Our preliminary studies show that the FTD/ALS-associated mitochondrial protein, CHCHD10, declines in brains of APP/PS1 mice and human AD patients, which negatively correlates with A? levels. Restoration of CHCHD10 in APP/PS1 mice reduces A? deposition in vivo. In transfected cells, wild type CHCHD10 promotes mitochondrial respiration as well as mitophagy and autophagy via PINK1/Parkin and p62/LC3 pathways.
In aim 1, we take advantage of the APP/PS1 AD model, our newly generated CHCHD10 transgenic mice, and the mitophagy reporter mice (mito-QC) to test the hypothesis that CHCHD10 restoration mitigates A? pathology and neuroinflammation while enhancing mitochondrial function, synaptic integrity, synaptic plasticity, and mitophagy flux in APP/PS1 mice. Natural antisense transcripts (NATs) located on the opposite strand of sense genes can suppress expression of sense genes. Therefore, suppression of NATs by short sense oligonucleotides targeting NATs (antagoNATs) can upregulate sense gene expression. As preliminary studies show that A?42 oligomers reduce CHCHD10 mRNA and protein, we will test the hypothesis that CHCHD10 reduction in APP/PS1 mouse brains and A?42 oligomer treated primary neurons is, at least in part, due to increases in specific NATs suppressing endogenous CHCHD10 expression. Indeed, we have identified several mouse NATs expressed in the antisense direction of CHCHD10, and expression of short sense oligonucleotides targeting CHCHD10 NATs (antagoNATs) significantly increase endogenous CHCHD10 expression. Hence, we will extend studies to human neurons directly converted from primary fibroblasts. Specifically, we will test the hypothesis that corresponding CHCHD10 NATs are expressed in human neurons, that such NATs and CHCHD10 are inversely regulated by A? oligomers, and that antagoNATs directed against CHCHD10 NATs not only increase CHCHD10 expression (mRNA & protein) but also protect against A?42 oligomer-induced defects in mitochondrial function in human neurons. Successful conclusion of this study will: 1. Validate the role of CHCHD10 in promoting mitochondrial health and autophagy/mitophagy to reduce A? deposition and synaptic integrity/function in brain. 2. Identify a potential mechanistic basis for CHCHD10 decline in AD; 3. Establish an important platform for developing an antagoNAT strategy to therapeutically increase CHCHD10 levels in mice and humans, an approach that could be applied to targets beyond CHCHD10 and diseases beyond AD.
A? pathology is a prevailing hallmark of Alzheimer?s disease (AD). This proposal aims to validate and extend the role of CHCHD10 in mitophagy and A? accumulation in brain as well as to develop a strategy to enhance endogenous CHCHD10 levels as a potential therapeutic approach.