TY - JOUR
T1 - The mitochondrial permeability transition contributes to acute ethanol-induced apoptosis in rat hepatocytes
AU - Higuchi, Hajime
AU - Adachi, Masayuki
AU - Miura, Soichiro
AU - Gores, Gregory J.
AU - Ishii, Hiromasa
N1 - Funding Information:
Abbreviations: MPT, mitochondrial permeability transition; VDAC, voltage-dependent anion channel; ANT, adenine nucleotide transporter; DMEM, Dulbecco’s modified Eagle medium; GFP, green fluorescent protein; Cyt-c, cytochrome c; PMSF, phenylmethylsulfonyl fluoride; DMTU, N′N′-dimethylthiourea; NAC, N-acetyl-cysteine; Cys-A, cyclosporin A; TMRM, tetra methyl rhodamine methyl ester. From the 1Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan; 2Second Department of Internal Medicine, National Defense Medical College, Saitama, Japan; and 3Center for Basic Research in Digestive Diseases, Mayo Clinic, Rochester, MN. Received November 13, 2000; accepted May 21, 2001. Supported by a Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Science and Culture of Japan, and by a grant from Keio University, School of Medicine. Address reprint requests to: Hiromasa Ishii, M.D., Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. E-mail: hishii@sc.itc.keio.ac.jp; fax: (81) 3-3356-9654. Copyright © 2001 by the American Association for the Study of Liver Diseases. 0270-9139/01/3402-0015$35.00/0 doi:10.1053/jhep.2001.26380
PY - 2001
Y1 - 2001
N2 - Acute ethanol intoxication induces oxidative stress and apoptosis in primary cultured hepatocytes. Oxidative stress can trigger mitochondrial cytochrome c release initiating the mitochondrial pathway of apoptosis. Based on this information, we formulated the hypothesis that ethanol-induced oxidative stress causes mitochondrial dysfunction resulting in apoptosis. In the present study, we found that the mitochondrial membrane permeability transition (MPT) is essential for induction of mitochondrial cytochrome c release and caspase activation of ethanol. The short-term incubation with ethanol (50 mmol/L) induced the MPT, cytochrome c release, caspase activation, and apoptosis of cultured rat hepatocytes. Hepatocyte apoptosis was prevented by caspase inhibitors (i.e., Z-VAD-fmk, DEVD-cho, and DMQD-cho). An MPT inhibitor, cyclosporin A, also prevented ethanol-induced cytochrome c release, caspase activation, and apoptosis, suggesting that acute ethanol-induced apoptosis is MPT dependent. Ethanol-induced MPT was also attenuated by N′N′-dimethylthiourea (DMTU, a scavenger of hydrogen peroxide, 10 mmol/L) and N-acetyl-cysteine (NAC, an antioxidant, 5 mmol/L). Preventing hepatocyte MPT by DMTU or NAC attenuated cytochrome c release as well as caspase activation, suggesting that ethanol-induced oxidative stress mediates the MPT. Thus, acute ethanol induces MPT via oxidative stress, and the MPT mediates mitochondrial pathway of apoptosis in hepatocytes exposed to acute ethanol.
AB - Acute ethanol intoxication induces oxidative stress and apoptosis in primary cultured hepatocytes. Oxidative stress can trigger mitochondrial cytochrome c release initiating the mitochondrial pathway of apoptosis. Based on this information, we formulated the hypothesis that ethanol-induced oxidative stress causes mitochondrial dysfunction resulting in apoptosis. In the present study, we found that the mitochondrial membrane permeability transition (MPT) is essential for induction of mitochondrial cytochrome c release and caspase activation of ethanol. The short-term incubation with ethanol (50 mmol/L) induced the MPT, cytochrome c release, caspase activation, and apoptosis of cultured rat hepatocytes. Hepatocyte apoptosis was prevented by caspase inhibitors (i.e., Z-VAD-fmk, DEVD-cho, and DMQD-cho). An MPT inhibitor, cyclosporin A, also prevented ethanol-induced cytochrome c release, caspase activation, and apoptosis, suggesting that acute ethanol-induced apoptosis is MPT dependent. Ethanol-induced MPT was also attenuated by N′N′-dimethylthiourea (DMTU, a scavenger of hydrogen peroxide, 10 mmol/L) and N-acetyl-cysteine (NAC, an antioxidant, 5 mmol/L). Preventing hepatocyte MPT by DMTU or NAC attenuated cytochrome c release as well as caspase activation, suggesting that ethanol-induced oxidative stress mediates the MPT. Thus, acute ethanol induces MPT via oxidative stress, and the MPT mediates mitochondrial pathway of apoptosis in hepatocytes exposed to acute ethanol.
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U2 - 10.1053/jhep.2001.26380
DO - 10.1053/jhep.2001.26380
M3 - Article
C2 - 11481617
AN - SCOPUS:0034925049
SN - 0270-9139
VL - 34
SP - 320
EP - 328
JO - Hepatology
JF - Hepatology
IS - 2
ER -