Project description:The autism spectrum disorders (ASD) are a collection of disorders with heterogeneous etiology, exhibiting common traits including impaired social interactions and communications, repetitive behaviors. 15q11-q13 copy number variations (CNV) were found in 1-3% of ASD cases; of which the detailed mechanism of the major contributor UBE3A gene acted still remained elusive. Here we identified a key enzyme in RA synthesis, negatively regulated in ubiquitination-dependent mode promoted by UBE3A. Our data provide evidences linking UBE3A hyperactivity with ASD phenotypes, with implications for understanding ASD etiology and providing potential interventions in ASD clinical therapy.
Project description:Autism spectrum disorders (ASD) are characterized by a high degree of genetic heterogeneity. Genomic studies identified common pathological processes underlying the heterogeneous clinical manifestations of ASD, and transcriptome analyses revealed that gene networks involved in synapse development, neuronal activity and immune function are deregulated in ASD. Mouse models provide unique tools to investigate the neurobiological basis of ASD. Here we used the BTBR (BTBR T+ Itpr3tf/J) ASD mouse model to identify conserved ASD-related molecular signatures. Gene expression in the BTBR mouse prefrontal cortex was measured by microarrays and compared to the gene expression profile of C57Bl6/J controls (5 months old, n= 3 mice per group).
Project description:Autism spectrum disorders (ASD) are characterized by a high degree of genetic heterogeneity. Genomic studies identified common pathological processes underlying the heterogeneous clinical manifestations of ASD, and transcriptome analyses revealed that gene networks involved in synapse development, neuronal activity and immune function are deregulated in ASD. Mouse models provide unique tools to investigate the neurobiological basis of ASD. Here we used the BTBR (BTBR T+ Itpr3tf/J) ASD mouse model to identify conserved ASD-related molecular signatures. Gene expression in the BTBR mouse hippocampus was measured by microarrays and compared to the gene expression profile of C57Bl6/J controls (5 months old, n= 4 mice per group).
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Autism spectrum disorder (ASD) and mental retardation (MR) represent clinically distinct neurodevelopmental disorders with a complex genetic etiology. Using microarrays we identified de novo copy number variations in the SHANK2 synaptic scaffolding gene in two unrelated ASD and MR patients; DNA sequencing of SHANK2 revealed additional variants including a de novo nonsense mutation and 7 rare inherited changes. Our findings further link common genes between ASD and intellectual disability.
Project description:Autism spectrum disorders (ASD) are neurodevelopmental disorders characterized by abnormalities in reciprocal social interactions and language development and/or usage, and by restricted interests and repetitive behaviors. Differential gene expression of neurologically relevant genes in lymphoblastoid cell lines from monozygotic twins discordant in diagnosis or severity of autism suggested that epigenetic factors such as DNA methylation or microRNAs (miRNAs) may be involved in ASD. The goal of this study was to reveal dysregulation in miRNA levels that are inversely correlated with altered levels of target genes that, in turn, may be associated with the underlying pathophysiology of ASD, and to provide a better understanding of the role of miRNAs as a post-transcriptional gene regulatory mechanism associated with ASD.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Autism spectrum disorders (ASD) are characterized by a high degree of genetic heterogeneity. Genomic studies identified common pathological processes underlying the heterogeneous clinical manifestations of ASD, and transcriptome analyses revealed that gene networks involved in synapse development, neuronal activity and immune function are deregulated in ASD. Mouse models provide unique tools to investigate the neurobiological basis of ASD. Here we used the BTBR (BTBR T+ Itpr3tf/J) ASD mouse model to identify conserved ASD-related molecular signatures.