The endocannabinoid (eCB) system is involved in a vast array of physiological processes including regulating metabolism through insulin secretion and action. In this physiological study of 21 healthy men, we investigated the acute effects of a nonspecific cannabinoid receptor agonist nabilone (NAB 2 mg) and a specific cannabinoid receptor 1 (CB1R) antagonist CP-945,598 at two concentrations (low dose CP, LDCP 15 mg and high dose CP, HDCP 45 mg) on insulin secretion, insulin action, and glucose disposal-all compared with placebo (PL). One of the following compounds-NAB, LDCP, HDCP, or PL-was administered in a randomized and blinded fashion during each of the four visits, where in-between visit was spaced at least 6 wk apart. We used the sequential hyperglycemic, euglycemic-hyperinsulinemic clamp procedure carried out after >10 h of fasting to assess glucose-induced insulin secretion and insulin sensitivity, and we measured glucose utilization and production by means of the deuterated glucose disposal test. In addition, we measured serum levels of endocannabinoids and various N-acylethanolamines over the course of the sequential clamps. Our major findings were as follows: 1) insulin secretion was not impacted by NAB or CP during the hyperglycemic clamp compared with PL; 2) insulin sensitivity was significantly increased by NAB but decreased by HDCP, both compared with PL, during the euglycemic-hyperinsulinemic clamp; 3) under the conditions of the experiments outlined, non-esterified fatty acids, and many circulating N-acylethanolamines levels, including the endocannabinoid anandamide (AEA), were reduced in a saturable insulin-dependent manner during the clamps.NEW & NOTEWORTHY Under controlled environment of the clamps in healthy, non-obese men, cannabinoid receptor agonist enhanced whereas cannabinoid receptor 1 antagonist diminished insulin sensitivity in a dose-dependent manner. During the clamps, elevated plasma insulin levels had a suppressive effect on circulating non-esterified fatty acids (NEFAs), anandamides (AEAs), and several N-acylethanolamines. Insulin, however, had no impact on circulating 2-arachidonoylglycerol (2-AG) levels. Neither the cannabinoid receptor agonist nor the cannabinoid receptor-1 antagonist had an effect on insulin secretion.

As the principal lipid transporter in the human brain, apolipoprotein E (ApoE) is tasked with transport and protection of highly vulnerable lipids that are required to support and remodel neuronal membranes, in a process that is dependent on ApoE receptors. APOE allele variants that encode proteins differing only in the number of cysteine (Cys)-to-arginine (Arg) exchanges (ApoE2 [2 Cys], ApoE3 [1 Cys], ApoE4 [0 Cys]) comprise the strongest genetic risk factor for sporadic Alzheimer's disease (AD); however, the specific molecular feature(s) and resultant mechanisms that underlie these isoform-dependent effects are unknown. One signature feature of Cys is the capacity to form disulfide (Cys-Cys) bridges, which are required to form disulfide-linked dimers and multimers. Here we propose the overarching hypothesis that super-ability (for ApoE2), intermediate ability (for ApoE3) or inability (for ApoE4) to form lipid-protecting intermolecular disulfide bridges, is the central molecular determinant accounting for the disparate effects of APOE alleles on AD risk and amyloid-β and Tau pathologies in humans. We posit that presence and abundance of Cys in human ApoE3 and ApoE2 respectively, conceal and protect vulnerable lipids transported by ApoE from peroxidation by enabling formation of disulfide-linked homo- and heteromeric ApoE complexes. We thus propose that inability to form intermolecular disulfide bridges makes ApoE4-containing lipoproteins uniquely vulnerable to peroxidation and its downstream consequences. Consistent with our model, we found that brain-enriched polyunsaturated fatty acid-containing phospholipids induce disulfide-dependent dimerization and multimerization of ApoE3 and ApoE2 (but not ApoE4). By contrast, incubation with the peroxidation-resistant lipid DMPC or cholesterol alone had minimal effects on dimerization. These novel concepts and findings are integrated into our unifying model implicating peroxidation of ApoE-containing lipoproteins, with consequent ApoE receptor-ligand disruption, as initiating molecular events that ultimately lead to AD in humans.

BACKGROUND:Dyslipidemia increases cardiovascular disease risk, the leading cause of death worldwide. Under time-restricted feeding (TRF), wherein food intake is restricted to a consistent window of <12 hours, weight gain, glucose intolerance, inflammation, dyslipidemia, and hypercholesterolemia are all reduced in mice fed an obesogenic diet. LDLR (low-density lipoprotein receptor) mutations are a major cause of familial hypercholesterolemia and early-onset cardiovascular disease. METHODS:We subjected benchmark preclinical models, mice lacking LDLR-knockout or ApoE knockout to ad libitum feeding of an isocaloric atherogenic diet either ad libitum or 9 hours TRF for up to 13 weeks and assessed disease development, mechanism, and global changes in hepatic gene expression and plasma lipids. In a regression model, a subset of LDLR-knockout mice were ad libitum fed and then subject to TRF. RESULTS:TRF could significantly attenuate weight gain, hypercholesterolemia, and atherosclerosis in mice lacking the LDLR-knockout mice under experimental conditions of both prevention and regression. In LDLR-knockout mice, increased hepatic expression of genes mediating β-oxidation during fasting is associated with reduced VLDL (very-low-density lipoprotein) secretion and lipid accumulation. Additionally, increased sterol catabolism coupled with fecal loss of cholesterol and bile acids contributes to the atheroprotective effect of TRF. Finally, TRF alone or combined with a cholesterol-free diet can reduce atherosclerosis in LDLR-knockout mice. However, mice lacking ApoE, which is an important protein for hepatic lipoprotein reuptake do not respond to TRF. CONCLUSIONS:In a preclinical animal model, TRF is effective in both the prevention and regression of atherosclerosis in LDLR knockout mice. The results suggest TRF alone or in combination with a low-cholesterol diet can be a lifestyle intervention for reducing cardiovascular disease risk in humans.

The linoleic acid (LA)-arachidonic acid (ARA)-inflammatory axis suggests dietary LA lowering benefits health because it lowers ARA and ARA-derived endocannabinoids (ECB). Dietary LA reduction increases concentrations of omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and DHA derived ECB. The aim of this study was to examine targeted reduction of dietary LA, with and without EPA and DHA, on plasma EPA and DHA and ECB (2-arachidonoyl glycerol [2-AG], anandamide [AEA], and docosahexaenoyl ethanolamide [DHA-EA]). Healthy, pre-menopausal women (n = 62, BMI 30 ± 3 kg/m2 , age 35 ± 7 years; mean ± SD) were randomized to three 12-week controlled diets: (1) high LA, low omega-3 EPA and DHA (H6L3); (2) low LA, low omega-3 EPA and DHA (L6L3); or (3) low LA, high omega-3 EPA and DHA (L6H3). Baseline plasma fatty acids and ECB were similar between diets. Starting at 4 weeks, L6L3 and L6H3 lowered plasma LA compared to H6L3 (p < 0.001). While plasma ARA changed from baseline by 8% in L6L3 and -8% in L6H3, there were no group differences. After 4 weeks, plasma EPA and DHA increased from baseline in women on the L6H3 diet (ps < 0.001) and were different than the H6L3 and L6L3 diets. No differences were found between diets for AEA or 2-AG, however, in L6L3 and L6H3, AEA increased by 14% (ps < 0.02). L6H3 resulted in 35% higher DHA-EA (p = 0.013) whereas no changes were seen with the other diets. Lowering dietary LA did not result in the expected changes in fatty acids associated with the LA-ARA inflammatory axis in women with overweight and obesity.

Background Excess adiposity at diagnosis and weight gain during chemotherapy is associated with tumour recurrence and chemotherapy toxicity. We assessed the efficacy of intermittent energy restriction (IER) vs continuous energy restriction (CER) for weight control and toxicity reduction during chemotherapy. Methods One hundred and seventy-two women were randomised to follow IER or CER throughout adjuvant/neoadjuvant chemotherapy. Primary endpoints were weight and body fat change. Secondary endpoints included chemotherapy toxicity, cardiovascular risk markers, and correlative markers of metabolism, inflammation and oxidative stress. Results Primary analyses showed non-significant reductions in weight (−1.1 (−2.4 to +0.2) kg, p = 0.11) and body fat (−1.0 (−2.1 to +0.1) kg, p = 0.086) in IER compared with CER. Predefined secondary analyses adjusted for body water showed significantly greater reductions in weight (−1.4 (−2.5 to −0.2) kg, p = 0.024) and body fat (−1.1 (−2.1 to −0.2) kg, p = 0.046) in IER compared with CER. Incidence of grade 3/4 toxicities were comparable overall (IER 31.0 vs CER 36.5%, p = 0.45) with a trend to fewer grade 3/4 toxicities with IER (18%) vs CER (31%) during cycles 4–6 of primarily taxane therapy ( p = 0.063). Conclusions IER is feasible during chemotherapy. The potential efficacy for weight control and reducing toxicity needs to be tested in future larger trials. Clinical trial registration ISRCTN04156504.

Neuritic plaques, a pathological hallmark in Alzheimer’s disease (AD) brains, comprise extracellular aggregates of amyloid-beta (Aβ) peptide and degenerating neurites that accumulate autolysosomes. We found that, in the brains of patients with AD and in AD mouse models, Aβ plaque-associated Olig2- and NG2-expressing oligodendrocyte progenitor cells (OPCs), but not astrocytes, microglia, or oligodendrocytes, exhibit a senescence-like phenotype characterized by the upregulation of p21/CDKN1A, p16/INK4/CDKN2A proteins, and senescence-associated β-galactosidase activity. Molecular interrogation of the Aβ plaque environment revealed elevated levels of transcripts encoding proteins involved in OPC function, replicative senescence, and inflammation. Direct exposure of cultured OPCs to aggregating Aβ triggered cell senescence. Senolytic treatment of AD mice selectively removed senescent cells from the plaque environment, reduced neuroinflammation, lessened Aβ load, and ameliorated cognitive deficits. Our findings suggest a role for Aβ-induced OPC cell senescence in neuroinflammation and cognitive deficits in AD, and a potential therapeutic benefit of senolytic treatments.

Among mammals, there is a positive correlation between serum uric acid (UA) levels and life span. Humans have high levels of UA because they lack a functional urate oxidase (UOX) enzyme that is present in shorter lived mammals. Here, we show that male and female mice with UOX haploinsufficiency exhibit an age-related elevation of UA levels, and that the life span of female but not male UOX+/- mice is significantly increased compared to wild-type mice. Serum UA levels are elevated in response to treadmill exercise in UOX+/- mice, but not wild-type mice, and the endurance of the UOX+/- mice is significantly greater than wild-type mice. UOX+/- mice exhibit elevated levels of brain-derived neurotrophic factor, reduced brain damage and improved functional outcome in a model of focal ischemic stroke. Levels of oxidative protein nitration and lipid peroxidation are reduced in muscle and brain tissues of UOX+/- mice under conditions of metabolic and oxidative stress (running in the case of muscle and ischemia in the case of the brain), consistent with prior evidence that UA can scavenge peroxynitrite and hydroxyl radical. Our findings reveal roles for UA in life span determination, endurance and adaptive responses to brain injury, and suggest novel approaches for protecting cells against injury and for optimizing physical performance.

During age-associated thymic involution, thymocytes decrease and lipid-laden cells accumulate. However, if and how aging affects the thymic lipid profile is not well understood, nor is it known if the hormonal milieu modifies this process. Here we demonstrate a correlation between reduced thymocyte numbers and markers of inflammation and oxidative stress with age. Evaluating the lipidomics profile of the whole thymus, between the ages of 4 (young) and 18 months (old), we found increased amounts of triacylglycerides, free cholesterol, cholesterol ester and 4-hydroxynonenal (4-HNE) with age. Moreover, levels of C24:0 and C24:1 sphingomyelins and ceramide C16:0 were elevated in 12-14 month-old (middle-aged) mice while the levels of sulfatide ceramide and ganglioside GD1a increased in the old thymus. Evaluating isolated thymocytes, we found increased levels of cholesterol ester and 4-HNE adducts, as compared to young mice. Next, we treated middle-aged mice with growth hormone (GH), which has been considered a potent immunomodulator. GH reduced thymic levels of TNF-α and 4-HNE and increased the number of thymocytes as well as the thymic levels of dihydroceramide, a ceramide precursor and autophagic stimuli for cell survival. In conclusion, GH treatment attenuated inflammation and age-related increases in oxidative stress and lipotoxicity in the thymus.

Whole-body vibration (WBV) has gained attention as a potential exercise mimetic, but direct comparisons with the metabolic effects of exercise are scarce. To determine whether WBV recapitulates the metabolic and osteogenic effects of physical activity, we exposed male wild-type (WT) and leptin receptor-deficient (db/db) mice to daily treadmill exercise (TE) or WBV for 3 months. Body weights were analyzed and compared with WT and db/db mice that remained sedentary. Glucose and insulin tolerance testing revealed comparable attenuation of hyperglycemia and insulin resistance in db/db mice following TE or WBV. Both interventions reduced body weight in db/db mice and normalized muscle fiber diameter. TE or WBV also attenuated adipocyte hypertrophy in visceral adipose tissue and reduced hepatic lipid content in db/db mice. Although the effects of leptin receptor deficiency on cortical bone structure were not eliminated by either intervention, exercise and WBV increased circulating levels of osteocalcin in db/db mice. In the context of increased serum osteocalcin, the modest effects of TE and WBV on bone geometry, mineralization, and biomechanics may reflect subtle increases in osteoblast activity in multiple areas of the skeleton. Taken together, these observations indicate that WBV recapitulates the effects of exercise on metabolism in type 2 diabetes.

During fasting and vigorous exercise, a shift of brain cell energy substrate utilization from glucose to the ketone 3-hydroxybutyrate (3OHB) occurs. Studies have shown that 3OHB can protect neurons against excitotoxicity and oxidative stress, but the underlying mechanisms remain unclear. Neurons maintained in the presence of 3OHB exhibited increased oxygen consumption and ATP production, and an elevated NAD(+)/NADH ratio. We found that 3OHB metabolism increases mitochondrial respiration which drives changes in expression of brain-derived neurotrophic factor (BDNF) in cultured cerebral cortical neurons. The mechanism by which 3OHB induces Bdnf gene expression involves generation of reactive oxygen species, activation of the transcription factor NF-B, and activity of the histone acetyltransferase p300/EP300. Because BDNF plays important roles in synaptic plasticity and neuronal stress resistance, our findings suggest cellular signaling mechanisms by which 3OHB may mediate adaptive responses of neurons to fasting, exercise, and ketogenic diets.

Deficits of sensorimotor integration with periodic limb movements during sleep (PLMS) and hyperarousal and sleep disturbances in Restless Legs Syndrome (RLS) constitute two pathophysiologically distinct but interrelated clinical phenomena, which seem to depend mostly on alterations in dopaminergic and glutamatergic neurotransmission, respectively. Brain iron deficiency is considered as a main pathogenetic mechanism in RLS. Rodents with brain iron deficiency represent a valuable pathophysiological model of RLS, although they do not display motor disturbances. Nevertheless, they develop the main neurochemical dopaminergic changes found in RLS, such as decrease in striatal dopamine D2 receptor density. On the other hand, brain iron deficient mice exhibit the characteristic pattern of hyperarousal in RLS, providing a tool to find the link between brain iron deficiency and sleep disturbances in RLS. The present study provides evidence for a role of the endogenous sleep-promoting factor adenosine. Three different experimental preparations, long-term (22 weeks) severe or moderate iron-deficient (ID) diets (3- or 7-ppm iron diet) in mice and short-term (3 weeks) severe ID diet (3-ppm iron diet) in rats, demonstrated a significant downregulation (Western blotting in mouse and radioligand binding saturation experiments in rat brain tissue) of adenosine A1 receptors (A1R) in the cortex and striatum, concomitant to striatal D2R downregulation. On the other hand, the previously reported upregulation of adenosine A2A receptors (A2AR) was only observed with severe ID in both mice and rats. The results suggest a key role for A1R downregulation in the PLMS and hyperarousal in RLS.

A high calorie diet (HCD) can impair hippocampal synaptic plasticity and cognitive function in animal models. Mitochondrial thioredoxin 2 (TRX-2) is critical for maintaining intracellular redox status, but whether it can protect against HCD-induced impairment of synaptic plasticity is unknown. We found that levels of TRX-2 are reduced in the hippocampus of wild type mice maintained for 8 months on a HCD, and that the mice on the HCD exhibit impaired hippocampal synaptic plasticity (long-term potentiation at CA1 synapses) and cognitive function (novel object recognition). Transgenic mice overexpressing human TRX-2 (hTRX-2) exhibit increased resistance to diquat-induced oxidative stress in peripheral tissues. However, neither the HCD nor hTRX-2 overexpression affected levels of lipid peroxidation products (F2 isoprostanes) in the hippocampus, and hTRX-2 transgenic mice were not protected against the adverse effects of the HCD on hippocampal synaptic plasticity and cognitive function. Our findings indicate that TRX-2 overexpression does not mitigate adverse effects of a HCD on synaptic plasticity, and also suggest that oxidative stress may not be a pivotal factor in the impairment of synaptic plasticity and cognitive function caused by HCDs.

High uric acid (UA levels have been correlated with a reduced risk of many neurodegenerative diseases through mechanisms involving chelating Fenton reaction transitional metals, antioxidant quenching of superoxide and hydroxyl free radicals, and as an electron donor that increases antioxidant enzyme activity (e.g. SOD. However, the clinical usefulness of UA is limited by its' low water solubility and propensity to form inflammatory crystals at hyperuricemic levels. This review focuses on the role of UA in neuroprotection, as well as potential strategies aimed at increasing UA levels in the soluble range, and the potential therapeutic use of more water-soluble methyl-UA derivatives from the natural catabolic end-products of dietary caffeine, theophylline, and theobromine.

Mitochondrial metabolism is highly responsive to nutrient availability and ongoing activity in neuronal circuits. The molecular mechanisms by which brain cells respond to an increase in cellular energy expenditure are largely unknown. Mild mitochondrial uncoupling enhances cellular energy expenditure in mitochondria and can be induced with 2,4-dinitrophenol (DNP), a proton ionophore previously used for weight loss. We found that DNP treatment reduces mitochondrial membrane potential, increases intracellular Ca2+ levels and reduces oxidative stress in cerebral cortical neurons. Gene expression profiling of the cerebral cortex of DNP-treated mice revealed reprogramming of signaling cascades that included suppression of the mammalian target of rapamycin (mTOR) and insulin - PI3K - MAPK pathways, and up-regulation of tuberous sclerosis complex 2, a negative regulator of mTOR. Genes encoding proteins involved in autophagy processes were up-regulated in response to DNP. CREB (cAMP-response element-binding protein) signaling, Arc and brain-derived neurotrophic factor, which play important roles in synaptic plasticity and adaptive cellular stress responses, were up-regulated in response to DNP, and DNP-treated mice exhibited improved performance in a test of learning and memory. Immunoblot analysis verified that key DNP-induced changes in gene expression resulted in corresponding changes at the protein level. Our findings suggest that mild mitochondrial uncoupling triggers an integrated signaling response in brain cells characterized by reprogramming of mTOR and insulin signaling, and up-regulation of pathways involved in adaptive stress responses, molecular waste disposal, and synaptic plasticity.

Molecular turnover is the balance between synthesis and degradation. The rate of molecular turnover has been shown to decrease with old age and concomitant accumulation of damaged molecules. The onset and progression of the major age-related neurodegenerative diseases has been linked to the accumulation of protein aggregates (e.g. Alzheimer's: beta-amyloid; Parkinson's: alpha-synuclein; Huntington's: Huntingtin; Amyotrophic lateral sclerosis (ALS): mutated SOD1). Researchers have been exploring the use of increasing the rate of molecular turnover to prevent and "clean up" the accumulation of aberrant disease causing molecules by activating catabolic pathways via intermittent fasting, exercise, and drugs aimed at activating autophagy (e.g. rapamycin). However, the often ignored but equally important requirement for increasing molecular renewal is the activation of anabolic pathways to synthesize new proteins, lipids, and carbohydrates. By exploring the connections between the oxidative/reduction control of AMP activated protein kinases (AMPK), autophagy and gluconeogenesis, we propose a protocol using a properly timed cycle approach of diet, exercise, and drugs to enhance the catabolic/anabolic phases of molecular turnover.

Elongation factor-2 (eEF2) catalyzes the movement of the ribosome along the mRNA. A single histidine residue in eEF2 (H715) is modified to form diphthamide. A role for eEF2 in the cellular stress response is highlighted by the fact that eEF2 is sensitive to oxidative stress and that it must be active to drive the synthesis of proteins that help cells to mitigate the adverse effects of oxidative stress. Many of these proteins are encoded by mRNAs containing a sequence called an "internal ribosomal entry site" (IRES). Under high oxidative stress conditions diphthamide-deficient cells were significantly more sensitive to cell death. These results suggest that diphthamide may play a role in protection against the degradation of eEF2. This protection is especially important in those situations in which eEF2 is necessary for the reprogramming of translation from global to IRES synthesis. Indeed, we found that the expression of X-linked inhibitor of apoptosis (XIAP) and fibroblast growth factor 2 (FGF2), two proteins synthesized from mRNAs with IRESs that promote cell survival, is deregulated in diphthamide-deficient cells. Our findings therefore suggest that eEF2 diphthamide controls the selective translation of IRES-dependent protein targets XIAP and FGF2, critical for cell survival under conditions of oxidative stress.

Sphingolipids are a highly conserved lipid component of cell membranes involved in the formation of lipid raft domains that house many of the receptors and cell-to-cell signaling factors involved in regulating cell division, maturation, and terminal differentiation. By measuring and manipulating sphingolipid metabolism using pharmacological and genetic tools in Caenorhabditis elegans, we provide evidence that the synthesis and remodeling of specific ceramides (e.g., dC18:1-C24:1), gangliosides (e.g., GM1-C24:1), and sphingomyelins (e.g., dC18:1-C18:1) influence development rate and lifespan. We found that the levels of fatty acid chain desaturation and elongation in many sphingolipid species increased during development and aging, with no such changes in developmentally-arrested dauer larvae or normal adults after food withdrawal (an anti-aging intervention). Pharmacological inhibitors and small interfering RNAs directed against serine palmitoyl transferase and glucosylceramide synthase acted to slow development rate, extend the reproductive period, and increase lifespan. In contrast, worms fed an egg yolk diet rich in sphingolipids exhibited accelerated development and reduced lifespan. Our findings demonstrate that sphingolipid accumulation and remodeling are critical events that determine development rate and lifespan in the nematode model, with both development rate and aging being accelerated by the synthesis of sphingomyelin, and its metabolism to ceramides and gangliosides.

We investigated the role of Toll-like receptor 4 (TLR4), a major mediator of innate immune responses, on cognitive performance in a type 1 diabetes model (T1D). After administration of streptozotocin, both TLR4 knockout (TLR4 KO) and wild type (WT) diabetic mice displayed metabolic alterations similar to those observed in T1D patients, including increased levels of glucose, cholesterol, triglycerides and ketones. T1D mice exhibited cognitive impairment which was less severe in TLR4 KO mice compared to WT mice. WT mice with higher glucose and those with higher triglyceride levels exhibited significantly more anxiety and impaired memory compared to those with lower levels of glucose and triglycerides; these correlations were absent in TLR4 KO mice. Additional findings suggest roles for TLR4 signaling in modifying the expression of enzymes involved in energy metabolism in brain cells in the setting of T1D. Our data show that TLR4 contributes to the negative impact of T1D on anxiety and cognition.

Eukaryotic elongation factor 2 (eEF-2) is an important regulator of the protein translation machinery whereby it controls the movement of the ribosome along the mRNA. The activity of eEF-2 is regulated by changes in cellular energy status and nutrient availability and by posttranslational modifications such as phosphorylation and mono-ADP-ribosylation. However, the mechanisms regulating protein translation under conditions of cellular stress in neurons are unknown. Here we show that when rat hippocampal neurons experience oxidative stress (lipid peroxidation induced by exposure to cumene hydroperoxide; CH), eEF-2 is hyperphosphorylated and ribosylated, resulting in reduced translational activity. The degradation of eEF-2 requires calpain proteolytic activity and is accompanied by accumulation of eEF-2 in the nuclear compartment. The subcellular localization of both native and phosphorylated forms of eEF-2 is influenced by CRM1 and 14.3.3, respectively. In hippocampal neurons p53 interacts with nonphosphorylated (active) eEF-2, but not with its phosphorylated form. The p53–eEF-2 complexes are present in cytoplasm and nucleus, and their abundance increases when neurons experience oxidative stress. The nuclear localization of active eEF-2 depends upon its interaction with p53, as cells lacking p53 contain less active eEF-2 in the nuclear compartment. Overexpression of eEF-2 in hippocampal neurons results in increased nuclear levels of eEF-2 and decreased cell death after exposure to CH. Our results reveal novel molecular mechanisms controlling the differential subcellular localization and activity state of eEF-2 that may influence the survival status of neurons during periods of elevated oxidative stress.