30 research outputs found
LG2 agrin mutation causing severe congenital myasthenic syndrome mimics functional characteristics of non-neural (z-) agrin
We describe a severe form of congenital myasthenic syndrome (CMS) caused by two heteroallelic mutations: a nonsense and a missense mutation in the gene encoding agrin (AGRN). The identified mutations, Q353X and V1727F, are located at the N-terminal and at the second laminin G-like (LG2) domain of agrin, respectively. A motor-point muscle biopsy demonstrated severe disruption of the architecture of the neuromuscular junction (NMJ), including: dispersion and fragmentation of endplate areas with normal expression of acetylcholinesterase; simplification of postsynaptic membranes; pronounced reduction of the axon terminal size; widening of the primary synaptic cleft; and, collection of membranous debris material in the primary synaptic cleft and in the subsynaptic cytoplasm. Expression studies in heterologous cells revealed that the Q353X mutation abolished expression of full-length agrin. Moreover, the V1727F mutation decreased agrin-induced clustering of the acetylcholine receptor (AChR) in cultured C2 muscle cells by >100-fold, and phosphorylation of the MuSK receptor and AChR beta subunit by ~tenfold. Surprisingly, the V1727F mutant also displayed increased binding to α-dystroglycan but decreased binding to a neural (z+) agrin-specific antibody. Our findings demonstrate that agrin mutations can associate with a severe form of CMS and cause profound distortion of the architecture and function of the NMJ. The impaired ability of V1727F agrin to activate MuSK and cluster AChRs, together with its increased affinity to α-dystroglycan, mimics non-neural (z-) agrin and are important determinants of the pathogenesis of the disease
Determination of antibiotics and detergent residues in decellularized tissue-engineered heart valves using LC–MS/MS
Cytosolic Ca2+ alteration mediates both ryanodine receptor and IP3 receptor in TE671/RD cells
Intellectual and Psychological Performance in Males Born Small for Gestational Age With and Without Catch-Up Growth
Diverse correlation patterns between microRNAs and their targets during tomato fruit development indicates different modes of microRNA actions
Maternal serum levels of perfluoroalkyl substances and organochlorines and indices of fetal growth: a Scandinavian case-cohort study
Background: The associations between prenatal exposure
to endocrine disruptive chemicals (EDCs) and fetal growth are
inconsistent, and few studies have considered small-for-gestational-age
(SGA) birth as an outcome. Our current study of
Scandinavian parous women aimed to address these inconsistencies
and gaps in the literature.
Methods: This case–cohort study included 424 mother–
child pairs who participated in a prospective, multi-center
study of parous women in Norway (Trondheim and Bergen)
and Sweden (Uppsala). We used linear and logistic regression
with 95% confidence intervals (CIs) to analyze the associations
between two perfluoroalkyl substances (PFASs) and five
organochlorines (OCs) from early second trimester and indices
of fetal growth.
Results: Among Swedish women, prenatal exposure to perfluorooctanoate
(PFOA), polychlorinated biphenyl (PCB) 153
and hexachlorobenzene (HCB) were associated with higher
odds for SGA birth. We found stronger associations among
Swedish male offspring. In the Norwegian cohort, we found
no significant associations between EDC exposure and indices
of fetal growth.
Conclusions: Some populations may be more vulnerable
to EDCs, possibly due to differences in exposure levels, exposure
sources and/or modifiable lifestyle factors. Male offspring
may be more vulnerable to endocrine disruption