PLX136795

GSE83963: Telomere Length Protects Mice from Human Disease Phenotype Caused By Notch1 Haploinsufficiency

• Organsim mouse
• Type RNASEQ
• Target gene
• Project ARCHS4

Diseases caused by gene haploinsufficiency in humans commonly lack a phenotype in mice heterozygous for the orthologous factor, although the source of this discrepancy is unknown. The inability to accurately model human disease in mice impedes the study of complex phenotypes and critically limits the discovery and testing of potential therapeutics. Laboratory mice have longer telomeres (>40 kilobases (kb)) compared to humans (~5-15 kb), potentially protecting them from age-related disease caused by haploinsufficiency. In humans, heterozygous non-sense mutations in the transcription factor, NOTCH1 (N1), lead to severe age-dependent aortic valve (AV) calcification. However, mice heterozygous for N1 do not develop calcific AV disease (CAVD)5. Here, we show that telomere shortening is sufficient to elicit age-dependent cardiac valve disease in N1+/- mice that closely mimics the human disease and that progressive shortening correlates with severity of disease, extending to AV thickening in the neonate. N1 haploinsufficiency led to increased proliferation in valves that further reduced telomere length. Calcified AVs exhibited downregulation of osteoclast factors and upregulation of pro-calcific regulatory nodes concordant with gene network alterations in human N1 heterozygous endothelial cells. Dysregulated genes in valves were enriched for those that have promoters normally contacted by telomere looping. These findings reveal a critical role for telomere length in a mouse model of age-dependent human disease that may have broader implications and provides an in vivo model in which to test therapeutic candidates to prevent or delay the progression of CAVD. SOURCE: Christina Theodoris (christina.theodoris@ucsf.edu) - Gladstone Institutes, University of California, San Francisco