to be crucial in the proliferation and differentiation of various types of cells, while the impact of oxygen tension on the lineage commitment of epithelial cells remains elusive. In this study, we investigated the effect of hypoxia on the differentiation of corneal limbal epithelium using an ex vivo squamous metaplasia model. Under normoxic conditions when exposed to air, the hyperproliferation and abnormal epidermal-like differentiation of human corneal limbal epithelium was induced, whereas when exposed to air under hypoxic conditions, although we observed augmented proliferation, the abnormal differentiation was inhibited. The Notch signaling pathway was activated in hypoxic cultures, whereas the p38 MAPK signaling pathway was downregulated. The addition of Notch inhibitor under hypoxic conditions restored the activation of p38 MAPK and resulted in the recidivation of limbal epithelial cells to epidermal-like differentiation. Moreover, the epidermal-like differentiation of rabbit limbal epithelial cells was also blocked under hypoxic conditions in corneal epithelial cell sheets engineered ex vivo. We concluded that hypoxia can prevent abnormal differentiation while enhancing the proliferation of corneal limbal epithelial cells. Hypoxia coupled with air exposure can be used in the tissue engineering of corneal limbal epithelium.
authors.affiliation: Eye Institute & Affiliated Xiamen Eye Center, Xiamen University Medical College, Xiamen, Fujian, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.forename: Tingting
authors.initials: T
authors.lastname: Yin
authors.forename: Nuo
authors.initials: N
authors.lastname: Dong
authors.forename: Fei
authors.initials: F
authors.lastname: Dong
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Fang
authors.forename: Yang-Luowa
authors.initials: YL
authors.lastname: Qu
authors.forename: Yehui
authors.initials: Y
authors.lastname: Tan
authors.forename: Huping
authors.initials: H
authors.lastname: Wu
authors.forename: Zuguo
authors.initials: Z
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects*; D015687:Cell Hypoxia / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D016850:Limbus Corneae / Q000166:cytology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology*; D011817:Rabbits; D051880:Receptors, Notch / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D051880:Receptors, Notch; D048051:p38 Mitogen-Activated Protein Kinases; D010100:Oxygen