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 2 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.

Decreased DNA methylation in the promoter region of the WNT5A and GDNF genes may promote the osteogenicity of mesenchymal stem cells from patients with ossified spinal ligaments

“…Characterization of these cells was presented in our previous study (11). Cells identified as MSCs by flow cytometry, as described previously (13), were used.…”

“…We previously identified the presence of MSCs in human spinal ligaments and, using immunohistochemistry, demonstrated enrichment of MSCs in ossified areas of human spinal ligaments (11,12). Furthermore, the osteogenic differentiation potential of MSCs from patients with ossified spinal ligaments was increased; this propensity toward the osteogenic lineage might be a causal factor in the ossification of these ligaments (13). However, the mechanism by which MSCs obtain their osteogenicity remains unclear.…”

Hyperglycemia induces osteogenic differentiation of bone marrow derived stem cells: an in vitro study

“…Several studies discussed the adverse effects of MSCs in pathogenic conditions, including vascular calcification 13 , aortic valve calcification 14 , fibrodysplasia ossificans progressive 11 . Recently the role of MSCs has been studied in the ossification process of the posterior longitudinal ligament of the spine 15 , but the mechanism leading to the differentiation of MSCs is still unknown. The microenvironment may play a key role.…”

Facilitation of Chemotaxis Activity of Mesenchymal Stem Cells via Stromal Cell–Derived Factor-1 and Its Receptor May Promote Ectopic Ossification of Human Spinal Ligaments

“…Cell Isolation and Culture. We isolated MSCs as described previously (Harada et al, 2014). Cells were identified as MSCs by fluorescence-activated flow cytometry.…”

“…Furthermore, an enhancement in the osteogenic differentiation potentiality has been found in MSCs from ossified ligament samples. This leaning toward the osteogenic lineage may constitute causality in the ossification (Harada et al, 2014;Chiba et al, 2015). Based on these findings, MSCs are thought to be involved in the process of ectopic ossification occurring in spinal ligaments.…”