Human ciliary muscle cell responses to FP-class prostaglandin analogs: phosphoinositide hydrolysis, intracellular Ca2+ mobilization and MAP kinase activation.
Phospholipase C induced phosphoinositide (PI) turnover, intracellular Ca(2+) ([Ca(2+)](i)) mobilization and mitogen-activated protein (MAP) kinase activation by FP-class prostaglandin analogs was studied in normal human ciliary muscle (h-CM) cells. Agonist potencies obtained in the PI turnover assays were: travoprost acid ((+)-fluprostenol; EC(50) = 2.6 +/- 0.8 nM) > bimatoprost acid (EC(50) = 3.6 +/- 1.2 nM) > (+/-)-fluprostenol (EC(50) = 4.3 +/- 1.3 nM) >> prostaglandin F(2 alpha) (PGF(2 alpha)) (EC(50) = 134 +/- 17 nM) > latanoprost acid (EC(50) = 198 +/- 83 nM) > S-1033 (EC(50) = 2930 +/- 1420 nM) > unoprostone (EC(50) = 5590 +/- 1490 nM) > bimatoprost (EC(50) = 9600 +/- 1100 nM). Agonist potencies in h-CM cells correlated well with those previously obtained for the cloned human ciliary body-derived FP receptor (r = 0.96, p< 0.001) and that present on h-TM cells (r = 0.94, p< 0.0001). Travoprost acid, PGF(2 alpha) and unoprostone also stimulated [Ca(2+)](i) mobilization in h-CM cells with travoprost acid being the most potent agonist. MAP kinase activity was stimulated in the h-CM cells with the following rank order of activity (at 100 nM): travoprost acid > PGF(2 alpha) > latanoprost acid > PGD(2) > bimatoprost > latanoprost = bimatoprost acid = fluprostenol > PGE(2) = S-1033 > unoprostone > PGI(2). The PI turnover, [Ca(2+)](i) mobilization and MAP kinase activation induced by several of these agonists was blocked by the FP receptor antagonist, AL-8810 (11 beta-fluoro-15-epiindanyl PGF(2 alpha)) (e.g. K(i) = 5.7 microM versus PI turnover). These studies have characterized the biochemical and pharmacological properties of the native FP prostaglandin receptor present on h-CM cells using three signal transduction mechanism assays and a broad panel of FP-class agonist analogs (including free acids of bimatoprost, travoprost and latanoprost) and the FP receptor antagonist, AL-8810.
Sharif
Naj A
NA
Molecular Pharmacology Unit, Alcon Research, Ltd., Fort Worth, TX 76134-2099, USA. naj.sharif@alconlab.com
Crider
Julie Y
JY
Husain
Shahid
S
Kaddour-Djebbar
Ismail
I
Ansari
Habib R
HR
Abdel-Latif
Ata A
AA
D000328:Adult; D000368:Aged; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D002924:Ciliary Body / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D007424:Intracellular Fluid / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D032342:Muscle Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010716:Phosphatidylinositols / Q000378:metabolism*; D011460:Prostaglandins F / Q000737:chemistry / Q000494:pharmacology*
D010716:Phosphatidylinositols; D011460:Prostaglandins F; D020928:Mitogen-Activated Protein Kinases