title: Kupffer cell-expressed membrane-bound TNF mediates melphalan hepatotoxicity via activation of both TNF receptors.
abstract: Isolated hepatic perfusion of nonresectable liver cancer using the combination of TNF and melphalan can be associated with a treatment-related hepatotoxicity. We investigated whether, apart from TNF, also melphalan is cytotoxic in primary murine liver cells in vitro and investigated mediators, mode of cell death, and cell types involved. Melphalan induced a caspase-dependent apoptosis in hepatocytes, which was not seen in liver cell preparations depleted of Kupffer cells. Neutralization of TNF prevented melphalan-induced apoptosis and liver cells derived from mice genetically deficient in either TNFR 1 or 2, but not from lpr mice lacking a functional CD95 receptor, were completely resistant. Cell-cell contact between hepatocytes and Kupffer cells was required for apoptosis to occur. Melphalan increased membrane-bound but not secreted TNF in Kupffer cells and inhibited recombinant TNF-alpha converting enzyme in vitro. Melphalan induced also severe hepatotoxicity in the isolated recirculating perfused mouse liver from wild-type mice but not from TNFR 1 or 2 knockout mice. In conclusion, this study shows that melphalan elicits membrane TNF on Kupffer cells due to inhibition of TNF processing and thereby initiates apoptosis of hepatocytes via obligatory activation of both TNFRs. The identification of this novel mechanism allows a causal understanding of melphalan-induced hepatotoxicity.
authors.affiliation: Biochemical Pharmacology, University of Konstanz, Konstanz, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kresse
authors.forename: Markus
authors.initials: M
authors.lastname: Latta
authors.forename: Gerald
authors.initials: G
authors.lastname: Künstle
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Riehle
authors.forename: Nico
authors.initials: N
authors.lastname: van Rooijen
authors.forename: Hannes
authors.initials: H
authors.lastname: Hentze
authors.forename: Gisa
authors.initials: G
authors.lastname: Tiegs
authors.forename: Markus
authors.initials: M
authors.lastname: Biburger
authors.forename: Rudolf
authors.initials: R
authors.lastname: Lucas
authors.forename: Albrecht
authors.initials: A
authors.lastname: Wendel
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors; D000072198:ADAM17 Protein; D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D002450:Cell Communication; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury; D022781:Hepatocytes / Q000473:pathology; D007728:Kupffer Cells / Q000378:metabolism*; D008107:Liver Diseases / Q000209:etiology; D008297:Male; D008558:Melphalan / Q000009:adverse effects*; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000378:metabolism*; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D014409:Tumor Necrosis Factor-alpha; D020169:Caspases; D051722:ADAM Proteins; D000072198:ADAM17 Protein; D008558:Melphalan