ABSTRACT
BACKGROUND AND PURPOSE: Mutations in fused in sarcoma (FUS) were recently identified as a cause of familial amyotrophic lateral sclerosis (ALS). The frequency of occurrence of mutations in FUS in sets of patients with familial ALS remains to be established. METHODS: We sequenced the FUS gene in a cohort of patients with familial ALS seen at the neuromuscular clinic in Leuven. A total of 28 patients with SOD1-negative ALS from 22 families were analyzed. RESULTS: We identified a R521H mutation in 4 patients, belonging to a kindred of dominantly inherited classical ALS. The mutation segregated with disease. Mutations in FUS were observed in 2.9% of ALS pedigrees in our cohort. CONCLUSIONS: These results show that mutations in FUS are also a significant cause of familial ALS in Belgium.
Subject(s)
Amyotrophic Lateral Sclerosis/genetics , Genetic Predisposition to Disease/genetics , Mutation/genetics , RNA-Binding Protein FUS/genetics , Adult , Age of Onset , Aged , Amyotrophic Lateral Sclerosis/epidemiology , Belgium , Cohort Studies , Disease Progression , Female , Gene Frequency/genetics , Genetic Markers/genetics , Genetic Predisposition to Disease/epidemiology , Genetic Testing , Humans , Male , Middle Aged , PedigreeSubject(s)
Alleles , Amino Acid Substitution/genetics , Amyotrophic Lateral Sclerosis/genetics , Chromosome Aberrations , Codon/genetics , DNA Mutational Analysis , DNA-Binding Proteins/genetics , Exons/genetics , Genes, Dominant/genetics , Methionine/genetics , Superoxide Dismutase/genetics , Valine/genetics , Adult , Aged , Belgium , Female , Humans , Male , Middle Aged , Pedigree , Sequence Analysis, DNA , Superoxide Dismutase-1ABSTRACT
Treatment for 40 h of reaggregate pituitary cell cultures from 14-day-old female rats with nanomolar concentrations of gamma3-melanocyte-stimulating hormone (MSH) increased prolactin mRNA but not growth hormone (GH) mRNA expression levels as measured by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). During the 40 h incubation, gamma3-MSH stimulated prolactin accumulation in the culture medium. alpha-MSH, a potent agonist of the rat melanocortin-3 receptor (MC3R) and Ala(8)-gamma2-MSH, a very weak agonist of the MC3R, increased prolactin mRNA expression at a similar concentration range as gamma3-MSH. The effect of gamma3-MSH on prolactin mRNA expression was abolished when aggregates were cultured in the presence of thyroid or glucocorticoid hormones, but not of oestradiol. By contrast, oestradiol abolished the stimulatory effect of Ala(8)-gamma2-MSH on prolactin mRNA expression. In GH3 cells stably transfected with the enhanced green fluorescent protein (eGFP) gene under control of a 3-kb prolactin promoter fragment, a dose as low as 1 nMgamma3-MSH, added for 24 h, significantly increased eGFP fluorescence. Agouti-related protein (AgRP(83-132)), a known endogenous MC3R and MC4R antagonist, did not reduce the stimulation of prolactin mRNA expression by gamma3-MSH or Ala(8)-gamma2-MSH. On its own, AgRP(83-132) significantly increased prolactin mRNA expression level and prolactin accumulation. Both gamma2-MSH and Ala(8)-gamma2-MSH increased [S(35)]GTPgammaS binding in membrane preparations of 14-day-old rat pituitaries and of GH3 cells. Whereas MC3R and MC5R mRNA were detectable by RT-PCR in normal pituitary, these receptor mRNAs were undetectable in GH3 cells using various oligonucleotide primer sets. The present findings indicate that melanocortin peptides stimulate prolactin gene expression and production and that, at least in part, a receptor different from the classic MCR is involved. AgRP appears to have other actions than its known antagonistic activity on the MC3R and MC4R.