Glutamate and lipid metabolic perturbation in the hippocampi of asymptomatic borna disease virus-infected horses.
Authors: Zhang Liang, Lei Yang, Liu Xia, Wang Xiao, Liu Zhao, Li Dan, Zheng Peng, Zhang Lujun, Chen Shigang, Xie Peng
Journal: PloS one
Summary
Borna disease virus is a neurotropic pathogen capable of infecting horses globally, yet many infected animals remain clinically silent despite harbouring active infection—a phenomenon whose underlying biological mechanisms have received limited investigation. Using quantitative PCR and Western blotting to confirm infection status in 18 equine hippocampi, researchers employed gas chromatography-mass spectrometry metabolomics to map biochemical changes in eight BDV-positive horses against ten uninfected controls. Infected hippocampi demonstrated substantial metabolic perturbation characterised by significantly reduced levels of glutamate, linoleic acid, heptadecanoic acid, phosphoethanolamine, and D-myo-inositol-1-phosphate, alongside elevated ammonia—alterations concentrated within glutamate neurotransmission and lipid metabolism pathways. These findings suggest that asymptomatic BDV infection induces measurable neurochemical dysfunction affecting both energy metabolism and excitatory neurotransmission, potentially explaining subclinical cognitive or neurological changes that may escape routine clinical observation. For equine practitioners, this research underscores the possibility that BDV-infected but behaviourally normal horses may nevertheless experience metabolic brain changes warranting consideration during lameness investigations, behavioural assessments, or cases of unexplained performance decline.
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Practical Takeaways
- •Horses can carry BDV infection with significant brain metabolic changes while appearing clinically normal, highlighting the importance of testing for neurotropic viruses in horses with subtle neurological signs
- •Understanding asymptomatic BDV infection may help explain subclinical behavioral or performance changes in some horses and supports targeted diagnostic screening in at-risk populations
- •The metabolic signature of asymptomatic BDV infection could potentially develop diagnostic markers for early detection before clinical disease progression
Key Findings
- •BDV-infected horse hippocampi showed significantly lower levels of glutamate, linoleic acid, heptadecanoic acid, phosphoethanolamine, and D-myo-inositol-1-phosphate compared to controls (n=8 infected vs n=10 control)
- •Ammonia levels were significantly elevated in BDV-infected hippocampi despite asymptomatic presentation
- •Metabolic perturbations were primarily in glutamate and lipid metabolism pathways
- •Asymptomatic BDV infection demonstrates detectable molecular changes in brain tissue metabolism without clinical behavioral signs