Project description:Transcriptional profiling of E18.5 livers derived from Wnt5a-deficient (KO) mice compared to those from littermate wild-type (WT) mice. RNA samples were extracted from whole livers derived from E18.5 fetuses.
Project description:The decline of cognitive function is a feature of normal human aging and is exacerbated in AlzheimerM-bM-^@M-^Ys disease (AD). DNA repair declines in brain cells during normal aging and even more so in AD. Here we show that experimental reduction in levels of the base excision repair enzyme, DNA polymerase M-NM-2 (Polb) renders neurons vulnerable to age-related dysfunction and degeneration in a mouse model of AD. Whereas 3xTgAD mice exhibit age-related extracellular amyloid b-peptide (Ab) accumulation and cognitive deficits, but no neuronal death, 3xTg/Polb+/- mice accumulates intracellular Ab and neurons die in the hippocampus and cerebral cortex. The DNA repair-deficient 3xTgAD mice exhibited increased DNA strand breaks and apoptotic caspase activation with loss of hippocampal volume, and impaired synaptic plasticity and memory retention. Molecular profiling revealed remarkable similarities in gene expression alterations in brain cells of AD patients and 3xTgAD/Polb+/- mice including multiple abnormalities suggestive of impaired cellular bioenergetics. Our findings demonstrate that a modest decrement in oxidative DNA damage processing is sufficient to render neurons vulnerable to AD-related pathogenic molecular and cellular alterations that result in the dysfunction and death of neurons, and associated cognitive deficits. 4 mouse strains were used in these experiments, the 3xTgAD and Pol M-NM-2 (+/-) mice were bred at the National Institute on Aging (Baltimore, Maryland). The original line 3xTgAD line was generated as described previously (Oddo, et. al 2003) and possess APPswe, PS1M146V, and tauP301L mutations. DNA polymerase beta heterozygous mice, Pol M-NM-2 (+/-), were crossed with the 3xTgAD mice to generate a 3xTgAD/Pol M-NM-2 (+/-) mouse. The Wt strain is C57Bl/6. At 20 months of age these mice were euthanized by cervical dislocation, the brain removed from the skull and dissected into regions of interest, the prefrontal cortex was used for the microarray studies.
Project description:We report mRNA profiles of subcellularly localized transcriptomes (soma and neurite) of two mouse cell lines, N2A and CAD, as well as primary cortical neurons from E18.5 mice. We also performed this fractionation and sequencing after RNAi knockdown (cell lines) or in knockout mice (primary cortical neurons) of the RNA-binding proteins muscleblind 1 and 2 (Mbnl1 and Mbnl2). Fractionate neurons using porous transwell membranes. Isolate poly-A RNA.
Project description:Emerging findings suggest that compromised cellular bioenergetics and DNA repair contribute to the pathogenesis of Alzheimer's disease (AD), but their role in disease-defining pathology is unclear. We developed a DNA repair-deficient 3xTgAD/Polb+/- mouse that exacerbates major features of human AD including pTau pathologies, synaptic dysfunction, neuronal death and cognitive impairment. Here we report that 3xTgAD/Polb+/- mice have reduced cerebral NAD+/NADH ratio indicating impaired cerebral energy metabolism, which is normalized by nicotinamide riboside (NR) treatment. NR lessened pTau pathology in both 3xTgAD and 3xTgAD/Polb+/- mice, but had no impact on Abeta accumulation. NR-treated 3xTgAD/Polb+/- mice exhibited reduced DNA damage, neuroinflammation, apoptosis of hippocampal neurons, and increased activity of SIRT3 in the brain. NR improves cognitive function in multiple behavioral tests, and restored hippocampal synaptic plasticity in 3xTgAD mice and 3xTgAD/Polb+/- mice. In general, the deficits and the benefits of NR were greater in 3xTgAD/Polb+/- mice than in 3xTgAD mice. Our findings suggest a pivotal role for cellular NAD+ depletion upstream of neuroinflammation, pTau, DNA damage, synaptic dysfunction and neuronal degeneration in AD. Interventions that bolster neuronal NAD+ levels therefore have potential in AD.
Project description:Transcriptional profiling of E18.5 livers derived from Wnt5a-deficient (KO) mice compared to those from littermate wild-type (WT) mice. RNA samples were extracted from whole livers derived from E18.5 fetuses. Two-condition experiment: Wnt5a KO vs. WT whole livers. Total RNA samples were extracted from E18.5 whole livers. KO and WT samples were a mixture of RNA solutions derived from two Wnt5a KO livers and two WT livers, respectively.
Project description:The decline of cognitive function is a feature of normal human aging and is exacerbated in Alzheimer’s disease (AD). DNA repair declines in brain cells during normal aging and even more so in AD. Here we show that experimental reduction in levels of the base excision repair enzyme, DNA polymerase β (Polb) renders neurons vulnerable to age-related dysfunction and degeneration in a mouse model of AD. Whereas 3xTgAD mice exhibit age-related extracellular amyloid b-peptide (Ab) accumulation and cognitive deficits, but no neuronal death, 3xTg/Polb+/- mice accumulates intracellular Ab and neurons die in the hippocampus and cerebral cortex. The DNA repair-deficient 3xTgAD mice exhibited increased DNA strand breaks and apoptotic caspase activation with loss of hippocampal volume, and impaired synaptic plasticity and memory retention. Molecular profiling revealed remarkable similarities in gene expression alterations in brain cells of AD patients and 3xTgAD/Polb+/- mice including multiple abnormalities suggestive of impaired cellular bioenergetics. Our findings demonstrate that a modest decrement in oxidative DNA damage processing is sufficient to render neurons vulnerable to AD-related pathogenic molecular and cellular alterations that result in the dysfunction and death of neurons, and associated cognitive deficits.
Project description:We report mRNA profiles of subcellularly localized transcriptomes (soma and neurite) of two mouse cell lines, N2A and CAD, as well as primary cortical neurons from E18.5 mice. We also performed this fractionation and sequencing after RNAi knockdown (cell lines) or in knockout mice (primary cortical neurons) of the RNA-binding proteins muscleblind 1 and 2 (Mbnl1 and Mbnl2).
Project description:Biallelic mutations in the gene that encodes the enzyme N-glycanase 1 (NGLY1) cause a rare disease with multi-symptomatic features including developmental delay, intellectual disability, neuropathy and seizures. NGLY1’s activity in human neural cells is currently not well understood. To understand how NGLY1 gene loss leads to the specific phenotypes of NGLY1 deficiency, we employed direct conversion of NGLY1 patient-derived induced pluripotent stem cells (iPSCs) to functional cortical neurons. Transcriptomic, proteomic, and functional studies of iPSC-derived neurons lacking NGLY1 function revealed several major cellular processes that were altered, including protein aggregate-clearing functionality, mitochondrial homeostasis, and synaptic dysfunctions. These phenotypes were rescued by introduction of a functional NGLY1 gene and were observed in iPSC-derived mature neurons, but not astrocytes. Finally, laser capture microscopy followed by mass spectrometry provided detailed characterization of the composition of protein aggregates specific to NGLY1-deficient neurons. Future studies will harness this knowledge for therapeutic development.
Project description:Periventricular heterotopia (PH), the most common form of grey matter heterotopia, represents a cortical malformation that is often associated with developmental delay and drug-resistant seizures1,2. The detailed neurophysiological underpinnings of PH symptoms in humans remain, however, elusive. Human cerebral organoids (hCOs) derived from patients with causative mutations in FAT4 or DCHS1 exhibit key features of PH3, but neuronal activity in these 3D models has not yet been investigated. Here, using silicon probe recordings, we detected exaggerated spontaneous spike activity in FAT4 and DCHS1 hCOs, suggesting functional changes in neuronal networks. Patch-clamp recordings revealed a decreased spike threshold exclusively for DCHS1 neurons, which presumably results from an enhanced density of somatic voltage-gated sodium channels. Furthermore, single-cell morphological reconstructions and immunostainings demonstrated greater morphological complexity of neurons and synaptic alterations, rather than an imbalance of excitatory-inhibitory neuron number, as contributing to the hyperactivity observed in FAT4 and DCHS1 hCOs. The morphological phenotype was rescued by an expression of wild-type DCHS1 in DCHS1 neurons. In addition, transcriptome and proteome analyses uncovered changes in GO terms associated with neuronal morphology and synaptic function. Overall, we provide detailed new insights into cellular alterations likely contributing to the emergence of symptoms in grey matter heterotopia.
Project description:Ovarian clear cell carcinoma (OCCC) is the most lethal gynecological cancer. It is characterized by somatic inactivating mutations of ARID1A, a component of the SWI/SNF chromatin-remodeling complex, occurring in up to 70% of patients. Patients with these mutations in their tumors have considerably poorer outcomes compared to those without such mutations. ARID1A-deficient cells have been shown to have a higher dependence on mitochondrial respiration, suggesting that targeting mitochondrial respiration is a promising approach to eliminating ARID1A-deficient cancer cells. Here we generated and characterized OCCC-derived ARID1A wild type and knock-out cell lines. Our proteomic data provide evidence of the increased relative abundance of mETC proteins in the ARID1A knock-out OCCC cells. Taken together, our data provides a rationale for identifying therapeutic vulnerabilities within the mETC in the context of treating ARID1A-deficient OCCC.