The long noncoding RNA HOTAIR promotes Parkinson's disease by upregulating LRRK2 expression

Long noncoding RNAs (lncRNAs) have emerged recently as a new class of genes that regulate cellular processes. HOTAIR (Hox transcript antisense intergenic RNA), an approximately 2.2 kb long noncoding RNA transcribed from the HOXC locus, is upregulated in various diseases. However, the role of HOTAIR in Parkinson's disease (PD) remains unclear. A mouse model of PD was developed by intraperitoneal injection of MPTP. The expression of HOTAIR and LRRK2 were detected in the PD mice and in human neuroblastoma cell lines SH-SY5Y pretreated with MPP+. The effect of HOTAIR on the expression of LRRK2 was examined in SH-SY5Y cells through overexpressing or knockdown of HOTAIR. MTT and flow cytometry assay were performed to measure the cell viability and apoptosis of SH-SY5Y cells. We found that HOTAIR was up-regulated in midbrain tissue of MTPT induced PD mice and in SH-SY5Y cells exposed to MPP+. With the presence of HOTAIR overexpression in SH-SY5Y cells, the expression of LRRK2 was increased compared with that in the control. HOTAIR knockdown showed a protective effect on the cell viability of SH-SY5Y cells pretreated with MPP+. HOTAIR knockdown provided protection against MPP+-induced DA neuronal apoptosis by repressing caspase 3 activity. The finding that HOTAIR promoted PD induced by MPTP could add our understanding of the molecular mechanisms in PD. These findings suggested that inhibition of HOTAIR levels is an effective disease-modifying strategy in PD.