NIH Research Festival
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Alagille syndrome (ALGS) is a rare autosomal dominant disorder caused by mutations mainly in the JAG1 gene, which encodes a fundamental ligand of the Notch signaling pathway. Clinically, presentations of ALGS patients are multiorgan system malfunctions with cholestasis as a common symptom due to bile duct paucity. Currently, there is no effective treatment available for ALGS patients. To facilitate drug development, we have generated induced pluripotent stem cells (iPSC) from ALGS patients (ALGS-iPSC) and differentiated them into hepatic organoids. The results showed that expression of JAG1 was significantly reduced in the ALGS-iPSC compared to the iPSC derived from healthy volunteers (WT-iPSC). The organoids derived from ALGS-iPSC show a similar morphology and proliferation potential to the organoids derived from WT-iPSC. We quantified the number of hepatocytes and cholangiocytes in organoids based on the expression of albumin or cytokeratin 19 and cytokeratin 7, respectively. We found that the cholangiocytes were significantly reduced in ALGS-iPSC derived organoids compared to that of WT-iPSC derived organoids. We then tested a set of compounds identified from a drug repurposing screen in ALGS-iPSC derived vascular smooth cells and found an increase in JAG1 expression and JAG1-Notch2 signaling pathway activation in ALGS-iPSC derived organoids. We further confirmed that the cholangiocytes also increased in ALGS-iPSC derived organoids when treated with the compounds. Therefore, the results demonstrate that the ALGS-iPSC derived organoids are a valid model system to study disease pathophysiology and evaluate drug efficacy for drug development.
Scientific Focus Area: Stem Cell Biology
This page was last updated on Tuesday, August 6, 2024