Poster abstracts
Poster number 9 submitted by Sushant Bangru
Alternative splicing rewires Hippo signaling pathway in hepatocytes to promote liver regeneration
Sushant Bangru (Dept. of Biochemistry, University of Illinois, Urbana-Champaign), Waqar Arif (Dept. of Biochemistry, University of Illinois, Urbana-Champaign), Joe Seimetz, Amruta Bhate, Jackie Chen, Edrees H Rashan (Dept. of Biochemistry, University of Illinois, Urbana-Champaign), Russ P Carstens (Dept. of genetics, University of Pennsylvania), Sayeepriyadarshini Anakk (Dept. of Molecular & Integrative Physiology, University of Illinois, Urbana-Champaign), Auinash Kalsotra (Dept. of Biochemistry, University of Illinois, Urbana-Champaign)
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.
Keywords: alternative splicing, hippo pathway, liver regeneration