Comparative studies on prostanoid receptors in human non-pigmented ciliary epithelial and mouse fibroblast cell lines.
To examine the expression of functional prostanoid receptors in the human non-pigmented ciliary epithelial (ODMC1-2) and mouse fibroblast cell lines (NIH 3T3) we have measured the generation of the second messengers, cyclic AMP, inositol phosphates and the mobilization of intracellular calcium ([Ca2+]i) following stimulation by prostaglandin receptor agonists. The amount of cyclic AMP generated was measured by a protein binding method. Radiolabeled inositol phosphates were separated using ion exchange columns and quantified by counting the radioactivity. For intracellular calcium measurements, Fura 2-AM loaded cells were stimulated by PG receptor agonists and the calcium activated fluorescence was measured in a spectrofluorometer. In the ODMC1-2 cell line, the formation of cyclic AMP was stimulated by prostaglandin E2, butaprost and 11-deoxy-prostaglandin E1. The stimulation of cyclic AMP production by prostaglandin E2 was partially inhibited by the EP4 receptor antagonist AH23848. Prostaglandin E2 and 11-deoxy-prostaglandin E1 stimulated the formation of cyclic AMP in NIH 3T3 cells. In ODMC1-2 cells, total inositol phosphate turnover was not increased by 17-phenyl-trinor-prostaglandin F2 alpha, 17-phenyl-trinor-prostaglandin E2 or 11-deoxy-prostaglandin E1. In contrast, all these agonists, with the exception of 11-deoxy-prostaglandin E1, significantly increased total inositol phosphates in NIH 3T3 cells. In the NIH 3T3 cell line, only prostaglandin F2 alpha and 17-phenyl-trinor-prostaglandin F2 alpha increased [Ca2+]i in a dose-dependent manner; in ODMC1-2 cells, neither these agonists nor 17-phenyl-trinor-prostaglandin E2 increased [Ca2+]i. The present studies suggest that in ODMC1-2 cells, EP2 and EP4 receptors but neither EP1 nor FP receptors are expressed; these studies also imply, NIH 3T3 cells express EP2 and FP receptors, while EP1 receptors appear to be absent in this cell line.
Liu
L
L
Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, KY 40292, USA.
Eta
E
E
Bhattacherjee
P
P
Paterson
C A
CA
D016475:3T3 Cells; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002924:Ciliary Body / Q000166:cytology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D051379:Mice; D010858:Pigmentation; D011982:Receptors, Prostaglandin / Q000819:agonists / Q000378:metabolism*; D015290:Second Messenger Systems; D010738:Type C Phospholipases / Q000378:metabolism
D011982:Receptors, Prostaglandin; D010738:Type C Phospholipases; D000262:Adenylyl Cyclases; D002118:Calcium