Human adipose tissue-derived SSEA-4 subpopulation multi-differentiation potential towards the endothelial and osteogenic lineages

• Published in: Tissue engineering. Part A Vol. 19; no. 1-2; p. 235
• Main Authors: Mihaila, Silvia M, Frias, Ana M, Pirraco, Rogério P, Rada, Tommaso, Reis, Rui L, Gomes, Manuela E, Marques, Alexandra P
• Format: Journal Article
• Language: English
• Published: United States 01-01-2013
• Subjects: Adipocytes - cytology; Adipocytes - metabolism; Blood Vessels - cytology; Blood Vessels - growth & development; Cell Differentiation; Cells, Cultured; Endothelial Cells - cytology; Endothelial Cells - physiology; Female; Humans; Middle Aged; Osteoblasts - cytology; Osteoblasts - physiology; Osteogenesis - physiology; Stage-Specific Embryonic Antigens - metabolism; Tissue Engineering - methods
• ISSN: 1937-335X
• DOI: 10.1089/ten.tea.2012.0092

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.