title: Hypoxia is a key regulator of limbal epithelial stem cell growth and differentiation.
abstract: The aim of this study was to determine whether the growth and differentiation of limbal epithelial stem cell cultures could be controlled through manipulation of the oxygen tension. Limbal epithelial cells were isolated from corneoscleral disks, and cultured using either feeder cells in a growth medium supplemented with serum (3T3 system) or without feeder cells in a dedicated serum-free medium (EpiLife). During the culture, the cells were maintained either at ambient oxygen tension (20%) or at different levels of hypoxia (15, 10, 5, and 2% oxygen). The effect of oxygen on cell growth, progression through cell cycle, colony forming efficiency (CFE), and expression of stem cell (ABCG2 and p63α) and differentiation (CK3) markers was determined throughout the culture period of up to 18 days. Low oxygen levels favored a stem cell phenotype with a lower proliferative rate, high CFE, and a relatively higher expression of ABCG2 and p63α, while higher levels of oxygen led not only to decreased CFE but also to increased proportion of differentiated cells positive for CK3. Hypoxic cultures may thus potentially improve stem cell grafts for cultured limbal epithelial transplantation (CLET).
authors: Department of Ophthalmology, Aalborg University Hospital, 9100 Aalborg, and Laboratory for Stem Cell Research, Aalborg University, 9220 Aalborg, Denmark.
authors: Chris
authors: C
authors: Bath
authors: Sufang
authors: S
authors: Yang
authors: Danson
authors: D
authors: Muttuvelu
authors: Trine
authors: T
authors: Fink
authors: Jeppe
authors: J
authors: Emmersen
authors: Henrik
authors: H
authors: Vorum
authors: Jesper
authors: J
authors: Hjortdal
authors: Vladimir
authors: V
authors: Zachar
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002454:Cell Differentiation; D015687:Cell Hypoxia; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D061252:Feeder Cells / Q000166:cytology; D006801:Humans; D053558:Keratin-3 / Q000378:metabolism; D016850:Limbus Corneae / Q000166:cytology*; D051379:Mice; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D053558:Keratin-3