ABSTRACT Hereditary angioedema (HAE) with C1 esterase inhibitor (C1INH) deficiency is caused by pathogenic SERPING1 mutations that disrupt production of the plasma protease inhibitor C1INH. However, the molecular mechanisms and consequences of patient‐specific mutations remain poorly understood due to the lack of physiologically relevant human models. Here, we established a personalized, isogenic, stem‐cell‐derived hepatocyte platform to investigate the underlying mutation‐specific mechanisms of HAE. Specifically, peripheral blood mononuclear cell (PBMC)‐expanded erythroblasts from four representative HAE‐C1INH‐Type1 patients containing distinct point, insertion, deletion, or large fragment SERPING1 mutations were reprogrammed into expanded potential stem cells (EPSCs) and further differentiated into hepatocyte‐like cells (HLCs). These HLCs exhibited appropriate transcriptional transitions, mature hepatic features, and C1INH secretion comparable to that observed in human plasma. All patient‐derived HLCs demonstrated impaired C1INH secretion with mutation‐specific differences in both SERPING1 transcription and intracellular accumulation. Moreover, to verify that the mutations directly drive the phenotype, we performed CRISPR/Cas9‐mediated genome repair, which restored SERPING1 mRNA expression and C1INH secretion. Conversely, identical patient mutations installed into healthy EPSCs showed the same transcriptional and secretory defects, confirming sufficiency. Collectively, we have established a robust human hepatocyte model that accurately recapitulates key hepatocyte‐specific aspects of HAE pathophysiology and provides a scalable foundation for investigation of future precision therapies.
Liu et al. (Sat,) studied this question.