Abstract
Purpose :
The Secreted Ly-6/uPAR Related Protein-1 (SLURP1) is expressed in different epithelial tissues including the cornea and is secreted into the tear fluid. It is a marker of epithelial differentiation with anti-angiogenic, anti-proliferative and anti-tumor properties. Previously we demonstrated that Slurp1supresses TGF-b induced phosphorylation of Smad2/3 pathway and dampens canonical TGF-b signaling in human corneal limbal epithelial (HCLE) cells. Here we have studied the influence of SLURP1 on TGF-b-induced epithelial-mesenchymal transition (EMT) in HCLE cells.
Methods :
The effect of SLURP1 on TGF-b-induced expression of E-cadherin, N-Cadherin and vimentin was evaluated by qRTPCR and immunoblots in HCLE and HCLE-SLURP1 cells treated with control vehicle or TGF-b (5ng/ml for 5 days). Effect of TGF-b on CE barrier function was monitored by xCELLigence Real-Time Cell Analysis (RTCA) instrument and the data analyzed by RTCA Software Pro.
Results :
TGF-b treatment resulted in decreased expression of E-Cadherin transcripts in both HCLE and HCLE-SLURP1 cells (statistically significant only in HCLE cells). This difference however was not reflected in the corresponding protein levels as determined by immunoblots. N-Cadherin and Vimentin mRNA and protein levels increased with TGF-b treatment in all cells, but the extent of increase was much lower in HCLE-SLURP1-2, that expresses higher amounts of SLURP1, compared with HCLE and HCLE-SLURP1-1 that expresses negligible and moderate amounts of SLURP1, respectively. Real time cell analysis using xCELLigence reader revealed greater disruption of CE barrier function upon TGF-b-treatment in HCLE compared with HCLE-SLURP1 cells.
Conclusions :
Based on these results, we conclude that SLURP1 suppresses TGF-b -induced EMT in HCLE cells, and promotes epithelial barrier integrity, consistent with the role of SLURP1 as an epithelial differentiation marker.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.