Prusty BK, Hedau S, Singh A, Kar P, Das BC.. Selective suppression of NF-kBp65 in hepatitis virus-infected pregnant women manifesting severe liver damage and high mortality. Mol Med 13: 518-526

Division of Molecular Oncology, Institute of Cytology and Preventive Oncology, Noida, India.
Molecular Medicine (Impact Factor: 4.51). 09/2007; 13(9-10):518-26. DOI: 10.2119/2007-00055.Prusty
Source: PubMed


Fulminant hepatitis in Asian pregnant women is generally caused by hepatitis E virus infection, and extremely high mortality is most common in them. Decreased cell-mediated immunity is considered a major cause of death in these cases, but what exactly influences decreased immunity and high mortality specifically during pregnancy is not known. We used electrophoretic mobility shift assays, immunoblotting, and immunohistochemical analysis to study the expression and DNA binding activity of NF-kB p50 and NF-kB p65 in pregnant fulminant hepatic failure (FHF) patients and compared them with their nonpregnant counterparts. In both PBMC and postmortem liver biopsy specimens the DNA-binding activity of NF-kB was very high in samples from pregnant FHF patients compared with those from nonpregnant women as well as pregnant women with acute viral hepatitis (AVH) without FHF. Further dissection of the NF-kB complex in supershift assays demonstrated complete absence of p65 in the NF-kB complex, which is formed by homodimerization of the p50 component in pregnant FHF patients. Western blotting and immunohistochemical analysis of the expression of p50 and p65 proteins both showed higher levels of p50 expression and a complete absence or a minimal expression of p65, indicating its nonparticipation in NF-kB-dependent transactivation in pregnant FHF patients. We suggest that the exclusion of p65 from the NF-kB transactivation complex seems to be a crucial step that may cause deregulated immunity and severe liver damage, leading to the death of the patient. Our findings provide a molecular basis, for developing novel therapeutic approaches.

Download full-text


Available from: Bhupesh Prusty, Oct 05, 2015
23 Reads
  • Source
    • "Hence it is important to understand the molecular mechanism by which HEV completes its life cycle inside the host. A recent study done by Prusty and coworkers revealed that NF-κB activity is inhibited in the PBMC and liver of fulminant hepatic failure patients [9]. Our findings that the ORF2 protein has the ability to inhibit NF-κB activity in human hepatoma cells provide a possible molecular explanation to their observation. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Nuclear factor kappa B (NF-κB) is a key transcription factor that plays a crucial role in host survival during infection by pathogens. Therefore, it has been a priority of many pathogens to manipulate the cellular NF-κB activity in order to create a favorable environment for their survival inside the host. We observed that heterologous expression of the open reading frame 2 (ORF2) protein in human hepatoma cells led to stabilization of the cellular I kappa B alpha (IκBα) pool, with a concomitant reduction in the nuclear localization of the p65 subunit of NF-κB and inhibition of NF-κB activity. Although basal or TPA induced phosphorylation of IκBα was not altered, its ubiquitination was markedly reduced in ORF2 expressing cells. Further analysis revealed that ORF2 protein could directly associate with the F-box protein, beta transducin repeat containing protein (βTRCP) and ORF2 over expression resulted in reduced association of IκBα with the SKP1 and CUL1 components of the SCFβTRCP complex. Chromatin immunoprecipitation (ChIP) assay of the proximal promoter regions of MHC-I heavy chain and IL-8 genes using p65 antibody and LPS stimulated ORF2 expressing cell extract revealed decreased association of p65 with the above regions, indicating that ORF2 inhibited p65 binding at endogenous promoters. In this report we suggest a mechanism by which ORF2 protein of HEV may inhibit host cell NF-κB activity during the course of a viral infection.
    BMC Biochemistry 05/2012; 13(1):7. DOI:10.1186/1471-2091-13-7 · 1.44 Impact Factor
  • Source
    • "This alteration in hormones may enhance viral replication, leading to severe liver disease during pregnancy [16]. Severe liver damage following HEV infection has also been correlated to the absence of NF-κB p65 subunit [17]. These observations suggest that the severity of HEV infection is influenced by the host response; identifying disease related host signatures would thus be important to understand disease pathogenesis and improving prognosis. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases and large waterborne outbreaks. The disease severity ranges from acute self-limited hepatitis with low mortality to fulminant hepatic failure with high mortality. It is believed that the host response plays an important role in determining the progression and outcome of this disease. We profiled the plasma peptidome from hepatitis E patients to discover suitable biomarkers and understand disease pathogenesis. The peptidome (< 10 kDa) fraction of plasma was enriched and analyzed by mass spectrometry. A comparative analysis of the peptide pattern of hepatitis E patients versus healthy controls was performed using ClinPro Tools. We generated a peptide profile that could be used for selective identification of hepatitis E cases. We have identified five potential biomarker peaks with m/z values of 9288.6, 7763.6, 4961.5, 1060.572 and 2365.139 that can be used to reliably differentiate between hepatitis E patients and controls with areas under the receiver operating characteristic curve (AUROC) values of 1.00, 0.954, 0.989, 0.960 and 0.829 respectively. A number of proteins involved in innate immunity were identified to be differentially present in the plasma of patients compared to healthy controls. Besides the utility of this approach for biomarker discovery, identification of changes in endogenous peptides in hepatitis E patient plasma has increased our understanding of disease pathogenesis. We have identified peptides in plasma that can reliably distinguish hepatitis E patients from healthy controls. Results from this and an earlier proteomics study are discussed.
    Proteome Science 02/2011; 9:5. DOI:10.1186/1477-5956-9-5 · 1.73 Impact Factor
  • Source
    • "NFκB is activated in the livers of subjects with chronic hepatitis C, and expression of RelA in these livers is associated with lower degree of apoptosis, and slower progression to fibrosisassociated chirrosis (Boya et al., 2001). Likewise, RelA expression is suppressed in pregnant women with chronic hepatitis E (HEV) infection and correlates with the severe liver damage and high mortality seen in these patients (Prusty et al., 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The liver plays a central role in the transformation and degradation of endogenous and exogenous chemicals, and in the removal of unwanted cells such as damaged, genetically mutated and virus-infected cells. Because of this function, the liver is susceptible to toxicity caused by the products generated during these natural occurrences. Hepatocyte death is the major feature of liver injury. In response to liver injury, specific intracellular processes are initiated to maintain liver integrity. Inflammatory cytokines including tumor necrosis factor (TNF)alpha and interleukin-6 (IL-6) are key mediators of these processes and activate different cellular response such as proliferation, survival and death. TNFalpha induces specific signaling pathways in hepatocytes that lead to activation of either pro-survival mediators or effectors of cell death. Whereas activation of transcription factor NF-kappaB promotes survival, c-Jun N-terminal kinases (JNKs) and caspases are strategic effectors of cell death in the TNFalpha-mediated signaling pathway. This review summarizes recent advances in the mechanisms of TNFalpha-induced hepatotoxicity and suggests that NF-kappaB plays a protective role against JNK-induced hepatocyte death. Identification of the mechanisms regulating interplay between the NF-kappaB and JNK pathways is required in the search for novel targets for the treatment of liver disease, including hepatitis and hepatocellular carcinoma.
    Biological Chemistry 08/2009; 390(10):965-76. DOI:10.1515/BC.2009.111 · 3.27 Impact Factor
Show more