Reduced SHARPIN and LUBAC Formation May Contribute to CCl₄- or Acetaminophen-Induced Liver Cirrhosis in Mice.
Linear ubiquitin chain assembly complex (LUBAC), composed of SHARPIN (SHANK-associated RH domain-interacting protein), HOIL-1L (longer isoform of heme-oxidized iron-regulatory protein 2 ubiquitin ligase-1), and HOIP (HOIL-1L interacting protein), forms linear ubiquitin on nuclear factor-κB (NF-κB) essential modulator (NEMO) and induces NF-κB pathway activation. SHARPIN expression and LUBAC formation were significantly reduced in the livers of mice 24 h after the injection of either carbon tetrachloride (CCl₄) or acetaminophen (APAP), both of which produced the fulminant hepatitis phenotype. To elucidate its pathological significance, hepatic SHARPIN expression was suppressed in mice by injecting shRNA adenovirus via the tail vein. Seven days after this transduction, without additional inflammatory stimuli, substantial inflammation and fibrosis with enhanced hepatocyte apoptosis occurred in the livers. A similar but more severe phenotype was observed with suppression of HOIP, which is responsible for the E3 ligase activity of LUBAC. Furthermore, in good agreement with these in vivo results, transduction of Hepa1-6 hepatoma cells with SHARPIN, HOIL-1L, or HOIP shRNA adenovirus induced apoptosis of these cells in response to tumor necrosis factor-α (TNFα) stimulation. Thus, LUBAC is essential for the survival of hepatocytes, and it is likely that reduction of LUBAC is a factor promoting hepatocyte death in addition to the direct effect of drug toxicity.
Department of Medical Science, Graduate School of Medicine, University of Hiroshima, 1-2-3 Kasumi, Minami-ku, Hiroshima City, Hiroshima 734-8551, Japan. ymmty@hiroshima-u.ac.jp.
Takeshi
T
Yamamotoya
Department of Medical Science, Graduate School of Medicine, University of Hiroshima, 1-2-3 Kasumi, Minami-ku, Hiroshima City, Hiroshima 734-8551, Japan. nakatsu@hiroshima-u.ac.jp.
Yusuke
Y
Nakatsu
Department of Medical Science, Graduate School of Medicine, University of Hiroshima, 1-2-3 Kasumi, Minami-ku, Hiroshima City, Hiroshima 734-8551, Japan. ymatsunaga@hiroshima-u.ac.jp.
Yasuka
Y
Matsunaga
CellBiology Unit, Institute of Innovative Research, Tokyo Institute of Technology, 4259-B16 Nagatsuta, Midori, Yokohama 226-8501, Japan. tofu@bio.titech.ac.jp.
Toshiaki
T
Fukushima
Division of Diabetes and Metabolism, The Institute for Adult Diseases, Asahi Life Foundation, Chuo-ku, Tokyo 103-0002, Japan. hiyamazaki-tky@umin.ac.jp.
Hiroki
H
Yamazaki
Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. kanekos-tky@umin.ac.jp.
Sunao
S
Kaneko
Division of Diabetes and Metabolic Diseases, Nihon University School of Medicine, Itabashi, Tokyo 173-8610, Japan. midori-tky@umin.ac.jp.
Midori
M
Fujishiro
Division of Diabetes and Metabolism, The Institute for Adult Diseases, Asahi Life Foundation, Chuo-ku, Tokyo 103-0002, Japan. kikuchi-tk@umin.ac.jp.
Takako
T
Kikuchi
Division of Diabetes and Metabolism, The Institute for Adult Diseases, Asahi Life Foundation, Chuo-ku, Tokyo 103-0002, Japan. kusiyaa-tky@umin.ac.jp.
Akifumi
A
Kushiyama
Laboratory of Pathobiochemistry, Graduate School of Medicine, Osaka City University, 1-4-3 Asahi-machi, Abeno-ku, Osaka City, Osaka 545-8585, Japan. ftokunaga@med.osaka-cu.ac.jp.
Fuminori
F
Tokunaga
Department of Medical Science, Graduate School of Medicine, University of Hiroshima, 1-2-3 Kasumi, Minami-ku, Hiroshima City, Hiroshima 734-8551, Japan. tasano@hiroshima-u.ac.jp.
Tomoichiro
T
Asano
Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan. hideyuki_sakoda@med.miyazaki-u.ac.jp.
Hideyuki
H
Sakoda
D000082:Acetaminophen / Q000009:adverse effects; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002251:Carbon Tetrachloride / Q000009:adverse effects; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D005355:Fibrosis; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D022781:Hepatocytes / Q000378:metabolism; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D047908:Intracellular Signaling Peptides and Proteins; D008103:Liver Cirrhosis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D046912:Multiprotein Complexes / Q000378:metabolism*; D011485:Protein Binding; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D046912:Multiprotein Complexes; C554944:Sipl1 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000082:Acetaminophen; D002251:Carbon Tetrachloride; C492590:Rnf31 protein, mouse; D044767:Ubiquitin-Protein Ligases
CCl4 and APAP-induced hepatitis; LUBAC; fibrosis; hepatocyte apoptosis; inflammation