Bezine M, Debbabi M, Nury T, Ben-Khalifa R, Samadi M, Cherkaoui-Malki M, Vejux A, Raas Q, de Sèze J, Moreau T, El-Ayeb M, Lizard G. Evidence of K+ homeostasis disruption in cellular dysfunction triggered by 7-ketocholesterol, 24S-hydroxycholesterol, and tetracosanoic acid (C24:0) in 158N murine oligodendrocytes. Chem Phys Lipids. 2017 pii: S0009-3084(17)30011-7
Imbalance in the homeostasis of K+ ions has been reported to contribute to the pathogenesis of neurodegenerative diseases. 7-ketocholesterol (7KC), 24S-hydroxycholesterol (24S-OHC), and tetracosanoic acid (C24:0), often found at increased levels in patients with Alzheimer’s disease and Multiple Sclerosis, are able to trigger numerous nerve cell dysfunctions. We therefore studied the impact of 7KC, 24S-OHC, and C24:0 on 158N mouse oligodendrocytes, and determined their impact on K+ homeostasis. The effects of 7KC, 24S-OHC and C24:0 on lipid membrane organization and membrane potential were examined. 7KC, 24S-OHC and C24:0 induced changes in lipid content and the cytoplasmic membrane. These events were associated with increased [K+]i. The positive correlation between [K+]i and cell death supports the potential involvement of K+ in 7KC-, 24S-OHC-, and C24:0-induced cytotoxicity.