Long noncoding RNA NEAT1 knockdown inhibits MPP⁺-induced apoptosis, inflammation and cytotoxicity in SK-N-SH cells by regulating miR-212-5p/RAB3IP axis

Background: Some long non-coding RNAs (lncRNAs) have been suggested to play critical roles in Parkinson's disease (PD) pathogenesis, including nuclear enriched abundant transcript 1 (NEAT1). The purpose of this study was to further elucidate the molecular mechanism of NEAT1 in PD.

Methods: The expression levels of NEAT1, miR-212-5p and RAB3A-interacting protein (RAB3IP) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were evaluated by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis, respectively. Western blot analysis was applied to detect the protein expression of IL-1β, TNF-α and RAB3IP. The LDH activity, ROS generation and SOD activity were measured by Lactate LDH activity assay kit, ROS assay kit, and SOD activity assay kit, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the relationship between miR-212-5p and NEAT1 or mRNA of RAB3IP. 1-methyl-4-phenylpyridinium ion (MPP⁺)-treated SK-N-SH cells were used as an in vitro model of PD.

Results: NEAT1 and RAB3IP were upregulated while miR-212-5p was downregulated in SK-N-SH cells treated with MPP⁺. NEAT1 knockdown or miR-212-5p overexpression inhibited MPP⁺-induced apoptosis, inflammation and cytotoxicity in SK-N-SH cells. Moreover, miR-212-5p was a direct target of NEAT1 and its downregulation reversed the eff ;ects caused by NEAT1 knockdown in MPP⁺-induced SK-N-SH cells. Furthermore, RAB3IP was a downstream target of miR-212-5p and its overexpression attenuated the effects of miR-212-5p restoration in MPP⁺-induced SK-N-SH cells. Besides, NEAT1 acted as a molecular sponge of miR-212-5p to regulate RAB3IP expression.

Conclusion: NEAT1 knockdown suppressed MPP⁺-induced apoptosis, inflammation and cytotoxicity in SK-N-SH cells through regulating miR-212-5p and RAB3IP expression, providing a possible therapeutic strategy for PD patients.