title: D2-40/podoplanin expression in the human placenta.
abstract: Placental tissue expresses many lymphatic markers. The current study was undertaken to examine if D2-40/podoplanin, a lymphatic endothelial marker, was expressed in the human placenta, and how it is altered developmentally and pathologically. We examined D2-40/podoplanin and VEGFR-3 expressions in placentas from normotensive pregnancies at different gestational ages and in placentas from women with clinically defined preeclampsia. D2-40 expression in systemic lymphatic vessel endothelium served as a positive control. Protein expression for D2-40, VEGFR-3, and β-actin was determined by Western blot in placentas from normotensive (n = 6) and preeclamptic (n = 5) pregnancies. Our results show that D2-40/podoplanin was strongly expressed in the placenta, mainly as a network plexus pattern in the villous stroma throughout gestation. CD31 was limited to villous core fetal vessel endothelium and VEGFR-3 was found in both villous core fetal vessel endothelium and trophoblasts. D2-40/podoplanin expression was significantly decreased, and VEGFR-3 significantly increased in preeclamptic placental tissues compared to normotensive placental controls. Placental villous stroma is a reticular-like structure, and the localization of D2-40 to the stroma suggests that a lymphatic-like conductive network may exist in the human placenta. D2-40/podoplanin is an O-linked sialoglycoprotein. Although little is known regarding biological functions of sialylated glycoproteins within the placenta, placental D2-40/podoplanin may support fetal vessel angiogenesis during placenta development and reduced D2-40/podoplanin expression in preeclamptic placenta may contribute to altered interstitial fluid homeostasis and impaired angiogenesis in this pregnancy disorder.
authors.affiliation: Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center, Shreveport, LA, USA. ywang1@lsuhsc.edu
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: Y
authors.initials: Y
authors.lastname: Gu
authors.forename: S
authors.initials: S
authors.lastname: Zhao
authors.forename: L J
authors.initials: LJ
authors.lastname: Groome
authors.forename: J S
authors.initials: JS
authors.lastname: Alexander
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism*; D058846:Antibodies, Monoclonal, Murine-Derived; D016022:Case-Control Studies; D002824:Chorionic Villi / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism* / Q000473:pathology; D011225:Pre-Eclampsia / Q000378:metabolism / Q000473:pathology; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism; D011262:Pregnancy Trimester, Second / Q000378:metabolism; D017154:Stromal Cells / Q000378:metabolism; D000098853:Podoplanin
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D008562:Membrane Glycoproteins; C117468:PDPN protein, human; D000098853:Podoplanin; C500987:monoclonal antibody D2-40