Protection of Thymosin Beta-4 on Corneal Endothelial Cells from UVB-Induced Apoptosis

10.4077/CJP.2010.AMH091

Jennifer Hui-Chun Ho；Yeu Su；Ko-Hua Chen；Oscar Kuang-Sheng Lee

thymosin β4 ； corneal endothelial cells ； ultraviolet B

The Chinese Journal of Physiology

53卷3期（2010 / 06 / 01）

190 - 195

英文

Cornea absorbs most of daily ultraviolet (UV) light. An excess of UV damages results in not only keratopathy and cataract but also maculopathy. It has been reported that thymosin beta-4 (Tβ4) promotes wound healing, decreases inflammatory response and prevents apoptosis of corneal epithelial cells. However, it is not clear whether Tβ4 protects UVB-induced corneal injury, particularly in corneal endothelial cells because of its non-proliferation in nature. The purpose of this study is to compare the protective effects of Tβ4 on bovine corneal endothelial (BCE) cells from low- and high-dose UVB damage. In this study, 1μg/ml of Tβ4 was added to BCE cells 2 h before low (12.5 mj/cm^2) or high dosage (100 mj/cm^2) UVB exposure. Using a fluorogenic substrate cleavage assay, we found that Tβ4 diminished the reactive oxygen species level in BCE cells elicited by UVB. However, the protection of viability by Tβ4 could only be detected under low-dose UVB exposure. Moreover, both caspase-9 activity and annexin V/propidium iodine staining demonstrated that Tβ4 only protected BCE cells from low-dose UVB-induced apoptosis but not high-dose UVB-induced necrosis. Together, Tβ4 protected corneal endothelial cells from UVB-induced oxidative stress and apoptosis after low-dose UVB exposure. The results support further investigation towards topical use or anterior chamber injection of this small hydrophilic peptide in treating and preventing UVB-induced corneal endothelial damage.

1. Bock-Marquette, I.,Saxena, A.,White, M. D.,Dimaio, J. M.,Srivastava, D.(2004).Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair.Nature,432,466-472.
2. Farman, J.,Gardiner, B.,Shanklin, J.(1985).Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction.Nature,315,207-210.
3. Frost, N. A.,Wu, J.,Lai, T. F.,Coster, D. J.(2006).A review of randomized controlled trials of penetrating keratoplasty techniques.Ophthalmology,113,942-949.
4. Gnecchi, M.,He, H.,Noiseux, N.,Liang, O. D.,Zhang, L.,Morello, F.,Mu, H.,Melo, L. G.,Pratt, R. E.,Ingwall, J. S.,Dzau, V. J.(2006).Evidence supporting paracrine hypothesis for Akt-modified mesenchymal stem cell-mediated cardiac protection and functional improvement.FASEB J.,20,661-669.
5. Gondhowiardjo, T. D.,van Haeringen, N. J.,Hoekzema, R.,Pels, L.,Kijlstra, A.(1991).Detection of aldehyde dehydrogenase activity in human corneal extracts.Curr. Eye Res.,10,1001-1007.
6. Harding, J. J.(ed.)(1997).Biochemistry of the Eye.London:Chapman & Hall.
7. Ho, J. H. C.,Chuang, C. H.,Ho, C. Y.,Shih, Y. R.,Lee, O. K.,Su, Y.(2007).Internalization is essential for the antiapoptotic effects of exogenous thymosin beta-4 on human corneal epithelial cells.Invest. Ophthalmol. Vis. Sci.,48,27-33.
8. Ho, J. H. C.,Tseng, K. C.,Ma, W. H.,Chen, K. H.,Lee, O. K.,Su, Y.(2008).Thymosin beta-4 up-regulates anti-oxidative enzymes and protects human cornea epithelial cells against oxidative damage.Brit. J. Ophthalmol.,92,992-997.
9. Huff, T.,Muller, C. S.,Otto, A. M.,Netzker, R.,Hannappel, E.(2001).beta-Thymosins, small acidic peptides with multiple functions.Int. J. Biochem. Cell Biol.,33,205-220.
10. Kim, T. I.,Lee, S. Y.,Pak, J. H.,Tchah, H.,Kook, M. S.(2006).Mitomycin C, ceramide, and 5-fluorouracil inhibit corneal haze and apoptosis after PRK.Cornea,25,55-60.
11. Koh, S. W.,Waschek, J. A.(2000).Corneal endothelial cell survival in organ cultures under acute oxidative stress: Effect of VIP.Invest. Ophthalmol. Vis. Sci.,41,4085-4092.
12. Krachmer, J. H.(ed.),Mannis, M. J.(ed.),Holland, E. J.(ed.)(1997).Cornea: Fundamentals of Cornea and External Disease Cornea.St Louis:Mosby.
13. Kulms, D.,Schwarz, T.(2002).Independent contribution of three different pathways to ultraviolet-B-induced apoptosis.Biochem. Pharmacol.,64,837-841.
14. Kurz, S.,Krummenauer, F.,Gabriel, P.,Pfeiffer, N.,Dick, H. B.(2006).Biaxial microincision versus coaxial small-incision clear cornea cataract surgery.Ophthalmology,113,1818-1826.
15. Lavker, R. M.,Tseng, S. C.,Sun, T. T.(2004).Corneal epithelial stem cells at the limbus: Looking at some old problems from a new angle.Exp. Eye Res.,78,433-446.
16. Manzer, R.,Pappa, A.,Estey, T.,Sladek, N.,Carpenter, J. F.,Vasiliou, V.(2003).Ultraviolet radiation decreases expression and induces aggregation of corneal ALDH3A1.Chem. Biol. Interact.,143-144,45-53.
17. Pappa, A.,Brown, D.,Koutalos, Y.,DeGregori, J.,White, C.,Vasiliou, V.(2005).Human aldehyde dehydrogenase 3A1 inhibits proliferation and promotes survival of human corneal epithelial cells.J. Biol. Chem.,280,27998-28006.
18. Pappa, A.,Estey, T.,Manzer, R.,Brown, D.,Vasiliou, V.(2003).Human aldehyde dehydrogenase 3A1 (ALDH3A1): biochemical characterization and immunohistochemical localization in the cornea.Biochem. J.,376,615-623.
19. Pfeifer, G. P.,You, Y. H.,Besaratinia, A.(2005).Mutations induced by ultraviolet light.Mutat. Res.,571,19-31.
20. Podskochy, A.,Gan, L.,Fagerholm, P.(2000).Apoptosis in UV-exposed rabbit corneas.Cornea,19,99-103.
21. Rogers, B. S.,Symons, R. C.,Komeima, K.,Shen, J.,Xiao, W.,Swaim, M. E.,Gong, Y. Y.,Kachi, S.,Campochiaro, P. A.(2007).Differential sensitivity of cones to iron-mediated oxidative damage.Invest. Ophthalmol. Vis. Sci.,48,438-445.
22. Rosette, C.,Karin, M.(1996).Ultraviolet light and osmotic stress: activation of the JNK cascade through multiple growth factor and cytokine receptors.Science,274,1194-1197.
23. Serbecic, N.,Beutelspacher, S. C.(2006).Indoleamine 2,3-dioxygenase protects corneal endothelial cells from UV mediated damage.Exp. Eye Res.,82,416-426.
24. Shi, B.,Isseroff, R. R.(2006).Arsenite pre-conditioning reduces UVBinduced apoptosis in corneal epithelial cells through the antiapoptotic activity of 27 kDa heat shock protein (HSP27).J. Cell Physiol.,206,301-308.
25. Shimmura, S.,Tadano, K.,Tsubota, K.(2004).UV dose-dependent caspase activation in a corneal epithelial cell line.Curr. Eye Res.,28,85-92.
26. Sosne, G.,Albeiruti, A. R.,Hollis, B.,Siddiqi, A.,Ellenberg, D.,Kurpakus-Wheater, M.(2006).Thymosin β4 inhibits benzalkonium chloride-mediated apoptosis in corneal and conjunctival epithelial cells in vitro.Exp. Eye Res.,83,502-507.
27. Sosne, G.,Siddiqi, A.,Kurpakus-Wheater, M.(2004).Thymosin-beta4 inhibits corneal epithelial cell apoptosis after ethanol exposure in vitro.Invest. Ophthalmol. Vis. Sci.,45,1095-1100.
28. Tanito, M.,Takanashi, T.,Kaidzu, S.,Yoshida, Y.,Ohira, A.(2003).Cytoprotective effects of rebamipide and carteolol hydrochloride against ultraviolet B-induced corneal damage in mice.Invest. Ophthalmol. Vis. Sci.,44,2980-2985.
29. Weatherhead, E. C.,Andersen, S. B.(2006).The search for signs of recovery of the ozone layer.Nature,441,39-45.
30. Young, A. R.(2006).Acute effects of UVR on human eyes and skin.Prog. Biophys. Mol. Biol.,92,80-85.