Fig. 1

Expression of Beclin1 and LC3 mRNA in OPLL tissues and correlation between autophagy level and osteogenic differentiation markers. Reverse transcription-quantitative PCR assay to measure the mRNA expression of Beclin1 (a), LC3 (b), and ULK1 (c) in spinal ligament tissues from patients with OPLL and non-OPLL patients (n = 21 for OPLL group; n = 16 for OPLL group). The relative gene expression was normalized against β-actin. *P < 0.05, **P < 0.01. Pearson’s correlation was used to analyze the correlation between Beclin1 level and osteogenic biomarkers ALP (d), COL 1 (e), and OCN (f) in spinal ligament tissues from patients with OPLL and non-OPLL patients (n = 21 for OPLL group; n = 16 for OPLL group). Correlation between LC3 level and ALP (g), COL 1 (h), and OCN (i) spinal ligament tissues from patients with OPLL and non-OPLL patients (n = 21 for OPLL group; n = 16 for OPLL group). LC3, microtubule-associated protein 1 light chain 3; OPLL, ossification of the posterior longitudinal ligament; ULK1, Unc-51 like autophagy activating kinase 1; ALP, alkaline phosphatase, biomineralization associated; COL 1, collagen type 1; OCN, osteocalcin