title: MicroRNA regulation of mitogenic signaling networks in the human placenta.
abstract: Placental cell growth depends on an adaptable combination of an endogenous developmental program and the exogenous influence of maternal growth factors, both of which may be influenced by microRNA (miR)-dependent effects on gene expression. We have previously shown that global miR suppression in placenta accelerates proliferation and enhances levels of growth factor signaling mediators in cytotrophoblast. This study aimed to identify miRs involved in regulating placental growth. An initial array revealed 58 miR species whose expression differs between first trimester, when cytotrophoblast proliferation is rapid, and term, by which time proliferation has slowed. In silico analysis defined potential growth-regulatory miRs; among these, hsa-miR-145, hsa-miR-377, and hsa-let-7a were predicted to target known placental growth genes and were higher at term than in the first trimester, so they were selected for further analysis. Overexpression of miR-377 and let-7a, but not miR-145, in first trimester placental explants significantly reduced basal cytotrophoblast proliferation and expression of ERK and MYC. PCR arrays, in silico analysis, Western blotting, and 3'-UTR luciferase reporter assays revealed targets of miR-145 within the insulin-like growth factor axis. Analysis of proliferation in placental explants overexpressing miR-145 demonstrated its role as a mediator of insulin-like growth factor-induced trophoblast proliferation. These findings identify miR-377 and let-7a in regulation of endogenous cell growth and miR-145 in the placental response to maternal stimulation and will aid the development of therapeutic strategies for problem pregnancies.
authors: Maternal and Fetal Health Research Centre, Institute of Human Development, University of Manchester, Manchester M13 9WL, United Kingdom and; St. Mary's Hospital, Central Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom.
authors: Farkhondeh
authors: F
authors: Farrokhnia
authors: Maternal and Fetal Health Research Centre, Institute of Human Development, University of Manchester, Manchester M13 9WL, United Kingdom and; St. Mary's Hospital, Central Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom.
authors: John D
authors: JD
authors: Aplin
authors: Maternal and Fetal Health Research Centre, Institute of Human Development, University of Manchester, Manchester M13 9WL, United Kingdom and; St. Mary's Hospital, Central Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom.
authors: Melissa
authors: M
authors: Westwood
authors: Maternal and Fetal Health Research Centre, Institute of Human Development, University of Manchester, Manchester M13 9WL, United Kingdom and; St. Mary's Hospital, Central Manchester University Hospitals National Health Service Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom. Electronic address: karen.forbes@manchester.ac.uk.
authors: Karen
authors: K
authors: Forbes
mesh_terms: D002460:Cell Line; D049109:Cell Proliferation; D005260:Female; D053263:Gene Regulatory Networks; D006801:Humans; D035683:MicroRNAs / Q000502:physiology*; D008938:Mitosis / Q000235:genetics*; D010920:Placenta / Q000166:cytology / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D034622:RNA Interference; D015398:Signal Transduction; D013002:Somatomedins / Q000502:physiology; D059467:Transcriptome; D014327:Trophoblasts / Q000502:physiology*
chemical_list: C541010:MIRN145 microRNA, human; C534063:MIRN377 microRNA, human; D035683:MicroRNAs; D013002:Somatomedins; C487931:mirnlet7 microRNA, human
keywords: Developmental Factor; Gene Regulation; Insulin-like Growth Factor (IGF); MicroRNA (miRNA); Placenta; Proliferation; Reproduction; Trophoblast