HSP90AA1 and age-related macular degeneration: HSP90AA1 (heat shock protein 90) mRNA levels were the most strongly upregulated by exposure to MG-132 and bafilomycin A1 in both cell lines, with mRNA levels increasing by more than 15-fold compared to the situation in cells that were only primed with IL-1α (30.8-fold in control-RPE cells and 16.7-fold in AMD-RPE cells exposed to MG-132 and bafilomycin A1 when compared to their respective vehicle-treated controls).