TY - JOUR
T1 - Role of inducible nitric oxide synthase in mitochondrial depolarization and graft injury after transplantation of fatty livers
AU - Liu, Qinlong
AU - Rehman, Hasibur
AU - Krishnasamy, Yasodha
AU - Ramshesh, Venkat K.
AU - Theruvath, Tom P.
AU - Chavin, Kenneth D.
AU - Schnellmann, Rick G.
AU - Lemasters, John J.
AU - Zhong, Zhi
N1 - Funding Information:
This study was supported, in part, by Grants DK70844, DK70844S1, AA017756, DK84632, and DK37034 from the National Institutes of Health. We thank the Cell & Molecular Imaging Core of the Hollings Cancer Center at the Medical University of South Carolina supported by NIH Grant 1P30 CA138313 for providing instrumentation and assistance for confocal/multiphoton microscopy.
PY - 2012/7/15
Y1 - 2012/7/15
N2 - This study investigated the role of inducible nitric oxide synthase (iNOS) in failure of ethanol-induced fatty liver grafts. Rat livers were explanted 20 h after gavaging with ethanol (5 g/kg) and storing in UW solution for 24 h before implantation. Hepatic oil red O staining-positive areas increased from ∼2 to ∼33% after ethanol treatment, indicating steatosis. iNOS expression increased ∼8-fold after transplantation of lean grafts (LG) and 25-fold in fatty grafts (FG). Alanine aminotransferase release, total bilirubin, hepatic necrosis, TUNEL-positive cells, and cleaved caspase-3 were higher in FG than LG. A specific iNOS inhibitor 1400W (5 μM in the cold-storage solution) blunted these alterations by >42% and increased survival of fatty grafts from 25 to 88%. Serum nitrite/nitrate and hepatic nitrotyrosine adducts increased to a greater extent after transplantation of FG than LG, indicating reactive nitrogen species (RNS) overproduction. Phospho-c-Jun and phospho-c-Jun N-terminal kinase-1/2 (JNK1/2) were higher in FG than in LG, indicating more JNK activation in fatty grafts. RNS formation and JNK activation were blunted by 1400W. Mitochondrial polarization and cell death were visualized by intravital multiphoton microscopy of rhodamine 123 and propidium iodide, respectively. After implantation, viable cells with depolarized mitochondria were 3-fold higher in FG than in LG and 1400W decreased mitochondrial depolarization in FG to the levels of LG. Taken together, iNOS is upregulated after transplantation of FG, leading to excessive RNS formation, JNK activation, mitochondrial dysfunction, and severe graft injury. The iNOS inhibitor 1400W could be an effective therapy for primary nonfunction of fatty liver grafts.
AB - This study investigated the role of inducible nitric oxide synthase (iNOS) in failure of ethanol-induced fatty liver grafts. Rat livers were explanted 20 h after gavaging with ethanol (5 g/kg) and storing in UW solution for 24 h before implantation. Hepatic oil red O staining-positive areas increased from ∼2 to ∼33% after ethanol treatment, indicating steatosis. iNOS expression increased ∼8-fold after transplantation of lean grafts (LG) and 25-fold in fatty grafts (FG). Alanine aminotransferase release, total bilirubin, hepatic necrosis, TUNEL-positive cells, and cleaved caspase-3 were higher in FG than LG. A specific iNOS inhibitor 1400W (5 μM in the cold-storage solution) blunted these alterations by >42% and increased survival of fatty grafts from 25 to 88%. Serum nitrite/nitrate and hepatic nitrotyrosine adducts increased to a greater extent after transplantation of FG than LG, indicating reactive nitrogen species (RNS) overproduction. Phospho-c-Jun and phospho-c-Jun N-terminal kinase-1/2 (JNK1/2) were higher in FG than in LG, indicating more JNK activation in fatty grafts. RNS formation and JNK activation were blunted by 1400W. Mitochondrial polarization and cell death were visualized by intravital multiphoton microscopy of rhodamine 123 and propidium iodide, respectively. After implantation, viable cells with depolarized mitochondria were 3-fold higher in FG than in LG and 1400W decreased mitochondrial depolarization in FG to the levels of LG. Taken together, iNOS is upregulated after transplantation of FG, leading to excessive RNS formation, JNK activation, mitochondrial dysfunction, and severe graft injury. The iNOS inhibitor 1400W could be an effective therapy for primary nonfunction of fatty liver grafts.
KW - ALCOHOL
KW - Depolarization
KW - Inos
KW - Liver
KW - Mitochondrial
KW - Steatosis
KW - Transplantation
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UR - http://www.scopus.com/inward/citedby.url?scp=84862175335&partnerID=8YFLogxK
U2 - 10.1016/j.freeradbiomed.2012.05.012
DO - 10.1016/j.freeradbiomed.2012.05.012
M3 - Article
C2 - 22609250
AN - SCOPUS:84862175335
SN - 0891-5849
VL - 53
SP - 250
EP - 259
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 2
ER -