Modeling Autism by SHANK Gene Mutations in Mice

In the paper

“Conserved features of synaptic dysfunction and corresponding behaviors in Shank mouse mutants may help dissect the pathophysiology of ASD, but also highlight divergent phenotypes that arise from different mutations in the same gene.”

In the paper

“Genetic risk contributes significantly to idiopathic ASD, but the specific genetic alterations remain elusive in the majority of cases (Abrahams and Geschwind, 2008; Folstein and Rosen-Sheidley, 2001; State, 2010b).”

What the sources say

• Not checked yetcites Abrahams and Geschwind, 2008 source
• Not checked yetcites Folstein and Rosen-Sheidley, 2001
• Not checked yetcites State, 2010b

In the paper

“Diagnostic evaluations for ASD were not conducted in the majority of cases or were carried out using different evaluation protocols.”

In the paper

“Together, these data strongly support a conclusion that molecular defects of SHANK3 can cause ASD but with variable presentations.”

In the paper

“Many missense mutations have been identified in SHANK3 (Gauthier et al., 2009; Moessner et al., 2007; Schaaf et al., 2011), but their clinical relevance has not been determined.”

What the sources say

• Not checked yetcites Gauthier et al., 2009 source
• Not checked yetcites Moessner et al., 2007 source
• Not checked yetcites Schaaf et al., 2011 source

In the paper

“For example, genes implicated in metachromatic leukodystrophy (ARSA), congenital disorders of glycosylation (ALG12), and spinocerebellar ataxia type 10 (ATXN10) are mapped within the 22q13.3 region.”

In the paper

“Importantly, the quality of clinical data varies and is often incomplete in these reports and thus direct comparisons should be made with caution.”

In the paper

“More recently, point mutations of SHANK2 and microdeletions of SHANK1 and SHANK2 have been found in patients with ASD and intellectual disability (Figures 1B and 1C) (Berkel et al., 2010; Leblond et al., 2012; O’Roak et al., 2012b; Pinto et al., 2010; Sato et al., 2012).”

What the sources say

• Not checked yetcites Berkel et al., 2010 source
• Not checked yetcites Leblond et al., 2012 source
• Not checked yetcites O’Roak et al., 2012b

In the paper

“The key clinical features associated with PMS are global developmental delay, hypotonia, absent or severely delayed language, autistic behaviors, and intellectual disability (Phelan, 2007).”

What the sources say

• Not checked yetcites Phelan, 2007

In the paper

“This observation is consistent with recent reports that similar copy number variants (CNVs) are found across many genomic loci in both ASD and schizophrenia (Cook and Scherer, 2008; Gejman et al., 2011; Moreno-De-Luca et al., 2010; Sanders et al., 2011).”

What the sources say

• Not checked yetcites Cook and Scherer, 2008 source
• Not checked yetcites Gejman et al., 2011 source
• Not checked yetcites Moreno-De-Luca et al., 2010 source

In the paper

“Compared to SHANK3, the number of cases with SHANK2 mutations is small but convincing.”

In the paper

“Because the number of ASD cases with two genetic hits including SHANK2 is small, the validity of the model remains to be tested in additional patient cohorts or by functional studies.”

In the paper

“Mutations of SHANK3 were the first (Durand et al., 2007) and remain the best characterized SHANK mutations in human ASD (Boccuto et al., 2012; Moessner et al., 2007).”

What the sources say

• Not checked yetcites Durand et al., 2007 source
• Not checked yetcites Boccuto et al., 2012
• Not checked yetcites Moessner et al., 2007 source

In the paper

“Among the various Shank binding proteins, Homer family members have been shown to regulate diverse synaptic functions (Hayashi et al., 2009; Sala et al., 2001; Tu et al., 1999).”

What the sources say

• Not checked yetcites Hayashi et al., 2009 source
• Not checked yetcites Sala et al., 2001 source
• Not checked yetcites Tu et al., 1999

In the paper

“When overexpressed in cultured neurons from mice, Shanks recruit GluA1 AMPA receptors and increases the formation of new synapses (Roussignol et al., 2005).”

What the sources say

• Not checked yetcites Roussignol et al., 2005 source

In the paper

“Shank3 forms multimers via its C terminal SAM domain (Boeckers et al., 2005; Hayashi et al., 2009; Naisbitt et al., 1999) as well as its PDZ domain (Iskenderian-Epps and Imperiali, 2010).”

What the sources say

• Not checked yetcites Boeckers et al., 2005 source
• Not checked yetcites Hayashi et al., 2009 source
• Not checked yetcites Naisbitt et al., 1999 source

In the paper

“In cultured rat neurons, knock-down of Shank3 selectively reduces synaptic mGluR5 receptor and impairs mGluR5-dependent signaling and plasticity (Verpelli et al., 2011).”

What the sources say

• Not checked yetcites Verpelli et al., 2011 source

In the paper

“Shank/ProSAP family members including Shank3 have five conserved protein domains – an ankyrin repeat domain (ANK), Src homology 3 (SH3) domain, PSD-95/Discs large/ZO-1 (PDZ) domain, a proline-rich region containing homer- and cortactin-binding sites, and a sterile alpha motif (SAM) domain (Figure 2A).”

In the paper

“The SAM domain of Shank3 has a Zn2+ binding site that is important for Shank3 protein folding at the PSD as well as for synaptogenesis and synapse maturation in vitro (Baron et al., 2006; Grabrucker et al., 2011a).”

What the sources say

• Not checked yetcites Baron et al., 2006 source
• Not checked yetcites Grabrucker et al., 2011a

In the paper

“Different SHANK mutations may thus act through different mechanisms to alter protein-protein interactions at the PSD and cause synaptic dysfunction that may underlie clinical presentations of disorder.”

In the paper

“Shank3 shares very similar protein domain structure to Shank1, suggesting that Shank3 participates in a similar protein network with Homer1.”

In the paper

“In contrast, mutation in the cortactin binding site results in longer spines with reduced spine head area (Roussignol et al., 2005).”

What the sources say

• Not checked yetcites Roussignol et al., 2005 source

In the paper

“although excessive mGluR5 signaling has been implicated in fragile X syndrome (Krueger and Bear, 2011), which has clinical overlap with 22q13.3 deletions (Phelan, 2008).”

What the sources say

• Not checked yetcites Krueger and Bear, 2011
• Not checked yetcites Phelan, 2008 source

In the paper

“Shank3 shares a similar protein domain structure but has a different expression pattern and subcellular localization than Shank1 and Shank2 (Bockers et al., 2004; Peca et al., 2011; Tao-Cheng et al., 2010).”

What the sources say

• Not checked yetcites Bockers et al., 2004 source
• Not checked yetcites Peca et al., 2011 source
• Not checked yetcites Tao-Cheng et al., 2010 source

In the paper

“The large protein complex organized by Shanks performs a variety of functions at the postsynaptic membrane including actin-based cytoskeletal remodeling, synapse formation, AMPA receptor endocytosis, and regulation of synaptic transmission and plasticity (Table 2).”

In the paper

“Biochemically, Shank family proteins are ubiquitinated in an activity-dependent manner in neurons (Ehlers, 2003).”

What the sources say

• Not checked yetcites Ehlers, 2003 source

In the paper

“For example, mutation of the PDZ domain of Shank3 results in a reduction in dendritic spine formation while mutation of ANK-SH3 domains leads to spines with normal length but reduced spine head area.”

What the sources say

• Not checked yetcites Roussignol et al., 2005 source

In the paper

“The expression of Shank3 isoforms is cell type-specific and developmentally regulated (Lim et al., 1999; Maunakea et al., 2010).”

What the sources say

• Not checked yetcites Lim et al., 1999 source
• Not checked yetcites Maunakea et al., 2010 source

In the paper

“Consistent with this notion, many known ASD genes, such as neuroligins and neurexins, display a complex pattern of isoform-specific expression in brain (Boucard et al., 2005; Sudhof, 2008), with different isoforms having very distinct functions (Chih et al., 2006).”

What the sources say

• Not checked yetcites Boucard et al., 2005 source
• Not checked yetcites Sudhof, 2008 source
• Not checked yetcites Chih et al., 2006 source

In the paper

“Homer1 and Shank1 form a mesh-like matrix that is thought to function as an organizing lattice for PSD proteins (Hayashi et al., 2009).”

What the sources say

• Not checked yetcites Hayashi et al., 2009 source

In the paper

“The intron 19 splicing mutation will disrupt most isoforms but leave SHANK3f and other short isoforms intact.”

In the paper

“The alternative splicing of exons 19-20 and isoforms of SHANK2E (Jiang, unpublished data), SHANK2A, and SHANK2B (Lim et al., 1999) were conserved in mice but the status of SHANK2C and other spliced exons has not been confirmed.”

What the sources say

• Not checked yetcites Lim et al., 1999 source

In the paper

“Smaller dendritic spines were observed, but the ultrastructure of the PSD is unaffected at CA1 synapses of Shank1−/− mice.”

What the sources say

• Not checked yetcites Hung et al., 2008 source

In the paper

“The deletion of exon 7 and exon 6-7 of Shank2a (exons 17 and exons 16-17 of predicted full length Shank2) resulted in a frame shift of the open reading frame immediately after exon 7.”

In the paper

“mEPSCs recorded from CA1 hippocampal neurons were unaltered in Shank2 Δex6-7−/− mice, but reduced in Shank2 Δex7−/−.”

What the sources say

• Not checked yetcites Won et al., 2012 source
• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“Analyses of protein composition, synaptic development and function, and behaviors have revealed similarity but also significant differences between these two lines of Shank2 mutant mice”

In the paper

“Spatial learning and memory was impaired in Shank2 Δex6-7−/− but normal in Shank2 Δex7−/− mice.”

What the sources say

• Not checked yetcites Won et al., 2012 source
• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“Interestingly, the ratio of NMDA/AMPA currents was reduced at CA1 synapses in Shank2 Δex6-7−/− mice but increased at the same synapses of Shank2 Δex7−/− mice.”

What the sources say

• Not checked yetcites Won et al., 2012 source
• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“Because the transcript structure has not been fully worked out, the possibility that this is not a complete Shank1 knockout cannot be ruled out.”

In the paper

“In Shank2 Δex7−/− mice, GluN1 and GluN2B NMDA-type glutamate receptors in hippocampus and GluN1, GluN2A, and GluA1 in striatum are increased (Schmeisser et al., 2012).”

What the sources say

• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“NMDA receptor-dependent LTP in hippocampal CA1 synapses was increased and LTD was unaffected in Shank2 Δex7−/− mice.”

What the sources say

• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“Whereas baseline synaptic transmission was reduced in Shank2 Δex7−/− mice (Schmeisser et al., 2012), normal synaptic transmission was observed in Shank2 Δex6-7−/− mice (Won et al., 2012).”

What the sources say

• Not checked yetcites Schmeisser et al., 2012 source
• Not checked yetcites Won et al., 2012 source

In the paper

“To add further complexity, SHANK3 has five CpG islands across the gene and these CpG islands display brain-specific and cell type-specific DNA methylation (Figure 1A) (Beri et al., 2007; Ching et al., 2005; Maunakea et al., 2010).”

What the sources say

• Not checked yetcites Beri et al., 2007 source
• Not checked yetcites Ching et al., 2005 source
• Not checked yetcites Maunakea et al., 2010 source

In the paper

“Basal synaptic transmission was reduced but long-term potentiation (LTP) and long-term depression (LTD) in CA1 hippocampus were unaffected (Hung et al., 2008).”

What the sources say

• Not checked yetcites Hung et al., 2008 source

In the paper

“However, a recent report indicates that SHANK2E is also expressed in brain tissues in humans (Leblond et al., 2012).”

What the sources say

• Not checked yetcites Leblond et al., 2012 source

In the paper

“Interestingly, treatment with D-cycloserine, a NMDA receptor agonist, restored the NMDA/AMPA ratio and improved social interaction in the three-chamber social interaction assay in Shank2 Δex6-7−/− mice (Won et al., 2012).”

What the sources say

• Not checked yetcites Won et al., 2012 source

In the paper

“Behaviorally, hyperactivity, impaired social interaction, altered ultrasonic vocalizations, and increased self-grooming were observed in both Shank2 Δex6-7−/− and Shank2 Δex7−/− mice.”

What the sources say

• Not checked yetcites Won et al., 2012 source
• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“Behavioral analyses revealed subtle impairments in social interaction and communication as well as increased repetitive behaviors (Silverman et al., 2011; Wohr et al., 2011).”

What the sources say

• Not checked yetcites Silverman et al., 2011 source
• Not checked yetcites Wohr et al., 2011 source

In the paper

“In contrast, both NMDA receptor-dependent LTP and LTD at CA1 synapses were reduced in Shank2 Δex6-7−/− mice.”

What the sources say

• Not checked yetcites Won et al., 2012 source

In the paper

“Shank1 mutant mice with a deletion of exons 14-15 encoding the PDZ domain were first reported in 2007 (Hung et al., 2008) (Figure 3C) and more extensive behavioral analyses were conducted subsequently (Silverman et al., 2011; Wohr et al., 2011).”

What the sources say

• Not checked yetcites Hung et al., 2008 source
• Not checked yetcites Silverman et al., 2011 source
• Not checked yetcites Wohr et al., 2011 source

In the paper

“In addition, treatment with CDPPB, an mGluR5-selective positive allosteric modulator, not only rescued the reduced NMDA/AMPA ratio but also recovered the defective LTP and LTD in hippocampus as well as biochemical changes in Shank2 Δex6-7−/− mice.”

• Also stated in: § Modeling SHANKs Mutations in Mice · plain

  “CDPPB also reversed the impaired social interaction impairment in Shank2 Δex6-7−/− mice without affecting other behavioral impairments in these mice (Won et al., 2012).”

What the sources say

• Not checked yetcites Won et al., 2012 source

In the paper

“Overall, the data obtained from these studies support a general conclusion that synaptic function is impaired and social behaviors are abnormal in mice with Shank3 mutations.”

In the paper

“but they were unchanged in the stratum of Δex11−/− mice (Schmeisser et al., 2012).”

What the sources say

• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“The mRNAs with joining of exons 2-10 and exons 3-10 were stable and were predicted to result in a frame shift in protein sequence shortly after exon 10.”

In the paper

“The Δex11 mutation (Schmeisser et al., 2012) is predicted to disrupt promoters 1 to 3 for Shank3a-c but not promoters 4 to 6 for Shank3d-f”

What the sources say

• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“Such variation may be due to isoform-specific effects of different mutations.”

In the paper

“Different brain regions including hippocampus, striatum, and neocortex were analyzed in different lines of mutant mice.”

In the paper

“Because all these deletions cause a frame shift for targeted transcripts, they all resulted in either a truncated Shank3 protein or possible disruption of full length RNA or protein isoforms due to the stability of encoded mRNA or protein.”

In the paper

“but not in the hippocampal CA1 synapses in ex4-9J−/− mice (Wang et al., 2011) or Δex11−/− mice (Schmeisser et al., 2012).”

What the sources say

• Not checked yetcites Wang et al., 2011 source
• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“spine density was decreased in the striatum and CA1 hippocampus of Δex13-16−/− and Δex4-9J−/− mice, respectively.”

What the sources say

• Not checked yetcites Peca et al., 2011 source
• Not checked yetcites Wang et al., 2011 source

In the paper

“The methods and techniques used in these analyses were similar but not identical.”

In the paper

“The mutations in these mice include deletions of exons 4-9 by two groups with slightly different design [(Δex4-9Buxbaum(B)) (Bozdagi et al., 2010) and Δex4-9Jiang (J) (Wang et al., 2011)], deletion of exons 4-7(Δex4-7) (Peca et al., 2011) encoding the ANK repeat domain, deletion of exon 11(Δex11) encoding the SH3 domain (Schmeisser et al., 2012), and deletion of exons 13-16 (Δex13-16) encoding the”

What the sources say

• Not checked yetcites Bozdagi et al., 2010 source
• Not checked yetcites Peca et al., 2011 source
• Not checked yetcites Schmeisser et al., 2012 source

In the paper

“In general, mutation of Shank3 leads to loss of spines, a reduction in spine volume, and decreased PSD thickness in the adult.”

In the paper

“synaptic transmission is reduced at hippocampal CA1 synapses of Δex4-9B+/− (Bozdagi et al., 2010) and Δex4-9B−/− (Yang et al., 2012), but not in Δex4-9J−/− (Wang et al., 2011) or Δex13-16−/− mice (Peca et al., 2011)”

What the sources say

• Not checked yetcites Bozdagi et al., 2010 source
• Not checked yetcites Yang et al., 2012 source
• Not checked yetcites Wang et al., 2011 source

In the paper

“Short-term and long-term memory in a social transmission test were impaired in Δex4-9J−/− mice (Wang et al., 2011).”

What the sources say

• Not checked yetcites Wang et al., 2011 source

In the paper

“In human patients, ASD is a behavioral diagnosis with considerable clinical heterogeneity.”

In the paper

“NMDA receptor-dependent long-term depression (LTD) induced by low frequency stimulus and mGluR-dependent LTD induced by PP-LFS were not affected in CA1 hippocampus of ex4-9B mice”

What the sources say

• Not checked yetcites Bozdagi et al., 2010 source
• Not checked yetcites Yang et al., 2012 source

In the paper

“In striatum, the frequency of mEPSCs and amplitude of population spikes were significantly decreased in Δex13-16−/− mice, but only mildly affected in Δex4-7−/− mice (Peca et al., 2011).”

What the sources say

• Not checked yetcites Peca et al., 2011 source

In the paper

“A naturally occurring Disc1 (Disrupted in schizophrenia) mutation in the 129 strain of ES cells (Clapcote et al., 2007; Clapcote and Roder, 2006) was segregated from the Δex4-9J−/− deletion (Wang et al., 2011) but was not reported in other Shank3 mutant mice using mouse 129 ES cells (Peca et al., 2011; Schmeisser et al., 2012).”

What the sources say

• Not checked yetcites Clapcote et al., 2007 source
• Not checked yetcites Clapcote and Roder, 2006
• Not checked yetcites Wang et al., 2011 source

In the paper

“In addition, mouse genetic background, animal age, and specific protocols used for the studies may contribute to the variability.”

In the paper

“perhaps due to differential spatial and temporal expression of other Shank family members or to compositional variation across different populations of glutamatergic synapses.”

In the paper

“Notably, synapse structure phenotypes vary with specific Shank3 mutations, are different in different brain regions, and display developmental heterogeneity”

In the paper

“Impaired performance in the Morris water maze task was seen in Δex4-9J−/− mice (Wang et al., 2011) but not in Δex13-16−/− (Peca et al., 2011) and Δex4-9B−/− animals (Yang et al., 2012).”

What the sources say

• Not checked yetcites Wang et al., 2011 source
• Not checked yetcites Peca et al., 2011 source
• Not checked yetcites Yang et al., 2012 source

In the paper

“However, analysis of heterozygotes versus homozygotes, different measurements in different brain regions, as well as different genetic backgrounds could all contribute to phenotypic heterogeneity.”

In the paper

“Mutations in the SH3 and PDZ domains are missense mutations in humans (Boccuto et al., 2012; Waga et al., 2011), but mouse mutation of Δex11 and Δex13-16 are exon deletion and frame shift mutations (Peca et al., 2011; Schmeisser et al., 2012).”

What the sources say

• Not checked yetcites Boccuto et al., 2012
• Not checked yetcites Waga et al., 2011 source
• Not checked yetcites Peca et al., 2011 source

In the paper

“Despite the consistent intellectual disability reported in patients with multiple types of SHANK3 mutations, Shank3 mutant mice differed significantly in performance of learning and memory tasks.”

In the paper

“Several competing hypotheses have been proposed to account for core deficits and ancillary symptomatic domains in ASD, but none have been widely accepted (Belmonte et al., 2004; Courchesne et al., 2007; Geschwind and Levitt, 2007; Rubenstein, 2010; Zoghbi, 2003).”

What the sources say

• Not checked yetcites Belmonte et al., 2004 source
• Not checked yetcites Courchesne et al., 2007 source
• Not checked yetcites Geschwind and Levitt, 2007 source

In the paper

“Although the triad of impaired social interaction, communication, and stereotypical behaviors is recognized as core to ASD, the clinical presentation of these impairments is highly varied in humans.”

In the paper

“Remarkably little is known about the neurological basis of ASD, and many brain regions and circuits have been implicated in ASD (Amaral et al., 2008; Anagnostou and Taylor, 2011; Bauman and Kemper, 2005; Courchesne et al., 2007).”

What the sources say

• Not checked yetcites Amaral et al., 2008 source
• Not checked yetcites Anagnostou and Taylor, 2011
• Not checked yetcites Bauman and Kemper, 2005 source

In the paper

“Functional studies are thus a critical component to determine the pathogenicity of specific genetic variants.”

In the paper

“Because of the rarity of sequence variants across the population, it has been challenge to establish a causal role for specific variants in human disease.”

In the paper

“Specific mutations are likely to produce specific phenotypes in patients and hence must be modeled accordingly in mice for the mutant mice to have full translational potential.”

In the paper

“In mouse behavioral studies, testing paradigms for learning and memory have been widely accepted (Crawley, 2008; Crawley and Paylor, 1997; Morris, 1981).”

What the sources say

• Not checked yetcites Crawley, 2008 source
• Not checked yetcites Crawley and Paylor, 1997
• Not checked yetcites Morris, 1981 source

In the paper

“Ultimately, the value of Shank mutant mice will depend critically on the ability to use human patients to validate their predictive utility.”

In the paper

“The lesson learned from modeling SHANK mutations in mice will almost certainly be valuable to modeling other ASD candidate genes in the future.”