Purchase this article with an account.
J. Ouyang, C.–Y. Liu, M.E. Fini; Role of Transcription Factor Pax6 in Corneal Epithelial Cell Migration . Invest. Ophthalmol. Vis. Sci. 2006;47(13):5021.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Transcription factor Pax6 resides at the top of a regulatory hierarchy controlling formation of the eye during embryological development. Pax6 is also expressed in several tissues of the adult eye. The goal of this study was to learn more about the role of Pax6 in corneal epithelial cell migration.
To study Pax6’s role in corneal epithelial cell migration, we increased its expression level by two methods. A rabbit corneal epithelial cell line, SIRC (ATCC, CCL–60), was used to establish stable transformant clones carrying a mouse wild–type Pax6 full–length coding region or a mutant Pax6Δ286, lacking the c–terminal transactivation domain. The mPax6 or Pax6 Δ286 transgene was regulated using a tet–on inducible gene expression system. Cell migration was compared in induced and non–induced Pax6 or Pax6Δ286 transformed SIRCs. To further assess biological relevance, Pax6 over–expression was also performed in primary cultures of rabbit corneal epithelial cells (RCECs) using the adenoviral–mediated transfection method. Several replication deficient recombinant adenoviruses have been constructed to express Pax6 or Pax6Δ286 protein.
The linear wound in the SIRCs was able to move to the center of wound and nearly healed it in 24 hours. In contrast, SIRCs with Pax6 over–expression did not move to the center of the wound by 24 hours. Transwell Boyden chambers results showed that an average of 93 (±4) cells per field migrated to the undersides of the well in 4 hours in SIRCs without DOX treatment, however only 55(±3) cells migrated to the underside of the well in Pax6 over–expressed SIRCs. The similar results also obtained from primary RCECs. An average of 40 (±17) cells migrated to the underside of the wells in 4 hours in Ad–Pax6 (recombinant adenovirus carrying full–length Pax6 cDNA) transduced RCECs, which was much less than the RCECs without treatment, RCECs transduced with Ad–EGFP (recombinant adenovirus vector only), or RCECs transduced with Ad–Pax6Δ286 (recombinant adenovirus carrying Pax6Δ286 cDNA).
Our results showed that over–expression of Pax6, but not truncated Pax6 inhibited cell migration in SIRCs and RCECs, which suggested that normal dosage of Pax6 protein plays a pivotal role in the maintenance of corneal epithelial cell function. The effects of Pax6 on cell migration are consistent with a proposed role in controlling corneal re–epithelialization.
This PDF is available to Subscribers Only