Effects of elevated pressure on prostanoid receptor gene expression levels in human trabecular meshwork

The purpose of this study was to assess the effects of increased intraocular pressure on the expression levels of the prostanoid receptor genes (DP, EP(1-4), FP, IP, TP) in the trabecular meshwork of human donor eyes. Anterior segments of human donor eyes were perfused in an ex vivo anterior segment perfusion system under different pressure regimes. The expression levels of the prostanoid receptors and of several housekeeping genes were assessed by non-competitive real-time quantitative polymerase chain reaction (Q-PCR). Perfusion of the anterior segments for 24 h at 10 mm Hg, followed by 24 h at 30 mm Hg, caused a significant decrease in the expression of the EP(2) receptor compared to a constant perfusion under 10 mm Hg. No significant changes were found for the other prostanoid receptor transcripts. When the pressure was raised to 30 mm Hg for only 1 or 3 h, no changes in the EP(2) receptor expression levels were evident. However, a transient DP and TP receptor expression increase was found after 1-hour perfusion at 30 mm Hg. Whether these changes in expression are part of a response of the trabecular meshwork cells in order to normalise intraocular pressure needs to be studied further.