Moxibustion alleviates intervertebral disc degeneration via activation of the HIF-1α/VEGF pathway in a rat model

Intervertebral disc degeneration (IDD) induces serious back, neck and radicular pain. Recently, moxibustion has been suggested as an effective treatment for IDD. Thus, our study aims to investigate the molecular mechanism of moxibustion in IDD. A rat model of IDD was established by moxibustion treatment. Nucleus pulposus (NP) cells isolated from IDD rats or IDD rats treated with moxibustion were transfected with plasmids harboring overexpressed hypoxia-inducible factor-1 alpha (HIF-1α) to understand the role of treatment on cell autophagy and apoptosis. To investigate the mechanism of moxibustion in IDD, aggrecan, cyclo-oxygenase 2 (COX-2), HIF-1α and vascular endothelial growth factor (VEGF) expression in NP cells was measured. The expression of aggrecan and COX-2 was elevated by moxibustion treatment. Moxibustion induced autophagy and suppressed apoptosis of NP cells from IDD rats. Compared with IDD rats, the expression of light chain 3 (LC3) II/I, Beclin-1, B-cell lymphoma-2 (Bcl-2) and HIF-1α was regulated significantly after moxibustion treatment, while the expression of cleaved-caspase-3, Bcl-2 associated protein X and VEGF was downregulated. In general, moxibustion may be beneficial to IDD by enhancing autophagy and reducing apoptosis of NP cells via the HIF-1α/VEGF pathway.