Project description:Monogenic neurodevelopmental disorders provide key insights into the pathogenesis of disease and help us understand how specific genes control the development of the human brain. Timothy syndrome is caused by a missense mutation in the L-type calcium channel Cav1.2 that is associated with developmental delay and autism. We generated cortical neuronal precursor cells and neurons from induced pluripotent stem cells derived from individuals with Timothy syndrome. Cells from these individuals have defects in calcium (Ca2+) signaling and activity-dependent gene expression and show abnormalities in differentiation. Neurons from individuals with Timothy syndrome show increased expression of markers of the upper cortical layer and decreased expression of callosal projection markers. In addition, the mutation that causes Timothy syndrome leads to an increase in the production of neurons that synthesize norepinephrine and dopamine. This phenotype can be reversed by treatment with roscovitine, a cyclin-dependent kinase and atypical L-type–channel blocker. These findings provide strong evidence that Cav1.2 regulates the differentiation of cortical neurons in humans and offer new insights into the causes of autism in individuals with Timothy syndrome. Total RNA was isolated from control and TS cells: fibroblasts, iPSCs, neurospheres (at day 7 in suspension), neurons at rest (day 45 of differentiation) and neurons kept in 67mM KCl for 9h. For sample titles, D1,D2 and D3 represent independent differentiation experiments. The number after - represents the iPSC cell line number. GSE25542_non-normalized.txt.gz contains data for 5 outliers.
Project description:Mutation of marA, rob, and soxS causes a clinical strain of E.coli to be attenuated at d3 post-infection in a mouse model of pyelonephritis, here we extract RNA at d2 post infection to analyze transcriptional differences between the two strains.
2010-10-01 | GSE23417 | GEO
Project description:Gene Mutation Causes a Syndrome of Combined Immunodeficiency
Project description:Monogenic neurodevelopmental disorders provide key insights into the pathogenesis of disease and help us understand how specific genes control the development of the human brain. Timothy syndrome is caused by a missense mutation in the L-type calcium channel Cav1.2 that is associated with developmental delay and autism. We generated cortical neuronal precursor cells and neurons from induced pluripotent stem cells derived from individuals with Timothy syndrome. Cells from these individuals have defects in calcium (Ca2+) signaling and activity-dependent gene expression and show abnormalities in differentiation. Neurons from individuals with Timothy syndrome show increased expression of markers of the upper cortical layer and decreased expression of callosal projection markers. In addition, the mutation that causes Timothy syndrome leads to an increase in the production of neurons that synthesize norepinephrine and dopamine. This phenotype can be reversed by treatment with roscovitine, a cyclin-dependent kinase and atypical L-type–channel blocker. These findings provide strong evidence that Cav1.2 regulates the differentiation of cortical neurons in humans and offer new insights into the causes of autism in individuals with Timothy syndrome.
Project description:Grainyhead-like transcription factor 3 (GRHL3) directs surface ectoderm differentiation under the control of the canonical Wnt/β-catenin pathway. However, the molecular mechanisms that control nuclear GRHL3 expression through β-catenin are not fully understood. Here, we show that the essential for mitotic growth 1 (EMG1) protein constitutes a protein complex with GRHL3, and that EMG1 is required for correct nuclear localization of GRHL3, and for activation of the canonical Wnt signaling pathway. Conditional knockout mutation of Emg1 in the GRHL3-positive surface ectoderm causes neural tube defects at the level of the spinal cord, i.e. spina bifida. Additionally, the severity of compound mutant phenotypes of the Emg1 and Grhl3 genes indicates that they interact genetically in neurulation and palate development. These lines of evidence demonstrate that EMG1 cooperates with GRHL3 in β-catenin–mediated surface ectoderm differentiation. Since the EMG1 mutation causes Bowen-Conradi syndrome and the GRHL3 mutation causes Van der Woude syndrome 2, both of which are associated with neural tube dysplasia and cleft palate, our study will help to better understand the pathogenic mechanisms of these two human genetic diseases.
Project description:Loss-of-function of the chromatin remodeler CHD7 causes CHARGE syndrome, characterized by variable penetrance and diverse abnormalities. However, establishing genotype-phenotype correlations has been challenging, as most CHD7 inactivating mutations are null alleles. Through CHD7 missense variant analysis at potential phosphorylation sites, we identified T730 (T720 in mice) as a critical residue associated with pathogenesis. Using a CHD7 T730 missense mutation (Chd7T720A) and a frameshift null allele (Chd7fs) in a mouse model, we found that Chd7fs/fs mice were non-viable, while Chd7fs/+ mice exhibited haploinsufficiency-related circling behavior. Notably, Chd7fs/T720A mice died before postnatal day 2, indicating the Chd7T720A allele is hypomorphic. Micro-CT analysis at E18.5 revealed heterozygous mice primarily exhibited hypertrophic cardiomyopathy (HCM), while homozygous mice developed both HCM and dilated cardiomyopathy (DCM). RNA-seq analysis of neonatal Chd7T720A/T720A hearts revealed a disrupted transcriptome, which in males and females was characterized by downregulation of mitochondrial energy metabolism genes and enrichment of ETS family transcription factor targets. We further identified GSK3β, GSK3α, HIPK1, and DYRK2 as candidate kinases for this site, suggesting a regulatory role in CHD7. This missense mutation causing developmental heart abnormalities establishes the first genotype-phenotype correlation for CHD7, and offers new insights into CHARGE syndrome pathogenesis.
Project description:The aim of this study was to understand why two siblings carrying both the same homozygous causal mutation for the auto-inflammatory disease hyper IgD syndrome show opposite phenotypes, i.e. the first being asymptomatic, the second presenting all classical characteristics of the disease.