摘要
AIM: To characterize the mitochondrial dysfunction in experimental cirrhosis and to study whether insulin-like growth factor-Ⅰ(IGF-Ⅰ) therapy (4 wk) is able to induce beneficial effects on damaged mitochondria leading to cellular protection. METHODS: Wistar rats were divided into three groups: Control group, untreated cirrhotic rats and cirrhotic rats treated with IGF-Ⅰtreatment (2 μg/100 g bw/d). Mitochondrial function was analyzed by flow cytometry in isolated hepatic mitochondria, caspase 3 activation was assessed by Western blot and apoptosis by TUNEL in the three experimental groups. RESULTS: Untreated cirrhotic rats showed a mitochon- drial dysfunction characterized by a significant reduction of mitochondrial membrane potential (in status 4 and 3); an increase of intramitochondrial reactive oxigen species (ROS) generation and a significant reduction of ATPase activity. IGF-Ⅰtherapy normalized mitochondrial func-tion by increasing the membrane potential and ATPase activity and reducing the intramitochondrial free radical production. Activity of the electron transport complexes Ⅰand Ⅲ was increased in both cirrhotic groups. In addition, untreated cirrhotic rats showed an increase of caspase 3 activation and apoptosis. IGF-Ⅰtherapy reduced the expression of the active peptide of caspase 3 and resulted in reduced apoptosis.
AIM: To characterize the mitochondrial dysfunction in experimental cirrhosis and to study whether insulin-like growth factor-Ⅰ (IGF-Ⅰ ) therapy (4 wk) is able to induce beneficial effects on damaged mitochondria leading to cellular protection.
METHODS: Wistar rats were divided into three groups: Control group, untreated cirrhotic rats and cirrhotic rats treated with IGF-Ⅰ treatment (2 μg/1O0 g bw/d). Mitochondrial function was analyzed by flow cytometry in isolated hepatic mitochondria, caspase 3 activation was assessed by Western blot and apoptosis by TUNEL in the three expedmental groups.
RESULTS: Untreated cirrhotic rats showed a mitochondrial dysfunction characterized by a significant reduction of mitochondrial membrane potential (in status 4 and 3); an increase of intramitochondrial reactive oxigen species (ROS) generation and a significant reduction of ATPase activity. IGF-Ⅰ therapy normalized mitochondrial function by increasing the membrane potential and ATPase activity and reducing the intramitochondrial free radical production. Activity of the electron transport complexes Ⅰ and Ⅲ was increased in both cirrhotic groups. In addition, untreated cirrhotic rats showed an increase of caspase 3 activation and apoptosis. IGF- Ⅰ therapy reduced the expression of the active peptide of caspase 3 and resulted in reduced apoptosis.
CONCLUSION: These results show that IGF- Ⅰ exerts a mitochondrial protection in experimental cirrhosis leading to reduced apoptosis and increased ATP production.
基金
Supported by The Spanish Program I + D, SAF 2005/08113
关键词
胰岛素增长因素
细胞凋亡
症状
实验研究
Insulin-like growth factor- Ⅰ
Cirrhosis
Mitochondrial protection
Caspases
Apoptosis
Oxidativedamage