title: Amnion-Epithelial-Cell-Derived Exosomes Demonstrate Physiologic State of Cell under Oxidative Stress.
abstract: At term, the signals of fetal maturity and feto-placental tissue aging prompt uterine readiness for delivery by transitioning quiescent myometrium to an active stage. It is still unclear how the signals reach the distant myometrium. Exosomes are a specific type of extracellular vesicle (EVs) that transport molecular signals between cells, and are released from a wide range of cells, including the maternal and fetal cells. In this study, we hypothesize that i) exosomes act as carriers of signals in utero-placental compartments and ii) exosomes reflect the physiologic status of the origin cells. The primary aims of this study were to determine exosomal contents in exosomes derived from primary amnion epithelial cells (AEC). We also determined the effect of oxidative stress on AEC derived exosomal cargo contents. AEC were isolated from amniotic membrane obtained from normal, term, not in labor placentae at delivery, and culture under standard conditions. Oxidative stress was induced using cigarette smoke extract for 48 hours. AEC-conditioned media were collected and exosomes isolated by differential centrifugations. Both growth conditions (normal and oxidative stress induced) produced cup shaped exosomes of around 50 nm, expressed exosomes enriched markers, such as CD9, CD63, CD81 and HSC70, embryonic stem cell marker Nanog, and contained similar amounts of cell free AEC DNA. Using confocal microscopy, the colocalization of histone (H) 3, heat shock protein (HSP) 70 and activated form of pro-senescence and term parturition associated marker p38 mitogen activated protein kinase (MAPK) (P-p38 MAPK) co-localized with exosome enrich marker CD9. HSP70 and P-p38 MAPK were significantly higher in exosomes from AEC grown under oxidative stress conditions than standard conditions (p<0.05). Finally, mass spectrometry and bioinformatics analysis identified 221 different proteins involved in immunomodulatory response and cell-to-cell communication. This study determined AEC exosome characteristics and their cargo reflected the physiologic status of the cell of origin and suggests that AEC-derived exosomal p38 MAPK plays a major role in determining the fate of pregnancy. Understanding the propagation of fetal signals and their mechanisms in normal term pregnancies can provide insights into pathologic activation of such signals associated with spontaneous preterm parturitions.
authors.affiliation: Division of Maternal-Fetal Medicine & Perinatal Research, Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.|Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.
authors.forename: Samantha
authors.initials: S
authors.lastname: Sheller
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Papaconstantinou
authors.affiliation: Division of Maternal-Fetal Medicine & Perinatal Research, Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.
authors.forename: Rheanna
authors.initials: R
authors.lastname: Urrabaz-Garza
authors.affiliation: Division of Maternal-Fetal Medicine & Perinatal Research, Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.
authors.forename: Lauren
authors.initials: L
authors.lastname: Richardson
authors.affiliation: Division of Maternal-Fetal Medicine & Perinatal Research, Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.
authors.forename: George
authors.initials: G
authors.lastname: Saade
authors.affiliation: Exosome Biology Laboratory, Centre for Clinical Diagnostics, UQ Centre for Clinical Research, Faculty of Health Sciences, University of Queensland, Herston, Queensland, Australia.
authors.forename: Carlos
authors.initials: C
authors.lastname: Salomon
authors.affiliation: Division of Maternal-Fetal Medicine & Perinatal Research, Department of Obstetrics & Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America.
authors.forename: Ramkumar
authors.initials: R
authors.lastname: Menon
mesh_terms: D000293:Adolescent; D000328:Adult; D000650:Amnion / Q000473:pathology*; D015415:Biomarkers / Q000378:metabolism; D002453:Cell Cycle; D002478:Cells, Cultured; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D055354:Exosomes / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D007633:Keratins / Q000378:metabolism; D018384:Oxidative Stress; D011247:Pregnancy; D040901:Proteomics; D012907:Smoking; D060245:Tetraspanin 29 / Q000378:metabolism; D055815:Young Adult; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018840:HSP70 Heat-Shock Proteins; D006657:Histones; D060245:Tetraspanin 29; D007633:Keratins; D048051:p38 Mitogen-Activated Protein Kinases