Reduced mitochondrial fusion and Huntingtin levels contribute to impaired dendritic maturation and behavioral deficits in Fmr1-mutant mice.
Minjie ShenFeifei WangMeng LiNirnath SahMichael E StocktonJoseph J TideiYu GaoTomer KorabelnikovSudharsan KannanJason D VeveaEdwin R ChapmanAnita BhattacharyyaHenriette van PraagXinyu ZhaoPublished in: Nature neuroscience (2019)
Fragile X syndrome results from a loss of the RNA-binding protein fragile X mental retardation protein (FMRP). How FMRP regulates neuronal development and function remains unclear. Here we show that FMRP-deficient immature neurons exhibit impaired dendritic maturation, altered expression of mitochondrial genes, fragmented mitochondria, impaired mitochondrial function, and increased oxidative stress. Enhancing mitochondrial fusion partially rescued dendritic abnormalities in FMRP-deficient immature neurons. We show that FMRP deficiency leads to reduced Htt mRNA and protein levels and that HTT mediates FMRP regulation of mitochondrial fusion and dendritic maturation. Mice with hippocampal Htt knockdown and Fmr1-knockout mice showed similar behavioral deficits that could be rescued by treatment with a mitochondrial fusion compound. Our data unveil mitochondrial dysfunction as a contributor to the impaired dendritic maturation of FMRP-deficient neurons and suggest a role for interactions between FMRP and HTT in the pathogenesis of fragile X syndrome.
Keyphrases
- oxidative stress
- binding protein
- wild type
- spinal cord
- poor prognosis
- dna damage
- induced apoptosis
- ischemia reperfusion injury
- high fat diet induced
- dna methylation
- genome wide
- mental health
- electronic health record
- protein protein
- brain injury
- small molecule
- long non coding rna
- combination therapy
- heat shock
- heat shock protein