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'''Related Pages:''' [http://embryology.med.unsw.edu.au/Notes/placenta7.htm Villi Development] | [http://embryology.med.unsw.edu.au/Notes/placenta8.htm Maternal Decidua] |  [http://embryology.med.unsw.edu.au/Notes/placenta2.htm Placental Abnormalities] | [http://embryology.med.unsw.edu.au/Notes/placenta3.htm  Stage 13/14] | [http://embryology.med.unsw.edu.au/Notes/placenta4.htm  Stage22] |  [http://embryology.med.unsw.edu.au/Notes/placenta5.htm Placental Histology] |  
'''Related Pages:''' [http://embryology.med.unsw.edu.au/Notes/placenta7.htm Villi Development] | [http://embryology.med.unsw.edu.au/Notes/placenta8.htm Maternal Decidua] |  [http://embryology.med.unsw.edu.au/Notes/placenta2.htm Placental Abnormalities] | [http://embryology.med.unsw.edu.au/Notes/placenta3.htm  Stage 13/14] | [http://embryology.med.unsw.edu.au/Notes/placenta4.htm  Stage22] |  [http://embryology.med.unsw.edu.au/Notes/placenta5.htm Placental Histology] |  
[[http://embryology.med.unsw.edu.au/Notes/placenta6.htm  Placental Vascular Beds]  | [http://embryology.med.unsw.edu.au/Notes/heart20.htm Blood] | [http://embryology.med.unsw.edu.au/Notes/heart19.htm Blood Vessels]] | [http://embryology.med.unsw.edu.au/Child/birth1.htm Birth] | [http://embryology.med.unsw.edu.au/Notes/stemcell4.htm Stem Cells - Cord Blood]
[[http://embryology.med.unsw.edu.au/Notes/placenta6.htm  Placental Vascular Beds]  | [http://embryology.med.unsw.edu.au/Notes/heart20.htm Blood] | [http://embryology.med.unsw.edu.au/Notes/heart19.htm Blood Vessels] | [http://embryology.med.unsw.edu.au/Child/birth1.htm Birth] | [http://embryology.med.unsw.edu.au/Notes/stemcell4.htm Stem Cells - Cord Blood]





Revision as of 23:16, 26 May 2010

Original Pages

Related Pages: Villi Development | Maternal Decidua | Placental Abnormalities | Stage 13/14 | Stage22 | Placental Histology | [Placental Vascular Beds | Blood | Blood Vessels | Birth | Stem Cells - Cord Blood


Vol. 54 Nos. 2/3 (2010) Placenta

http://www.ijdb.ehu.es/web/contents.php?vol=54&issue=2-3

The human placenta is a hematopoietic organ during the embryonic and fetal periods of development.

http://www.ncbi.nlm.nih.gov/pubmed/19073167

"We studied the potential role of the human placenta as a hematopoietic organ during embryonic and fetal development. Placental samples contained two cell populations-CD34(++)CD45(low) and CD34(+)CD45(low)-that were found in chorionic villi and in the chorioamniotic membrane. CD34(++)CD45(low) cells express many cell surface antigens found on multipotent primitive hematopoietic progenitors and hematopoietic stem cells. CD34(++)CD45(low) cells contained colony-forming units culture (CFU-C) with myeloid and erythroid potential in clonogenic in vitro assays, and they generated CD56(+) natural killer cells and CD19(+)CD20(+)sIgM(+) B cells in polyclonal liquid cultures. CD34(+)CD45(low) cells mostly comprised erythroid- and myeloid-committed progenitors, while CD34(-) cells lacked CFU-C. The placenta-derived precursors were fetal in origin, as demonstrated by FISH using repeat-sequence chromosome-specific probes for X and Y. The number of CD34(++)CD45(low) cells increased with gestational age, but their density (cells per gram of tissue) peaked at 5-8 wk, decreasing more than sevenfold at the onset of the fetal phase (9 wk of gestation). In addition to multipotent progenitors, the placenta contained myeloid- and erythroid-committed progenitors indicative of active in situ hematopoiesis. These data suggest that the human placenta is an important hematopoietic organ, raising the possibility of banking placental hematopoietic stem cells along with cord blood for transplantation."

De novo synthesis of estrogen in pregnant uterus is critical for stromal decidualization and angiogenesis. Das A, Mantena SR, Kannan A, Evans DB, Bagchi MK, Bagchi IC. Proc Natl Acad Sci U S A. 2009 Jul 28;106(30):12542-7. Epub 2009 Jul 20. Erratum in: Proc Natl Acad Sci U S A. 2009 Sep 15;106(37):16003. PMID: 19620711 | PNAS

  • Implantation is initiated when the embryo attaches to the uterine luminal epithelium during early pregnancy.
  • Following this event, uterine stromal cells undergo steroid hormone-dependent transformation into morphologically and functionally distinct decidual cells in a unique process known as decidualization.
  • An angiogenic network is also formed in the uterine stromal bed, critically supporting the early development of the embryo.
  • ovarian progesterone as a key regulator of decidualization is well established
  • these studies in mice - identified the decidual uterus as a novel site of estrogen biosynthesis and uncovered estrogen-regulated maternal signaling pathways that critically control uterine differentiation and angiogenesis during early pregnancy.