Purchase this article with an account.
Naoko Kato, Hideyuki Miyashita, Naoko Okada, Tetsuya Kawakita, Satoru Yoshida, Masaru Takeuchi, Kazuo Tsubota; Simultaneous TGFβ1 and TNFα Stimulation and Ultraviolet Irradiation Induces Intranuclear Transition of β-catenin and Epithelial-Mesenchymal Transition in Corneal Epithelial Cells. Invest. Ophthalmol. Vis. Sci. 2012;53(14):1835.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Corneal epithelial cells are exposed to sunlight (ultraviolet-A), producing reactive oxygen species (ROS). We previously reported corneal epithelial cells produced ROS in response to ultraviolet-A (UVA) irradiation, and simultaneously caused phosphorylation of p38 MAPK and upregulation of snail. However, upregulation of mesenchymal markers such as αSMA or vimentin, was low. In the present investigation, we assessed the combination of ultraviolet radiation and cytokines as stimuli for induction of complete epithelial mesenchymal transition (EMT).
TKE2 cells (mouse corneal epithelial cell line) were cultured in 5% CO 2 at 37°C using the defined KSFM medium. When cells were semi-confluent, 2.5 ng/ml of TGFβ1 and 10 ng/ml of TNFα, and/or BIO (6-bromoindirubin-3'-oxime), an inhibitor of GSK3β, were added to culture medium and the cells were exposed to 2J of UVA (370 nm). The elevation of EMT-related factors was assessed by RT-PCR and immunofluorescence.
Cells exposed to UVA alone or combination of TGFβ1, TNFα and UVA revealed decreased membrane staining of β-catenin. mRNA of snail was upregulated in cells exposed to UVA. mRNA of αSMA was upregulated in cells exposed to TGFβ1 and TNFα, and more prominently in cells exposed to TGFβ1, TNFα and UVA. Immunofluorescence showed addition of BIO increased expression of αSMA in cytoplasm of cells exposed to TGFβ1, TNFα and UVA.
UVA exposure alone is not sufficient to cause EMT, and stimuli that promote intranuclear transition of β-catenin may also be required for complete EMT induction in corneal epithelial cells.
This PDF is available to Subscribers Only