Polyinosinic: polycytidylic acid [Poly(I:C)] treated liver organoids as a research model for biliary atresia

Abstract

Background: Biliary atresia (BA) is congenital disorder characterized by immune-mediated inflammation of the biliary systems resulting in life-threatening cholangiopathy In recent years, organoid technology has opened a new avenue for research in hepatobiliary diseases. Yet, the rarity of BA has limited the availability of human samples In this study, we explore the feasibility of creating a BA-like organoid by treating organoids from normal liver with Polyinosinic:Polycytidylic acid [Poly (I:C)], a synthetic immunostimulant that is structurally similar to a double-stranded RNA in virus Methods: BA organoids were developed from liver parenchyma collected during Kasai portoenterostomy Control organoids were developed from the non-tumor part of hepatoblastoma and they were co-cultured with Poly I:C (40 µg/ml). The organoid morphology was compared on day 17 In addition, RNAsequencing were performed to determine the transcriptomic difference between these samples Results: Control organoids without any treatment developed into well-expanded spherical organoids with a single-cell layer of epithelial cells and a single vacuole inside In contrast, after Poly I:C treatment, majority of these organoids developed into an aberrant morphology with a high index of similarity to BA organoids which were multivacuole and/or unexpanded (Figure 1A) RNA-sequencing analysis revealed that 19 inflammatory genes were commonly expressed in both groups They were selected for conditional cluster analysis and several genes that are involved in immune-mediated signaling pathway (SOCS6, SOCS6 1, ARAF, CAMK2G, GNA1C, ITGA2, PRKACA, PTEN ) we found to have a distinct pattern of expression in the Poly I:C treated control organoids, resembling the expression profile in BA multi-vacuole and unexpanded organoids (p<0.05) (Figure 1B). Conclusion: Poly I:C treated human liver organoids exhibit morphology and genetic signature highly compatible to organoids developed from liver samples collected from BA patients. They are potential research materials to study immune-mediated inflammation in BA.re