title: Placental DAPK1 and autophagy marker LC3B-II are dysregulated by TNF-α in a gestational age-dependent manner.
abstract: Autophagy, a cell-survival process responsible for degradation of protein aggregates and damaged organelles, is increasingly recognized as another mechanism essential for human placentation. A substantial body of experiments suggests inflammation and oxidative stress as the underlying stimuli for altered placental autophagy, giving rise to placenta dysfunction and pregnancy pathologies. Here, the hypothesis is tested whether or not pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α are able to influence the expression profile of autophagy genes in human first-trimester villous placenta. Autophagy-focused qPCR arrays identified substantial downregulation of death-associated protein kinase 1 (DAPK1) in first-trimester placental explants in response to IL-6 and TNF-α, respectively. Immunohistochemistry of placental explants detected considerable DAPK1 staining in placental macrophages, villous cytotrophoblasts and less intense in the syncytiotrophoblast. Both immunohistochemistry and Western blot showed decreased DAPK1 protein in TNF-α-treated placental explants compared to control. On cellular level, DAPK1 expression decreased in SGHPL-4 trophoblasts in response to TNF-α. Observed changes in the expression profile of autophagy-related genes were reflected by significantly decreased lipidation of autophagy marker microtubule-associated protein light chain 3 beta (LC3B-II) in first trimester placental explants in response to TNF-α. Analysis of TNF-α-treated term placental explants showed decreased DAPK1 protein, whereas in contrast to first-trimester LC3B expression and lipidation increased. Immunohistochemistry of placental tissues from early-onset preeclampsia (PE) showed less DAPK1 staining, when compared to controls. Accordingly, DAPK1 mRNA and protein were decreased in primary trophoblasts isolated from early-onset PE, while LC3B-I and -II were increased. Results from this study suggest that DAPK1, a regulator of apoptosis, autophagy and programmed necrosis, decreases in human placenta in response to elevated maternal TNF-α, irrespective of gestational age. In contrast, TNF-α differentially regulates levels of autophagy marker LC3B in human placenta over gestation.
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Medical University Graz, Harrachgasse 21/VII, 8010, Graz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Prokesch
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Medical University Graz, Harrachgasse 21/VII, 8010, Graz, Austria.
authors.forename: Astrid
authors.initials: A
authors.lastname: Blaschitz
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Medical University Graz, Harrachgasse 21/VII, 8010, Graz, Austria.
authors.forename: Tamara
authors.initials: T
authors.lastname: Bauer
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Medical University Graz, Harrachgasse 21/VII, 8010, Graz, Austria.
authors.forename: Gerit
authors.initials: G
authors.lastname: Moser
authors.affiliation: Department of Obstetrics and Gynaecology, Medical University Graz, Graz, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Hiden
authors.affiliation: Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Berlin, Germany.|Berlin Institute of Health (BIH), Berlin, Germany.
authors.forename: Julianna
authors.initials: J
authors.lastname: Zadora
authors.affiliation: Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Berlin, Germany.|Berlin Institute of Health (BIH), Berlin, Germany.|HELIOS-Klinikum Berlin, Berlin, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Dechend
authors.affiliation: Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Berlin, Germany.|Berlin Institute of Health (BIH), Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Herse
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Medical University Graz, Harrachgasse 21/VII, 8010, Graz, Austria. martin.gauster@medunigraz.at.
authors.forename: Martin
authors.identifier: http://orcid.org/0000-0003-0386-6857
authors.initials: M
authors.lastname: Gauster
mesh_terms: D000328:Adult; D001343:Autophagy; D015415:Biomarkers / Q000378:metabolism; D064550:Death-Associated Protein Kinases / Q000096:biosynthesis* / Q000172:deficiency; D005260:Female; D005865:Gestational Age; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis* / Q000172:deficiency; D010920:Placenta / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000187:drug effects* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; C502070:MAP1LC3B protein, human; D008869:Microtubule-Associated Proteins; D014409:Tumor Necrosis Factor-alpha; C579096:DAPK1 protein, human; D064550:Death-Associated Protein Kinases
keywords: Autophagy; Inflammation; Placenta; Preeclampsia; Pregnancy; Trophoblast