OMENTIN-1 PROMOTED PROLIFERATION AND AMELIORATED INFLAMMATION, APOPTOSIS, AND DEGENERATION IN HUMAN NUCLEUS PULPOSUS CELLS
Purpose - Intervertebral disc degeneration (IVDD) is an abnormal cellular process of tissue remodeling that is recognized as the leading cause of low back pain and affects 80% of the world's population. The inflammatory cytokine interleukin-1β (IL-1β) is concerned withinside the manner of degenerative disc disease (DDD) and is upregulated in degenerative disc disease. Omentin-1, also known as Intellectin-1, is a new adipocytokine with anti-inflammatory, anti-apoptotic, proliferative, and angiogenic properties in a variety of cell types. However, little is known about the effect of Omentin-1 on human nucleus pulposus cells (NPCs). The purpose of this study is to investigate the effect of Omentin-1 on healthy human nucleus pulposus cells (NPCs) in terms of proliferation, and further to investigate the effect of Omentin-1 on IL-1β-induced inflammation, apoptosis and degeneration of human NPCs.
Methods - Proliferation was assessed by cck8, EdU staining, KI-67 immunofluorescence, and immunoblotting detection of Cyclin D1, PCNA, and p21 protein levels. Inflammation was detected by mRNA and protein levels of iNOS, COX-2, TNF-alpha, and IL-6. Apoptosis was assessed by Annexin V/PI flow cytometry, mitochondrial matrix potential (JC-1), and protein levels of Bcl-2, BAX, and Cleaved-caspase-3. Extracellular matrix degradation was evaluated by mRNA and protein levels of Col2A1, Aggrecan, Adamts-4, MMP-13, and by immunofluorescence of Col-2A1 and MMP-13.
Results: Our study showed that Omentin-1 enhanced the proliferation of normal human NPCs. In addition, Omentin-1 expression was reduced in IL-1β-treated human NPCs. Omentin-1 protected human NPCs from IL-1β-induced inflammation, apoptosis, and degeneration in vitro through activation of the PI3K/Akt pathway.
Conclusion - The results obtained contribute to an understanding of the role of Omentin-1 in human NPCs and may be a potential therapeutic candidate for intervertebral disc degeneration.