Activation of the c-Jun N-Terminal Kinase Pathway Aggravates Proteotoxicity of Hepatic Mutant Z Alpha1-Antitrypsin

作者：Pastore Nunzia; Attanasio Sergio; Granese Barbara; Castello Raffaele; Teckman Jeffrey; Wilson Andrew A; Ballabio Andrea; Brunetti Pierri Nicola

来源：Hepatology, 2017, 65(6): 1865-1874.

DOI：10.1002/hep.29035

Alpha1-antitrypsin deficiency is a genetic disease that can affect both the lung and the liver. The vast majority of patients harbor a mutation in the serine protease inhibitor 1A (SERPINA1) gene leading to a single amino acid substitution that results in an unfolded protein that is prone to polymerization. Alpha1-antitrypsin defciency-related liver disease is therefore caused by a gain-of-function mechanism due to accumulation of the mutant Z alpha1-antitrypsin (ATZ) and is a key example of an disease mechanism induced by protein toxicity. Intracellular retention of ATZ triggers a complex injury cascade including apoptosis and other mechanisms, although several aspects of the disease pathogenesis are still unclear. We show that ATZ induces activation of c-Jun N-terminal kinase (JNK) and c-Jun and that genetic ablation of JNK1 or JNK2 decreased ATZ levels in vivo by reducing c-Jun-mediated SERPINA1 gene expression. JNK activation was confirmed in livers of patients homozygous for the Z allele, with severe liver disease requiring hepatic transplantation. Treatment of patient-derived induced pluripotent stem cell-hepatic cells with a JNK inhibitor reduced accumulation of ATZ. Conclusion: These data reveal that JNK is a key pathway in the disease pathogenesis and add new therapeutic entry points for liver disease caused by ATZ.

• 出版日期2017-6