Purchase this article with an account.
J. WANG, L. Lu; Protective Effect of Stress-responsive Protein CTCF on Hypoxia-induced Corneal Epithelial Cell Apoptosis. Invest. Ophthalmol. Vis. Sci. 2009;50(13):2592.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
CCCTC binding factor (CTCF) is a multifunctional protein in various cells involving proliferation and apoptosis. The purpose of the present study is to investigate the role of CTCF in preventing human corneal epithelial (HCE) cells from hypoxia-induced apoptosis.
HCE cells were cultured in DMEM/F12 medium contained 10% FBS in 37 °C incubator supplied with 5% CO2. Hypoxia-treated cells were exposed to 1% (hypoxia) or to CoCl2 compared to cells in 21% oxygen (normoxia) for 4-12 h. Expressions of CTCF and Pax6 were examined by Westen Blot analysis. Apoptosis was determined by measuring DNA fragmentation and caspase 3 activity.
Hypoxia induced down-regulation of CTCF activity and increased apoptotic responses. We found: 1) down-regulation of CTCF was required in hypoxia-induced HCE cells to initiate apoptosis; 2) the effect of hypoxia-induced CTCF suppression was also observed in CoCl2 treated cells; 3) hypoxia/reoxygenation-induced cellular ROS levels were measured; 4) over-expression of CTCF demonstrated increased protection of HCE cells from hypoxia-induced apoptosis; and 5) the role of CTCF in hypoxia-induced apoptotic response of HCE cells was attributed to the control of Pax6 activity by CTCF in these cells.
Hypoxia induces suppression of CTCF expression to increase Pax6 activity, leading to apoptosis in HCE cells. We conclude that CTCF acts as a stress-responsive protein to play a significant role in protecting HCE cells from hypoxia-induced apoptosis.
This PDF is available to Subscribers Only