Abstract
Purpose::
To investigate the regulation of the pro-inflammatory RAGE receptor and the soluble RAGE isoform on RPE cells by different growth factors
Methods::
Surgically removed PVR membranes were immunohistochemically stained for the expression of the RAGE receptor. In addition, cultured human RPE cells were treated with the inflammatory cytokine TNF-α, and the regulation of RAGE was evaluated by Western blot. The shedding of the soluble RAGE fragment by RPE cells in conditioned medium was investigated by use of an ELISA assay. In these experiments, RPE cells were pretreated with the RAGE ligands HMGB-I and S100B.
Results::
The RAGE receptor is expressed in PVR membranes. The expression of this receptor is upregulated by TNF-α on RPE cells. In addition, the shedding of soluble RAGE by RPE cells is enhanced after HMGB-I, S100B and AGE treatment of the cells.
Conclusions::
The RAGE receptor system and its soluble isoform may be important for the progression of PVR. The soluble RAGE isoform can be regarded as a self defense mechanism for the RPE cell. Further investigations into the regulation of RAGE may provide insight into novel approaches for the treatment of PVR.
Keywords: proliferative vitreoretinopathy • retinal pigment epithelium • inflammation