title: Term Amniotic membrane is a high throughput source for multipotent Mesenchymal Stem Cells with the ability to differentiate into endothelial cells in vitro.
abstract: BACKGROUND
  Term Amniotic membrane (AM) is a very attractive source of Mesenchymal Stem Cells (MSCs) due to the fact that this fetal tissue is usually discarded without ethical conflicts, leading to high efficiency in MSC recovery with no intrusive procedures. Here we confirmed that term AM, as previously reported in the literature, is an abundant source of hMSCs; in particular we further investigated the AM differentiation potential by assessing whether these cells may also be committed to the angiogenic fate. In agreement with the recommendation of the International Society for Cellular Therapy, the mesenchymal cells herein investigated were named Amniotic Membrane-human Mesenchymal Stromal Cells (AM-hMSC).
  
  
  RESULTS
  The recovery of hMSCs and their in vitro expansion potential were greater in amniotic membrane than in bone marrow stroma. At flow cytometry analysis AM-hMSCs showed an immunophenotypical profile, i.e., positive for CD105, CD73, CD29, CD44, CD166 and negative for CD14, CD34, CD45, consistent with that reported for bone marrow-derived MSCs. In addition, amniotic membrane-isolated cells underwent in vitro osteogenic (von Kossa stain), adipogenic (Oil Red-O stain), chondrogenic (collagen type II immunohistochemichal detection) and myogenic (RT-PCR MyoD and Myogenin expression as well as desmin immunohistochemical detection) differentiation. In angiogenic experiments, a spontaneous differentiation into endothelial cells was detected by in vitro matrigel assay and this behaviour has been enhanced through Vascular Endothelial Growth Factor (VEGF) induction. According to these findings, VEGF receptor 1 and 2 (FLT-1 and KDR) were basally expressed in AM-hMSCs and the expression of endothelial-specific markers like FLT-1 KDR, ICAM-1 increased after exposure to VEGF together with the occurrence of CD34 and von Willebrand Factor positive cells.
  
  
  CONCLUSIONS
  The current study suggests that AM-hMSCs may emerge as a remarkable tool for the cell therapy of multiple diseased tissues. AM-hMSCs may potentially assist both bone and cartilage repair, nevertheless, due to their angiogenic potential, they may also pave the way for novel approaches in the development of tissue-engineered vascular grafts which are useful when vascularization of ischemic tissues is required.
authors.affiliation: Department of Histology, Embryology and Applied Biology, University of Bologna, Italy. alvifran@libero.it <alvifran@libero.it>
authors.forename: Francesco
authors.initials: F
authors.lastname: Alviano
authors.forename: Valentina
authors.initials: V
authors.lastname: Fossati
authors.forename: Cosetta
authors.initials: C
authors.lastname: Marchionni
authors.forename: Mario
authors.initials: M
authors.lastname: Arpinati
authors.forename: Laura
authors.initials: L
authors.lastname: Bonsi
authors.forename: Michele
authors.initials: M
authors.lastname: Franchina
authors.forename: Giacomo
authors.initials: G
authors.lastname: Lanzoni
authors.forename: Silvia
authors.initials: S
authors.lastname: Cantoni
authors.forename: Claudia
authors.initials: C
authors.lastname: Cavallini
authors.forename: Francesca
authors.initials: F
authors.lastname: Bianchi
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Tazzari
authors.forename: Gianandrea
authors.initials: G
authors.lastname: Pasquinelli
authors.forename: Laura
authors.initials: L
authors.lastname: Foroni
authors.forename: Carlo
authors.initials: C
authors.lastname: Ventura
authors.forename: Alberto
authors.initials: A
authors.lastname: Grossi
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Bagnara
mesh_terms: D017667:Adipocytes / Q000166:cytology; D000650:Amnion / Q000166:cytology*; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology; D004730:Endothelium, Vascular / Q000166:cytology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008875:Middle Aged; D039902:Multipotent Stem Cells / Q000166:cytology*; D032342:Muscle Cells / Q000166:cytology; D010006:Osteoblasts / Q000166:cytology; D011247:Pregnancy