AUTHOR=Tang Ning , Dong Yulei , Liu Jiaming , Zhao Hong 

TITLE=Silencing of Long Non-coding RNA NEAT1 Upregulates miR-195a to Attenuate Intervertebral Disk Degeneration via the BAX/BAK Pathway

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2020.00147

DOI=10.3389/fmolb.2020.00147

ISSN=2296-889X

ABSTRACT=<sec><title>Background/Aims</title><p>An increasing body of evidence has demonstrated that long non-coding RNAs (lncRNAs) play a vital regulatory role in intervertebral disk degeneration (IVDD). Nucleus enriched abundant transcript 1 (<italic>NEAT1</italic>), a novel cancer-related lncRNA, is associated with many malignancies, including ovarian cancer, and esophageal squamous cell carcinoma. Nevertheless, the role of <italic>NEAT1</italic> in the progression of IVDD remains to be studied. Here, we explored the effect of <italic>NEAT1</italic> on the progression of IVDD and the mechanisms involved.</p></sec><sec><title>Methods</title><p>An IVDD model was constructed in SD rats <italic>in vivo</italic>, and degeneration was induced by advanced glycation end product (AGE) in human nucleus pulposus cells (HNPC) <italic>in vitro</italic>. Quantitative real-time PCR was performed to detect the relative <italic>NEAT1</italic> and miR-195a expressions and further confirmed the relationship between <italic>NEAT1</italic> and miR-195a. Cell apoptosis was evaluated by TUNEL assay. The related mechanisms were explored by Western blot assay.</p></sec><sec><title>Results</title><p>The relative <italic>NEAT1</italic> expression was significantly upregulated in the IVDD rat model and the denatured HNPC. Silencing of <italic>NEAT1</italic> expression in HNPC significantly promoted the Collagen II and TIMP-1 expression induced by AGE while greatly suppressing the expressions of MMP-3 and cleaved caspase-3. Besides, downregulation of <italic>NEAT1</italic> obviously reversed the AGE-induced apoptosis in HNPC. More interestingly, these effects of <italic>NEAT1</italic> knockout on HNPC were largely reversed by silencing of miR-195a or overexpression of BAX under the AGE treatment. Mechanically, the direct combination of <italic>NEAT1</italic> with miR-195a resulted in upregulation of MMP-3, cleaved caspase-3, BAX, and BAK, as well as downregulation of Collagen II and TIMP-1, which are associated with EMT and apoptosis. We also demonstrated similar results in the <italic>in vivo</italic> experiments.</p></sec><sec><title>Conclusion</title><p><italic>NEAT1</italic> played its role in IVDD progression via partly by mediating the miR-195 expression and might be used as a potential target for IVDD therapy.</p></sec>