The effects of cyclic AMP, sex steroids and global hypomethylation on the expression of genes controlling the activity of the renin-angiotensin system in placental cell lines.
The placental renin-angiotensin system (RAS) is involved in placentation. We have shown that prorenin mRNA (REN) is expressed in a first trimester trophoblast cell line (HTR-8/SVneo) but not in a choriocarcinoma cell line (BeWo). We attempted to stimulate RAS expression in these cells by cAMP, 5'-aza-2'-deoxycytidine (AZA; an inhibitor of methylation), cAMP and AZA combined, and the sex steroids medroxyprogesterone acetate (MPA) and estradiol-17β (E(2)) with and without cAMP. RAS mRNAs were measured by qPCR and prorenin concentration in supernatants measured by an ELISA. In HTR-8/SVneo cells, all treatments increased REN expression compared to controls and cAMP + AZA combined was more effective than either treatment alone. Prorenin levels in supernatants were similarly upregulated. In HTR-8/SVneo cells, angiotensinogen (AGT) mRNA expression was increased by MPA + E(2) either with or without cAMP. AGT expression was also significantly increased by AZA. BeWo cells did not express REN or prorenin and it was not inducible with any treatment. AGT expression was significantly increased with AZA, the combination of cAMP + AZA, and MPA + E(2) + cAMP treatments. Since cAMP, AZA, cAMP and AZA combined, or MPA and E(2) with and without cAMP in HTR-8/SVneo cells, a cell line most similar in its RAS expression to the in vivo placenta, these factors may affect placental RAS activity. Surprisingly, these treatments also induced AGT expression in BeWo cells. Whether they are involved in regulating AGT in choriocarcinomas in vivo remains to be determined.
School of Biomedical Sciences & Pharmacy, Mothers & Babies Research Centre, University of Newcastle, Hunter Medical Research Institute & John Hunter Hospital, Newcastle, NSW 2300, Australia.
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Wang
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Pringle
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Lumbers
D000328:Adult; D001374:Azacitidine / Q000494:pharmacology; D045744:Cell Line, Tumor; D002822:Choriocarcinoma / Q000188:drug therapy / Q000378:metabolism; D000242:Cyclic AMP / Q000494:pharmacology*; D019175:DNA Methylation; D004359:Drug Therapy, Combination; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D020868:Gene Silencing; D006801:Humans; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000235:genetics*; D014327:Trophoblasts / Q000187:drug effects* / Q000378:metabolism
D004958:Estradiol; D017258:Medroxyprogesterone Acetate; D000242:Cyclic AMP; D001374:Azacitidine