title: Comparison of mesenchymal stem cells from human placenta and bone marrow.
abstract: BACKGROUND
  Nowadays bone marrow represents the main source of mesenchymal stem cells (MSCs). We identified a new population of MSCs derived from human placenta and compared its biological characterization with bone marrow derived MSCs.
  
  
  METHODS
  Mononucleated cells (MNC) were isolated from the human placenta tissue perfusate by density gradient fractionation. Individual colonies were selected and cultured in tissue dishes. At the same time, human bone marrow derived MSCs were identified. Culture-expanded cells were characterized by immune phenotyping and cultured under conditions promoting differentiation to osteoblasts or adipocytes. The hematopoietic cytokines were assayed using reverse transcriptase polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  Human placental MSCs exhibited fibroblastoid morphology. Flow cytometric analyses showed that the placental MSC were CD29, CD44, CD73, CD105, CD166, HLA-ABC positive; but were negative for CD34, CD45, and HLA-DR. Functionally, they could be induced into adipocytes or osteocytes. Moreover, several hematopoietic cytokine mRNA was found in placenta-derived MSCs by RT-PCR analysis, including IL-6, M-CSF, Flt3-ligand and SCF. These results were consistent with the properties of bone marrow derived MSCs.
  
  
  CONCLUSIONS
  These observations implicate the postpartum human placenta as an important and novel source of multipotent stem cells that could potentially be used for investigating mesenchymal differentiation and regulation of hematopoiesis.
authors.affiliation: Institute of Basic Medical Sciences, Academy of Military Medical Sciences, Beijing 100850, China. zhangyi@nic.bmi.ac.cn
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Chang-dong
authors.initials: CD
authors.lastname: Li
authors.forename: Xiao-xia
authors.initials: XX
authors.lastname: Jiang
authors.forename: He-lian
authors.initials: HL
authors.lastname: Li
authors.forename: Pei-hsien
authors.initials: PH
authors.lastname: Tang
authors.forename: Ning
authors.initials: N
authors.lastname: Mao
mesh_terms: D001854:Bone Marrow Cells / Q000502:physiology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D010920:Placenta / Q000166:cytology*; D011247:Pregnancy