title: Human adipose tissue-derived SSEA-4 subpopulation multi-differentiation potential towards the endothelial and osteogenic lineages.
abstract: Human adipose tissue has been recently recognized as a potential source of stem cells for regenerative medicine applications, including bone tissue engineering (TE). Despite the gathered knowledge regarding the differentiation potential of human adipose tissue-derived stem cells (hASCs), in what concerns the endothelial lineage many uncertainties are still present. The existence of a cell subpopulation within the human adipose tissue that expresses a SSEA-4 marker, usually associated to pluripotency, raises expectations on the differentiation capacity of these cells (SSEA-4(+)hASCs). In the present study, the endothelial and osteogenic differentiation potential of the SSEA-4(+)hASCs was analyzed, aiming at proposing a single-cell source/subpopulation for the development of vascularized bone TE constructs. SSEA-4(+)hASCs were isolated using immunomagnetic sorting and cultured either in α-MEM, in EGM-2 MV (endothelial growth medium), or in osteogenic medium. SSEA-4(+)hASCs cultured in EGM-2 MV formed endothelial cell-like colonies characterized by a cobblestone morphology and expression of CD31, CD34, CD105, and von Willebrand factor as determined by quantitative reverse transcriptase (RT)-polymerase chain reaction, immunofluorescence, and flow cytometry. The endothelial phenotype was also confirmed by their ability to incorporate acetylated low-density lipoprotein and to form capillary-like structures when seeded on Matrigel. SSEA-4(+)hASCs cultured in α-MEM displayed fibroblastic-like morphology and exhibited a mesenchymal surface marker profile (>90% CD90(+)/CD73(+)/CD105(+)). After culture in osteogenic conditions, an overexpression of osteogenic-related markers (osteopontin and osteocalcin) was observed both at molecular and protein levels. Matrix mineralization detected by Alizarin Red staining confirmed SSEA-4(+)hASCs osteogenic differentiation. Herein, we demonstrate that from a single-cell source, human adipose tissue, and by selecting the appropriate subpopulation it is possible to obtain microvascular-like endothelial cells and osteoblasts, the most relevant cell types for the creation of vascularized bone tissue-engineered constructs.
authors.affiliation: Department of Polymer Engineering, 3B's Research Group, University of Minho, Guimarães, Portugal.
authors.forename: Silvia M
authors.initials: SM
authors.lastname: Mihaila
authors.forename: Ana M
authors.initials: AM
authors.lastname: Frias
authors.forename: Rogério P
authors.initials: RP
authors.lastname: Pirraco
authors.forename: Tommaso
authors.initials: T
authors.lastname: Rada
authors.forename: Rui L
authors.initials: RL
authors.lastname: Reis
authors.forename: Manuela E
authors.initials: ME
authors.lastname: Gomes
authors.forename: Alexandra P
authors.initials: AP
authors.lastname: Marques
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism*; D001808:Blood Vessels / Q000166:cytology / Q000254:growth & development*; D002454:Cell Differentiation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000502:physiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D055746:Stage-Specific Embryonic Antigens / Q000378:metabolism*; D023822:Tissue Engineering / Q000379:methods
chemical_list: D055746:Stage-Specific Embryonic Antigens; C066584:stage-specific embryonic antigen-4