Loss of Frataxin activates the iron/sphingolipid/PDK1/Mef2 pathway in mammals

eLife

Hugo J Bellen¹  Guang Lin²  Tammy Szu-Yu Ho³  Matthew N Rasband⁴  Kai Li Tan⁴  Kuchuan Chen⁴ 

[1] Department of Neuroscience, Baylor College of Medicine, Houston, United States;Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States;Department of Neuroscience, Baylor College of Medicine, Houston, United States;Program in Developmental Biology, Baylor College of Medicine, Houston, United States;

关键词: Frataxin;    iron;    sphingolipid;    PDK1;    Mef2;    Friedreich's ataxia;   

DOI  :  10.7554/eLife.20732

来源: DOAJ

【 摘 要 】

Friedreich’s ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by mutations in Frataxin (FXN). Loss of FXN causes impaired mitochondrial function and iron homeostasis. An elevated production of reactive oxygen species (ROS) was previously proposed to contribute to the pathogenesis of FRDA. We recently showed that loss of frataxin homolog (fh), a Drosophila homolog of FXN, causes a ROS independent neurodegeneration in flies (Chen et al., 2016). In fh mutants, iron accumulation in the nervous system enhances the synthesis of sphingolipids, which in turn activates 3-phosphoinositide dependent protein kinase-1 (Pdk1) and myocyte enhancer factor-2 (Mef2) to trigger neurodegeneration of adult photoreceptors. Here, we show that loss of Fxn in the nervous system in mice also activates an iron/sphingolipid/PDK1/Mef2 pathway, indicating that the mechanism is evolutionarily conserved. Furthermore, sphingolipid levels and PDK1 activity are also increased in hearts of FRDA patients, suggesting that a similar pathway is affected in FRDA.

【 授权许可】

Unknown