title: N-myc down-regulated gene 1 modulates the response of term human trophoblasts to hypoxic injury.
abstract: The placenta is susceptible to diverse insults during human pregnancy. The expression of the protein N-myc down-regulated gene 1 (NDRG1) is regulated during cell proliferation, differentiation, and in response to stress. Nevertheless, the function of this protein in humans remains unknown. We tested the hypothesis that NDRG1 is up-regulated in hypoxic primary human trophoblasts and that NDRG1 modulates trophoblast response to hypoxia. We initially demonstrated that the expression of NDRG1 is enhanced in primary human trophoblasts exposed to hypoxia. Importantly, we found a similar increase in NDRG1 expression in placental samples derived from either singleton gestations complicated by intrauterine growth restriction or from dizygotic twin gestation where one twin exhibited growth restriction. Having established efficient lentivirus-mediated transfection of primary human trophoblasts, we overexpressed NDRG1 in trophoblasts, which resulted in enhanced trophoblast differentiation. In contrast, lentivirus-driven short interfering RNA-mediated silencing of NDRG1 diminished trophoblast viability and differentiation. Consistent with these results, NDRG1 reduced the expression level of p53 in trophoblasts cultured in standard or hypoxic conditions. Furthermore, NDRG1 expression was regulated by the activity of SIRT1 (Sir2-like protein 1), which promotes cell survival. Together, our data indicate that NDRG1 interacts with SIRT1/p53 signaling to attenuate hypoxic injury in human trophoblasts.
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Baosheng
authors.initials: B
authors.lastname: Chen
authors.forename: D Michael
authors.initials: DM
authors.lastname: Nelson
authors.forename: Yoel
authors.initials: Y
authors.lastname: Sadovsky
mesh_terms: D018797:Cell Cycle Proteins; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D015536:Down-Regulation; D005260:Female; D006655:Histone Deacetylases; D006801:Humans; D000860:Hypoxia / Q000473:pathology*; D047908:Intracellular Signaling Peptides and Proteins; D011247:Pregnancy; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction; D056564:Sirtuin 1; D037761:Sirtuins; D014327:Trophoblasts / Q000473:pathology* / Q000502:physiology; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D000099259:N-myc Downstream-Regulated Gene 1 Protein
chemical_list: D018797:Cell Cycle Proteins; D006655:Histone Deacetylases; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D034741:RNA, Small Interfering; D056564:Sirtuin 1; D037761:Sirtuins; D016159:Tumor Suppressor Protein p53; D000099259:N-myc Downstream-Regulated Gene 1 Protein; C447939:SIRT1 protein, human