Rescue of ATP7B function in hepatocyte-like cells from Wilson's disease induced pluripotent stem cells using gene therapy or the chaperone drug curcumin

Abstract

Directed hepatocyte differentiation from human induced pluripotent stem cells (iPSCs) potentially provides a unique platform for modeling liver genetic diseases and performing drug-toxicity screening in vitro. Wilson's disease is a genetic disease caused by mutations in the ATP7B gene, whose product is a liver transporter protein responsible for coordinated copper export into bile and blood. Interestingly, the spectrum of ATP7B mutations is vast and can influence clinical presentation (a variable spectrum of hepatic and neural manifestations), though the reason is not well understood. We describe the generation of iPSCs from a Chinese patient with Wilson's disease that bears the R778L Chinese hotspot mutation in the ATP7B gene. These iPSCs were pluripotent and could be readily differentiated into hepatocyte-like cells that displayed abnormal cytoplasmic localization of mutated ATP7B and defective copper transport. Moreover, gene correction using a self-inactivating lentiviral vector that expresses codon optimized-ATP7B or treatment with the chaperone drug curcumin could reverse the functional defect in vitro. Hence, our work describes an attractive model for studying the pathogenesis of Wilson's disease that is valuable for screening compounds or gene therapy approaches aimed to correct the abnormality. In the future, once relevant safety concerns (including the stability of the mature liver-like phenotype) and technical issues for the transplantation procedure are solved, hepatocyte-like cells from similarly genetically corrected iPSCs could be an option for autologous transplantation in Wilson's disease.

Human induced pluripotent stem cells derived hepatocytes: rising promise for disease modeling, drug development and cell therapy

“…The significance of this report is profound as it is the first proof-ofprinciple study demonstrating the feasibility of modeling hepatic diseases in which the pathological defects are only seen in terminally differentiated adult hepatocytes (late-onset disease). Later on, Zhang et al (2011) reported modeling of the Wilson's disease, another type of liver metabolic disease, using patient iPSC. The iPSC-hepatocytes differentiated from Wilson's disease patient iPSC demonstrated abnormal cytoplasmic localization of mutated ATP7B protein and defective copper transportation.…”

“…The iPSC-hepatocytes differentiated from Wilson's disease patient iPSC demonstrated abnormal cytoplasmic localization of mutated ATP7B protein and defective copper transportation. Moreover, the authors showed that these functional defects could be reversed by lentivirus mediated gene therapy or chaperon drug treatment (Zhang et al, 2011). Interestingly, the first iPSC model of human liver infectious disease has also been reported recently.…”

Pluripotent stem cells to hepatocytes, the journey so far

“…A number of iPSC lines from patients suffering from tyrosinemia, glycogen storage disease, progressive familial hereditary cholestasis and Crigler-Najjar syndrome have also been generated successfully (63). Wilson's disease-specific iPSC lines with the R778L hotspot mutation in the ATP7B gene were able to produce hepatocytes with defective copper transport in culture (64). The modelling of other inherited diseases, such as hemochromatosis, hepatobiliary cystic fibrosis and idiosyncratic drug reactions would be helpful for understanding the respective disease processes and devising clinical interventions.…”

Reprogrammed Cell?based Therapy for Liver Disease: From Lab to Clinic

“…Yusa et al (55) showed that a combination of iPSCs and a transposon-based vector technology results in biallelic correction of a point mutation in α1-antitrypsin gene which is responsible for α1-antitrypsin deficiency. Additionally, genetic correction of iPSCs in patients with Wilson's disease using a lenti-viral vector could reverse the functional genetic defect of Wilson's disease gene in vitro (56). In principle, genetic correction of patient-derived cells is plausible in inherent liver diseases with known mutations (Figure 3) (57).…”