Abcd1 deficiency accelerates cuprizone-induced oligodendrocyte loss and axonopathy in a demyelinating mouse model of X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD), the most frequent, inherited peroxisomal disease, is caused by mutations in the ABCD1 gene encoding a peroxisomal lipid transporter importing very long-chain fatty acids (VLCFAs) from the cytosol into peroxisomes for degradation via ß-oxidation. ABCD1 deficiency results in accumulation of VLCFAs in tissues and body fluids of X-ALD patients with a wide range of phenotypic manifestations. The most severe variant, cerebral X-ALD (CALD) is characterized by progressive inflammation, loss of the myelin-producing oligodendrocytes and demyelination of the cerebral white matter. Whether the oligodendrocyte loss and demyelination in CALD are caused by a primary cell autonomous defect or injury to oligodendrocytes or by a secondary effect of the inflammatory reaction remains unresolved. To address the role of X-ALD oligodendrocytes in demyelinating pathophysiology, we combined the Abcd1 deficient X-ALD mouse model, in which VLCFAs accumulate without spontaneous demyelination, with the cuprizone model of toxic demyelination. In mice, the copper chelator cuprizone induces reproducible demyelination in the corpus callosum, followed by remyelination upon cuprizone removal. By immunohistochemical analyses of oligodendrocytes, myelin, axonal damage and microglia activation during de-and remyelination, we found that the mature oligodendrocytes of Abcd1 KO mice are more susceptible to cuprizone-induced cell death compared to WT mice in the early demyelinating phase. Furthermore, this effect was mirrored by a greater extent of acute axonal damage during demyelination in the KO mice. Abcd1 deficiency did not affect the function of microglia in either phase of the treatment. Also, the proliferation and differentiation of oligodendrocyte precursor cells and remyelination progressed at similar rates in both genotypes. Taken together, our findings point to an effect of Abcd1 deficiency on mature oligodendrocytes and the oligodendrocyte-axon unit, leading to increased vulnerability in the context of a demyelinating insult.

25-hydroxycholesterol contributes to cerebral inflammation of X-linked adrenoleukodystrophy through activation of the NLRP3 inflammasome.

X-linked adrenoleukodystrophy (X-ALD), caused by an ABCD1 mutation, is a progressive neurodegenerative disorder associated with the accumulation of very long-chain fatty acids (VLCFA). Cerebral inflammatory demyelination is the major feature of childhood cerebral ALD (CCALD), the most severe form of ALD, but its underlying mechanism remains poorly understood. Here, we identify the aberrant production of cholesterol 25-hydroxylase (CH25H) and 25-hydroxycholesterol (25-HC) in the cellular context of CCALD based on the analysis of ALD patient-derived induced pluripotent stem cells and ex vivo fibroblasts. Intriguingly, 25-HC, but not VLCFA, promotes robust NLRP3 inflammasome assembly and activation via potassium efflux-, mitochondrial reactive oxygen species (ROS)- and liver X receptor (LXR)-mediated pathways. Furthermore, stereotaxic injection of 25-HC into the corpus callosum of mouse brains induces microglial recruitment, interleukin-1ß production, and oligodendrocyte cell death in an NLRP3 inflammasome-dependent manner. Collectively, our results indicate that 25-HC mediates the neuroinflammation of X-ALD via activation of the NLRP3 inflammasome.

[Adrenoleukodystrophy: clinical and histopathological study of a case associated to the use of abortifacient agents in the second month of pregnancy]. / Adrenoleucodistrofia. Estudo clínico e histopatológico de um caso associado ao uso de abortivos no segundo mês de gestação.

The authors report a case of adrenoleukodystrophy in a 8 years old male patient whose mother has taken several abortive drugs during the first three months of pregnancy. The disease was progressive starting with auditory, visual and mental disturbances, followed by neurovegetatives and motor changes with convulsion and fetal position. At the final stage the patient became blind, deaf, quadriplegic and dementiated. Death resulted from lung infection. The diagnosis was confirmed by the CSF, electrophysiological, radiological and necropsy findings. Necropsy changes in the brain and adrenal cortex are detailed.

Adrenoleucodistrofia: estudo clínico e histopatológico de um caso associado ao uso de abortivos no segundo mês de gestaçäo / Adrenoleukodystrophy: clinical and histopathological study of a case associated to the use of abortifacient agents in the second month of pregnancy

Os autores descrevem um caso de adrenoleucodistrofia (ALD) em um paciente do sexo masculino, com 8 anos de idade, cuja genitora no primeiro trimestre da gravidez tomou miscelânia de drogas com fins abortivos. O curso da doença foi progressivo iniciando-se por distúrbios auditivos, visuais e mentais, seguindo-se alteraçöes neurovegetativas, motoras, convulsivas e postura fetal. No estágio final o paciente tornou-se amaurótico, surdo, quadriplégico e demente. O óbito ocorreu por infecçäo respiratória. O diagnóstico foi confirmado pelo estudos do LCR, eletrofisiológicos e pelos achados de necrópsia (cérebro e glândulas adrenais)