Dataset Information

A novel dominant-negative FGFR1 variant causes Hartsfield syndrome by deregulating RAS/ERK1/2 pathway.

ABSTRACT: Hartsfield syndrome (HS) is an ultrarare developmental disorder mainly featuring holoprosencephaly and ectrodactyly. It is caused by heterozygous or biallelic variants in FGFR1. Recently, a dominant-negative effect was suggested for FGFR1 variants associated with HS. Here, exome sequencing analysis in a 12-year-old boy with HS disclosed a novel de novo heterozygous variant c.1934C>T in FGFR1 predicted to cause the p.(Ala645Val) amino-acid substitution. In order to evaluate whether the variant, changing a highly conserved residue of the kinase domain, affects FGFR1 function, biochemical studies were employed. We measured the FGFR1 receptor activity in FGF2-treated cell lines exogenously expressing wild-type or Ala645Val FGFR1 by monitoring the activation status of FGF2/FGFR1 downstream pathways. Our analysis highlighted that RAS/ERK1/2 signaling was significantly perturbed in cells expressing mutated FGFR1, in comparison with control cells. We also provided preliminary evidence showing a modulation of the autophagic process in cells expressing mutated FGFR1. This study expands the FGFR1 mutational spectrum associated with HS, provides functional evidence further supporting a dominant-negative effect of this category of FGFR1 variants and offers initial insights on dysregulation of autophagy in HS.

SUBMITTER: Palumbo P

PROVIDER: S-EPMC6777633 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A novel dominant-negative FGFR1 variant causes Hartsfield syndrome by deregulating RAS/ERK1/2 pathway.

Palumbo Pietro P Petracca Antonio A Maggi Roberto R Biagini Tommaso T Nardella Grazia G Sacco Michele Carmine MC Di Schiavi Elia E Carella Massimo M Micale Lucia L Castori Marco M

European journal of human genetics : EJHG 20190220 7

Hartsfield syndrome (HS) is an ultrarare developmental disorder mainly featuring holoprosencephaly and ectrodactyly. It is caused by heterozygous or biallelic variants in FGFR1. Recently, a dominant-negative effect was suggested for FGFR1 variants associated with HS. Here, exome sequencing analysis in a 12-year-old boy with HS disclosed a novel de novo heterozygous variant c.1934C>T in FGFR1 predicted to cause the p.(Ala645Val) amino-acid substitution. In order to evaluate whether the variant, c ...[more]

PMID: 30787447

Similar Datasets

Project description:Loss-of-function mutations in the cardiac Na+ channel α-subunit Nav1.5, encoded by SCN5A, cause Brugada syndrome (BrS), a hereditary disease characterized by sudden cardiac death due to ventricular fibrillation. We previously evidenced in vitro the dominant-negative effect of the BrS Nav1.5-R104W variant, inducing retention of wild-type (WT) channels and leading to a drastic reduction of the resulting Na+ current (I Na ). To explore this dominant-negative effect in vivo, we created a murine model using adeno-associated viruses (AAVs).MethodsDue to the large size of SCN5A, a dual AAV vector strategy was used combining viral DNA recombination and trans-splicing. Mice were injected with two AAV serotypes capsid 9: one packaging the cardiac specific troponin-T promoter, the 5' half of hSCN5A cDNA, a splicing donor site and a recombinogenic sequence; and another packaging the complementary recombinogenic sequence, a splicing acceptor site, the 3' half of hSCN5A cDNA fused to the gfp gene sequence, and the SV40 polyA signal. Eight weeks after AAV systemic injection in wild-type (WT) mice, echocardiography and ECG were recorded and mice were sacrificed. The full-length hSCN5A-gfp expression was assessed by western blot and immunohistochemistry in transduced heart tissues and the Na+ current was recorded by the patch-clamp technique in isolated adult GFP-expressing heart cells.ResultsAlmost 75% of the cardiomyocytes were transduced in hearts of mice injected with hNav1.5 and ∼30% in hNav1.5-R104W overexpressing tissues. In ventricular mice cardiomyocytes expressing R104W mutant channels, the endogenous I Na was significantly decreased. Moreover, overexpression of R104W channels in normal hearts led to a decrease of total Nav1.5 expression. The R104W mutant also induced a slight dilatation of mice left ventricles and a prolongation of RR interval and P-wave duration in transduced mice. Altogether, our results demonstrated an in vivo dominant-negative effect of defective R104W channels on endogenous ones.ConclusionUsing a trans-splicing and viral DNA recombination strategy to overexpress the Na+ channel in mouse hearts allowed us to demonstrate in vivo the dominant-negative effect of a BrS variant identified in the N-terminus of Nav1.5.

Dataset Information

A novel dominant-negative FGFR1 variant causes Hartsfield syndrome by deregulating RAS/ERK1/2 pathway.

Publications

A novel dominant-negative FGFR1 variant causes Hartsfield syndrome by deregulating RAS/ERK1/2 pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets