Huntington’s disease (HD) is a devastating neurodegenerative disease caused by cytosine-adenine-guanine trinucleotide repeat expansion in the huntingtin gene. Growing evidence supports the regulatory functions of long noncoding RNAs (lncRNAs) in the disease process, but little is known about the association between lncRNAs and neuronal death in HD.
Here, researchers from Seoul National University Hospital evaluated the altered expression profiles of lncRNA in HD by using microarrays. Among dysregulated lncRNAs, they focused on the upregulation of nuclear paraspeckle assembly transcript 1 (NEAT1). Quantitative PCR analysis validated increased NEAT1 levels in the R6/2 mouse brain as well as the human HD postmortem brain. To determine the biological effects of NEAT1 on neuronal survival, neuro2A cells were transfected with the NEAT1 short isoform vector and were subjected to H2O2-induced injury. Subsequently, NEAT1-transfected cells showed increased viability under oxidative stress. These observations support the notion that NEAT1 upregulation in HD contributes to the neuroprotective mechanism against neuronal injury rather than the pathological process underlying neurodegeneration in HD.
Increased NEAT1 expression in the brain of individuals with Huntington’s disease
a Microarray analysis shows differentially expressed long noncoding RNAs in human HD brain samples (absolute fold change >1.5 or <0.67, adjusted p value <0.05, n = 4 per group). The colors correspond to a normalized expression level of each transcript, where red indicates upregulation and green indicates downregulation. b Quantitative reverse transcription PCR (qRTPCR) validated upregulated NEAT1 expression in the human HD brain (n = 5 per group). c Increased expression of NEAT1 in the R6/2 mouse brain was confirmed by qRT-PCR (n = 4 per group). Human and mouse GAPDH were used as an internal control. Bars show mean ± SEM.