title: Osteogenic lineage commitment of mesenchymal stem cells from patients with ossification of the posterior longitudinal ligament.
abstract: Ectopic bone formation is thought to be responsible for ossification of the posterior longitudinal ligament of the spine (OPLL). Mesenchymal stem cells (MSCs) were isolated from spinal ligaments and shown to play a key role in the process of ectopic ossification. The purpose of this study was to explore the capacity of these MSCs to undergo lineage commitment and to assess the gene expression changes between these committed and uncommitted MSCs between OPLL and non-OPLL patients. Spinal ligament-derived cells were obtained from OPLL patients or patients with cervical spondylotic myelopathy (non-ossified) for comparison (n=8 in each group). MSCs from the two patient cohorts were evaluated for changes in colony forming ability; osteogenic, adipogenic and chondrogenic differentiation potential; and changes in gene expression following induction with lineage-specific conditions. We show that the osteogenic differentiation potential was significantly higher in MSCs from OPLL patients than in those from non-OPLL patients. In addition, alkaline phosphatase activity and several osteogenic-related genes expressions (bone morphogenetic protein 2, runt-related transcription factor 2 and alkaline phosphatase) were significantly higher in the OPLL group than in the non-OPLL group. However, single cell cloning efficiency, adipogenic and chondrogenic differentiation, and the expression of adipogenic and chondrogenic-related genes were equivalent between MSCs harvested from OPLL and non-OPLL patient samples. These findings suggest an increase in the osteogenic differentiation potential of MSCs from OPLL patients and that this propensity toward the osteogenic lineage may be a causal factor in the ossification in these ligaments.
authors.affiliation: Department of Pharmacology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan; Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Department of Pharmacology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan. Electronic address: furukawa@cc.hirosaki-u.ac.jp.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Furukawa
authors.affiliation: Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Asari
authors.affiliation: Department of Pharmacology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan; Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Shunfu
authors.initials: S
authors.lastname: Chin
authors.affiliation: Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ono
authors.affiliation: Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Mizukami
authors.affiliation: Department of Pharmacology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Soroku
authors.initials: S
authors.lastname: Yagihashi
authors.affiliation: Department of Pharmacology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Motomura
authors.affiliation: Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ishibashi
mesh_terms: D050156:Adipogenesis / Q000235:genetics; D000368:Aged; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D002469:Cell Separation; D020219:Chondrogenesis / Q000235:genetics; D002999:Clone Cells; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D017846:Longitudinal Ligaments / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000378:metabolism / Q000473:pathology*; D010012:Osteogenesis / Q000235:genetics
keywords: Ectopic ossification; Mesenchymal stem cells; Ossification of the posterior longitudinal ligament; Osteogenic differentiation; Pathogenesis; Spinal ligament