Genetic background modulates phenotypes of serotonin transporter Ala56 knock-in mice / Travis KERR in Molecular Autism, (October 2013)  

Public ISBD [article]  inMolecular Autism > (October 2013) Titre : Genetic background modulates phenotypes of serotonin transporter Ala56 knock-in mice Type de document : Texte imprimé et/ou numérique Auteurs : Travis KERR, Auteur ; Christopher MULLER, Auteur ; Mahfuzur MIAH, Auteur ; Christopher JETTER, Auteur ; Rita PFEIFFER, Auteur ; Charisma SHAH, Auteur ; Nicole BAGANZ, Auteur ; George M. ANDERSON, Auteur ; Jacqueline N. CRAWLEY, Auteur ; James SUTCLIFFE, Auteur ; Randy BLAKELY, Auteur ; Jeremy VEENSTRA-VANDERWEELE, Auteur Langues : Anglais (eng) Index. décimale : PER Périodiques Résumé : Previously, we identified multiple, rare serotonin (5-HT) transporter (SERT) variants in children with autism spectrum disorder (ASD). Although in our study the SERT Ala56 variant was over-transmitted to ASD probands, it was also seen in some unaffected individuals, suggesting that associated ASD risk is influenced by the epistatic effects of other genetic variation. Subsequently, we established that mice expressing the SERT Ala56 variant on a 129S6/S4 genetic background display multiple biochemical, physiological and behavioral changes, including hyperserotonemia, altered 5-HT receptor sensitivity, and altered social, communication, and repetitive behavior. Here we explore the effects of genetic background on SERT Ala56 knock-in phenotypes. To explore the effects of genetic background, we backcrossed SERT Ala56 mice on the 129 background into a C57BL/6 (B6) background to achieve congenic B6 SERT Ala56 mice, and assessed autism-relevant behavior, including sociability, ultrasonic vocalizations, and repetitive behavior in the home cage, as well as serotonergic phenotypes, including whole blood serotonin levels and serotonin receptor sensitivity. One consistent phenotype between the two strains was performance in the tube test for dominance, where mutant mice displayed a greater tendency to withdraw from a social encounter in a narrow tube as compared to wildtype littermate controls. On the B6 background, mutant pup ultrasonic vocalizations were significantly increased, in contrast to decreased vocalizations seen previously on the 129 background. Several phenotypes seen on the 129 background were reduced or absent when the mutation was placed on the B6 background, including hyperserotonemia, 5-HT receptor hypersensivity, and repetitive behavior. Our findings provide a cogent example of how epistatic interactions can modulate the impact of functional genetic variation and suggest that some aspects of social behavior may be especially sensitive to changes in SERT function. Finally, these results provide a platform for the identification of genes that may modulate the risk of ASD in humans. En ligne : http://dx.doi.org/10.1186/2040-2392-4-35 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=227 [article] Genetic background modulates phenotypes of serotonin transporter Ala56 knock-in mice [Texte imprimé et/ou numérique] / Travis KERR, Auteur ; Christopher MULLER, Auteur ; Mahfuzur MIAH, Auteur ; Christopher JETTER, Auteur ; Rita PFEIFFER, Auteur ; Charisma SHAH, Auteur ; Nicole BAGANZ, Auteur ; George M. ANDERSON, Auteur ; Jacqueline N. CRAWLEY, Auteur ; James SUTCLIFFE, Auteur ; Randy BLAKELY, Auteur ; Jeremy VEENSTRA-VANDERWEELE, Auteur. Langues : Anglais (eng) in Molecular Autism > (October 2013) Index. décimale : PER Périodiques Résumé : Previously, we identified multiple, rare serotonin (5-HT) transporter (SERT) variants in children with autism spectrum disorder (ASD). Although in our study the SERT Ala56 variant was over-transmitted to ASD probands, it was also seen in some unaffected individuals, suggesting that associated ASD risk is influenced by the epistatic effects of other genetic variation. Subsequently, we established that mice expressing the SERT Ala56 variant on a 129S6/S4 genetic background display multiple biochemical, physiological and behavioral changes, including hyperserotonemia, altered 5-HT receptor sensitivity, and altered social, communication, and repetitive behavior. Here we explore the effects of genetic background on SERT Ala56 knock-in phenotypes. To explore the effects of genetic background, we backcrossed SERT Ala56 mice on the 129 background into a C57BL/6 (B6) background to achieve congenic B6 SERT Ala56 mice, and assessed autism-relevant behavior, including sociability, ultrasonic vocalizations, and repetitive behavior in the home cage, as well as serotonergic phenotypes, including whole blood serotonin levels and serotonin receptor sensitivity. One consistent phenotype between the two strains was performance in the tube test for dominance, where mutant mice displayed a greater tendency to withdraw from a social encounter in a narrow tube as compared to wildtype littermate controls. On the B6 background, mutant pup ultrasonic vocalizations were significantly increased, in contrast to decreased vocalizations seen previously on the 129 background. Several phenotypes seen on the 129 background were reduced or absent when the mutation was placed on the B6 background, including hyperserotonemia, 5-HT receptor hypersensivity, and repetitive behavior. Our findings provide a cogent example of how epistatic interactions can modulate the impact of functional genetic variation and suggest that some aspects of social behavior may be especially sensitive to changes in SERT function. Finally, these results provide a platform for the identification of genes that may modulate the risk of ASD in humans. En ligne : http://dx.doi.org/10.1186/2040-2392-4-35 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=227

Rare coding variants of the adenosine A3 receptor are increased in autism: on the trail of the serotonin transporter regulome / Nicholas G. CAMPBELL in Molecular Autism, (August 2013)  

Public ISBD [article]  inMolecular Autism > (August 2013) Titre : Rare coding variants of the adenosine A3 receptor are increased in autism: on the trail of the serotonin transporter regulome Type de document : Texte imprimé et/ou numérique Auteurs : Nicholas G. CAMPBELL, Auteur ; Chong-Bin ZHU, Auteur ; Kathryn LINDLER, Auteur ; Brian YASPAN, Auteur ; Emily KISTNER-GRIFFIN, Auteur ; NIH ARRA CONSORTIUM,, Auteur ; William HEWLETT, Auteur ; Christopher TATE, Auteur ; Randy BLAKELY, Auteur ; James SUTCLIFFE, Auteur Langues : Anglais (eng) Index. décimale : PER Périodiques Résumé : BACKGROUND:Rare genetic variation is an important class of autism spectrum disorder (ASD) risk factors and can implicate biological networks for investigation. Altered serotonin (5-HT) signaling has been implicated in ASD, and we and others have discovered multiple, rare, ASD-associated variants in the 5-HT transporter (SERT) gene leading to elevated 5-HT re-uptake and perturbed regulation. We hypothesized that loci encoding SERT regulators harbor variants that impact SERT function and/or regulation and therefore could contribute to ASD risk. The adenosine A3 receptor (A3AR) regulates SERT via protein kinase G (PKG) and other signaling pathways leading to enhanced SERT surface expression and catalytic activity.METHODS:To test our hypothesis, we asked whether rare variants in the A3AR gene (ADORA3) were increased in ASD cases vs. controls. Discovery sequencing in a case-control sample and subsequent analysis of comparison exome sequence data were conducted. We evaluated the functional impact of two variants from the discovery sample on A3AR signaling and SERT activity.RESULTS:Sequencing discovery showed an increase of rare coding variants in cases vs. controls (P=0.013). While comparison exome sequence data did not show a significant enrichment (P=0.071), combined analysis strengthened evidence for association (P=0.0025). Two variants discovered in ASD cases (Leu90Val and Val171Ile) lie in or near the ligand-binding pocket, and Leu90Val was enriched individually in cases (P=0.040). In vitro analysis of cells expressing Val90-A3AR revealed elevated basal cGMP levels compared with the wildtype receptor. Additionally, a specific A3AR agonist increased cGMP levels across the full time course studied in Val90-A3AR cells, compared to wildtype receptor. In Val90-A3AR/SERT co-transfections, agonist stimulation elevated SERT activity over the wildtype receptor with delayed 5-HT uptake activity recovery. In contrast, Ile171-A3AR was unable to support agonist stimulation of SERT. Although both Val90 and Ile171 were present in greater numbers in these ASD cases, segregation analysis in families showed incomplete penetrance, consistent with other rare ASD risk alleles.CONCLUSIONS:Our results validate the hypothesis that the SERT regulatory network harbors rare, functional variants that impact SERT activity and regulation in ASD, and encourages further investigation of this network for other variation that may impact ASD risk. En ligne : http://dx.doi.org/10.1186/2040-2392-4-28 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=227 [article] Rare coding variants of the adenosine A3 receptor are increased in autism: on the trail of the serotonin transporter regulome [Texte imprimé et/ou numérique] / Nicholas G. CAMPBELL, Auteur ; Chong-Bin ZHU, Auteur ; Kathryn LINDLER, Auteur ; Brian YASPAN, Auteur ; Emily KISTNER-GRIFFIN, Auteur ; NIH ARRA CONSORTIUM,, Auteur ; William HEWLETT, Auteur ; Christopher TATE, Auteur ; Randy BLAKELY, Auteur ; James SUTCLIFFE, Auteur. Langues : Anglais (eng) in Molecular Autism > (August 2013) Index. décimale : PER Périodiques Résumé : BACKGROUND:Rare genetic variation is an important class of autism spectrum disorder (ASD) risk factors and can implicate biological networks for investigation. Altered serotonin (5-HT) signaling has been implicated in ASD, and we and others have discovered multiple, rare, ASD-associated variants in the 5-HT transporter (SERT) gene leading to elevated 5-HT re-uptake and perturbed regulation. We hypothesized that loci encoding SERT regulators harbor variants that impact SERT function and/or regulation and therefore could contribute to ASD risk. The adenosine A3 receptor (A3AR) regulates SERT via protein kinase G (PKG) and other signaling pathways leading to enhanced SERT surface expression and catalytic activity.METHODS:To test our hypothesis, we asked whether rare variants in the A3AR gene (ADORA3) were increased in ASD cases vs. controls. Discovery sequencing in a case-control sample and subsequent analysis of comparison exome sequence data were conducted. We evaluated the functional impact of two variants from the discovery sample on A3AR signaling and SERT activity.RESULTS:Sequencing discovery showed an increase of rare coding variants in cases vs. controls (P=0.013). While comparison exome sequence data did not show a significant enrichment (P=0.071), combined analysis strengthened evidence for association (P=0.0025). Two variants discovered in ASD cases (Leu90Val and Val171Ile) lie in or near the ligand-binding pocket, and Leu90Val was enriched individually in cases (P=0.040). In vitro analysis of cells expressing Val90-A3AR revealed elevated basal cGMP levels compared with the wildtype receptor. Additionally, a specific A3AR agonist increased cGMP levels across the full time course studied in Val90-A3AR cells, compared to wildtype receptor. In Val90-A3AR/SERT co-transfections, agonist stimulation elevated SERT activity over the wildtype receptor with delayed 5-HT uptake activity recovery. In contrast, Ile171-A3AR was unable to support agonist stimulation of SERT. Although both Val90 and Ile171 were present in greater numbers in these ASD cases, segregation analysis in families showed incomplete penetrance, consistent with other rare ASD risk alleles.CONCLUSIONS:Our results validate the hypothesis that the SERT regulatory network harbors rare, functional variants that impact SERT activity and regulation in ASD, and encourages further investigation of this network for other variation that may impact ASD risk. En ligne : http://dx.doi.org/10.1186/2040-2392-4-28 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=227

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