Long noncoding RNA NORAD regulates MPP plus -induced Parkinson's disease model cells

Background: Long non-coding RNAs (lncRNAs) have been demonstrated to play important roles in human diseases. Yet, the functions of lncRNAs in neurodegenerative disorders, such as Parkinson's disease (PD) are poorly understood. In this study, we used human neuroblastoma SH-SY5Y cell line as a cell-basedin vitro PD model, and investigated the role of lncRNA, Non-Coding RNA Activated By DNA Damage (NORAD) in 1-methyl-4-phenylpyridinium (MPP +)-induced PD-like cytotoxicity. Methods: SH-SY5Y cells were culturedin vitro, and treated with MPP + at various concentrations, or of various durations of times to induce PD-like cytotoxic events. qRT-PCR was used to measure MPP + -induced NORAD expression changes. Lentiviral transduction was applied to stably upregulate or downregulate NORAD in SH-SY5Y cells. The effects of NORAD upregulation or downregulation on MPP + -induced cytotoxic events, including dose-dependent and time-dependent cell death, apoptosis, caspase 3/7, reactive Oxygen Species (ROS) and lactate dehydrogenase (LDH) activities, were quantitatively investigated. Results: MPP + induced cytotoxicity, and downregulated NORAD in both dose- and time- dependent manners in SH-SY5Y cells. Lentiviral-induced NORAD upregulation was found to protect against MPP + -induced cytotoxicity in SH-SY5Y cells, as it rescued MPP + -induced cellular destruction and apoptosis, as well as decreased MPP + -induced caspase 3/7, ROS and LDH activities. Alternatively, NORAD downregulation was found to significantly deteriorate MPP + -induced cytotoxicity in SH-SY5Y cells. Conclusion: We presented a novel functional role of IncRNA NORAD in regulating human Parkinson's disease.