Abstract
Purpose: :
Pax6 is an important transcription factor contributing to the eye development. The purpose of the present study is to investigate whether the position of pax6 locus relative to its chromosome territory can impact pax6 expression and how pax6 transcriptional regulation was related to long-range chromosome rearrangement.
Methods: :
Human telomerase-immortalized corneal epithelial (HTCE) cells were cultured in ker medium contained in 37 °C incubator supplied with 5% CO2. The paint for human chromosomes 11p (HSA11p) was obtained from Q-Bio-gene. The cosmid probe for human Pax6 was labeled with digoxigenin using a nick translation kit. FISH was carried out using a standard protocol. Lentivirus-mediated infection was used to establish stable HTCE cell line with CTCF gene deletion.
Results: :
Stresses and growth factor stimulations caused different pattern of pax6 locus position in relative to 11p territory. We found: 1) transcriptional inhibitors treatment changed pax6 locus position indicating that Pax6 transcriptional regulation involved chromatin structure alteration; 2) the expression of pax6 altered after growth factor (EGF) or stress challenges (UV and hypoxia); 3) EGF and stress challenges could induce pax6 locus position alterations, which was related to pax6 transcriptional regulation; and 4) pax6 expression and its locus positions differed in wildtype and CTCF-deletion HTCE cells.
Conclusions: :
Chromosome rearrangement turned out to be a novel mechanism to regulate pax6 gene transcription. CTCF was one of the important chromatin architecture organizers participating in gene transcriptional regulation.
Keywords: cornea: epithelium • gene/expression • apoptosis/cell death