cells Article The Energy Status of Astrocytes Is the Achilles’ Heel of eIF2B-Leukodystrophy Melisa Herrero 1, Maron Daw 1, Andrea Atzmon 1 and Orna Elroy-Stein 1,2,* 1 Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel;
[email protected] (M.H.);
[email protected] (M.D.);
[email protected] (A.A.) 2 Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel * Correspondence:
[email protected] Abstract: Translation initiation factor 2B (eIF2B) is a master regulator of global protein synthesis in all cell types. The mild genetic Eif2b5(R132H) mutation causes a slight reduction in eIF2B enzymatic activity which leads to abnormal composition of mitochondrial electron transfer chain complexes and impaired oxidative phosphorylation. Previous work using primary fibroblasts isolated from Eif2b5(R132H/R132H) mice revealed that owing to increased mitochondrial biogenesis they exhibit normal cellular ATP level. In contrast to fibroblasts, here we show that primary astrocytes isolated from Eif2b5(R132H/R132H) mice are unable to compensate for their metabolic impairment and exhibit chronic state of low ATP level regardless of extensive adaptation efforts. Mutant astrocytes are hypersensitive to oxidative stress and to further energy stress. Moreover, they show migration deficit upon exposure to glucose starvation. The mutation in Eif2b5 prompts reactive oxygen species (ROS)-mediated inferior ability to stimulate the AMP-activated protein kinase (AMPK) axis, due to a requirement to increase the mammalian target of rapamycin complex-1 (mTORC1) Citation: Herrero, M.; Daw, M.; signalling in order to enable oxidative glycolysis and generation of specific subclass of ROS-regulating Atzmon, A.; Elroy-Stein, O.