BACKGROUND/AIMS: Apoptosis is a key mechanism of reperfusion injury in the ischemic liver. The apoptotic pathway is highly regulated by anti-apoptotic factors, such as Bcl-2. We evaluated the effect of Bcl-2 overexpression on apoptosis and the activation of the apoptotic cascade after hepatic ischemia and reperfusion. METHODS: Ninety minutes of ischemia and reperfusion was performed in Bcl-2 transgenic and non-transgenic mice. Bcl-2 overexpression was determined by immunohistochemistry and Western blot. Liver injury was determined by aspartate aminotransferase (AST), Tunel test and the activation of the apoptotic cascade and animal survival. RESULTS: Bcl-2 overexpression was present in all hepatocytes and non-parenchymal liver cells in transgenic mice. Bcl-2 overexpression resulted in significant decreased AST levels after ischemic injury, and complete inhibition of apoptosis. After 90 min of total hepatic ischemia all control mice died, while four transgenic mice survived permanently. Bcl-2 overexpression was associated with inhibition of caspase 3 activation after reperfusion and increased baseline levels of cytoplasmic cytochrome c, caspase 3, and a reduction of Bcl-x(L) production. CONCLUSIONS: Bcl-2 overexpression protects against ischemic injury by inhibiting apoptosis. Extensive overproduction of Bcl-2 is associated with a compensatory increase of baseline levels of cytoplasmic cytochrome c and caspase 3, and a deletion of Bcl-x(L).
BACKGROUND/AIMS: Apoptosis is a key mechanism of reperfusion injury in the ischemic liver. The apoptotic pathway is highly regulated by anti-apoptotic factors, such as Bcl-2. We evaluated the effect of Bcl-2 overexpression on apoptosis and the activation of the apoptotic cascade after hepatic ischemia and reperfusion. METHODS: Ninety minutes of ischemia and reperfusion was performed in Bcl-2transgenic and non-transgenic mice. Bcl-2 overexpression was determined by immunohistochemistry and Western blot. Liver injury was determined by aspartate aminotransferase (AST), Tunel test and the activation of the apoptotic cascade and animal survival. RESULTS:Bcl-2 overexpression was present in all hepatocytes and non-parenchymal liver cells in transgenic mice. Bcl-2 overexpression resulted in significant decreased AST levels after ischemic injury, and complete inhibition of apoptosis. After 90 min of total hepatic ischemia all control mice died, while four transgenic mice survived permanently. Bcl-2 overexpression was associated with inhibition of caspase 3 activation after reperfusion and increased baseline levels of cytoplasmic cytochrome c, caspase 3, and a reduction of Bcl-x(L) production. CONCLUSIONS:Bcl-2 overexpression protects against ischemic injury by inhibiting apoptosis. Extensive overproduction of Bcl-2 is associated with a compensatory increase of baseline levels of cytoplasmic cytochrome c and caspase 3, and a deletion of Bcl-x(L).
Authors: Nozomu Sakai; Heather L Van Sweringen; Ritha M Belizaire; Ralph Cutler Quillin; Rebecca Schuster; John Blanchard; Justin M Burns; Amit D Tevar; Michael J Edwards; Alex B Lentsch Journal: J Gastroenterol Hepatol Date: 2012-10 Impact factor: 4.029
Authors: Nozomu Sakai; Heather L Van Sweringen; Rebecca Schuster; John Blanchard; Justin M Burns; Amit D Tevar; Michael J Edwards; Alex B Lentsch Journal: Hepatology Date: 2012-01-13 Impact factor: 17.425
Authors: Nozomu Sakai; Heather L Van Sweringen; R Cutler Quillin; Rebecca Schuster; John Blanchard; Justin M Burns; Amit D Tevar; Michael J Edwards; Alex B Lentsch Journal: Hepatology Date: 2012-10 Impact factor: 17.425
Authors: Akiko Iwata; Vicki Morgan-Stevenson; Barbara Schwartz; Li Liu; Joan Tupper; Xiaodong Zhu; John Harlan; Robert Winn Journal: PLoS One Date: 2010-02-08 Impact factor: 3.240