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Khera, S.

Publications and source records attributed to Khera, S..

2 recordsLinked to original sources

The mitochondrial transaminase GOT2 supports Japanese encephalitis virus replication in neuronal cells

Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in Asia, yet the host pathways that sustain its replication in the central nervous system remain poorly defined, and no antiviral therapies exist. Here we combine time-resolved transcriptomics and proteomics in mouse neuroblastoma (Neuro-2a) cells with time-resolved proteomics of infected mouse brain, integrated using directionality-penalized p-value merging. JEV infection was accompanied by progressive induction of interferon-stimulated proteins and by changes in the abundance of enzymes of central carbon and energy metabolism, spanning the tricarboxylic acid cycle, glycolysis, oxidative phosphorylation and glutaminolysis. Temporal clustering of the brain proteome linked oxidative phosphorylation remodelling to a dependence on glutamine metabolism. Glutamine antagonism with DON reduced viral RNA, whereas glycolytic inhibition and AKT modulation did not significantly alter it under the conditions tested. Silencing of the mitochondrial transaminase GOT2 reduced JEV RNA, viral protein, and infectious virus production in human SH-SY5Y cells. Our findings identify a glutamine-GOT2 axis as a metabolic dependency of JEV and a candidate host-directed antiviral target.

microbiology↗

Methotrimeprazine exerts antiviral and neuroprotective effects in Japanese encephalitis virus infection through activation of adaptive ER stress and autophagy

Japanese encephalitis virus (JEV) is the leading global cause of virus-induced encephalitis. Its pathogenesis is driven by a combination of neuronal cell death and neuroinflammation. We hypothesized that pharmacological upregulation of autophagy could exert a neuroprotective antiviral effect, and tested a panel of forty-two FDA-approved drugs that were shown to induce autophagy. Four drugs were tested in the JE mouse model based on in vitro protective effects on neuronal cell death, inhibition of viral replication, and anti-inflammatory effects in microglial cells. The antipsychotic phenothiazines Methotrimeprazine (MTP) and Trifluoperazine (TFP) showed a significant survival benefit with reduced virus titers in the brain, prevention of blood-brain barrier (BBB) breach, and inhibition of neuroinflammation. Both drugs were potent mTOR-independent autophagy flux inducers. Mechanistically MTP inhibited SERCA channel functioning, thereby resulting in rise in cytosolic calcium levels, and induction of a unique adaptive ER stress response. In virus infected drug treated cells, there was a strong transcriptional downregulation of type I interferon and interferon-stimulated genes and upregulation of cholesterol metabolic pathway genes. The drugs exerted an autophagy-dependent antiviral effect at the level of JEV protein translation/replication complex formation in diverse cell types. Inhibition of inflammatory cytokine/chemokine release from mouse microglial cells was partly autophagy-dependent. Our study suggests that MTP exerts a combined antiviral and anti-inflammatory effect in JEV infection, and has therapeutic potential to be repurposed for JE treatment.

microbiology↗