Inhibition of GSK-3beta ameliorates hepatic ischemia-reperfusion injury through GSK-3beta/beta-catenin signaling pathway in mice.
BACKGROUND
Glycogen synthase kinase (GSK)-3beta/beta-catenin signaling regulates ischemia-reperfusion (I/R)-induced apoptosis and proliferation, and inhibition of GSK-3beta has beneficial effects on I/R injury in the heart and the central nervous system. However, the role of this signaling in hepatic I/R injury remains unclear. The present study aimed to investigate the effects and mechanism of GSK-3beta/beta-catenin signaling in hepatic I/R injury.


METHODS
Male C57BL/6 mice (weighing 22-25 g) were pretreated with either SB216763, an inhibitor of GSK-3beta, or vehicle. These mice were subjected to partial hepatic I/R. Blood was collected for test of alanine aminotransferase (ALT), and liver specimen for assays of phosphorylation at the Ser9 residue of GSK-3beta, GSK-3beta activity, axin 2 and the anti-apoptotic factors Bcl-2 and survivin, as well as the proliferative factors cyclin D1 and proliferating cell nuclear antigen, and apoptotic index (TUNEL). Real-time PCR, Western blotting and immunohistochemical staining were used.


RESULTS
SB216763 increased phospho-GSK-3beta levels and suppressed GSK-3beta activity (1880+/-229 vs 3280+/-272 cpm, P<0.01). ALT peaked at 6 hours after reperfusion. Compared with control, SB216763 decreased ALT after 6 hours of reperfusion (4451+/-424 vs 7868+/-845 IU/L, P<0.01), and alleviated hepatocyte necrosis and vacuolization. GSK-3beta inhibition led to the accumulation of beta-catenin in the cytosol (0.40+/-0.05 vs 1.31+/-0.11, P<0.05) and nucleus (0.62+/-0.14 vs 1.73+/-0.12, P<0.05), beta-catenin further upregulated the expression of axin 2. Upregulation of GSK-3beta/beta-catenin signaling increased Bcl-2, survivin and cyclin D1. Serological and histological analyses showed that SB216763 alleviated hepatic I/R-induced injury by reducing apoptosis (1.4+/-0.2% vs 3.6+/-0.4%, P<0.05) and enhanced liver proliferation (56+/-8% vs 19+/-4%, P<0.05).


CONCLUSIONS
Inhibition of GSK-3beta ameliorates hepatic I/R injury through the GSK-3beta/beta-catenin signaling pathway.
Liver Transplantation Center, Nanjing Medical University, Nanjing, China.
Yong-Xiang
YX
Xia
Ling
L
Lu
Zheng-Shan
ZS
Wu
Li-Yong
LY
Pu
Bei-Cheng
BC
Sun
Xue-Hao
XH
Wang
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D060466:Axin Protein / Q000378:metabolism; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D019938:Cyclin D1 / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D007150:Immunohistochemistry; D007211:Indoles / Q000494:pharmacology*; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D008099:Liver / Q000098:blood supply / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008115:Liver Regeneration / Q000187:drug effects; D008297:Male; D008301:Maleimides / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D060888:Real-Time Polymerase Chain Reaction; D015427:Reperfusion Injury / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D012097:Repressor Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D000077022:Survivin; D013997:Time Factors; D051176:beta Catenin / Q000378:metabolism*
D060466:Axin Protein; C111729:Axin2 protein, mouse; C117749:Birc5 protein, mouse; C495267:CTNNB1 protein, mouse; C530105:Ccnd1 protein, mouse; D007211:Indoles; D051034:Inhibitor of Apoptosis Proteins; D008301:Maleimides; D047428:Protein Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012097:Repressor Proteins; C417521:SB 216763; D000077022:Survivin; D051176:beta Catenin; C052617:Bcl2 protein, mouse; D019938:Cyclin D1; D000410:Alanine Transaminase; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3