Project description:DNA damage has been implicated in neurodegenerative disorders, including Alzheimer’s disease and other tauopathies, but the consequences of genotoxic stress to postmitotic neurons are poorly understood. Here we demonstrate that p53, a key mediator of the DNA damage response, plays a neuroprotective role in a Drosophila model of tauopathy. Further, through a whole-genome ChIP-chip analysis we identify genes controlled by p53 in postmitotic neurons. We genetically validate a specific pathway, synaptic function, in p53-mediated neuroprotection. We then demonstrate that the control of synaptic genes by p53 is conserved in mammals. Collectively, our results implicate synaptic function as a central target in p53-dependent protection from neurodegeneration. 4 samples: tau vs. control
Project description:DNA damage has been implicated in neurodegenerative disorders, including Alzheimer’s disease and other tauopathies, but the consequences of genotoxic stress to postmitotic neurons are poorly understood. Here we demonstrate that p53, a key mediator of the DNA damage response, plays a neuroprotective role in a Drosophila model of tauopathy. Further, through a whole-genome ChIP-chip analysis we identify genes controlled by p53 in postmitotic neurons. We genetically validate a specific pathway, synaptic function, in p53-mediated neuroprotection. We then demonstrate that the control of synaptic genes by p53 is conserved in mammals. Collectively, our results implicate synaptic function as a central target in p53-dependent protection from neurodegeneration.
Project description:Evidence suggests that impaired synaptic and firing homeostasis represents a driving force of early Alzheimer’s disease (AD) progression. Here, we examine synaptic and sleep homeostasis in a Drosophila model by overexpressing human amyloid precursor protein (APP), whose duplication and mutations cause familial early-onset AD. We find that APP overexpression induces synaptic hyperexcitability. RNA-seq data indicate exaggerated expression of Ca2+ related signaling genes in APP mutants, including genes encoding Dmca1D, calcineurin (CaN) complex, and IP3R, but not in hyperexcitable mutants caused by TrpA1 or Shal/Kv4. We further demonstrate that increased CaN activity triggers transcriptional activation of Itpr (IP3R) through activating nuclear factor of activated T cells (NFAT). Strikingly, APP overexpression causes defects in both synaptic downscaling and sleep deprivation induced sleep rebound, and both defects could be restored by inhibiting IP3R. Our findings uncover IP3R as a shared signaling molecular in synaptic downscaling and sleep homeostasis, and its dysregulation may lead to synaptic hyperexcitability and AD progression at early stage.