Coordinate regulation of the production and signaling of retinoic acid by estrogen in the human endometrium.
To determine whether estrogen regulates retinoic acid (RA) production and signaling in the human endometrium as it does in the rodent uterus, we investigated the effects of estrogens on the expression of RA-metabolizing enzymes, retinoid receptors, and biomarker genes in the post- and premenopausal human endometrium. Real-time quantitative PCR revealed that retinaldehyde dehydrogenase (RALDH) 2, a critical enzyme in RA biosynthesis, was induced 4-fold by estrogen replacement therapy with either Premarin or a mixture of estrone and equilin sulfates for 3 months. Estrogen replacement therapy also increased the expression of the RA receptor RAR alpha 1.9-fold. In parallel, there was a marked increase in the expression of two RA-regulated genes, cellular retinoic acid-binding protein II and tissue transglutaminase. In the premenopausal endometrium, the levels of RALDH1, RALDH2, RAR alpha, and cellular retinoic acid-binding protein II were increased in the estrogen-dominated proliferative phase, and the transcripts for the RA catabolic enzyme retinoic acid 4-hydroxylase (CYP26A1) and tissue transglutaminase were significantly increased in the secretory phase. Our results suggest that estrogen coordinately up-regulates RA production and signaling in the human endometrium. This coordinate mechanism may play a role in the antiproliferative effects that counterbalance the estrogen-induced endometrial proliferation.
Department of Integrative Biology and Pharmacology, University of Texas Houston Health Science Center, Houston, Texas 77030, USA.
Lei
L
Deng
Gregory L
GL
Shipley
David S
DS
Loose-Mitchell
George M
GM
Stancel
Russell
R
Broaddus
James H
JH
Pickar
Peter J A
PJ
Davies
D000445:Aldehyde Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D015415:Biomarkers / Q000032:analysis; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004717:Endometrium / Q000737:chemistry / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D004857:Equilin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000494:pharmacology*; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage; D004970:Estrone / Q000008:administration & dosage; D005260:Female; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008875:Middle Aged; D010919:Placebos; D016133:Polymerase Chain Reaction; D017698:Postmenopause; D017697:Premenopause; D012333:RNA, Messenger / Q000032:analysis; D018168:Receptors, Retinoic Acid / Q000032:analysis / Q000235:genetics; D050697:Retinal Dehydrogenase; D000072516:Retinoic Acid 4-Hydroxylase; D015398:Signal Transduction; D011503:Transglutaminases / Q000032:analysis; D014212:Tretinoin / Q000378:metabolism*
D015415:Biomarkers; D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D007527:Isoenzymes; D010919:Placebos; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; C082927:retinoic acid binding protein I, cellular; D004857:Equilin; D004970:Estrone; D014212:Tretinoin; D003577:Cytochrome P-450 Enzyme System; C037875:equilin sulfate; D000072516:Retinoic Acid 4-Hydroxylase; D000445:Aldehyde Oxidoreductases; D050697:Retinal Dehydrogenase; D011503:Transglutaminases