miR-142-5p Disrupts Neuronal Morphogenesis Underlying Porcine Hemagglutinating Encephalomyelitis Virus Infection by Targeting Ulk1

Li, Zi; Lan, Yungang; Zhao, Kui; Lv, Xiaoling; Ding, Ning; Lu, Huijun; Zhang, Jing; Yue, Huiqing; Shi, Junchao; Song, Deguang; Gao, Feng; He, Wenqi

In our previous study, a microRNA array was performed to identify the microRNAs involved in neurological dysfunction as a result of PHEV infection (unpublished data). Of the up-regulated microRNAs, miR-142-5p, the expression of which increased over 5-fold, was selected for confirmation by quantitative real-time polymerase chain reaction (qRT-PCR). miR-142-5p expression was time-dependently upregulated in response to PHEV infection in mice (Figure 1A) , consistent with the microarray analysis. Meanwhile, PHEV-infected primary cortical neurons also induced a significant increase in miR-142-5p RNA expression ( Figure 1B) . We used an in situ hybridization (ISH) protocol to examine the localization of miR-142-5p RNA and found widespread expression of microRNAs in the cerebral cortexes of the mice, especially near the prefrontal cortex and hippocampus ( Figure 1C) . Hybridization with the miR-142-5p-specific probe in primary cortical neurons revealed that miR-142-5p localization occurred in a punctuate pattern along the axon shaft and within dendrite protrusions, especially at branching points ( Figure 1D) . Also, the signal intensities confirmed significantly higher levels of the miR-142-5p in PHEVinfected neurons ( Figure 1E ). Some co-localization was observed in the axon and dendrite through two-color immunofluorescence staining of both miR-142-5p and PHEV ( Figure 1F) . These data suggest that miR-142-5p RNA expression was significantly upregulated in neurons infected with PHEV. Moreover, the colocalization of miR-142-5p and PHEV within neurites suggested that there is a possible functional role for this microRNA in PHEV-induced nerve cell injury.