Cover Image

Expression and Localization of Glycosaminoglycans/Proteoglycan in Pterygium: An Immunohistochemical Study

Constantinos D. GEORGAKOPOULOS, Olga E. MAKRI, Dionisios PAGOULATOS, Nikolaos K. KARAMANOS


Pterygium is a triangle-shaped fibrovascular hyperplasia of the bulbar conjunctiva on the cornea. The purpose of this study was to analyze Proteoglycans (PGs) by Immunohistochemistry (IHC) in pterygium tissues and to compare the results with normal conjunctiva. Twenty-four patients (14 males) undergoing primary pterygium excision and 17 healthy individuals (10 males), undergoing extracapsular cataract surgery, were included. Pterygium tissues and normal conjunctiva tissues were surgically removed. The tissue sections were fixed in 2% paraformaldehyde and incubated with monoclonal antibodies against PGs anti-mouse IgG. Immunohistochemical study showed stronger expression of keratan sulfate in the stroma of the pterygium compared to normal conjunctiva. An increased expression of heparan sulfate was observed in the epithelial layer and around the pterygium vessels. On the other hand, dermatan sulfate showed an increased expression and localization not only in the sub-epithelial area of the pterygium and normal conjunctiva, yet throughout the stroma of the pterygium. The differences in the expression and localization of the studied extracellular matrix proteoglycans in the pterygium tissue compared to normal conjunctiva may explain the tissue hyperplasia, structure, and the functional properties in pterygium.


Rezvan F, Khabazkhoob M, Hooshmand E, Yekta A, Saatchi M, Hashemi H. Prevalence and risk factors of pterygium: a systematic review and meta-analysis. Surv Ophthalmol. 2018;63(5):719-35. doi: 10.1016/j.survophthal.2018.03.001 pmid: 29551597

Coroneo MT. Pterygium as an early indicator of ultraviolet insolation: a hypothesis. Br J Ophthalmol. 1993;77(11):734-9. pmid: 8280691

Liang QF, Xu L, Jin XY, You QS, Yang XH, Cui TT. Epidemiology of pterygium in aged rural population of Beijing, China. Chin Med J (Engl). 2010;123(13):1699-701. pmid: 20819632

Nakagami T, Murakami A, Okisaka S, Ebihara N. Mast cells in pterygium: number and phenotype. Jpn J Ophthalmol. 1999;43(2):75-9. doi: 10.1016/s0021-5155(98)00069-0 pmid: 10340786

Liu L, Yang D. Immunological studies on the pathogenesis of pterygium. Chin Med Sci J. 1993;8(2):84-8. pmid: 8292805

Perez-Rico C, Pascual G, Sotomayor S, Asunsolo A, Cifuentes A, Garcia-Honduvilla N, et al. Elastin development-associated extracellular matrix constituents of subepithelial connective tissue in human pterygium. Invest Ophthalmol Vis Sci. 2014;55(10):6309-18. doi: 10.1167/iovs.14-14214 pmid: 25183766

Theocharis AD, Skandalis SS, Gialeli C, Karamanos NK. Extracellular matrix structure. Adv Drug Deliv Rev. 2016;97:4-27. doi: 10.1016/j.addr.2015.11.001 pmid: 26562801

Karamanos NK, Piperigkou Z, Theocharis AD, Watanabe H, Franchi M, Baud S, et al. Proteoglycan Chemical Diversity Drives Multifunctional Cell Regulation and Therapeutics. Chem Rev. 2018;118(18):9152-232. doi: 10.1021/acs.chemrev.8b00354 pmid: 30204432

Kaneko M, Takaku I, Katsura N. Glycosaminoglycans in pterygium tissues and normal conjunctiva. Jpn J Ophthalmol. 1986;30(2):165-73. pmid: 3761740

Karukonda SR, Thompson HW, Beuerman RW, Lam DS, Wilson R, Chew SJ, et al. Cell cycle kinetics in pterygium at three latitudes. Br J Ophthalmol. 1995;79(4):313-7. pmid: 7742273

Kaneko M. Proteoglycans from pterygium tissues. Ophthalmic Res. 1987;19(3):170-7. doi: 10.1159/000265490 pmid: 3658328

Akamatu Y, Sugita Y, Mori S. [Studies on the pterygium. VI. Histochemical studies]. Nippon Ganka Gakkai Zasshi. 1969;73(8):1046-52. pmid: 4188706

Zavala J, Hernandez-Camarena JC, Salvador-Galvez B, Perez-Saucedo JE, Vela-Martinez A, Valdez-Garcia JE. Extracellular matrix and fibroblast injection produces pterygium-like lesion in rabbits. Biol Res. 2018;51(1):15. doi: 10.1186/s40659-018-0165-8 pmid: 29866159

Pagoulatos D, Pharmakakis N, Lakoumentas J, Assimakopoulou M. Etaypoxia-inducible factor-1alpha, von Hippel-Lindau protein, and heat shock protein expression in ophthalmic pterygium and normal conjunctiva. Mol Vis. 2014;20:441-57. pmid: 24715760

Jaworski CJ, Aryankalayil-John M, Campos MM, Fariss RN, Rowsey J, Agarwalla N, et al. Expression analysis of human pterygium shows a predominance of conjunctival and limbal markers and genes associated with cell migration. Mol Vis. 2009;15:2421-34. pmid: 19956562

Golu T, Mogoanta L, Streba CT, Pirici DN, Malaescu D, Mateescu GO, et al. Pterygium: histological and immunohistochemical aspects. Rom J Morphol Embryol. 2011;52(1):153-8. pmid: 21424047

Full Text: Full Text PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.