scholarly journals RNA-dependent RNA Polymerase Assay for Hepatitis E Virus

BIO-PROTOCOL ◽  
2017 ◽  
Vol 7 (7) ◽  
Author(s):  
Vidya Nair ◽  
Saumya Anang ◽  
Akriti Srivastava ◽  
Milan Surjit
Hepatology ◽  
2021 ◽  
Author(s):  
Noémie Oechslin ◽  
Nathalie Da Silva ◽  
Dagmara Szkolnicka ◽  
François‐Xavier Cantrelle ◽  
Xavier Hanoulle ◽  
...  

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Nidhi Kaushik ◽  
Chandru Subramani ◽  
Saumya Anang ◽  
Rajagopalan Muthumohan ◽  
Shalimar ◽  
...  

ABSTRACT Hepatitis E virus (HEV) causes an acute, self-limiting hepatitis in healthy individuals and leads to chronic disease in immunocompromised individuals. HEV infection in pregnant women results in a more severe outcome, with the mortality rate going up to 30%. Though the virus usually causes sporadic infection, epidemics have been reported in developing and resource-starved countries. No specific antiviral exists against HEV. A combination of interferon and ribavirin therapy has been used to control the disease with some success. Zinc is an essential micronutrient that plays crucial roles in multiple cellular processes. Zinc salts are known to be effective in reducing infections caused by few viruses. Here, we investigated the effect of zinc salts on HEV replication. In a human hepatoma cell (Huh7) culture model, zinc salts inhibited the replication of genotype 1 (g-1) and g-3 HEV replicons and g-1 HEV infectious genomic RNA in a dose-dependent manner. Analysis of a replication-defective mutant of g-1 HEV genomic RNA under similar conditions ruled out the possibility of zinc salts acting on replication-independent processes. An ORF4-Huh7 cell line-based infection model of g-1 HEV further confirmed the above observations. Zinc salts did not show any effect on the entry of g-1 HEV into the host cell. Furthermore, our data reveal that zinc salts directly inhibit the activity of viral RNA-dependent RNA polymerase (RdRp), leading to inhibition of viral replication. Taken together, these studies unravel the ability of zinc salts in inhibiting HEV replication, suggesting their possible therapeutic value in controlling HEV infection. IMPORTANCE Hepatitis E virus (HEV) is a public health concern in resource-starved countries due to frequent outbreaks. It is also emerging as a health concern in developed countries owing to its ability to cause acute and chronic infection in organ transplant and immunocompromised individuals. Although antivirals such as ribavirin have been used to treat HEV cases, there are known side effects and limitations of such therapy. Our discovery of the ability of zinc salts to block HEV replication by virtue of their ability to inhibit the activity of viral RdRp is important because these findings pave the way to test the efficacy of zinc supplementation therapy in HEV-infected patients. Since zinc supplementation therapy is known to be safe in healthy individuals and since high-dose zinc is used in the treatment of Wilson's disease, it may be possible to control HEV-associated health problems following a similar treatment regimen.


1992 ◽  
Vol 89 (9) ◽  
pp. 3855-3858 ◽  
Author(s):  
M. Kaur ◽  
K. C. Hyams ◽  
M. A. Purdy ◽  
K. Krawczynski ◽  
W. M. Ching ◽  
...  

2016 ◽  
Vol 97 (9) ◽  
pp. 2231-2242 ◽  
Author(s):  
Shakuntala Mahilkar ◽  
Mandar S. Paingankar ◽  
Kavita S. Lole

2020 ◽  
Vol 8 (9) ◽  
pp. 1417
Author(s):  
Milagros Muñoz-Chimeno ◽  
Alejandro Cenalmor ◽  
Maira Alejandra Garcia-Lugo ◽  
Marta Hernandez ◽  
David Rodriguez-Lazaro ◽  
...  

The hepatitis E virus (HEV) hypervariable region (HVR) presents the highest divergence of the entire HEV genome. It is characteristically rich in proline, and so is also known as the “polyproline region” (PPR). HEV genotype 3 (HEV-3) exhibits different PPR lengths due to insertions, PPR and/or RNA-dependent RNA polymerase (RdRp) duplications and deletions. A total of 723 PPR-HEV sequences were analyzed, of which 137 HEV-3 sequences were obtained from clinical specimens (from acute and chronic infection) by Sanger sequencing. Eight swine stool/liver samples were also analyzed. N- and C-terminal fragments were confirmed as being conserved, but they harbored differences between genotypes and were not proline-plentiful regions. The genuine PPR is the intermediate region between them. HEV-3 PPR contains a higher percentage (30.4%) of prolines than other genotypes. We describe for the first time: (1) the specific placement of HEV-3 PPR rearrangements in sites 1 to 14 of the PPR, noting that duplications are more frequently attached to sites 11 and 12 (AAs 74–79 and 113–118, respectively); (2) the cadence of repetitions follows a circular-like pattern of blocks A to J, with F, G, H, and I being the most frequent; (3) a previously unreported insertion homologous to apolipoprotein C1; and (4) the increase in frequency of potential N-glycosylation sites and differences in AAs composition related to duplications.


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