Animal and organoid models to elucidate the anti-fibrotic effect of steroid on biliary atresia

Abstract Purpose We performed animal and organoid study to evaluate the anti-fibrotic effect of steroid on BA and the underlying patho-mechanism. Methods BA animal models were created by inoculation of mice on post-natal day 1 with Rhesus Rotavirus (RRV) They received either 20ul Phosphate-buffered saline (PBS) or steroid from day 21 to day 34. On day 34, their serum samples were collected for hormonal markers. Necrosis fibrosis and CK 19 expression in the liver were evaluated. Liver organoids were developed and their morphology as well as bulk RNA sequencing data were analyzed. Results Twenty-four mice developed BA features after RRV injection and were equally divided into steroid and PBS groups. On day 34, the weight gain of steroid group increased significantly than PBS group (p<0.0001). All mice in the PBS group developed liver fibrosis but only one mouse in the steroid group did. Serum bilirubin and liver parenchymal enzymes were significantly lower in steroid group. The morphology of liver organoids were different between the two groups. A total of 6359 differentially expressed genes were found between steroid group and PBS group. Conclusion Based on our findings obtained from RRV-induced BA animal and organoid models, steroid has the potential to mitigate liver fibrosis in BA.