Purpose: To examine the expression of five prostaglandin (PG) receptors, EP(1), EP(2), EP(3), EP(4), and FP and their corresponding mRNA transcripts in human sclera and cultured human scleral fibroblasts (HSFs).
Methods: Primary cultures of HSFs were established from donor eyes. Also, sclera from human donor eyes was snap frozen and sectioned. Immunocytochemistry was performed on HSFs and tissue sections with subtype-specific antibodies to the EP(1), EP(2), EP(3), EP(4), and FP receptors. The presence of mRNA for the receptor subtypes was examined from total RNA obtained from human sclera and confirmed with restriction digest analysis.
Results: Positive EP(1) and FP receptor immunoreactivity was observed in fibroblasts within the sections from human sclera. In primary cultures of HSFs, EP(1) and FP labeling was observed over the entire cell surface. EP(2) immunoreactivity within HSFs was mostly present in the juxtanuclear region. RT-PCR analysis of total RNA isolated from human sclera and HSFs confirmed the presence of EP(1), EP(2), and FP receptor subtypes. The identity of the polymerase chain reaction products was confirmed by restriction enzyme analysis. No mRNA or immunoreactivity above basal levels was detected for the EP(3) and EP(4) prostanoid receptor subtypes in tissue sections or primary cultures.
Conclusions: The EP(1), EP(2), and FP receptor subtypes are present in HSFs, suggesting that these cells may respond to endogenous PGs and their structural analogues through interaction with these receptor subtypes.