Apelin Promotes ECM Synthesis by Enhancing Autophagy Flux via TFEB in Human Degenerative NP Cells under Oxidative Stress

Figure 1

Low Apelin expression in NP of patients with DDD compared with that in NP of patients with LVF. (a) Representative MRI of patients. A1: patient with LVF; the red arrow indicates the experimental material position and the disc of T12/L1 is classified as grade I according to the Pfirrmann classification. A2: patient with DDD; the red arrow indicates the experimental material position and the disc of L5/S1 is herniated and classified as grade V according to the Pfirrmann classification. (b) RT-PCR analysis for Apelin, Collagen II, Aggrecan, and TFEB. The mRNA levels of Apelin, Collagen II, Aggrecan, and TFEB are decreased in NP cells from patients with DDD. (c) Western blot analysis for Apelin, Collagen II, Aggrecan, and TFEB (nucleoprotein) expression in NP cells from patients with LVF and DDD. The protein levels of Apelin, Collagen II, Aggrecan, and TFEB (nucleoprotein) are decreased in NP cells from patients with DDD. n = 3, , . All experiments were repeated at least three times. DDD: degenerative disc disease; NP: nucleus pulposus; LVF: lumbar vertebral fracture; TFEB: transcription factor EB.

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