title: Osseous differentiation of human fat tissue grafts: From tissue engineering to tissue differentiation.
abstract: Conventional bone tissue engineering approaches require isolation and in vitro propagation of autologous cells, followed by seeding on a variety of scaffolds. Those protracted procedures impede the clinical applications. Here we report the transdifferentiation of human fat tissue fragments retrieved from subcutaneous fat into tissue with bone characteristics in vitro without prior cell isolation and propagation. 3D collagen-I cultures of human fat tissue were cultivated either in growth medium or in osteogenic medium (OM) with or without addition of Bone Morphogenetic Proteins (BMPs) BMP-2, BMP-7 or BMP-9. Ca2+depositions were observed after two weeks of osteogenic induction which visibly increased when either type of BMP was added. mRNA levels of alkaline phosphatase (ALP) and osteocalcin (OCN) increased when cultured in OM alone but addition of BMP-2, BMP-7 or BMP-9 caused significantly higher expression levels of ALP and OCN. Immunofluorescent staining for OCN, osteopontin and sclerostin supported the observed real-time-PCR data. BMP-9 was the most effective osteogenic inducer in this system. Our findings reveal that tissue regeneration can be remarkably simplified by omitting prior cell isolation and propagation, therefore removing significant obstacles on the way to clinical applications of much needed regeneration treatments.
authors.affiliation: University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
authors.forename: Maryna
authors.initials: M
authors.lastname: Bondarava
authors.affiliation: University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
authors.forename: Chiara
authors.initials: C
authors.lastname: Cattaneo
authors.affiliation: University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
authors.forename: Bin
authors.initials: B
authors.lastname: Ren
authors.affiliation: University Hospital of Munich (LMU), Biobank under the administration of the Human Tissue and Cell Research (HTCR) Foundation, Department of General, Visceral, Transplantation, Vascular and Thoracic Surgery, Munich, DE, Germany.
authors.forename: Wolfgang E
authors.initials: WE
authors.lastname: Thasler
authors.affiliation: University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
authors.forename: Volkmar
authors.initials: V
authors.lastname: Jansson
authors.affiliation: University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Müller
authors.affiliation: University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
authors.forename: Oliver B
authors.initials: OB
authors.lastname: Betz
mesh_terms: D000273:Adipose Tissue / Q000502:physiology*; D000469:Alkaline Phosphatase / Q000235:genetics; D001842:Bone and Bones / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D054338:Cell Transdifferentiation; D002478:Cells, Cultured; D018920:Coculture Techniques; D024042:Collagen Type I / Q000378:metabolism; D005786:Gene Expression Regulation; D055427:Growth Differentiation Factor 2 / Q000378:metabolism*; D006801:Humans; D015675:Osteocalcin / Q000235:genetics; D010012:Osteogenesis; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism; D023822:Tissue Engineering
chemical_list: D024042:Collagen Type I; D055427:Growth Differentiation Factor 2; D015675:Osteocalcin; D053495:Osteopontin; D000469:Alkaline Phosphatase; D002118:Calcium