A post-test design biological experiment.
The aim of this study was to evaluate the osteogenic effects of riluzole
on human mesenchymal stromal cells and osteoblasts.
Summary of Background Data. Riluzole
may benefit patients with spinal cord injury
(SCI) from a neurologic perspective, but little is known about riluzole'
s effect on bone formation, fracture healing, or osteogenesis.
Human mesenchymal stromal cells (hMSCs) and human osteoblasts (hOB) were obtained and isolated from healthy donors and cultured. The cells were treated with riluzole
of different concentrations (50, 150, 450 ng/mL) for 1, 2, 3, and 4 weeks. Cytotoxicity was evaluated as was the induction of osteogenic differentiation of hMSCs. Differentiation was evaluated by measuring alkaline phosphatase (ALP) activity and with Alizarin red staining. Osteogenic gene expression of type I collagen (Col1), ALP, osteocalcin (Ocn), Runx2, Sox9, Runx2/Sox9 ratio were measured by qRT-PCR.
No cytotoxicity or increased proliferation was observed in bone marrow derived hMSCs and primary hOBs cultured with riluzole
over 7 days. ALP activity was slightly increased in hMSCs after treatment for 2 weeks with riluzole
150 ng/mL and slightly upregulated by 150% (150 ng/mL) and 90% (450 ng/mL) in hMSCs at 3 weeks. In hOBs, ALP activity almost doubled after 2 weeks of culture with riluzole
150 ng/mL (P
< 0.05). More pronounced 2.6-fold upregulation was noticed after 3 weeks of culture with riluzole
at both 150 ng/mL (P
= 0.05) and 450 ng/mL (P
= 0.05). No significant influence of riluzole
on the mRNA expression of osteocalcin (OCN) was observed.
The effect of riluzole
on bone formation is mixed; low-dose riluzole
has no effect on the viability or function of either hMSCs or hOBs. The activity of ALP in both cell types is upregulated by high-dose riluzole
, which may indicate that high-dose riluzole
can increase osteogenic metabolism and subsequently accelerate bone healing process. However, at high concentrations, riluzole
leads to a decrease in osteogenic gene expression, including Runx2 and type 1 collagen.
Level of Evidence: N/A