AsianScientist (Sep. 12, 2017) – In a study published in the journal Proceedings of the National Academy of Sciences, researchers in Japan have discovered how flaviruses hijack the transport system in neurons to cause brain disorders.
Flaviviruses are a significant threat to public health worldwide, and some infected patients develop severe—potentially fatal—neurological diseases. Tick-borne encephalitis virus (TBEV), an RNA virus belonging to the Flavivirus genus, causes encephalic diseases resulting in light sensitivity, irritability and sleep disorders. However, little is known about the disease and no effective treatment is available at present.
In this study, a research team at Hokkaido University analyzed the transportation mechanism of viral RNAs in neurons and discovered that viral RNAs hijack the cell’s transportation system, which is normally used to move neuronal RNAs in dendrites. A specific non-coding sequence near the end of viral RNAs was found to be pivotal in interacting with the transportation system.
When the end sequence was mutated, infected mice showed reduced neurological symptoms. The researchers also demonstrated that viral RNAs could bind to a protein responsible for neuronal granule formation, an essential component of the neuron’s transport system. Their experiments further revealed that the normal transportation of neuronal RNAs become affected by viral RNAs as a result of competition to use the transportation network.
“It is unprecedented for a neuropathogenic virus to hijack the neuronal granule system to transport their genomic RNA, which results in severe neurological diseases,” said Associate Professor Kentaro Yoshii of Hokkaido University who led the study.
“The disruption of the neuronal granule system is also known to be involved in non-viral diseases such as Alzheimer’s disease. Thus, the unique virus-host interaction we revealed should help us understand their pathogenesis and develop treatments in the future.”
The article can be found at: Hirano et al. (2017) Dendritic Transport of Tick-borne Flavivirus RNA by Neuronal Granules Affects Development of Neurological Disease.
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Source: Hokkaido University; Photo: Shutterstock.
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