title: Enhanced osteoblastogenesis of adipose-derived stem cells on spermine delivery via β-catenin activation.
abstract: The molecular mechanisms underlying spermine osteo-inductive activity on human adipose-derived stem cells (ASCs) grown in 3-dimensional (3D) cultures were investigated. Spermine belongs to the polyamine family, naturally occurring, positively charged polycations that are able to control several cellular processes. Spermine was used at a concentration close to that found in platelet-rich plasma (PRP), an autologous blood product containing growth and differentiation factors, which has recently become popular in in vitro and in vivo bone healing and engineering. Adipose tissue was surgically obtained from the hypodermis of patients undergoing hip arthroplasty. Patient age negatively affected both ASC yield and ASC ability to form 3D constructs. ASC 3D cultures were seeded in either non differentiating or chondrogenic conditions, with or without the addition of 5 μM spermine to evaluate its osteogenic potential across 1, 2, and 3 weeks of maturation. Osteogenic medium was used as a reference. The effects of the addition of spermine on molecular markers of osteogenesis, at both gene and protein level, and mineralization were evaluated. The effects of spermine were temporally defined and responsible for the progression from the early to the mature osteoblast differentiation phases. Spermine initially promoted gene and protein expression of Runx-2, an early marker of the osteoblast lineage; then, it increased β-catenin expression and activation, which led to the induction of Osterix gene expression, the mature osteoblast commitment factor. The finding that spermine induces ASC to differentiate toward mature osteoblasts supports the use of these easily accessible mesenchymal stem cells coupled with PRP for orthopedic applications.
authors.affiliation: Laboratorio di Immunoreumatologia e Rigenerazione Tessutale, Istituto Ortopedico Rizzoli, Bologna, Italy .
authors.forename: Serena
authors.initials: S
authors.lastname: Guidotti
authors.forename: Annalisa
authors.initials: A
authors.lastname: Facchini
authors.forename: Daniela
authors.initials: D
authors.lastname: Platano
authors.forename: Eleonora
authors.initials: E
authors.lastname: Olivotto
authors.forename: Manuela
authors.initials: M
authors.lastname: Minguzzi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Trisolino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Filardo
authors.forename: Silvia
authors.initials: S
authors.lastname: Cetrullo
authors.forename: Benedetta
authors.initials: B
authors.lastname: Tantini
authors.forename: Ermanno
authors.initials: E
authors.lastname: Martucci
authors.forename: Andrea
authors.initials: A
authors.lastname: Facchini
authors.forename: Flavio
authors.initials: F
authors.lastname: Flamigni
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Borzì
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000187:drug effects; D002449:Cell Aggregation / Q000187:drug effects; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D020219:Chondrogenesis / Q000187:drug effects; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects*; D053657:Platelet-Rich Plasma / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D013096:Spermine / Q000494:pharmacology*; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D014157:Transcription Factors; D051176:beta Catenin; D013096:Spermine