scholarly journals Effect of enforced expression of human bcl-2 on Japanese encephalitis virus-induced apoptosis in cultured cells.

1997 ◽  
Vol 71 (8) ◽  
pp. 5963-5971 ◽  
Author(s):  
C L Liao ◽  
Y L Lin ◽  
J J Wang ◽  
Y L Huang ◽  
C T Yeh ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Cultured Cells ◽  
Encephalitis Virus ◽  
Induced Apoptosis

scholarly journals Membrane Permeabilization by Small Hydrophobic Nonstructural Proteins of Japanese Encephalitis Virus

1999 ◽  
Vol 73 (8) ◽  
pp. 6257-6264 ◽  
Author(s):  
Yu-Shiu Chang ◽  
Ching-Len Liao ◽  
Chang-Huei Tsao ◽  
Mei-Chieh Chen ◽  
Chiu-I Liu ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Membrane Permeability ◽  
Japanese Encephalitis ◽  
Cultured Cells ◽  
Encephalitis Virus ◽  
Cell Membrane Permeability ◽  
Hygromycin B ◽  
Cytopathic Effects ◽  
Infected Cells ◽  
Small Hydrophobic

ABSTRACT Infection with Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, may cause acute encephalitis in humans and induce severe cytopathic effects in various types of cultured cells. We observed that JEV replication rendered infected baby hamster kidney (BHK-21) cells sensitive to the translational inhibitor hygromycin B or α-sarcine, to which mock-infected cells were insensitive. However, little is known about whether any JEV nonstructural (NS) proteins contribute to virus-induced changes in membrane permeability. Using an inducibleEscherichia coli system, we investigated which parts of JEV NS1 to NS4 are capable of modifying membrane penetrability. We found that overexpression of NS2B-NS3, the JEV protease, permeabilized bacterial cells to hygromycin B whereas NS1 expression failed to do so. When expressed separately, NS2B alone, but not NS3, was sufficient to alter bacterial membrane permeability. Similarly, expression of NS4A or NS4B also rendered bacteria susceptible to hygromycin B inhibition. Examination of the effect of NS1 to NS4 expression on bacterial growth rate showed that NS2B exhibited the greatest inhibitory capability, followed by a modest repression from NS2A and NS4A, whereas NS1, NS3, and NS4B had only trivial influence with respect to the vector control. Furthermore, when cotransfected with a reporter gene luciferase or β-galactosidase, transient expression of NS2A, NS2B, and NS4B markedly reduced the reporter activity in BHK-21 cells. Together, our results suggest that upon JEV infection, these four small hydrophobic NS proteins have various modification effects on host cell membrane permeability, thereby contributing in part to virus-induced cytopathic effects in infected cells.

scholarly journals Japanese Encephalitis Virus Induces Apoptosis and Encephalitis by Activating the PERK Pathway

2019 ◽  
Vol 93 (17) ◽  
Author(s):  
Qianruo Wang ◽  
Xiu Xin ◽  
Ting Wang ◽  
Jiawu Wan ◽  
Yangtao Ou ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Encephalitis Virus ◽  
Protein Kinase R ◽  
Apoptosis Pathway ◽  
Stress Sensor ◽  
Sensor Protein ◽  
Induced Apoptosis

ABSTRACTAccumulated evidence demonstrates that Japanese encephalitis virus (JEV) infection triggers endoplasmic reticulum (ER) stress and neuron apoptosis. ER stress sensor protein kinase R-like endoplasmic reticulum kinase (PERK) has been reported to induce apoptosis under acute or prolonged ER stress. However, the precise role of PERK in JEV-induced apoptosis and encephalitis remains unknown. Here, we report that JEV infection activates the PERK-ATF4-CHOP apoptosis pathway bothin vitroandin vivo. PERK activation also promotes the formation of stress granule, which in turn represses JEV-induced apoptosis. However, PERK inhibitor reduces apoptosis, indicating that JEV-activated PERK predominantly induces apoptosis via the PERK-ATF4-CHOP apoptosis pathway. Among JEV proteins that have been reported to induce ER stress, only JEV NS4B can induce PERK activation. PERK has been reported to form an active molecule by dimerization. The coimmunoprecipitation assay shows that NS4B interacts with PERK. Moreover, glycerol gradient centrifugation shows that NS4B induces PERK dimerization. Both the LIG-FHA and the LIG-WD40 domains within NS4B are required to induce PERK dimerization, suggesting that JEV NS4B pulls two PERK molecules together by simultaneously interacting with them via different motifs. PERK deactivation reduces brain cell damage and encephalitis during JEV infection. Furthermore, expression of JEV NS4B is sufficient to induce encephalitis via PERK in mice, indicating that JEV activates PERK primarily via its NS4B to cause encephalitis. Taken together, our findings provide a novel insight into JEV-caused encephalitis.IMPORTANCEJapanese encephalitis virus (JEV) infection triggers endoplasmic reticulum (ER) stress and neuron apoptosis. ER stress sensor protein kinase R-like endoplasmic reticulum kinase (PERK) has been reported to induce apoptosis under acute or prolonged ER stress. However, whether the PERK pathway of ER stress response plays important roles in JEV-induced apoptosis and encephalitis remains unknown. Here, we found that JEV infection activates ER stress sensor PERK in neuronal cells and mouse brains. PERK activation induces apoptosis via the PERK-ATF4-CHOP apoptosis pathway upon JEV infection. Among the JEV proteins prM, E, NS1, NS2A, NS2B, and NS4B, only NS4B activates PERK. Moreover, activated PERK participates in apoptosis and encephalitis induced by JEV and NS4B. These findings provide a novel therapeutic approach for JEV-caused encephalitis.

scholarly journals Nitazoxanide inhibits the replication of Japanese encephalitis virus in cultured cells and in a mouse model

2014 ◽  
Vol 11 (1) ◽  
pp. 10 ◽  
Author(s):  
Zixue Shi ◽  
Jianchao Wei ◽  
Xufang Deng ◽  
Shuqing Li ◽  
Yafeng Qiu ◽  
...  
Keyword(s):  
Mouse Model ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Cultured Cells ◽  
Encephalitis Virus

scholarly journals Japanese encephalitis virus infection activates caspase-8 and -9 in a FADD-independent and mitochondrion-dependent manner

2008 ◽  
Vol 89 (8) ◽  
pp. 1930-1941 ◽  
Author(s):  
Chang-Huei Tsao ◽  
Hong-Lin Su ◽  
Yi-Ling Lin ◽  
Han-Pang Yu ◽  
Shu-Ming Kuo ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Caspase 3 ◽  
Encephalitis Virus ◽  
Dominant Negative Mutant ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Effector Caspase ◽  
Induced Apoptosis

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, replicates primarily at the endoplasmic reticulum and thereby triggers apoptosis of infected cells. This study investigated the hierarchical activation of the caspase network induced by JEV infection. It was found that JEV activated the initiators caspase-8 and -9, as well as effector caspase-3, in infected baby hamster kidney and mouse neuroblastoma (N18) cells. In neuronal N18 cells, JEV infection triggered cytochrome c release from mitochondria, which in turn activated caspase-9 and -3. Treatment of JEV-infected N18 cells with cyclosporin A or ruthenium red, which attenuate mitochondrial injuries, blocked activation of caspase-9 or -3, typifying that, in neuronal cells, this apoptosis involves the mitochondrial pathway. Alternatively, in caspase-3-deficient MCF-7 cells, JEV persisted and readily triggered a typical apoptotic response, including cytochrome c release and full activation of caspase-9 and -8 along with caspase-6, indicating that JEV did not require caspase-3 to manifest caspase-8 activation and apoptosis. Interestingly, a Fas-associated death-domain-containing protein (FADD) dominant-negative mutant, which interfered with transmission of the extracellular death signals into cells through the Fas/tumour necrosis factor (TNF) receptor, failed to block JEV-induced apoptosis and caspase-8 activation, implying that receptor oligomerization of the Fas/TNF pathway might not participate in JEV-induced apoptosis. Taken together, these results illustrate that JEV infection triggers caspase cascades involving the initiators caspase-8 and -9, probably through FADD-independent but mitochondrion-dependent pathways.

scholarly journals La protein binds the predicted loop structures in the 3′ non-coding region of Japanese encephalitis virus genome: role in virus replication

2009 ◽  
Vol 90 (6) ◽  
pp. 1343-1352 ◽  
Author(s):  
Surender Vashist ◽  
Manu Anantpadma ◽  
Himani Sharma ◽  
Sudhanshu Vrati
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Protein Interaction ◽  
Cultured Cells ◽  
Virus Genome ◽  
Encephalitis Virus ◽  
Coding Region ◽  
Mobility Shift ◽  
Stem Loop ◽  
La Protein

Japanese encephalitis virus (JEV) genome is a single-stranded, positive-sense RNA with non-coding regions (NCRs) of 95 and 585 bases at its 5′ and 3′ ends, respectively. These may bind to viral or host proteins important for viral replication. It has been shown previously that three proteins of 32, 35 and 50 kDa bind the 3′ stem–loop (SL) structure of the JEV 3′ NCR, and one of these was identified as 36 kDa Mov34 protein. Using electrophoretic mobility-shift and UV cross-linking assays, as well as a yeast three-hybrid system, it was shown here that La protein binds to the 3′ SL of JEV. The binding was stable under high-salt conditions (300 mM KCl) and the affinity of the RNA–protein interaction was high; the dissociation constant (K d) for binding of La protein to the 3′ SL was 12 nM, indicating that this RNA–protein interaction is physiologically plausible. Only the N-terminal half of La protein containing RNA recognition motifs 1 and 2 interacted with JEV RNA. An RNA toe-printing assay followed by deletion mutagenesis showed that La protein bound to predicted loop structures in the 3′ SL RNA. Furthermore, it was shown that small interfering RNA-mediated downregulation of La protein resulted in repression of JEV replication in cultured cells.

Sign in / Sign up

Export Citation Format

Share Document