Unique DUOX2+ACE2+ small cholangiocytes are pathogenic targets for primary biliary cholangitis

Abstract

Cholangiocytes play a crucial role in bile formation. Cholangiocyte injury causes cholestasis, including primary biliary cholangitis (PBC). However, the etiology of PBC remains unclear despite being characterized as an autoimmune disease. Using single-cell RNA sequencing (scRNA-seq), fluorescence-activated-cell-sorting, multiplex immunofluorescence (IF) and RNAscope analyses, we identified unique DUOX2+ACE2+ small cholangiocytes in human and mouse livers. Their selective decrease in PBC patients was associated with the severity of disease. Moreover, proteomics, scRNA-seq, and qPCR analyses indicated that polymeric immunoglobulin receptor (pIgR) was highly expressed in DUOX2+ACE2+ cholangiocytes. Serum anti-pIgR autoantibody levels were significantly increased in PBC patients, regardless of positive and negative AMA-M2. Spatial transcriptomics and multiplex IF revealed that CD27+ memory B and plasma cells accumulated in the hepatic portal tracts of PBC patients. Collectively, DUOX2+ACE2+ small cholangiocytes are pathogenic targets in PBC, and preservation of DUOX2+ACE2+ cholangiocytes and targeting anti-pIgR autoantibodies may be valuable strategies for therapeutic interventions in PBC.

Runt-related transcription factor-1 ameliorates bile acid–induced hepatic inflammation in cholestasis through JAK/STAT3 signaling

“…Autoimmune hepatitis and other liver diseases were excluded by liver histology. Accordingly, control surgical liver samples were obtained from 4 patients with no evidence of PBC, cholestasis, viral hepatitis, or autoimmune hepatitis 20. The detailed clinical characteristics of these patients for the scRNA-seq analysis are listed in Supplemental Table 2 (http://links.lww.com/HEP/A63).…”

“…IF was performed as previously described 26,28. Multiplex IF were performed in human or mouse liver sections, as described previously,20,29 using a 4-color multiple fluorescent immunohistochemical staining kit (Cat# abs50012/abs50028; Absin) according to the manufacturer’s instructions. CK19 or HNF4α acted as specific biomarkers for cholangiocytes or hepatocytes, respectively 30,31.…”

“…For scRNA-seq analysis, a liver biopsy was obtained in patients with PBC (n = 5) with no history of ursodeoxycholic acid treatment and diagnosed by elevated serum alkaline phosphatase levels and positive antimitochondrial antibodies 20. Autoimmune hepatitis and other liver diseases were excluded by liver histology.…”

“…For scRNA-seq analysis, a liver biopsy was obtained in patients with PBC (n = 5) with no history of ursodeoxycholic acid treatment and diagnosed by elevated serum alkaline phosphatase levels and positive antimitochondrial antibodies. [20] Autoimmune hepatitis and other liver diseases were excluded by liver histology. Accordingly, control surgical liver samples were obtained from 4 patients with no evidence of PBC, cholestasis, viral hepatitis, or autoimmune hepatitis.…”

“…Recently, after re-analysis of our single-cell RNA sequencing (scRNA-seq) data in human livers,20 we found that RUNX1 is widely expressed in all liver cells and that its expression was substantially upregulated in hepatocytes and some immune cells from patients with primary biliary cholangitis (PBC). Previous studies have characterized the role of RUNX1 in liver nonparenchymal cells, including endothelial cells, stellate cells, and immune cells such as dendritic cells 18,21,22.…”