Anti-SHANK3 (C-terminal half) monoclonal antibody, clone 27F3.4

The molecular basis for the majority of cases of autism spectrum disorders (ASD) remains unknown. We tested the hypothesis that ASD have an epigenetic cause by performing DNA methylation profiling of five CpG islands (CGI-1 to CGI-5) in the SHANK3 gene in postmortem brain tissues from 54 ASD patients and 43 controls. We found significantly increased overall DNA methylation (epimutation) in three intragenic CGIs (CGI-2, CGI-3 and CGI-4). The increased methylation was clustered in the CGI-2 and CGI-4 in similar to 15% of ASD brain tissues. SHANK3 has an extensive array of mRNA splice variants resulting from combinations of five intragenic promoters and alternative splicing of coding exons. Altered expression and alternative splicing of SHANK3 isoforms were observed in brain tissues with increased methylation of SHANK3 CGIs in ASD brain tissues. A DNA methylation inhibitor modified the methylation of CGIs and altered the isoform-specific expression of SHANK3 in cultured cells. This study is the first to find altered methylation patterns in SHANK3 in ASD brain samples. Our finding provides evidence to support an alternative approach to investigating the molecular basis of ASD. The ability to alter the epigenetic modification and expression of SHANK3 by environmental factors suggests that SHANK3 may be a valuable biomarker for dissecting the role of gene and environment interaction in the etiology of ASD.

Mutations/deletions in the SHANK3 gene are associated with autism spectrum disorders and intellectual disability. Here, we present electrophysiological and behavioral consequences in novel heterozygous and homozygous mice with a transcriptional stop cassette inserted upstream of the PDZ domain-coding exons in Shank3 (Shank3(E13)). Insertion of a transcriptional stop cassette prior to exon 13 leads to loss of the two higher molecular weight isoforms of Shank3. Behaviorally, both Shank3(E13) heterozygous (HET) and homozygous knockout (KO) mice display increased repetitive grooming, deficits in social interaction tasks, and decreased rearing. Shank3(E13) KO mice also display deficits in spatial memory in the Morris water maze task. Baseline hippocampal synaptic transmission and short-term plasticity are preserved in Shank3(E13) HET and KO mice, while both HET and KO mice exhibit impaired hippocampal long-term plasticity. Additionally, Shank3(E13) HET and KO mice display impaired striatal glutamatergic synaptic transmission. These results demonstrate for the first time in this novel Shank3 mutant that both homozygous and heterozygous mutation of Shank3 lead to behavioral abnormalities with face validity for autism along with widespread synaptic dysfunction. Autism Res2017, 10: 42-65. (c) 2016 International Society for Autism Research, Wiley Periodicals, Inc.