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Caspase 8 small interfering RNA prevents acute liver failure in mice
Lars Zender1, Sebastian Hutker, Christian Liedtke
1Department of Gastroenterology, Medical School Hannover, 30625 Hannover, Germany.
Abstract:
A major concern in therapy of acute liver failure is protection of hepatocytes to prevent apoptosis and maintain liver function. Small interfering RNA (siRNA) is a powerful tool to silence gene expression in mammalian cells. To evaluate the therapeutic efficacy of siRNA in vivo we used different mouse models of acute liver failure. We directed 21-nt siRNAs against caspase 8, which is a key enzyme in death receptor-mediated apoptosis. Systemic application of caspase 8 siRNA results in inhibition of caspase 8 gene expression in the liver, thereby preventing Fas (CD95)-mediated apoptosis. Protection of hepatocytes by caspase 8 siRNA significantly attenuated acute liver damage induced by agonistic Fas (CD95) antibody (Jo2) or by adenovirus expressing Fas ligand (AdFasL). However, in a clinical situation the siRNAs most likely would be applied after the onset of acute liver failure. Therefore we injected caspase 8 siRNA at a time point during AdFasL- and adenovirus wild type (Adwt)-mediated liver failure with already elevated liver transaminases. Improvement of survival due to RNA interference was significant even when caspase 8 siRNA was applied during ongoing acute liver failure. In addition, it is of particular interest that caspase 8 siRNA treatment was successful not only in acute liver failure mediated by specific Fas agonistic agents (Jo2 and AdFasL) but also in acute liver failure mediated by Adwt, which is an animal model reflecting multiple molecular mechanisms involved in human acute viral hepatitis. Consequently, our data raise hope for future successful application of siRNA in patients with acute liver failure.
Insights
Small interfering RNA (siRNA) targeting caspase 8 protected liver cells from apoptosis in acute liver failure models. This RNA interference therapy improved survival even when administered after liver damage onset, offering hope for clinical applications.
Area of Science:
- Hepatology
- Molecular Biology
- RNA Interference Therapeutics
Background:
- Acute liver failure (ALF) therapy focuses on hepatocyte protection to prevent apoptosis and maintain liver function.
- Small interfering RNA (siRNA) is a gene silencing tool with therapeutic potential.
- Caspase 8 is a key enzyme in death receptor-mediated apoptosis, a critical pathway in ALF.
Purpose of the Study:
- To evaluate the therapeutic efficacy of siRNA targeting caspase 8 in vivo for ALF.
- To determine if caspase 8 siRNA can prevent or attenuate liver damage and improve survival in ALF models.
- To assess the effectiveness of caspase 8 siRNA when administered during established ALF.
Main Methods:
- Systemic administration of 21-nt siRNAs targeting caspase 8 in mouse models of ALF.
- Induction of ALF using agonistic Fas antibody (Jo2) or adenovirus expressing Fas ligand (AdFasL).
- Evaluation of caspase 8 gene expression inhibition, hepatocyte apoptosis, liver transaminases, and survival rates.
Main Results:
- Caspase 8 siRNA significantly inhibited caspase 8 expression in the liver, preventing Fas-mediated apoptosis.
- Hepatocyte protection by caspase 8 siRNA attenuated liver damage induced by Jo2 and AdFasL.
- Significant survival improvement was observed even when caspase 8 siRNA was administered during ongoing ALF (AdFasL and Adwt models).
- Therapeutic efficacy was demonstrated in ALF models reflecting both specific Fas agonistic agents and multiple mechanisms of human viral hepatitis.
Conclusions:
- Caspase 8 siRNA is a promising therapeutic strategy for ALF, effectively preventing hepatocyte apoptosis and improving survival.
- RNA interference targeting caspase 8 shows efficacy even when applied after ALF onset, suggesting clinical applicability.
- This approach holds potential for treating various forms of ALF, including those mimicking human viral hepatitis.