Epithelial splicing regulatory protein 2–mediated alternative splicing reprograms hepatocytes in severe alcoholic hepatitis
Jeongeun Hyun, … , Auinash Kalsotra, Anna Mae Diehl
Jeongeun Hyun, … , Auinash Kalsotra, Anna Mae Diehl
Published January 16, 2020
Citation Information: J Clin Invest. 2020;130(4):2129-2145. https://doi.org/10.1172/JCI132691.
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Research Article Cell biology Hepatology

Epithelial splicing regulatory protein 2–mediated alternative splicing reprograms hepatocytes in severe alcoholic hepatitis

Abstract

Severe alcoholic hepatitis (SAH) is a deadly liver disease without an effective medical therapy. Although SAH mortality is known to correlate with hepatic accumulation of immature liver cells, why this occurs and how it causes death are unclear. Here, we demonstrate that expression of epithelial splicing regulatory protein 2 (ESRP2), an RNA-splicing factor that maintains the nonproliferative, mature phenotype of adult hepatocytes, was suppressed in both human SAH and various mouse models of SAH in parallel with the severity of alcohol consumption and liver damage. Inflammatory cytokines released by excessive alcohol ingestion reprogrammed adult hepatocytes into proliferative, fetal-like cells by suppressing ESRP2. Sustained loss of ESRP2 permitted reemergence of a fetal RNA-splicing program that attenuates the Hippo signaling pathway and thus allows fetal transcriptional regulators to accumulate in adult liver. We further showed that depleting ESRP2 in mice exacerbated alcohol-induced steatohepatitis, enabling surviving hepatocytes to shed adult hepatocyte functions and become more regenerative, but threatening overall survival by populating the liver with functionally immature hepatocytes. Our findings revealed a mechanism that explains why liver failure develops in patients with the clinical syndrome of SAH, suggesting that recovery from SAH might be improved by limiting adult-to-fetal reprogramming in hepatocytes.

Authors

Jeongeun Hyun, Zhaoli Sun, Ali Reza Ahmadi, Sushant Bangru, Ullas V. Chembazhi, Kuo Du, Tianyi Chen, Hidekazu Tsukamoto, Ivan Rusyn, Auinash Kalsotra, Anna Mae Diehl

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Figure 6

Fetal reprogrammed hepatocytes lose adult liver-specific functions.

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Fetal reprogrammed hepatocytes lose adult liver-specific functions. (A) ...
(A) A schematic of ammonia (NH4+) detoxification pathway by hepatocytes in the liver. Glu, glutamate; Gln, glutamine; CP, carbamoyl phosphate. (B) qRT-PCR analysis for Cps1 and Glul in freshly isolated primary mouse hepatocytes and primary hepatocytes cultured under spheroid-forming system for 18 days continuously treated with TNF-α, IL-1β, or TNF-α + IL-1β. (C) The levels of urea, glutamine, and ammonia in conditioned medium of primary hepatocytes as specified. Results are graphed as box and whiskers plots (min to max), and means are indicated as plus signs. Statistical analysis was performed by 1-way ANOVA with Tukey’s corrections (n = 3 biological replicates/group). (D) scRNA-seq analysis for Cps1 and Glul in primary hepatocytes and hepatocyte spheroids under TNF-α–mediated expansion medium or TNF-α–withdrawn induction medium, as described in a previous publication (38). (E) qRT-PCR analysis for CPS1 and GLUL in human livers with SAH and healthy controls. Results are graphed as dot plots (SAH, black squares; healthy controls, white circles) showing mean ± SEM (red bars) (n = 5 individuals/group). Statistical analysis was performed by using 2-tailed Student’s t test between 2 groups. (F) qRT-PCR analysis for Cps1 and Glul in mouse livers from WT and Esrp2-KO mice at baseline. Results are graphed as dot plots (Esrp2-KO, black circles; WT, white circles) showing mean ± SEM (red bars) (n = 3–5 individuals/group). Statistical analysis was performed by using 2-tailed Student’s t test between 2 groups. (G) The serum levels of ammonia, urea, and albumin (ALB) in healthy WT and Esrp2-KO mice. Mean ± SEM results are graphed, and statistical analysis was performed by using 2-tailed Student’s t test between 2 groups (n = 3–5 mice/group).