Abstract
Purpose:
In human non-pigmented ciliary epithelial cells (HNPCECs) in vitro, we investigated changes in the mRNA and protein expression levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in the presence of tumor necrosis factor-alpha (TNF-α), and examined the effects of infliximab addition. Degradation of claudin-1 and occludin, and permeability changes in HNPCECs were also evaluated.
Methods:
HNPCECs were cultured in the presence or absence of TNF-α, and TNF-α-exposed cells were treated with or without infliximab. We measured the expression levels of MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, and TIMP-2 in HNPCECs by real-time polymerase chain reaction and by enzyme-linked immunosorbent assay. HNPCECs and swine ciliary body were treated with MMPs, and immunostained. Permeability of MMP-treated-HNPCECs was measured using a cell-based permeability assay.
Results:
The expressions of MMP-1, MMP-3, and MMP-9 increased in the presence of 10 ng/mL TNF-α, and these altered expression levels were reversed by the addition of infliximab. Immunostaining showed that MMP-1, MMP-3, and MMP-9 degraded claudin-1 and occludin, after which significant increases in HNPCEC permeability were detected.
Conclusions:
TNF-α increased the expressions of MMPs in cells comprising the blood-aqueous barrier (BAB). Components of the tight junctions of the BAB were degraded by MMPs, which increased permeability through the cells. Infliximab was effective at attenuating the TNF-α-induced increases in MMP expressions in cells comprising the BAB, suggesting that such treatment may clinically prevent anterior uveitis.
Keywords: 746 uveitis-clinical/animal model •
557 inflammation