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Constitutive release of powerful antioxidant‐scavenging activity by hepatic stellate cells: Protection of hepatocytes from ischemia/reperfusion injury
Author(s) -
Jameel Noor Mohamed,
Thirunavukkarasu Chinnasamy,
Murase Noriko,
Cascio Michael,
Prelich John,
Yang Shuting,
Harvey Stephen A. K,
Gandhi Chandrashekhar R
Publication year - 2010
Publication title -
liver transplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.814
H-Index - 150
eISSN - 1527-6473
pISSN - 1527-6465
DOI - 10.1002/lt.22172
Subject(s) - hepatic stellate cell , superoxide dismutase , superoxide , reactive oxygen species , antioxidant , biochemistry , population , hepatocyte , oxidative stress , reperfusion injury , medicine , microbiology and biotechnology , pharmacology , chemistry , in vitro , ischemia , biology , enzyme , environmental health
Abstract Within the liver, reactive oxygen species produced by infiltrating blood cells and Kupffer cells (resident macrophages) can injure hepatocytes. We hypothesized that hepatocyte survival is influenced by the relatively small juxtaposed population of hepatic stellate cells (HSCs). We used cultures of primary rat hepatocytes as targets for superoxide‐induced damage, which was determined by crystal violet assay and lactate dehydrogenase release. An HSC‐conditioned medium prevented the superoxide‐induced death of hepatocytes, and the protective factor released by HSCs was a protein or proteins (apparent molecular weight > 100 kDa) resistant to heat (70°C) and pH (4.5‐8.5). The protein or proteins were partially purified on DE52 cellulose, and the active fraction contained no detectable levels of superoxide dismutase: after separation by Sephadex G‐100 gel filtration, the antioxidant activity could be reconstituted by the combination of 2 protein peaks, and this reconstituted activity was protective both in vitro and against liver ischemia/reperfusion injury in intact rats. Mass spectrometry proteomic studies confirmed that this activity could not be attributed to any previously identified antioxidant protein. Thus, HSCs protect hepatocytes against oxidative damage through the production of a novel protein, the further purification of which may lead to the isolation of a powerful oxygen radical scavenger with clinical applications. Liver Transpl 16:1400–1409, 2010. © 2010 AASLD.