1.Rapid induction of mRNA for prostaglandin H synthase in ovine meningeal fibroblasts.
Myeong Jin NAM ; Clara THORE ; David BUSIJA
The Korean Journal of Physiology and Pharmacology 1998;2(4):435-441
We examined effects of interleukin 1 alpha (IL1 alpha) and phorbol 12, 13 dibutyrate (PDB), an activator of protein kinase C, on mRNA for Prostaglandin H synthase (PGHS) and prostanoid production in cultured ovine meningeal fibroblasts. Immuno- and morphologically-identified fibroblasts were derived from cerebral cortex and white matter from fetal lambs (approximately 120 days gestation) and grown to confluence on glass coverslips in 12 well plates. Levels of prostaglandin F2alpha and the stable hydrolysis product of prostacyclin (i.e., 6-keto-PGF1alpha) were determined using enzyme immunoassay. Relative amounts of mRNA were determined by in situ hybridization using ovine cDNA for PGHS1. IL1alpha (10 ng/ml) increased mRNA levels over baseline by 62 +/- 19% (p<0.05) at 60 min., 37 +/- 12% (NS) at 120 min., and 36 +/- 18 % (NS) at 240 min (n= 12). Levels of 6-keto-PGF1alpha were 148 +/- 18 pg/ml during baseline, 246 +/- 41 pg/ml at 60 min., 248 +/- 40 pg/ml at 120 min., and 259 +/- 62 pg/ml at 240 min (all p<0.05) (n=12). PGF2alpha was increased although it wasn't statistically significant. However, IL1alpha decreased PGE2 level significantly (all p<0.05). PDB (10-6 M) increased mRNA levels over baseline by 25+/-6% after 30 min., 40 +/- 6% after 60 min., and 20 +/- 8% after 90 min. (n=9) (all p<0.05). Levels of 6-keto-PGF1alpha were 200 +/- 43 pg/ml during baseline, 202 +/- 43 pg/ml after 30 min. (NS), 268 +/- 58 pg/ml after 60 min. (p<0.05), and 296 +/- 60 pg/ml after 90 min. (p<0.05) (n=9). Levels of PGF2alpha were 178 +/- 26 pg/ml during baseline, 300 +/- 30 pg/ml after 30 min., 299 +/- 35 pg/ml after 60 min., and 355 +/- 32 pg/ml after 90 min (all p <0.05) (n=6). Actinomycin-D (1 mg/ml) prevented increases in mRNA, 6-keto-PGF1alpha, and PGF2alpha at 60 min. for both I-L1 alpha and PDB. We conclude that cerebral fibroblasts are avid producers of prostanoids, and that enhanced production of PGHS is responsible for augmented PGF2alpha and prostacyclin production in the presence of an activator of protein kinase C and for decreased PGE2 and increased prostacyclin production in the presence of IL1alpha.
Cerebral Cortex
;
Dinoprost
;
Dinoprostone
;
DNA, Complementary
;
Epoprostenol
;
Fibroblasts*
;
Glass
;
Hydrolysis
;
Immunoenzyme Techniques
;
In Situ Hybridization
;
Interleukin-1alpha
;
Prostaglandin-Endoperoxide Synthases*
;
Prostaglandins
;
Protein Kinase C
;
RNA, Messenger*