Expression And Significance Of S100A8,S100A9,TLR2 And TLR4 In Pterygium

Purpose: To detect the expression of S100A8, S100A9, TLR2, TLR4 and IL-1? in pterygium, and explore their role in pterygium's occurrence, development and recurrence.Methods: 40 samples of patients(40 eyes) with pterygium were collected from January to June 2015 in the Second Affiliated Hospital of South China University. The pterygium samples included 12 cases of quiescent period pterygium, 22 cases of aggressive period pterygium and 6 cases of recurrent pterygium. The pterygium specimens were collected after all patients accepted pterygium excision with autologous conjunctival graft. We also collected 10 normal conjunctival specimens from 10 donors(10 eyes) who donoted cornea in our hospital. The normal conjunctival, quiescent period pterygium, aggressive period pterygium, and recurrent pterygium were classified as group A, B, C, and D. Pathological structure of the specimens was obsevered through hematoxylin-eosin staining, and the expressions of S100A8, S100A9, TLR2, TLR4, and IL-1? in each group were detected respectively through immunohistochemistry and western blot.Comparing the expressions of the above factors in each group. Correlation analysis was carried out between S100A8, S100A9, TLR2, TLR4 and IL-1?.Results:(1) Pathological structure of pterygium: 1) Epithelial hyperplasia in varying degrees was found. The layers of epithelium cells increased obviously, and epithelial keratosis were detected in part of specimens. 2)Numerous fibroblasts,new blood vessels and inflammatory cell infiltration were observed in stroma;3)Amorphous sediments existed in deep stroma.(2) Expression of S100A8, S100A9: Immunohistochemical staining showed expression of S100A8 was mainly concentrated on epithelial surface of normal conjunctival, little expression on the substrate, while expression of S100A9 on epithelial substrate. The expression of S100A8 and S100A9 in pterygium mainly concentrated on the epithelial surface. Analysis of the optical density values showed expressions of S100A8, S100A9 in pterygium were higher than in normal conjunctival, the difference was statistically significant(F=19.44?10.57,P=0.0021?0.0025). Moreover, the expressions of S100A8 in recurrent pterygium were higher than in primary pterygium(P <0.01). Western blot results were consistent with the results of immunohistochemical staining.(3) Expression of TLR2 ?TLR4: TLR2, TLR4 were mainly expressed in the epithelium of normal conjunctiva and pterygium. All epithelial layers of conjunctiva and pterygium expressed TLR2, the substrate was more focused. The expressions between primary pterygium and normal conjunctiva were no significant difference(P> 0.05), however, the expressions in recurrent pterygium were significantly higher than in normal conjunctiva(F=5.688, P=0.028). TLR4 was expressed in the substrate of normal conjunctival epithelium, and in pterygium, it was also expressed in the surface of epithelium. Statistical analysis showed that expressions of TLR4 in recurrent pterygium were higher than in normal conjunctiva, the difference was statistically significant(F = 8.233, P = 0.010). Western blot results were consistent with the results of immunohistochemistry.(4) The expression of IL-1?: IL-1? was expressed in all epithelial layers of normal conjunctiva and pterygium. The expressions in pterygium groups were significantly higher than conjunctiva group(F = 30.84, P <0.0001). In each pterygium group, the expression in recurrence pterygium was higher than primary pterygium(P<0.05).Morever, the expressions in aggressive period pterygium were higher than in quiescent period pterygium, the difference was statistically significant(P < 0.05). Westernblot gray value analysis was consistent with the above results.(5) There is a significantly positive correlation between S100A8, S100A9, TLR2, TLR4 and IL-1?(r=0.625?0.788?0.747?0.837,P=0.02?0.03?0.005?0.001).Conclusion:(1)Abnormal expression of S100A8, S100A9, TLR2, and TLR4 IL-?is likely involved in the pathogenesis of pterygium through initiation of inflammatory response.(2) S100A8, TLR2, and TLR4 likely play a role in the recurrence of pterygium.