Long non-coding RNA UCA1 regulates MPP+-induced neuronal damage through the miR-671-5p/KPNA4 pathway in SK-N-SH cells

Parkinson's disease (PD) is an age-related neurodegenerative disease. Long non-coding RNA urothelial carcinoma-associated 1 (UCA1) is involved in the pathogenesis of PD. However, the pathogenesis of PD regulated by UCA1 has not been fully explained. We used 1-Methyl-4-phenylpyridinium (MPP+)-induced SK-N-SH cells for functional analysis. Expression levels of UCA1, microRNA (miR)-671-5p, and KPNA4 (karyopherin subunit alpha 4) mRNA were detected using quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were analyzed using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) or flow cytometry assays. Some protein levels were measured by western blotting. The levels of pro-inflammatory cytokines were tested by ELISA (enzyme-linked immunosorbent assay). The levels of LDH (lactate dehydrogenase), MDA (malondialdehyde), and SOD (superoxide dismutase) were measured using corresponding kits. The relationship between UCA1 or KPNA4 and miR-671-5p was verified by dual-luciferase reporter assay and/or RNA immunoprecipitation (RIP) assay. MPP+ induced UCA1 expression in SK-N-SH cells in a concentration-dependent manner or time-dependent manner. UCA1 knockdown reduced MPP+-induced apoptosis, inflammation, and oxidative stress in SK-N-SH cells. MiR-671-5p was downregulated while KPNA4 was upregulated in MPP+-treated SK-N-SH cells. UCA1 sponged miR-671-5p to regulate KPNA4 expression. MiR-671-5p inhibition counteracted UCA1 knockdown-mediated influence on apoptosis, inflammation, and oxidative stress of MPP+-induced SK-N-SH cells. KPNA4 overexpression offset the inhibitory influence of miR-671-5p mimic on apoptosis, inflammation, and oxidative stress of MPP+-treated SK-N-SH cells. UCA1 inhibition reduced MPP+-induced neuronal damage through the miR-671-5p/KPNA4 pathway in SK-N-SH cells, providing a novel mechanism to understand the pathogenesis of PD.