The Heterochromatin protein 1 is a regulator in RNA splicing precision deficient in ulcerative colitis

Abstract

Defects in RNA splicing have been linked to human disorders, but remain poorly explored in inflammatory bowel disease (IBD). Here, we report that expression of the chromatin and alternative splicing regulator HP1? is reduced in ulcerative colitis (UC). Accordingly, HP1? gene inactivation in the mouse gut epithelium triggers IBD-like traits, including inflammation and dysbiosis. In parallel, we find that its loss of function broadly increases splicing noise, favoring the usage of cryptic splice sites at numerous genes with functions in gut biology. This results in the production of progerin, a toxic splice variant of prelamin A mRNA, responsible for the Hutchinson-Gilford Progeria Syndrome of premature aging. Splicing noise is also extensively detected in UC patients in association with inflammation, with progerin transcripts accumulating in the colon mucosa. We propose that monitoring HP1? activity and RNA splicing precision can help in the management of IBD and, more generally, of accelerated aging.