Hepatitis B virus X protein activates human hepatic stellate cells through upregulating TGFβ1

Abstract

ABSTRACT. We investigated the effects of the hepatitis B virus X gene (HBV X) on the activation of human hepatic stellate cells (HSCs) and the possible mechanisms underlying the pathway. Recombinant plasmid pHBV-X-IRES2-EGFP was constructed and transfected into HL-7702 cells using a lipid-mediated method. Transfected cells were screened by G418, which detected stable expression of the X gene by reverse transcription (RT)-PCR and Western blot analysis, and named L02/x. Cells not subjected to G418-selection were analyzed to confirm the transient expression of the X gene and named L02/48x. Subsequently, L02/x and L02/48x, together with non-HBx-expressing cells, were cocultured with HSCs in a non-contact transwell system. After 36 h of co-culture, the proliferation and migration of HSCs was detected using different cell counting methods. Finally, the mRNA and protein levels of α-SMA, Col I, and TGFβ1 in HSCs were detected by real-time PCR and western blot analysis. RT-PCR and Western blot analysis showed that L02/x and L02/48x cells can express HBV X gene mRNA and protein. Additionally, HSCs co-cultured with L02/x or L02/48x cells showed significantly higher proliferation and migration levels than

The evaluation of fibrotic effects of the hepatitis B virus pre-core in hepatic stellate cells

“…The present study demonstrated that, similar to previous efforts, HBX upregulates α-SMA, COLIA1 and TIMP-1 expression to a level comparable with leptin, a fibrosis inducer (24)(25)(26). Those reports employed HBX protein from a transfected hepatocyte supernatant, however, the current study investigated the endogenous HBX expression effect on fibrosis genes following direct HSC transfection.…”

“…Some previous studies demonstrated the definitive fibrotic role of the HBX protein on HSCs in vitro (24)(25)(26). However, the fibrotic role of other HBV proteins is not understood and requires more investigation.…”

Protective Effects of Moringa oleifera on HBV Genotypes C and H Transiently Transfected Huh7 Cells

“…HBV infection causes a profibrogenic environment with increase of CTGF and TGF- β 1 protein expressions in human hepatic stellate cells (HSCs) cocultivated with HBx [ 24 ]. Pan et al reported an increase of TGF- β 1 protein expression in HepG2 cells expressing HBxAg [ 25 ].…”

Hepatitis B virus X protein in liver tumor microenvironment

“…In addition to participating in hepatic stellate cell activation, TGF-β can also associate with pathways related to stem cell phenotypes such as Wnt and Ras signaling to induce EMT or can switch the phenotypes of tumor-infiltrating immune cells to create an EMT-permissive microenvironment. Accordingly, tumor cells undergoing EMT acquire invasive, migratory, and stem cell properties, which allows them to disseminate to distant sites [22, 24]. …”

“…Upregulating TGF-β in a paracrine-dependent mannerIn vitro studies of transfected cell lines hepatocyte cell lines Chang liver and HepG2 cellsMartin et al [20]2. Participation in hepatic stellate cells activationIn vitro studies of transfected cell lines HL-7702 and L02 cells using a lipid-mediated methodChen et al [22]3. Transforming intrahepatic TGF-β signaling pathway from tumor-suppressive pSmad3C to tumor-supportive pSmad3LIn vivo studies of transgenic CD-1 mice and clinical specimensMurata et al [23]4.…”