Effect of vitamin D supplementation on cerebral blood flow in male patients with adrenoleukodystrophy.

One-third of boys with X-linked adrenoleukodystrophy (ALD) develop inflammatory demyelinating lesions, typically at the splenium. These lesions share similarities with multiple sclerosis, including cerebral hypoperfusion and links to vitamin D insufficiency. We hypothesized that increasing vitamin D levels would increase cerebral blood flow (CBF) in ALD boys. We conducted an exploratory analysis of vitamin D supplementation and CBF using all available data from participants enrolled in a recent single-arm interventional study of vitamin D supplementation in boys with ALD. We measured whole brain and splenium CBF using arterial spin labeling (ASL) from three study time points (baseline, 6 months, and 12 months). We used linear generalized estimating equations to evaluate CBF changes between time points and to test for an association between CBF and vitamin D. ASL data were available for 16 participants, aged 2-22 years. Mean vitamin D levels increased by 72.7% (p < .001) after 6 months and 88.6% (p < .01) after 12 months. Relative to baseline measures, mean CBF of the whole brain (6 months: +2.5%, p = .57; 12 months: +6.1%, p = .18) and splenium (6 months: +1.2%, p = .80; 12 months: +7.4%, p = .058) were not significantly changed. Vitamin D levels were positively correlated with CBF in the splenium (slope = .59, p < .001). In this exploratory analysis, we observed a correlation between vitamin D levels and splenial CBF in ALD boys. We confirm the feasibility of measuring CBF in this brain region and population, but further work is needed to establish a causal role for vitamin D in modulating CBF.

Biomarker Identification, Safety, and Efficacy of High-Dose Antioxidants for Adrenomyeloneuropathy: a Phase II Pilot Study.

X-Adrenoleukodystrophy (X-ALD) and its adult-onset, most prevalent variant adrenomyeloneuropathy (AMN) are caused by mutations in the peroxisomal transporter of the very long-chain fatty acid ABCD1. AMN patients classically present spastic paraparesis that can progress over decades, and a satisfactory treatment is currently lacking. Oxidative stress is an early culprit in X-ALD pathogenesis. A combination of antioxidants halts the clinical progression and axonal damage in a murine model of AMN, providing a strong rationale for clinical translation. In this phase II pilot, open-label study, 13 subjects with AMN were administered a high dose of α-tocopherol, N-acetylcysteine, and α-lipoic acid in combination. The primary outcome was the validation of a set of biomarkers for monitoring the biological effects of this and future treatments. Functional clinical scales, the 6-minute walk test (6MWT), electrophysiological studies, and cerebral MRI served as secondary outcomes. Most biomarkers of oxidative damage and inflammation were normalized upon treatment, indicating an interlinked redox and inflammatory homeostasis. Two of the inflammatory markers, MCP1 and 15-HETE, were predictive of the response to treatment. We also observed a significant decrease in central motor conduction time, together with an improvement or stabilization of the 6MWT in 8/10 subjects. This study provides a series of biomarkers that are useful to monitor redox and pro-inflammatory target engagement in future trials, together with candidate biomarkers that may serve for patient stratification and disease progression, which merit replication in future clinical trials. Moreover, the clinical results suggest a positive signal for extending these studies to phase III randomized, placebo-controlled, longer-term trials with the actual identified dose. ClinicalTrials.gov Identifier: NCT01495260.

In vitro effect of N-acetyl-L-cysteine on glutathione and sulfhydryl levels in X-linked adrenoleukodystrophy patients

Introduction: Recent evidence shows that oxidative stress seems to be related with the pathophysiology of X-linked adrenoleukodystrophy (X-ALD), a neurodegenerative disorder. Methods: In the present study, the in vitro effect of N-acetyl-L-cysteine (NAC) on glutathione (GSH) and sulfhydryl levels in X-ALD patients was evaluated. Results: A significant reduction of GSH and sulfhydryl content was observed in X-ALD patients compared to the control group. Furthermore, 5 mM of NAC, in vitro, led to an increase in GSH content and sulfhydryl groups in these patients. Conclusion: These data probably indicate that an adjuvant therapy with the antioxidant NAC could improve the oxidative imbalance in X-ALD patients(AU)

Mechanisms of Antioxidant Induction with High-Dose N-Acetylcysteine in Childhood Cerebral Adrenoleukodystrophy.

BACKGROUND: Childhood cerebral adrenoleukodystrophy (CCALD), a progressive demyelinating disease affecting school-aged boys, causes death within a few years. Oxidative stress is an important contributing factor. N-acetylcysteine (NAC; 280 mg/kg/day) added as adjunctive therapy to reduced-intensity hematopoietic cell transplantation (HCT) improves survival in advanced cases. However, the mechanisms underlying the benefits of NAC are unclear. OBJECTIVE: The aim of this study was to understand the mechanism of action of NAC in the setting of HCT in CCALD. METHODS: Immunoassays were carried out to determine changes in heme oxygenase-1 (HO-1) and ferritin expression in plasma samples collected from boys with CCALD at three different timepoints during the course of transplantation. In addition, the induction of HO-1 was also confirmed in normal fibroblasts following incubation with 10-100 µmol/L NAC for 4 h. RESULTS: Following NAC therapy we observed an increase in expression of the antioxidants HO-1 (~4-fold) and its effector ferritin (~160-fold) in patient samples as compared with baseline. We also observed that NAC exposure significantly increased HO-1 expression in fibroblasts. CONCLUSION: Our data suggest that HO-1 is a possible target protein of NAC and a mediator of its cytoprotective effects in these patients.

Treatment of an adrenomyeloneuropathy patient with Lorenzo's oil and supplementation with docosahexaenoic acid--a case report.

This is a case report of adrenomyeloneuropathy (AMN), the adult variant of adrenoleukodystryphy (ALD). The diagnoses in the patient, aged 34, was confirmed via increased serum very long chain fatty acid concentration (VLCFA). Treatment started with the cholesterol lowering drug, atorvastatin, followed by add-on therapy with Lorenzo's oil (LO) and finally supplementation with docosahexaenoic acid (DHA). The magnetic resonance imaging (MRI) scan of the AMN patient before DHA treatment, already showed abnormal white matter in the brain. Although the MRI showed no neurological improvement after 6 months of DHA treatment, no selective progression of demyelination was detected in the AMN patient. Contrary to what was expected, LO failed to sustain or normalize the VLCFA levels or improve clinical symptoms. It was however, shown that DHA supplementation in addition to LO, increased DHA levels in both plasma and red blood cells (RBC). Additionally, the study showed evidence that the elongase activity in the elongation of eicosapentaenoic acid (EPA) to docosapentaenoic acid (DPA) might have been significantly compromised, due to the increased DHA levels.

The effect of Lorenzo's oil on oxidative stress in X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder biochemically characterized by the accumulation of very long chain fatty acids (VLCFA), particularly hexacosanoic acid (C(26:0)) and tetracosanoic acid (C(24:0)), in tissues and biological fluids. Although patients affected by this disorder predominantly present central and peripheral demyelination as well as adrenal insufficiency, the mechanisms underlying the brain damage in X-ALD are poorly known. The current treatment of X-ALD with glyceroltrioleate (C(18:1))/glyceroltrierucate (C(22:1)) (Lorenzo's oil, LO) combined with a VLCFA-poor diet normalizes VLCFA concentrations, but the neurological symptoms persist or even progress in symptomatic patients. Considering that free radical generation is involved in various neurodegenerative disorders and that in a previous study we showed evidence that oxidative stress is probably involved in the pathophysiology of X-ALD symptomatic patients, in the present study we evaluated various oxidative stress parameters, namely thiobarbituric acid reactive species (TBA-RS) and total antioxidant reactivity (TAR) in plasma, as well as the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes from symptomatic and asymptomatic X-ALD patients and verified whether LO treatment and a VLCFA restricted diet could change these parameters. We observed a significant increase of plasma TBA-RS in symptomatic and asymptomatic X-ALD patients, reflecting induction of lipid peroxidation even before the disease was manifested. In addition, LO treatment did not alter this profile. Furthermore, plasma TAR measurement of X-ALD patients was not different from that of controls. Similarly, the antioxidant enzyme activities CAT, SOD and GPx were not altered in erythrocyte from X-ALD patients as compared to controls. We also examined the in vitro effects of hexacosanoic acid (C(26:0)) and tetracosanoic acid (C(24:0)) alone or combined with oleic (C(18:1))/erucic (C(22:1)) acids on various oxidative stress parameters in cerebral cortex of young rats, namely chemiluminescence, TBA-RS, TAR, CAT, SOD and GPx in order to investigate whether those fatty acids were able to induce oxidative stress. We found that there was a significant increase of TBARS and of chemiluminescence in rat cerebral cortex exposed to C(26:0)/C(24:0), and that the addition of C(18:1)and C(22:1) to the assays did not prevent this effect. Furthermore, TAR measurement was not altered by C(26:0) and C(24:0) acids in rat cerebral cortex. Taken together, our results indicate that lipid peroxidation occurs in X-ALD and that LO treatment does not attenuate or prevent free radical generation in these patients. Therefore, it may be presumed that antioxidants should be considered as an adjuvant therapy for X-ALD patients.

Evaluation of the therapeutic potential of PPARalpha agonists for X-linked adrenoleukodystrophy.

Adrenoleukodystrophy protein (ABCD1), a peroxisomal membrane protein, is mutated in patients affected by X-linked adrenoleukodystrophy (X-ALD). Adrenoleukodystrophy-related protein (ABCD2) is the closest relative of ABCD1. Pharmacological induction of ABCD2 gene expression has been proposed as a novel therapy strategy for X-ALD. Fibrates induce peroxisome proliferation and Abcd2 expression in rodent liver. Here we evaluate the possibility of using peroxisome proliferator-activated receptor alpha (PPARalpha) agonists for pharmacological induction of ABCD2 expression. In the liver of PPARalpha-deficient mice, both the constitutive and the fenofibrate-inducible Abcd2 gene expression was found to be PPARalpha-dependent. In the brain, PPARalpha-deficiency has no effect on Abcd2 expression. In mice orally treated with the novel, highly selective, and potent PPARalpha agonists GW 7647, GW 6867, and tetradecylthioacetic acid, Abcd2 expression was induced in liver and adrenal glands, but not in brain and testis. None of four putative PPREs identified in the 5(')-flanking DNA and in intron 1 of the Abcd2 gene conferred fibrate response in luciferase reporter assays. Thus, although fibrate-mediated Abcd2 induction is PPARalpha-dependent, it appears to be an indirect mechanism. Within the mouse Abcd2 promoter, a putative sterol regulatory element (SRE) similar in sequence and position to the characterized SRE sequence of the human ABCD2 promoter, was identified. A PPARalpha dependent induction of the sterol regulatory-binding protein 2 (SREBP2) and a down-regulation of SREBP1c mRNA levels could be demonstrated after fenofibrate treatment of mice. Our results suggest that the PPARalpha agonist-mediated induction of Abcd2 expression seems to be indirect and possibly mediated by SREBP2.

Effect of dehydroepiandrosterone supplementation on fatty acid and hormone levels in patients with X-linked adrenoleucodystrophy.

OBJECTIVE: In X-linked adrenoleucodystrophy (X-ALD) the peroxisomal beta-oxidation of saturated very long-chain fatty acids (VLCFAs; carbon length > 22 atoms) is impaired. These fatty acids accumulate in blood and tissues, in particular in the nervous system, adrenal cortex and testis. Most patients have a primary adrenocortical insufficiency with low levels of cortisol and dehydroepiandrosterone (DHEA) and its sulphate ester (DHEA-S), collectively called DHEA(S). Surprisingly, very low plasma levels of DHEA(S) may be found when plasma cortisol and ACTH levels are normal. In animal studies DHEA administration had a peroxisome proliferating effect and induced the expression of peroxisomal enzymes involved in the beta-oxidation of fatty acids. PATIENTS AND DESIGN: To study the effect of DHEA on fatty acids in X-ALD patients, we conducted a randomized double-blind study in which 14 men (age range 21-63 years) and one boy (12 years) received 50 mg of DHEA or placebo for 3 months, followed by a 1-month wash-out period, then 3 months of placebo or vice versa. RESULTS: A significant rise was seen in the plasma levels of DHEA-S, Delta4-androstenedione and IGF-I. The elevated saturated VLCFAs in plasma and erythrocytes did not change. However, in erythrocytes significant decreases were found in the total amount of fatty acids, in C16:0, C18:0 and in C20:4omega-6, C22:5omega-6, C18:1omega-9, C20:1omega-9 and C20:3omega-9. In plasma, decreases were found for C18:1omega-9 and increases for C20:1omega-9. CONCLUSIONS: Dehydroepiandrosterone supplementation for 3 months did not lower the elevated plasma levels of saturated very long-chain fatty acids in patients with X-linked adrenoleucodystrophy. Instead, a decrease in saturated and mono- and polyunsaturated fatty acids in erythrocytes and plasma was found. An increase of C20:1omega-9 was found in plasma only.

Very long chain fatty acids in X-linked adrenoleukodystrophy brain after treatment with Lorenzo's oil.

The fatty acid composition of postmortem brain and liver from an adrenoleukodystrophy patient whose diet was supplemented with Lorenzo's oil (glycerol trioleate and glycerol trierucate) for 9 months was determined. The diet depressed plasma and liver saturated very long chain fatty acids (24:0 and 26:0) and increased plasma and liver erucic (22:1) and nervonic (24:1) acids. The levels of plasma linoleic (18:2 n-6), eicosopentaenoic (20:5 n-3), and docosahexaenoic (22:6 n-3) acids were also reduced, while the biochemical marker for essential fatty acid deficiency (20:3 n-9) was markedly increased in liver. However, we were unable to detect any corresponding changes in brain indicating that little erucic acid crossed the blood-brain barrier. Our findings suggest that dietary supplementation with Lorenzo's oil is of limited value in correcting the accumulation of saturated very long chain fatty acids in the brain of patients with adrenoleukodystrophy.