Abstract TP455: Treatment With Trifluoromethoxyphenyl-3 (1propionylpiperidin-4-yl) Urea Improves Cognitive Functions and Endothelium Dependent Dilation in Penetrating Arterioles From Hypertensive Rats With Bilateral Common Carotid Stenosis

Soluble epoxide hydrolase (sEH) converts epoxyeicosatrienoic acids (EETs), arachidonic acid metabolites produced by cytochrome 450 enzymes, into less metabolically active compounds. sEH inhibitors have been proposed to have vascular and neural protective effects in stroke models. Studies from our lab showed that bilateral carotid artery stenosis (BCAS), a physiologically relevant model of cognitive impairment, impairs endothelium dependent dilation in penetrating arterioles (PAs) from stroke prone spontaneously hypertensive rats (SHRSPs). We hypothesized that treatment of SHRSPs with BCAS with the sEH inhibitor, trifluoromethoxyphenyl-3 (1propionylpiperidin-4-yl) urea (TPPU) would alleviate cognitive dysfunction and improve endothelium dependent dilation in PAs. Data are shown as mean ± SEM, vehicle vs TPPU, and p <0.05 (an n=3 to 12 in each group). After 8 weeks of BCAS, TPPU treated rats showed improved short-term memory (novel exploration quotient, 90 minutes retention time: 0.5 ± 0.06 vs 0.6 ± 0.04), evaluated by novel object recognition test. PA reactivity and structure was assessed by pressure myography. TPPU restored endothelial function of PAs from SHRSP with BCAS, as evidenced by increased dilation to carbachol (% dilation at 10-6M: 2.7 ± 2.9 vs 16.5 ± 3.9). Inhibition of EET production with MS-PPOH (10-5M), enhanced dilation in PAs from TPPU treated SHRSP with BCAS (% dilation at 10-5M of carbachol, TPPU vs TPPU+MS-PPOH: 14.9 ± 2.9 vs 23.4 ± 3.5), while dilation in vehicle treated SHRSPs remained unaltered (% dilation at 10-5M, vehicle vs vehicle+MS-PPOH: 2.9 ± 2.9 vs -0.7 ± 5.1, p=0.96). This suggests that inhibiting EET production may unmask a compensatory dilatory mechanism in PAs from TPPU treated rats. Interestingly, PAs from TPPU treated rats were less sensitive to NO as evidenced by a reduction in the EC50 for NO- donor, sodium nitroprusside (logEC50: -7.1±0.14 vs -5.7± 0.2). This reduced sensitivity may be due to an overproduction of NO in PAs from TPPU treated rats. There was no difference in passive structure of the PAs with chronic TPPU administration. These data suggest that TPPU improves short-term memory after BCAS and this may be associated with improved endothelium-dependent dilation in the PAs.

Effect of fish oil on monoepoxides derived from fatty acids during cardiac surgery

Our objective was to assess the dynamics of monoepoxides derived from polyunsaturated fatty acids (MEFAs), and their response to n-3 PUFA supplementation, in the setting of acute tissue injury and inflammation (cardiac surgery) in humans. Patients (479) undergoing cardiac surgery in three countries were randomized to perioperative fish oil (EPA + DHA; 8-10 g over 2-5 days preoperatively, then 2 g/day postoperatively) or placebo (olive oil). Plasma MEFAs derived from n-3 and n-6 PUFAs were measured 2 days postoperatively. Based on serial measures in a subset of the placebo group, levels of all MEFAs declined substantially following surgery (at postoperative day 2), with declines ranging from 37% to 63% (P < 0.05 each). Compared with placebo at postoperative day 2, levels of EPA- and DHA-derived MEFAs were 40% and 18% higher, respectively (P ≤ 0.004). The n-3 PUFA supplementation did not significantly alter the decline in n-6 PUFA-derived MEFAs. Both enrollment level and changes in plasma phospholipid EPA and DHA were associated with their respective MEFAs at postoperative day 2 (P < 0.001). Under the acute stress of cardiac surgery, n-3 PUFA supplementation significantly ameliorated the reduction in postoperative n-3 MEFAs, but not n-6 MEFAs, and the degree of increase in n-3 MEFAs related positively to the circulating level of their n-3 PUFA precursors.

Abstract 1903: Application of lipidomics to a sulindac intervention of aromatase inhibitor-induced pain

(a) Introduction. The regular use of non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with a lower risk for epithelial cancers including breast. NSAIDs block cyclooxygenase (COX)-1 and -2 enzyme metabolism of Ω-6 polyunsaturated fatty acids (PUFA) to prostaglandins (PGs). Additionally, Ω-6 and Ω-3 PUFA are metabolized by lipoxygenases (LOX) and cytochrome P450 (CYP450) enzyme families to produce over 100 metabolites known as ‘oxylipins’. Oxylipins exhibit a wide spectrum of biological activity including mediators of pain and inflammation.

The overarching objective of the work is to determine if sulindac (an NSAID) intervention changes oxylipin profiles in breast cancer patients, and if individual oxylipins are related to pain caused by aromatase inhibitors (AI).

(b) Methods. This work takes place within the context of an R01-funded single arm, open-label clinical trial of sulindac (N = 100). Breast cancer patients that are stable on AIs complete pain and quality of life questionnaires, and provide blood and urine samples after a 4-week NSAID washout, after a 3 month observation period, at baseline and 3, 6 and 12 months on sulindac intervention (150 mg bid). Oxylipins were quantified in blood and urine (n = 10) at the end of washout, baseline, and after 3 months on sulindac using liquid chromatography (LC) mass spectrometry (MS)-based methods.

(c) Results. We quantified 62 total oxylipins in plasma and 87 in urine. Thus far, our analysis has focused on plasma oxylipins. Wilcoxon signed-rank tests were used to compare oxylipin levels at baseline and after 3 months of sulindac. COX metabolites of both Ω-6 and Ω-3 PUFA were non-significantly decreased. In terms of Ω-6 metabolites, 7 LOX products were significantly decreased 11-HETE (P = 0.028), 15-HETE (P = 0.037), 9,12,13-TriHOME (P = 0.017), 9,10,13-TriHOME (P = 0.012), 8-HETE (P = 0.028), 9-HETE (P = 0.028), and 12-HETE (P = 0.047). Significantly decreased Ω-6 CYP450 metabolites were 15(S)-HETrE (P = 0.028), and 5,6-DiHETrE (P = 0.028). The Ω-3 metabolites that significantly decreased were the LOX-derived 5-HEPE (P = 0.022), and 15-HEPE (P = 0.028), and CYP450-derived 5,15-DiHETE (P = 0.047), 5,6-DiHETE (P = 0.009), and 15,16-DiHODE (P = 0.012).

Thus far 53% of participants reported pain other than “every day types of pain” post-washout. The Ω-6 CYP450 metabolite 11(12)-EpETrE was significantly correlated with both “worst pain” (ρ = -0.669; P = 0.034) and severity (ρ = -0.778; P = 0.008). The Ω-6 CYP450 metabolite 20-HETE was significantly correlated with severity (ρ = -0.714; P = 0.047).

(d) Conclusions. Our preliminary data indicate that oxylipin profiles change in response to sulindac and may be related to pain. Success in shifting plasma oxylipin profiles toward an anti-inflammatory/anti-thromobotic/cardioprotective profile would maximize efficacy and to reduce potential toxicities of NSAIDs within the context of for prevention of breast and other cancers.

Citation Format: Jessica Anne Miller, Betsy Werthiem, Jun Yang, Bruce Hammock, Denise Roe, Alison Stopeck, Patricia A. Thompson. Application of lipidomics to a sulindac intervention of aromatase inhibitor-induced pain. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1903. doi:10.1158/1538-7445.AM2015-1903

The cpk model of recessive PKD shows glutamine dependence associated with the production of the oncometabolite 2-hydroxyglutarate

Since polycystic kidney disease (PKD) was first noted over 30 years ago to have neoplastic parallels, there has been a resurgent interest in elucidating neoplasia-relevant pathways in PKD. Taking a nontargeted metabolomics approach in the B6(Cg)-Cys1(cpk/)J (cpk) mouse model of recessive PKD, we have now characterized metabolic reprogramming in these tissues, leading to a glutamine-dependent TCA cycle shunt toward total 2-hydroxyglutarate (2-HG) production in cpk compared with B6 wild-type kidney tissue. After confirmation of increased 2-HG expression in immortalized collecting duct cpk cells as well as in human autosomal recessive PKD tissue using targeted analysis, we show that the increase in 2-HG is likely due to glutamine-sourced α-ketoglutarate. In addition, cpk cells require exogenous glutamine for growth such that inhibition of glutaminase-1 decreases cell viability as well as proliferation. This study is a demonstration of the striking parallels between recessive PKD and cancer metabolism. Our data, once confirmed in other PKD models, suggest that future therapeutic approaches targeting this pathway, such as using glutaminase inhibitors, have the potential to open novel treatment options for renal cystic disease.

Systemic alterations in the metabolome of diabetic NOD mice delineate increased oxidative stress accompanied by reduced inflammation and hypertriglyceremia

Nonobese diabetic (NOD) mice are a commonly used model of type 1 diabetes (T1D). However, not all animals will develop overt diabetes despite undergoing similar autoimmune insult. In this study, a comprehensive metabolomic approach, consisting of gas chromatography time-of-flight (GC-TOF) mass spectrometry (MS), ultra-high-performance liquid chromatography-accurate mass quadruple time-of-flight (UHPLC-qTOF) MS and targeted UHPLC-tandem mass spectrometry-based methodologies, was used to capture metabolic alterations in the metabolome and lipidome of plasma from NOD mice progressing or not progressing to T1D. Using this multi-platform approach, we identified >1,000 circulating lipids and metabolites in male and female progressor and nonprogressor animals (n = 71). Statistical and multivariate analyses were used to identify age- and sex-independent metabolic markers, which best differentiated metabolic profiles of progressors and nonprogressors. Key T1D-associated perturbations were related with 1) increases in oxidation products glucono-δ-lactone and galactonic acid and reductions in cysteine, methionine and threonic acid, suggesting increased oxidative stress; 2) reductions in circulating polyunsaturated fatty acids and lipid signaling mediators, most notably arachidonic acid (AA) and AA-derived eicosanoids, implying impaired states of systemic inflammation; 3) elevations in circulating triacylglyercides reflective of hypertriglyceridemia; and 4) reductions in major structural lipids, most notably lysophosphatidylcholines and phosphatidylcholines. Taken together, our results highlight the systemic perturbations that accompany a loss of glycemic control and development of overt T1D.

Soluble epoxide hydrolase deficiency ameliorates acute pancreatitis in mice

Acute pancreatitis (AP) is a frequent gastrointestinal disorder that causes significant morbidity and its incidence has been progressively increasing. AP starts as a local inflammation in the pancreas that often leads to systemic inflammatory response and complications. Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition in murine models has beneficial effects in inflammatory diseases, but its significance in AP remains unexplored. To investigate whether sEH may have a causal role in AP we utilized sEH knockout (KO) mice to determine the effects of sEH deficiency on ceruelin- and arginine-induced AP. sEH expression increased at the protein and messenger RNA levels, as well as sEH activity in the early phase of cerulein- and arginine-induced AP in mice. In addition, amylase and lipase levels were lower in cerulein-treated sEH KO mice compared with non-treated controls. Moreover, pancreatic mRNA and serum concentrations of the inflammatory cytokines IL-1ß and IL-6 were lower in sEH KO mice compared with controls. Further, sEH KO mice exhibited decreased cerulein- and arginine-induced NF-?B inflammatory response, MAPKs activation and decreased cell death. These findings demonstrate a novel role for sEH in the progression of cerulein- and arginine-induced AP.

Abstract 1867: Application of oxylipin metabolomics to a celecoxib intervention in men at risk for colorectal neoplasia recurrence

Background. In randomized controlled trials, non-steroidal anti-inflammatory agents (NSAIDs) have been shown to prevent the development of colorectal adenoma (CRA) by 15-40% depending on the agent, dose and duration of exposure. Toxicity concerns limit the acceptability of these agents for general use in the population, particularly for COX2 selective agents such as celecoxib. COX2 metabolizes arachidonic acid (AA) to the pro-inflammatory prostaglandins (PGs); an established pathway in CRA development. AA is also metabolized by cytochrome P450 (CYP450) and lipoxygenase (LOX) enzymes to produce other biologically active metabolites called oxylipins that mediate pain, hypertension, and other physiologic functions.

Methods. In 2001, we initiated a randomized phase III clinical trial to evaluate the chemopreventive effect of the COX2 inhibitor celecoxib in individuals at risk for CRA. In a subset of participants (N=126 men and N=59 women) who received celecoxib or placebo for a minimum of 12 months, we performed plasma oxylipin profiling analysis using HPLC coupled to a 4000 QTRAP mass spectrometer (MS). Fasting plasma samples for this ancillary study were collected at the one-year clinic visit and immediately stored at -80C at collection. These samples have never undergone prior freeze-thaw. Once thawed, triphenylphosphine (TPP) and butylated hydroxytoluene (BHT) (0.2% w/w) were added to preserve the oxylipins. Plasma samples (250 µL) were subjected to solid phase extraction before analysis as described previously (Liu et al 2009).

Results. Using HPLC-MS, we were able to separate and quantify 89 oxylipins (CV's &lt;30%). On average, the levels of the COX2 metabolite and primary target of the intervention, prostaglandin E2 (PGE2), were non-significantly lower (23%) in the celecoxib treated individuals when compared to placebo (P=0.20). The 5-LOX metabolite, 5-HETE (inducer of pulmonary vasoconstriction and edema) was higher in the celecoxib group (P=0.033) whereas CYP450 metabolites: 8,9-DiHETrE (P=0.018), 11,12-DiHETrE (P=0.053), 16,17-DiHDPE (P=0.059) and 10,11-DiHDPE (P=0.040) - associated with hypertension - were higher in the celecoxib treated individuals when compared to placebo.

Conclusions. Upregulation of COX2 (and subsequent production of pro-inflammatory PGE2) is a well-established mechanism in the pathogenesis of colorectal cancer, and thus an attractive chemoprevention target. Our results suggest that CYP450 and LOX metabolites increase in celecoxib treated subjects, when compared to placebo, while achieving only modest inhibition of COX2 dependent PGE2. These findings suggest that selective perturbation of the AA metabolic pathway may induce the P450 and LOX metabolism of AA resulting in increased levels of potentially harmful oxylipins. Preliminary analyses of the relationship between oxylipins, CRA and toxicity outcomes in this sub-study by treatment status will be presented.

Citation Format: Jessica Anne Miller, Jun Yang, Bruce Hammock, Peter Lance, Erin Ashbeck, Patricia A. Thompson. Application of oxylipin metabolomics to a celecoxib intervention in men at risk for colorectal neoplasia recurrence. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1867. doi:10.1158/1538-7445.AM2014-1867

Treatment of mice with 2,3,7,8-Tetrachlorodibenzo-p-dioxin markedly increases the levels of a number of cytochrome P450 metabolites of omega-3 polyunsaturated fatty acids in the liver and lung

We previously reported that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increased the levels of several cytochrome P450 metabolites of the omega-6 polyunsaturated fatty acids (PUFAs), arachidonic acid (ARA) and linoleic acid in the serum, liver, lung and spleen of C57BL/6 mice in an aryl hydrocarbon receptor (AHR)-dependent fashion. These increases correlated with increased levels of CYP1A1, CYP1A2 and/or CYP1B1. In the current study, we measured 77 oxylipins, including 59 that we had not measured previously, and demonstrate that TCDD also markedly increases the levels of many epoxide and diol metabolites of the omega-3 PUFAs, α-linolenic acid, eicosapentaenoic acid (EPA) and docasahexaenoic acid (DHA) in these mice. Since these epoxide metabolites have been reported to have opposite effects on angiogenesis, tumor growth and tumor metastasis compared with the equivalent metabolites of omega-6 PUFA, these observations have important implications with regard to the potential involvement of the cytochrome P450 metabolites of PUFAs in mediating the biological effects of TCDD and other agonists of AHR.

ω-3 polyunsaturated fatty acids-derived lipid metabolites on angiogenesis, inflammation and cancer

Epidemiological and pre-clinical studies support the anti-tumor effects of ω-3 PUFAs; however, the results from human trials are mixed, making it difficult to provide dietary guidelines or recommendations of ω-3 PUFAs for disease prevention or treatment. Understanding the molecular mechanisms by which ω-3 PUFAs inhibit cancer could lead to better nutritional paradigms and human trials to clarify their health effects. The ω-3 PUFAs exert their biological activities mainly through the formation of bioactive lipid metabolites. Here we discuss the biology of cyclooxygenase, lipoxygenase and cytochrome P450 enzymes-derived ω-3-series lipid metabolites on angiogenesis, inflammation and cancer.

Explorations of substituted urea functionality for the discovery of new activators of the heme-regulated inhibitor kinase

Heme-regulated inhibitor kinase (HRI), a eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, and adaptation to cytoplasmic stress. HRI is also a critical modifier of hemoglobin disorders such as β-thalassemia. We previously identified N,N'-diarylureas as potent activators of HRI suitable for studying the biology of this important kinase. To expand the repertoire of chemotypes that activate HRI, we screened a ∼1900 member N,N'-disubstituted urea library in the surrogate eIF2α phosphorylation assay, identifying N-aryl,N'-cyclohexylphenoxyurea as a promising scaffold. We validated hit compounds as a bona fide HRI activators in secondary assays and explored the contributions of substitutions on the N-aryl and N'-cyclohexylphenoxy groups to their activity by studying focused libraries of complementing analogues. We tested these N-aryl,N'-cyclohexylphenoxyureas in the surrogate eIF2α phosphorylation and cell proliferation assays, demonstrating significantly improved bioactivities and specificities. We consider these compounds to represent lead candidates for the development of potent and specific HRI activators.

Triclocarban mediates induction of xenobiotic metabolism through activation of the constitutive androstane receptor and the estrogen receptor alpha

Triclocarban (3,4,4′-trichlorocarbanilide, TCC) is used as a broad-based antimicrobial agent that is commonly added to personal hygiene products. Because of its extensive use in the health care industry and resistance to degradation in sewage treatment processes, TCC has become a significant waste product that is found in numerous environmental compartments where humans and wildlife can be exposed. While TCC has been linked to a range of health and environmental effects, few studies have been conducted linking exposure to TCC and induction of xenobiotic metabolism through regulation by environmental sensors such as the nuclear xenobiotic receptors (XenoRs). To identify the ability of TCC to activate xenobiotic sensors, we monitored XenoR activities in response to TCC treatment using luciferase-based reporter assays. Among the XenoRs in the reporter screening assay, TCC promotes both constitutive androstane receptor (CAR) and estrogen receptor alpha (ERα) activities. TCC treatment to hUGT1 mice resulted in induction of the UGT1A genes in liver. This induction was dependent upon the constitutive active/androstane receptor (CAR) because no induction occurred in hUGT1Car^−/− mice. Induction of the UGT1A genes by TCC corresponded with induction of Cyp2b10, another CAR target gene. TCC was demonstrated to be a phenobarbital-like activator of CAR in receptor-based assays. While it has been suggested that TCC be classified as an endocrine disruptor, it activates ERα leading to induction of Cyp1b1 in female ovaries as well as in promoter activity. Activation of ERα by TCC in receptor-based assays also promotes induction of human CYP2B6. These observations demonstrate that TCC activates nuclear xenobiotic receptors CAR and ERα both in vivo and in vitro and might have the potential to alter normal physiological homeostasis. Activation of these xenobiotic-sensing receptors amplifies gene expression profiles that might represent a mechanistic base for potential human health effects from exposure to TCC.

Identification and analysis of lipid mediators in a mouse model of allergic contact dermatitis (163.9)

Allergic contact dermatitis (CD) is a type of inflammatory skin disease resulting from delayed-typed hypersensitivity to haptenic antigens. The antigens are presented to T cells by dendritic cells in the skin and result in activation and recruitment of other immune cells to the skin. The inflammatory response is frequently accompanied by production of metabolic mediators. Here we sought to identify mediators involved in allergic CD by using a mouse model. C57BL/6 mice were sensitized with dinitrofluorobenzene or oxazolone and challenged with the same antigen on the ear. The treated ears were swollen and exhibited accumulation of leukocytes. The affected ears were subjected to targeted quantitative metabolomic analysis by mass spectrometry to identify lipid metabolites that displayed significant changes. A cyclooxygenase product, thromboxane A2, was remarkably induced by more than 10 fold compared to vehicle control. A number of other bioactive lipid metabolites were induced by more than two fold. We found that mice treated with aspirin or sEHi showed reduced ear thickness compared to vehicle treatment. Our data suggest that the cyclooxygenase and soluble epoxide hydrolase pathways are involved in the development of allergic CD by modulating the inflammatory skin response. Inhibitors of these two pathways and antagonists of prostanoid receptors for the elevated metabolites are expected to be effective therapeutically to treat allergic CD.

Impact of epoxyeicosatrienoic acids in lung ischemia-reperfusion injury

OBJECTIVE

Epoxyeicosatrienoic acids (EETs) are protective in both myocardial and brain ischemia, variously attributed to activation of K(ATP) channels or blockade of adhesion molecule upregulation. In this study, we tested whether EETs would be protective in lung ischemia-reperfusion injury.

METHODS

The filtration coefficient (K(f)), a measure of endothelial permeability, and expression of the adhesion molecules vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM) were measured after 45 minutes ischemia and 30 minutes reperfusion in isolated rat lungs.

RESULTS

K(f) increased significantly after ischemia-reperfusion alone vs time controls, an effect dependent upon extracellular Ca(2+) although not on the EET-regulated channel TRPV4. Inhibition of endogenous EET degradation or administration of exogenous 11,12- or 14,-15-EET at reperfusion significantly limited the permeability response to ischemia-reperfusion. The beneficial effect of 11,12-EET was not prevented by blockade of K(ATP) channels nor by blockade of TRPV4. Finally, 11,12-EET-dependent alteration in adhesion molecules expression is unlikely to explain its beneficial effect, since the expression of the adhesion molecules VCAM and ICAM in lung after ischemia-reperfusion was similar to that in controls.

CONCLUSION

EETs are beneficial in the setting of lung ischemia-reperfusion, when administered at reperfusion. However, further study will be needed to elucidate the mechanism of action.

Soluble epoxide hydrolase in atherosclerosis

Like many eicosanoids, epoxyeicosatrienoic acids (EETs) have multiple biological functions, including reduction of blood pressure, inflammation, and atherosclerosis in multiple species. Hydration of EETs by the soluble epoxide hydrolase (sEH) is the major route of their degradation to the less bioactive diols. Inhibition of the sEH stabilizes EETs, thus, enhancing the beneficial effects of EETs. Human data show an association of sEH (Ephx2) gene polymorphisms with increased risk of atherosclerosis and cardiovascular diseases. These data suggest a potential therapeutic effect of sEH inhibitors (sEHI) in the treatment of atherosclerosis. Indeed, two laboratories reported independently that using different sEHIs in apolipoprotein E-deficient mice significantly attenuated atherosclerosis development and aneurysm formation. The antiatherosclerotic effects of sEHI are correlated with elevation in EET levels and associated with reduction of low-density lipoprotein and elevation of high-density lipoprotein cholesterols, as well as attenuation of expression of proinflammatory genes and proteins. In addition, the antihypertensive effects and improvement of endothelial function also contribute to the mechanism of the antiatherosclerotic effects of sEHI. The broad spectrum of biological action of EETs and sEHIs with multiple biological beneficial actions provides a promising new class of therapeutics for atherosclerosis and other cardiovascular diseases.

Frataxin deficiency induces Schwann cell inflammation and death

Mutations in the frataxin gene cause dorsal root ganglion demyelination and neurodegeneration, which leads to Friedreich's ataxia. However the consequences of frataxin depletion have not been measured in dorsal root ganglia or Schwann cells. We knocked down frataxin in several neural cell lines, including two dorsal root ganglia neural lines, 2 neuronal lines, a human oligodendroglial line (HOG) and multiple Schwann cell lines and measured cell death and proliferation. Only Schwann cells demonstrated a significant decrease in viability. In addition to the death of Schwann cells, frataxin decreased proliferation in Schwann, oligodendroglia, and slightly in one neural cell line. Thus the most severe effects of frataxin deficiency were on Schwann cells, which enwrap dorsal root ganglia neurons. Microarray of frataxin-deficient Schwann cells demonstrated strong activations of inflammatory and cell death genes including interleukin-6 and Tumor Necrosis Factor which were confirmed at the mRNA and protein levels. Frataxin knockdown in Schwann cells also specifically induced inflammatory arachidonate metabolites. Anti-inflammatory and anti-apoptotic drugs significantly rescued frataxin-dependent Schwann cell toxicity. Thus, frataxin deficiency triggers inflammatory changes and death of Schwann cells that is inhibitable by inflammatory and anti-apoptotic drugs.