Hepatic Tissue Environment in NEMO-Deficient Mice Critically Regulates Positive Selection of Donor Cells after Hepatocyte Transplantation

Abstract

BackgroundHepatocyte transplantation (HT) is a promising alternative treatment strategy for end-stage liver diseases compared with orthotopic liver transplantation. A limitation for this approach is the low engraftment of donor cells. The deletion of the I-kappa B kinase-regulatory subunit IKKγ/NEMO in hepatocytes prevents nuclear factor (NF)-kB activation and triggers spontaneous liver apoptosis, chronic hepatitis and the development of liver fibrosis and hepatocellular carcinoma. We hypothesized that NEMOΔhepa mice may therefore serve as an experimental model to study HT.MethodsPre-conditioned NEMOΔhepa mice were transplanted with donor-hepatocytes from wildtype (WT) and mice deficient for the pro-apoptotic mediator Caspase-8 (Casp8Δhepa).ResultsTransplantation of isolated WT-hepatocytes into pre-conditioned NEMOΔhepa mice resulted in a 6-7 fold increase of donor cells 12 weeks after HT, while WT-recipients showed no liver repopulation. The use of apoptosis-resistant Casp8Δhepa-derived donor cells further enhanced the selection 3-fold after 12-weeks and up to 10-fold increase after 52 weeks compared with WT donors. While analysis of NEMOΔhepa mice revealed strong liver injury, HT-recipient NEMOΔhepa mice showed improved liver morphology and decrease in serum transaminases. Concomitant with these findings, the histological examination elicited an improved liver tissue architecture associated with significantly lower levels of apoptosis, decreased proliferation and a lesser amount of liver fibrogenesis. Altogether, our data clearly support the therapeutic benefit of the HT procedure into NEMOΔhepa mice.ConclusionThis study demonstrates the feasibility of the NEMOΔhepa mouse as an in vivo tool to study liver repopulation after HT. The improvement of the characteristic phenotype of chronic liver injury in NEMOΔhepa mice after HT suggests the therapeutic potential of HT in liver diseases with a chronic inflammatory phenotype and opens a new door for the applicability of this technique to combat liver disease in the human clinic.

MiR-200b attenuates IL-6 production through IKKβ and ZEB1 in human gingival fibroblasts

“…In the canonical pathway, IKKβ is necessary and sufficient for phosphorylation of IκBα, which leads to the activation of NF-κB and associated with prevention of apoptosis, cytokine production and inflammation. The deletion of the IKK-regulatory subunit IKKγ/NEMO in hepatocytes prevents NF-κB activation and triggers spontaneous liver apoptosis, chronic hepatitis and the development of liver fibrosis and hepatocellular carcinoma [ 43 ]. In addition, it has been shown that IKKβ activated NF-κB and induced IL-6 production [ 44 ].…”