Follistatin steady state messenger ribonucleic acid levels in confluent cultures of a rat renal mesangial cell line are regulated by multiple factors.
The regulation of steady state levels of follistatin (FS) messenger RNA (mRNA) was examined in a rat renal mesangial cell line in tissue culture. A specific 32P-radiolabeled antisense probe was used which corresponds to the 3' end of exon 5 together with the 5' end of exon 6 of the rat FS gene, and which distinguishes between the two different forms of FS mRNA. In addition, a specific 35S-radiolabeled probe for the ubiquitous protein cyclophilin was developed and used as an internal standard. Total RNA was harvested from confluent cell cultures to yield four independent samples per treatment/time point, and equal amounts of RNA from every sample in a given experiment were subjected to S1-nuclease analysis for the estimation of specific mRNA levels. Treatment of the cultured cells with epidermal growth factor (10 nM) caused an 8- to 9-fold increase in the FS mRNA level after 4 h, but no consistent change was observed after treatment with basic fibroblast growth factor (0.28 or 0.56 nM), somatostatin (3.7-73 nM), angiotensin II (0.1-2500 nM), or FS itself (0.29 nM) for between 4 and 48 h. Neither activin (0.5 or 1.2 nM) nor inhibin (0.64 nM) changed the FS mRNA level in the mesangial cell line during a 24-h treatment. FS mRNA levels in the cells also were not affected by a 48-h treatment with the steroids dihydrotestosterone (1-1000 nM), estradiol (1 and 100 nM), and the antiprogesterone RU 486 (1000 nM), whereas 100 nM RU 28362 (a synthetic glucocorticoid) caused a 5- to 6-fold increase and 1000 nM progesterone increased the FS mRNA level up to 3.5-fold above control. Retinoic acid, a vitamin A derivative, significantly increased the FS steady state mRNA level at 3 nM, and at 1000 nM stimulated FS mRNA up to 5-fold within 4 h, whereas incubation of the cells with 30 microM prostaglandin E2 for 4 h caused a 10-fold increase. The FS mRNA level increased 3- and 4-fold within 4 h during incubation of the cells with 100 nM phorbol 12-myristate, 13-acetate, and 25 microM forskolin, respectively, whereas the calcium ionophore A23187 (1-100 microM) caused no change within this timespan. None of the tested hormones had an obvious effect on the ratio of the two different forms of FS mRNA (FS 344:FS 317).(ABSTRACT TRUNCATED AT 400 WORDS)
Michel
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U
Prince Henry's Institute of Medical Research, Monash Medical Centre, Clayton, Victoria, Australia.
Farnworth
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P
D028341:Activins; D000591:Amino Acid Isomerases / Q000235:genetics; D000732:Androstanols / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D002460:Cell Line; D002478:Cells, Cultured; D003524:Cyclosporins / Q000378:metabolism; D013196:Dihydrotestosterone / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D038681:Follistatin; D015870:Gene Expression / Q000187:drug effects; D005920:Glomerular Mesangium / Q000502:physiology*; D006023:Glycoproteins / Q000235:genetics*; D007265:Inhibins / Q000494:pharmacology; D015735:Mifepristone / Q000494:pharmacology; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D019696:Peptidylprolyl Isomerase; D011374:Progesterone / Q000494:pharmacology; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D015347:RNA Probes; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013004:Somatostatin / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology
D000732:Androstanols; D002352:Carrier Proteins; D003524:Cyclosporins; D038681:Follistatin; D006023:Glycoproteins; D009838:Oligodeoxyribonucleotides; D015347:RNA Probes; D012333:RNA, Messenger; D013196:Dihydrotestosterone; D016222:Fibroblast Growth Factor 2; D028341:Activins; D000804:Angiotensin II; D015735:Mifepristone; D011374:Progesterone; D004958:Estradiol; D013004:Somatostatin; D014212:Tretinoin; D007265:Inhibins; D004815:Epidermal Growth Factor; D012313:RNA; C049154:11,17-dihydroxy-6-methyl-17-(1-propynyl)androsta-1,4,6-triene-3-one; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase; D015232:Dinoprostone