Abstract
Calcification of the aortic valve is the third leading cause of heart disease in adults. The incidence increases with age, and it is often associated with a bicuspid aortic valve present in 1-2% of the population. Despite the frequency, neither the mechanisms of valve calcification nor the developmental origin of a two, rather than three, leaflet aortic valve is known. Here, we show that mutations in the signalling and transcriptional regulator NOTCH1 cause a spectrum of developmental aortic valve anomalies and severe valve calcification in non-syndromic autosomal-dominant human pedigrees. Consistent with the valve calcification phenotype, Notch1 transcripts were most abundant in the developing aortic valve of mice, and Notch1 repressed the activity of Runx2, a central transcriptional regulator of osteoblast cell fate. The hairy-related family of transcriptional repressors (Hrt), which are activated by Notch1 signalling, physically interacted with Runx2 and repressed Runx2 transcriptional activity independent of histone deacetylase activity. These results suggest that NOTCH1 mutations cause an early developmental defect in the aortic valve and a later de-repression of calcium deposition that causes progressive aortic valve disease.
Publication types
-
Research Support, N.I.H., Extramural
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Adult
-
Animals
-
Aortic Valve / abnormalities*
-
Aortic Valve / pathology
-
Base Sequence
-
COS Cells
-
Calcinosis / genetics
-
Child
-
Chromosomes, Human, Pair 9 / genetics
-
Core Binding Factor Alpha 1 Subunit
-
DNA Mutational Analysis
-
Female
-
Gene Expression Regulation, Developmental
-
Heart Valve Diseases / congenital
-
Heart Valve Diseases / genetics*
-
Heart Valve Diseases / pathology
-
Heart Valve Diseases / physiopathology
-
Humans
-
In Situ Hybridization
-
Lod Score
-
Male
-
Mice
-
Mutation / genetics*
-
Neoplasm Proteins / genetics
-
Neoplasm Proteins / metabolism
-
Pedigree
-
Phenotype
-
RNA, Messenger / genetics
-
RNA, Messenger / metabolism
-
Receptor, Notch1
-
Receptors, Cell Surface / chemistry
-
Receptors, Cell Surface / genetics*
-
Receptors, Cell Surface / metabolism*
-
Repressor Proteins / genetics
-
Repressor Proteins / metabolism
-
Transcription Factors / chemistry
-
Transcription Factors / genetics*
-
Transcription Factors / metabolism*
Substances
-
Core Binding Factor Alpha 1 Subunit
-
NOTCH1 protein, human
-
Neoplasm Proteins
-
Notch1 protein, mouse
-
RNA, Messenger
-
Receptor, Notch1
-
Receptors, Cell Surface
-
Repressor Proteins
-
Transcription Factors