Effects of amniotic membrane transplantation on cytokines expression in chemically burned rat corneas

To investigate the effect of amniotic membrane transplantation (AMT) on the expressions of inflammatory-related, angiogenic-related and growth-related cytokines in rat corneas after chemical injury.

Alkali wounds were inflicted on the central corneas of rats by applying a round filter paper soaked in 1mol/L NaOH for 40 seconds. One week after alkali burn, 12 rats were randomly divided into 2 groups: the AMT group and the control group, and AMT was performed on the rats in the AMT group. Corneal opacity and neovascularization were observed by slit-lamp microscopy. The protein levels of interleukin (IL)-2, interferon (IFN)-γ, IL-10 and transforming growth factor (TGF)-β were determined by enzyme-linked immunosorbent assay 2 weeks after AMT. The mRNA levels of matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) were evaluated by real-time quantitative PCR.

In the AMT group, the corneal opacity was improved (P=0.011) and the area of corneal neovascularization was significantly decreased (P=0.005) compared with the control group. The amount of IL-2 and IFN-γ secreted by Th1 cells were decreased after AMT, whereas the amount of IL-10 and TGF-β secreted by Th2 cells were increased (P<0.05). The level of MMP-2 was significantly down-regulated (P=0.013) at the mRNA level in the AMT group, while the expression of EGF was significantly higher (P=0.022) compared with controls.

[corrected] AMT may suppress corneal neovascularization after chemical injury by modulating the expressions of soluble factors.