title: Bone morphogenetic proteins 4 and 2/7 induce osteogenic differentiation of mouse skin derived fibroblast and dermal papilla cells.
abstract: Heterotopic ossification is a pathological condition in which bone forms outside the skeletal system. It can also occur in skin, which is the case in some genetic disorders. In addition to precursor cells and the appropriate tissue environment, heterotopic ossification requires inductive signals such as bone morphogenetic proteins (BMP). BMPs are growth and differentiation factors that have the ability to induce cartilage and bone formation in ectopic sites. The objective of this study is to explore the effect of the BMP-4 homodimer and BMP-2/7 heterodimer on the osteogenic differentiation of primary mouse skin fibroblasts and hair follicle dermal papilla (DP) cells. Osteogenic differentiation was induced by osteogenic induction medium (OS) containing 10 nM dexamethasone. The effect of BMP-4 and BMP-2/7 was studied using alkaline phosphatase (ALP) and calcium assays after 1.5, 3 and 5 weeks of differentiation. Fibroblasts and DP cells were able to differentiate into osteoblast-like matrix mineralizing cells. The first visible sign of differentiation was the change of morphology from rounded to more spindle-shaped cells. BMP-4 and BMP-2/7 exposure elevated ALP activity and calcium production significantly more than OS alone. The osteogenic response to BMP-4 and BMP-2/7 was similar in fibroblasts, whereas, in DP cells, BMP-2/7 was more potent than BMP-4. OS alone could not induce osteogenic differentiation in DP cells. Clear and consistent results show that dermal fibroblasts and stem cells from the dermal papilla were capable of osteogenic differentiation. The BMP-2/7 heterodimer was significantly more effective on hair follicular dermal stem cell differentiation.
authors.affiliation: Department of Anatomy and Cell Biology, University of Oulu, Oulu, FI-90014, Finland, riina.myllyla@oulu.fi.
authors.forename: Riina M
authors.initials: RM
authors.lastname: Myllylä
authors.forename: Kirsi-Maria
authors.initials: KM
authors.lastname: Haapasaari
authors.forename: Petri
authors.initials: P
authors.lastname: Lehenkari
authors.forename: Juha
authors.initials: J
authors.lastname: Tuukkanen
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D055415:Bone Morphogenetic Protein 4 / Q000494:pharmacology*; D055419:Bone Morphogenetic Protein 7 / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D020405:Dermis / Q000166:cytology* / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D018859:Hair Follicle / Q000166:cytology; D008297:Male; D051379:Mice; D016348:Osseointegration / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects*
chemical_list: D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D000469:Alkaline Phosphatase; D002118:Calcium