TY - JOUR
T1 - Unravelling the interplay of sphingolipids and TGF-β signaling in the human corneal stroma
AU - Nicholas, Sarah E.
AU - Rowsey, Tyler G.
AU - Priyadarsini, Shrestha
AU - Mandal, Nawajes A.
AU - Karamichos, Dimitrios
N1 - Publisher Copyright:
© 2017 Nicholas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2017/8
Y1 - 2017/8
N2 - Purpose: To delineate the role of Sphingolipids (SPLs) in the human cornea and their cross-talks with transforming growth factor beta (TGF-β) in order to develop novel, non-invasive therapies. Methods: Human corneal fibroblasts (HCFs) were harvested from healthy donors, stimulated with Vitamin C to promote extracellular matrix assembly, treated with exogenous sphingosine-1phosphate (S1P) or sphingosine kinase inhibitor 2 (SPHK I2) and isolated after 4 weeks for further analysis. Results: Data showed that S1P led to a significant decrease in cellular migration where SPHK I2 just delayed it for 24h. Significant modulation of the sphingolipid pathway was also noted. Sphingosine kinase-1 (SphK1) was significantly downregulated upon exogenous stimulation with S1P at a concentration of 5μM and Sphingosine kinase-2 (SphK2) was also significantly downregulated at concentrations of 0.01μM, 0.1μM, and 5μM; whereas no effects were observed upon stimulation with SPHK I2. S1PR3 was significantly downregulated by 0.1μM and 5μM S1P and upregulated by 5μM and 10μM SPHK I2. Furthermore, both S1P and SPHK I2 regulated corneal fibrosis markers such as alpha-smooth muscle actin, collagen I, III, and V. We also investigated the interplay between two TGF-β isoforms and S1P/SPHK I2 treatments and found that TGF-β1 and TGF-β3 were both significantly upregulated with the 0.1μM S1P but were significantly downregulated with the 5μM S1P concentration. When TGF-β1 was compared directly to TGF-β3 expression, we observed that TGF-β3 was significantly downregulated compared to TGF-β1 in the 5μM concentration of S1P. No changes were observed upon SPHK I2 treatment. Conclusion: Our study delineates the role of sphingolipids in the human cornea and highlights their different activities based on the cell/tissue type.
AB - Purpose: To delineate the role of Sphingolipids (SPLs) in the human cornea and their cross-talks with transforming growth factor beta (TGF-β) in order to develop novel, non-invasive therapies. Methods: Human corneal fibroblasts (HCFs) were harvested from healthy donors, stimulated with Vitamin C to promote extracellular matrix assembly, treated with exogenous sphingosine-1phosphate (S1P) or sphingosine kinase inhibitor 2 (SPHK I2) and isolated after 4 weeks for further analysis. Results: Data showed that S1P led to a significant decrease in cellular migration where SPHK I2 just delayed it for 24h. Significant modulation of the sphingolipid pathway was also noted. Sphingosine kinase-1 (SphK1) was significantly downregulated upon exogenous stimulation with S1P at a concentration of 5μM and Sphingosine kinase-2 (SphK2) was also significantly downregulated at concentrations of 0.01μM, 0.1μM, and 5μM; whereas no effects were observed upon stimulation with SPHK I2. S1PR3 was significantly downregulated by 0.1μM and 5μM S1P and upregulated by 5μM and 10μM SPHK I2. Furthermore, both S1P and SPHK I2 regulated corneal fibrosis markers such as alpha-smooth muscle actin, collagen I, III, and V. We also investigated the interplay between two TGF-β isoforms and S1P/SPHK I2 treatments and found that TGF-β1 and TGF-β3 were both significantly upregulated with the 0.1μM S1P but were significantly downregulated with the 5μM S1P concentration. When TGF-β1 was compared directly to TGF-β3 expression, we observed that TGF-β3 was significantly downregulated compared to TGF-β1 in the 5μM concentration of S1P. No changes were observed upon SPHK I2 treatment. Conclusion: Our study delineates the role of sphingolipids in the human cornea and highlights their different activities based on the cell/tissue type.
UR - http://www.scopus.com/inward/record.url?scp=85027434924&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0182390
DO - 10.1371/journal.pone.0182390
M3 - Article
C2 - 28806736
AN - SCOPUS:85027434924
SN - 1932-6203
VL - 12
JO - PLoS ONE
JF - PLoS ONE
IS - 8
M1 - e0182390
ER -