Dataset Information

Ceramide Promotes Lytic Reactivation of Epstein-Barr Virus in Gastric Carcinoma

ABSTRACT: Epstein-Barr virus (EBV) has a lifelong latency period after initial infection. Rarely, however, when the EBV immediate early gene BZLF1 is expressed by a specific stimulus, the virus switches to the lytic cycle to produce progeny viruses. We found that EBV infection reduced levels of various ceramide species in gastric cancer cells. As ceramide is a bioactive lipid implicated in the infection of various viruses, we assessed the effect of ceramide on the EBV lytic cycle. Treatment with C6-ceramide (C6-Cer) induced an increase in the endogenous ceramide pool and increased production of the viral product as well as BZLF1 expression. Treatment with the ceramidase inhibitor ceranib-2 induced EBV lytic replication with an increase in the endogenous ceramide pool. The glucosylceramide synthase inhibitor Genz-123346 inhibited C6-Cer-induced lytic replication. C6-Cer induced ERK1/2 and CREB phosphorylation, c-JUN expression, and accumulation of the autophagosome marker LC3B. Treatment with MEK1/2 inhibitor U0126 or autophagy initiation inhibitor 3-MA suppressed C6-Cer-induced EBV lytic replication. In contrast, the autophagosome-lysosome fusion inhibitor chloroquine induced BZLF1 expression. Transfection with siCREB reduced ERK1/2 phosphorylation and C6-Cer-induced BZLF1 expression. On the other hand, siJUN transfection did not affect BZLF1 expression. Our results show that increased endogenous ceramide and glycosyl ceramide (GlyCer) following C6-Cer treatment induce EBV lytic replication in gastric cancer cells via ERK1/2 and CREB phosphorylation and autophagosome accumulation.

INSTRUMENT(S): Liquid Chromatography MS - positive - reverse phase

SUBMITTER: Youngjin Min

PROVIDER: MTBLS7649 | MetaboLights | 2023-12-20

REPOSITORIES: MetaboLights

ACCESS DATA

Similar Datasets

Project description:Background & Aims: Other than hepatitis B or C virus infection, Hepatitis E virus (HEV) infection is generally asymptomatic or leads to acute and self-limiting hepatitis. However, the mechanism of host cell defense against HEV is unclear. Viruses are known to perturb host cellular metabolism to enable their replication and spread. AMP-activated protein kinase (AMPK) activation is crucial for the regulation of cell homeostasis. We thus investigated the role of AMPK in HEV infection. Methods: Huh7, THP1 and HepG2 cells inoculated with infectious HEV viral particle or Huh7 and organoids transfected with in vitro generated subgenomic or full-length GT3 (Kernow-C1 p6 strain) HEV RNA, namely, p6Luc or p6 were used to model HEV infection. Viral replication and genes expression were quantified. Activation of AMPK, innate immune response and autophagy process were assessed. Results: We found HEV infection can trigger AMPK activation by phosphorylation of AMPK at threonine 172 by transfecting HEV viral RNA into host cells or inoculating host cells with infectious HEV viral particle. The activation of AMPK is associated with HEV induced mitochondrial damage and ATP deficiency. Pharmacological activation of AMPK using 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) attenuated HEV replication, which was reversed by an AMPK inhibitor (compound C). Lentivirus-mediated knockdown of AMPK provided further evidence that AMPK has an antiviral effect on HEV replication. These results suggested that AMPK activation is a potent strategy of host cells for HEV clearance. Consistent with its antiviral effect, AMPK activation potentiated the expression of genes with antiviral properties (e.g., IFNs, ISG15, and IRF9) and inhibited inflammatory response (e.g., NF-KB NLRP3 and IL-1β). Meanwhile, HEV and activated AMPK also decreased autophagosome accumulation by decreasing induction of autophagy and autophagic degradation. Consistently, we found inhibition of AMPK efficiently augmented HEV induced autophagosome accumulation, evidenced by a marked increase in LC3II. Our previous study showed that rapamycin, an activator of autophagic induction by inhibiting mTOR, and Bafilomycin A1, an inhibitor of autophagic degradation, has a potent pro-HEV effect under AICAR treatment. Moreover, Wortmannin inhibiting autophagic induction recover AMPK inhibitor induced HEV replication. Together, these results suggested that HEV induced AMPK activation can serve to protect HEV infected cells from HEV infection by attenuating autophagosome and promoting innate immunity. Conclusions: Here we show that HEV infection can activate AMPK phosphorylation, which attenuates autophagosome accumulation and increases innate immune signaling. Thus, the AMPK activation in response to HEV infection is critical in host cells for rapid viral clearance by coordinating autophagic process and establishing persistent antiviral immunity.

Dataset Information

Ceramide Promotes Lytic Reactivation of Epstein-Barr Virus in Gastric Carcinoma

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure