RNA-seq reveals outcome-specific gene expression of MMP7 and PCK1 in biliary atresia

The disease phenotype in biliary atresia (BA) is caused by a fibro-inflammatory process leading to destruction of cholangiocytes, obstruction of ductular pathways and eventual progression to liver cirrhosis. The first line of management is a Kasai portoenterostomy (KPE) followed by liver transplantation (LT) in some children. Several factors have been postulated to affect the outcome of KPE and/or the subsequent progression of liver disease. However, no biomarkers have been identified in the liver for BA. We aimed to address this deficit. Whole transcriptome mRNA sequencing was performed for 29 samples (25 BA and 4 Controls) to identify the candidate genes predicting the prognosis of KPE. These results were further confirmed with quantitative Realtime PCR (qPCR). Analysis from RNA-sequencing data identified matrix metalloproteinase7 (MMP7) and phosphoenolpyruvate carboxykinase (PCK1) as potential determinants of the outcome of KPE. MMP7 expression was significantly elevated in patients who failed to clear jaundice after KPE as well as in patients with End Stage Liver Disease (ESLD). In contrast, PCK1 level was upregulated in patients who had successful KPE, while there was a significant down regulation in patients who failed KPE. MMP7 and PCK1 expression patterns had an inverse relation to the outcome of KPE and hence could potentially be used as biomarkers to predict KPE outcome and disease progression, enabling clinicians to design new treatment strategies for BA.