| First Author | Swamynathan S | Year | 2011 |
| Journal | Invest Ophthalmol Vis Sci | Volume | 52 |
| Issue | 3 | Pages | 1762-9 |
| PubMed ID | 21051695 | Mgi Jnum | J:171551 |
| Mgi Id | MGI:4950346 | Doi | 10.1167/iovs.10-6134 |
| Citation | Swamynathan S, et al. (2011) Regulation of corneal epithelial barrier function by Kruppel-like transcription factor 4. Invest Ophthalmol Vis Sci 52(3):1762-9 |
| abstractText | PURPOSE: Previously, the authors showed that Klf4-conditional null (Klf4CN) corneas display epithelial fragility. Here, they investigated the mechanism by which Klf4 regulates corneal epithelial barrier function. METHODS: Klf4CN mice were generated by breeding Le-Cre with Klf4-LoxP mice. Fluorescein staining was used to test the corneal barrier function. RT-PCR, immunoblots, and immunofluorescence were used to detect the expression of cell junctional proteins. The effect of Klf4 on promoter activities was measured by transient cotransfection assays. Trans-epithelial electrical resistance (TEER) was used to measure the barrier-forming ability of control or anti-KLF4 siRNA-treated cells. RESULTS: Increased fluorescein staining and decreased tight junction protein Tjp1 expression demonstrated that the Klf4CN corneal epithelial barrier function is defective. Expression of desmosomal components Dsp, Dsg-1a, and Dsg-1b was downregulated in the Klf4CN corneas, and their corresponding promoter activities were upregulated by Klf4 in transient cotransfection assays. Hemidesmosomal alpha3- and beta4-integrin levels were not affected even though there were fewer hemidesmosomes in the Klf4CN corneas. The basement membrane components laminin-alpha5, -alpha3, -beta3, and -beta1-1 were downregulated, suggesting that the disrupted basement membrane is responsible for fewer hemidesmosomes in the Klf4CN cornea. Tight junction proteins OCLN1 and TJP1were downregulated in anti-KLF4 siRNA-treated cells, which failed to develop epithelial barrier function as measured by TEER. CONCLUSIONS: Klf4 contributes to corneal epithelial barrier function by upregulating the expression of functionally related subsets of cell junctional proteins and basement membrane components. |
