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. 2017 Aug:12:8-17.
doi: 10.1016/j.redox.2017.01.021. Epub 2017 Feb 1.

Ablation of ferroptosis regulator glutathione peroxidase 4 in forebrain neurons promotes cognitive impairment and neurodegeneration

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Ablation of ferroptosis regulator glutathione peroxidase 4 in forebrain neurons promotes cognitive impairment and neurodegeneration

William Sealy Hambright et al. Redox Biol. 2017 Aug.

Abstract

Synaptic loss and neuron death are the underlying cause of neurodegenerative diseases such as Alzheimer's disease (AD); however, the modalities of cell death in those diseases remain unclear. Ferroptosis, a newly identified oxidative cell death mechanism triggered by massive lipid peroxidation, is implicated in the degeneration of neurons populations such as spinal motor neurons and midbrain neurons VSports手机版. Here, we investigated whether neurons in forebrain regions (cerebral cortex and hippocampus) that are severely afflicted in AD patients might be vulnerable to ferroptosis. To this end, we generated Gpx4BIKO mouse, a mouse model with conditional deletion in forebrain neurons of glutathione peroxidase 4 (Gpx4), a key regulator of ferroptosis, and showed that treatment with tamoxifen led to deletion of Gpx4 primarily in forebrain neurons of adult Gpx4BIKO mice. Starting at 12 weeks after tamoxifen treatment, Gpx4BIKO mice exhibited significant deficits in spatial learning and memory function versus Control mice as determined by the Morris water maze task. Further examinations revealed that the cognitively impaired Gpx4BIKO mice exhibited hippocampal neurodegeneration. Notably, markers associated with ferroptosis, such as elevated lipid peroxidation, ERK activation and augmented neuroinflammation, were observed in Gpx4BIKO mice. We also showed that Gpx4BIKO mice fed a diet deficient in vitamin E, a lipid soluble antioxidant with anti-ferroptosis activity, had an expedited rate of hippocampal neurodegeneration and behavior dysfunction, and that treatment with a small-molecule ferroptosis inhibitor ameliorated neurodegeneration in those mice. Taken together, our results indicate that forebrain neurons are susceptible to ferroptosis, suggesting that ferroptosis may be an important neurodegenerative mechanism in diseases such as AD. .

Keywords: Alzheimer's disease; Cognitive impairment; Ferroptosis; Glutathione peroxidase 4; Neurodegeneration; Transgenic mice. V体育安卓版.

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Graphical abstract
Fig. 1.
Fig. 1
Conditional ablation of Gpx4 in forebrain neurons of Gpx4BIKO mice. A. A scheme to ablate Gpx4 in forebrain neurons of mice with graphic of the Gpx4 allele showing loxP sites and primer sites to detect recombined Gpx4 (rGpx4) using PCR. B. A gel image of PCR results to detect rGpx4 in cerebral cortex (CC), hippocampus (HC), spinal cord (SC), and liver (Li) at 2 weeks post TAM treatment. C. Western blots showing decreased Gpx4 expression in CC and HC tissues in Gpx4BIKO at 2 weeks and 15 weeks post TAM treatment with quantification (below). D. Images of hippocampus (CA1 region) indicating reduced Gpx4 immunoreactivity in Gpx4BIKO mice at 2 weeks post TAM treatment. E. Western blot indicating elevated 4-HNE protein adducts in Gpx4BIKO mice at 2 weeks post TAM treatment with quantification. Arrows indicate bands with elevated signal at different protein sizes, and the numbers on the right are markers of Molecular Weight (kD). n=4–5 for all groups; *p<0.05; Control animals (Con) were littermate Gpx4(f/f) mice.
Fig. 2.
Fig. 2
Impaired spatial learning and memory abilities in Gpx4BIKO mice. A. Escape latencies of Gpx4BIKO and Control (Con) mice in Morris water maze (MWM) task at 6 and 12 weeks post TAM treatment, respectively. B. Representative MWM swim plots for Gpx4BIKO and Con mice from day 5 of the 12-week MWM task. C. Percent time spent in the target quadrant in probe trials on day 6 of the 12-week MWM task. D. No difference in average swim speed between Gpx4BIKO and Control mice (collected from day 5 of acquisition trials). E. Rotarod performance of Gpx4BIKO and Con mice assessed after completion of the 12-week MWM task. Data shown are latencies to fall (average of 4 trials) after 1 day of training to acclimate the mice to the task. For all behavior tasks, n=15 for Gpx4BIKO mice, n=8 for Control mice (f/f). *p<0 0.05 for Gpx4BIKO versus Control for same day performance; ¥p<0.05 for Control mice at start of water maze testing versus control mice on the final day of water maze testing indicating learning; ns, the difference is not statistically significant.
Fig. 3.
Fig. 3
Hippocampal neurodegeneration in cognitively impaired Gpx4BIKO mice. A. Western blots showing levels of neural proteins synaptophysin (Syn), synaptosome associated protein-25 (SNAP), and NeuN, in cerebral cortex (CC) and hippocampus (HC) tissues of Gpx4BIKO mice with quantification (right), n=5. B. Nissl stained HC sections indicating neuronal loss in CA1 region (black arrows) in Gpx4BIKO mice with quantification representing average number of Nissl positive cells, n=3. C. Images of Fluoro-Jade C stained HC sections indicating degenerating CA1 neurons in Gpx4BIKO mice with quantification, n=3. * p<0.05; Control animals were Gpx4(f/f); tissues were collected after completion of behavioral tasks at 15 weeks post TAM treatment.
Fig. 4.
Fig. 4
Signatures of ferroptosis in cognitively impaired Gpx4BIKO mice. A. Western blot of 4-HNE adduct levels from cerebral cortex (CC) tissue (hippocampus (HC) blot not shown) with quantification for CC and HC. Arrows indicate bands with elevated signal at different protein sizes, and the numbers on the right are markers of Molecular Weight (kD). B. Western blots detecting phosphorylated (activated) ERK(1/2) and total ERK(1/2) in CC and HC tissues of Gpx4BIKO mice versus controls. pERK(1/2) levels were quantified relative to total ERK(1/2) expression levels. C. Western blot showing procaspase-3 and lack of cleaved (activated) caspase-3 in CC or HC in Gpx4BIKO animals versus controls. (+) control was cytochrome C-treated jurkat cell extracts (Cell Signaling, Inc.). n=5 for all groups; *p<0.05; Control animals were Gpx4(f/f).
Fig. 5.
Fig. 5
Neuroinflammation in cognitively impaired Gpx4BIKO mice. A. Western blots showing expression of astrogliosis marker (GFAP) and microgliosis marker (Iba-1) in cerebral cortex (CC) and hippocampus (HC) tissues of Gpx4BIKO mice with quantification (right), n=5. B. Immunofluorescent images indicating gliosis markers GFAP (green) and Iba-1 (red) in the CA1 region of the hippocampus at 20X and 63X with DAPI (blue). White arrows indicate microglia infiltration of CA1 pyramidal neuron layer. C. Relative mRNA expression of proinflammatory cytokines (IL-6, TNF-α) and gliosis markers (GFAP, Iba-1) in CC tissue using Real-Time qPCR, n=4. *p<0.05; Control animals were Gpx4(f/f) mice. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).
Fig. 6.
Fig. 6
Exacerbated neurodegeneration in Gpx4BIKO mice fed a vitamin E deficient diet. A. Rotarod performance for Gpx4BIKO mice and Control mice that were fed a vitamin E deficient diet after TAM treatment beginning on day 1 (n=6 for both groups). Image of Gpx4BIKO mice fed the vitamin E deficient diet (Gpx4BIKO-VED) demonstrating a hindlimb clasping phenotype at 1 week post TAM treatment. B. Western blots showing reduced levels of neural proteins NeuN, Synaptophysin, and SNAP25 as well as elevated levels of gliosis markers GFAP and Iba-1 at 1 week post TAM treatment in Gpx4BIKO-VED mice (n=5 for both groups). C. Western blots showing attenuated neurodegeneration (NeuN, Synaptophysin, SNAP25) and neuroinflammation (GFAP) in HC of Gpx4BIKO-VED mice treated with the ferroptosis inhibitor liproxstatin-1 compared to Gpx4BIKO-VED mice treated with vehicle (DMSO) at 1 week post TAM treatment (n=5 for all groups). * p<0.05 versus Con-VED; #p<0.05 versus Gpx4BIKO-VED treated with DMSO.

References

    1. Cotman C.W., Anderson A.J. A potential role for apoptosis in neurodegeneration and Alzheimer's disease. Mol. Neurobiol. 1995;10(1):19–45. - PubMed
    1. Mattson M.P. Neuronal life-and-death signaling, apoptosis, and neurodegenerative disorders. Antioxid. Redox Signal. 2006;8(11–12):1997–2006. - PubMed
    1. Khandelwal P.J., Herman A.M., Moussa C.E. Inflammation in the early stages of neurodegenerative pathology. J. Neuroimmunol. 2011;238(1–2):1–11. - PMC - PubMed
    1. Wang X., Wang W., Li L., Perry G., Lee H.G., Zhu X. Oxidative stress and mitochondrial dysfunction in Alzheimer's disease. Biochim. Biophys. Acta. 2013 - PMC (V体育安卓版) - PubMed
    1. Gordon P.H., Moore D.H., Miller R.G., Florence J.M., Verheijde J.L., Doorish C., Hilton J.F., Spitalny G.M., MacArthur R.B., Mitsumoto H. Efficacy of minocycline in patients with amyotrophic lateral sclerosis: a phase III randomised trial. Lancet Neurol. 2007;6(12):1045–1053. - PubMed

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