Alternative splicing rewires Hippo signaling pathway in hepatocytes to promote liver regeneration

Nat Struct Mol Biol. 2018 Oct;25(10):928-939. doi: 10.1038/s41594-018-0129-2. Epub 2018 Sep 24.

Abstract

During liver regeneration, most new hepatocytes arise via self-duplication; yet, the underlying mechanisms that drive hepatocyte proliferation following injury remain poorly defined. By combining high-resolution transcriptome and polysome profiling of hepatocytes purified from quiescent and toxin-injured mouse livers, we uncover pervasive alterations in messenger RNA translation of metabolic and RNA-processing factors, which modulate the protein levels of a set of splicing regulators. Specifically, downregulation of the splicing regulator ESRP2 activates a neonatal alternative splicing program that rewires the Hippo signaling pathway in regenerating hepatocytes. We show that production of neonatal splice isoforms attenuates Hippo signaling, enables greater transcriptional activation of downstream target genes, and facilitates liver regeneration. We further demonstrate that ESRP2 deletion in mice causes excessive hepatocyte proliferation upon injury, whereas forced expression of ESRP2 inhibits proliferation by suppressing the expression of neonatal Hippo pathway isoforms. Thus, our findings reveal an alternative splicing axis that supports regeneration following chronic liver injury.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Animals
  • Cell Proliferation / genetics
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Hepatocytes / cytology
  • Hepatocytes / metabolism
  • Hepatocytes / physiology
  • Hippo Signaling Pathway
  • Liver Regeneration / genetics*
  • Mice
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Protein Serine-Threonine Kinases / physiology*
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • RNA-Binding Proteins / physiology
  • Signal Transduction / genetics

Substances

  • ESRP2 protein, mouse
  • RNA, Messenger
  • RNA-Binding Proteins
  • Protein Serine-Threonine Kinases