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The Journal of Dermatology Jun 2024Peroxisomal acyl-CoA oxidase 1 (ACOX1), is a peroxisomal enzyme that catalyzes β-oxidation of very-long-chain fatty acids (VLCFA). The gain-of-function variant...
Peroxisomal acyl-CoA oxidase 1 (ACOX1), is a peroxisomal enzyme that catalyzes β-oxidation of very-long-chain fatty acids (VLCFA). The gain-of-function variant p.Asn237Ser in ACOX1 has been shown to cause Mitchell syndrome (MITCH), a neurodegenerative disorder characterized by episodic demyelination, hearing loss, and polyneuropathy, through the overproduction of hydrogen peroxide. Only eight cases of MITCH have been reported. While all these patients experienced cutaneous abnormalities, detailed skin features and potential treatment have not been documented. Herein, we report two MITCH patients who harbored a de novo heterozygous variant p.Asn237Ser in ACOX1 and experienced progressive ichthyosiform erythroderma. Skin histopathology revealed hyperkeratosis and parakeratosis with focal hypogranulosis as well as dyskeratotic keratinocytes. Lipid accumulation in the epidermis was observed using Oil Red O staining. Both patients exhibited a remarkable response to treatment with the topical antioxidant N-acetylcysteine (NAC), with Patient 1 achieving complete recovery after 3 months of consistent treatment. This study provides the first comprehensive description of the clinicopathological characteristics and effective treatment of skin lesions in MITCH patients. The successful treatment with topical NAC suggests excessive reactive oxygen species might play a significant role in the pathogenesis of skin lesions in MITCH.
PubMed: 38923010
DOI: 10.1111/1346-8138.17346 -
Degenerative Neurological and... 2024X-linked adrenoleukodystrophy (ALD) is a rare genetic disorder caused by a pathogenic variant of the ABCD1 gene, leading to impaired peroxisomal function and the...
BACKGROUND
X-linked adrenoleukodystrophy (ALD) is a rare genetic disorder caused by a pathogenic variant of the ABCD1 gene, leading to impaired peroxisomal function and the accumulation of very long-chain fatty acids (VLCFAs). ALD presents a wide range of neurological and adrenal symptoms, ranging from childhood cerebral adrenoleukodystrophy to adrenomyeloneuropathy and adrenal insufficiency. Newborn screening (NBS) for ALD is available in some regions but remains lacking in others, such as India.
CASE PRESENTATION
We present a case of a 10-year-old boy with ALD who presented with seizures, progressive weakness, visual impairment, and adrenal insufficiency. Despite symptomatic management and dietary adjustments, the disease progressed rapidly, leading to respiratory failure and eventual demise. The diagnosis was confirmed through molecular analysis and elevated VLCFA levels. Neuroimaging revealed characteristic white matter changes consistent with ALD.
CONCLUSION
ALD is a devastating disease with no cure, emphasizing the importance of early detection through newborn screening and genetic testing. Management strategies include adrenal hormone therapy, gene therapy, and allogenic stem cell transplantation, as well as investigational treatments such as VLCFA normalization. Our case advocates the need for worldwide NBS and pediatric neurologic follow-up to enable early intervention and improve patient outcomes. Additionally, the association between ALD, recurrent febrile seizures, and unexplained developmental delay warrants further investigation to better understand disease progression and potential therapeutic targets.
PubMed: 38912366
DOI: 10.2147/DNND.S442985 -
BioRxiv : the Preprint Server For... Jun 2024X-adrenoleukodystrophy (X-ALD) is a peroxisomal metabolic disorder caused by mutations in the ABCD1 gene encoding the peroxisomal ABC transporter adrenoleukodystrophy...
X-adrenoleukodystrophy (X-ALD) is a peroxisomal metabolic disorder caused by mutations in the ABCD1 gene encoding the peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). Similar mutations in ABCD1 may result in a spectrum of phenotypes in males with slow progressing adrenomyeloneuropathy (AMN) and fatal cerebral adrenoleukodystrophy (cALD) dominating the majority of cases. Mouse model of X-ALD does not capture the phenotype differences and an appropriate model to investigate mechanism of disease onset and progress remains a critical need. Induced pluripotent stem cell (iPSC)-derived and cell models derived from them have provided useful tools for investigating cell-type specific disease mechanisms. Here, we generated induced pluripotent stem cell (iPSC) lines from skin fibroblasts of two each of apparently healthy control, AMN and cALD patients with non-integrating mRNA-based reprogramming. iPSC lines expanded normally and expressed pluripotency markers Oct4, SOX2, Nanog, SSEA and TRA-1-60. Expression of markers SOX17, brachyury, Desmin, Oxt2 and beta tubulin III demonstrated the ability of the iPSCs to differentiate into all three germ layers. iPSC-derived lines from CTL, AMN and cALD male patients were differentiated into astrocytes. Differentiated AMN and cALD astrocytes lacked ABCD1 expression and accumulated VLCFA, a hallmark of X-ALD. These patient astrocytes provide disease-relevant tools to investigate mechanism of differential neuroinflammatory response and metabolic reprogramming in X-ALD. Further these patient-derived human astrocyte cell models will be valuable for testing new therapeutics.
PubMed: 38854155
DOI: 10.1101/2024.05.31.596696 -
Molecular Syndromology Jun 2024Acyl-CoA binding domain containing 5 (ACBD5) deficiency is a newly defined inborn peroxisomal disorder with only 7 patients reported to date. Herein, we report a patient...
INTRODUCTION
Acyl-CoA binding domain containing 5 (ACBD5) deficiency is a newly defined inborn peroxisomal disorder with only 7 patients reported to date. Herein, we report a patient with ACBD5 deficiency who was diagnosed after a complicated diagnostic process.
CASE PRESENTATION
A 6-year-old male patient was admitted with complaints of neuromotor regression and visual disturbances. He had spastic paraparesis dominated with axial hypotonic posturing and horizontal nystagmus. His very-long-chain fatty acid levels were within normal ranges with a slightly elevated C26:0/C22:0 ratio. Brain magnetic resonance imaging revealed white matter involvement. Clinical exome sequencing displayed a novel homozygous intronic splice site variant (c.936 + 2T>G) in the ACBD5 (NM_145698.5) gene.
CONCLUSION
With this report, a novel variant in ACBD5 deficiency was described. Macular dystrophy was demonstrated with optical coherence tomography imaging for the first time in the literature in ACBD5 deficiency. In order to contribute to the knowledge about the clinical, biochemical, and genetic spectrum of ACBD5 deficiency, new patients need to be defined.
PubMed: 38841324
DOI: 10.1159/000535534 -
Advances in Experimental Medicine and... May 2024One of the functions of peroxisomes is the oxidation of fatty acids (FAs). The importance of this function in our lives is evidenced by the presence of peroxisomal...
One of the functions of peroxisomes is the oxidation of fatty acids (FAs). The importance of this function in our lives is evidenced by the presence of peroxisomal disorders caused by the genetic deletion of proteins involved in these processes. Unlike mitochondrial oxidation, peroxisomal oxidation is not directly linked to ATP production. What is the role of FA oxidation in peroxisomes? Recent studies have revealed that peroxisomes supply the building blocks for lipid synthesis in the endoplasmic reticulum and facilitate intracellular carbon recycling for membrane quality control. Accumulation of very long-chain fatty acids (VLCFAs), which are peroxisomal substrates, is a diagnostic marker in many types of peroxisomal disorders. However, the relationship between VLCFA accumulation and various symptoms of these disorders remains unclear. Recently, we developed a method for solubilizing VLCFAs in aqueous media and found that VLCFA toxicity could be mitigated by oleic acid replenishment. In this chapter, we present the physiological role of peroxisomal FA oxidation and the knowledge obtained from VLCFA-accumulating peroxisome-deficient cells.
PubMed: 38811487
DOI: 10.1007/5584_2024_802 -
Molecular Therapy : the Journal of the... May 2024X-linked adrenoleukodystrophy (ALD), an inherited neurometabolic disorder caused by mutations in ABCD1, which encodes the peroxisomal ABC transporter, mainly affects the...
X-linked adrenoleukodystrophy (ALD), an inherited neurometabolic disorder caused by mutations in ABCD1, which encodes the peroxisomal ABC transporter, mainly affects the brain, spinal cord, adrenal glands, and testes. In ALD patients, very-long-chain fatty acids (VLCFAs) fail to enter the peroxisome and undergo subsequent β-oxidation, resulting in their accumulation in the body. It has not been tested whether in vivo base editing or prime editing can be harnessed to ameliorate ALD. We developed a humanized mouse model of ALD by inserting a human cDNA containing the pathogenic variant into the mouse Abcd1 locus. The humanized ALD model showed increased levels of VLCFAs. To correct the mutation, we tested both base editing and prime editing and found that base editing using ABE8e(V106W) could correct the mutation in patient-derived fibroblasts at an efficiency of 7.4%. Adeno-associated virus (AAV)-mediated systemic delivery of NG-ABE8e(V106W) enabled robust correction of the pathogenic variant in the mouse brain (correction efficiency: ∼5.5%), spinal cord (∼5.1%), and adrenal gland (∼2%), leading to a significant reduction in the plasma levels of C26:0/C22:0. This established humanized mouse model and the successful correction of the pathogenic variant using a base editor serve as a significant step toward treating human ALD disease.
PubMed: 38796705
DOI: 10.1016/j.ymthe.2024.05.027 -
Journal of Lipid Research Jun 2024Lipids play pivotal roles in an extensive range of metabolic and physiological processes. In recent years, the convergence of trapped ion mobility spectrometry and MS...
Lipids play pivotal roles in an extensive range of metabolic and physiological processes. In recent years, the convergence of trapped ion mobility spectrometry and MS has enabled 4D-lipidomics, a highly promising technology for comprehensive lipid analysis. 4D-lipidomics assesses lipid annotations across four distinct dimensions-retention time, collisional cross section, m/z (mass-to-charge ratio), and MS/MS spectra-providing a heightened level of confidence in lipid annotation. These advantages prove particularly valuable when investigating complex disorders involving lipid metabolism, such as adrenoleukodystrophy (ALD). ALD is characterized by the accumulation of very-long-chain fatty acids (VLCFAs) due to pathogenic variants in the ABCD1 gene. A comprehensive 4D-lipidomics strategy of ALD fibroblasts demonstrated significant elevations of various lipids from multiple classes. This indicates that the changes observed in ALD are not confined to a single lipid class and likely impacts a broad spectrum of lipid-mediated physiological processes. Our findings highlight the incorporation of mainly saturated and monounsaturated VLCFA variants into a range of lipid classes, encompassing phosphatidylcholines, triacylglycerols, and cholesterol esters. These include ultra-long-chain fatty acids with a length of up to thirty carbon atoms. Lipid species containing C26:0 and C26:1 were the most frequently detected VLCFA lipids in our study. Furthermore, we report a panel of 121 new candidate biomarkers in fibroblasts, exhibiting significant differentiation between controls and individuals with ALD. In summary, this study demonstrates the capabilities of a 4D-lipid profiling workflow in unraveling novel insights into the intricate lipid modifications associated with metabolic disorders like ALD.
Topics: Adrenoleukodystrophy; Humans; Lipidomics; Ion Mobility Spectrometry; Lipids; Lipid Metabolism
PubMed: 38795862
DOI: 10.1016/j.jlr.2024.100567 -
Pediatric Blood & Cancer Aug 2024
Topics: Humans; Zellweger Syndrome; Blood Coagulation Disorders; Male; Female
PubMed: 38773729
DOI: 10.1002/pbc.31094 -
Nature Communications May 2024Peroxisomes are eukaryotic organelles that are essential for multiple metabolic pathways, including fatty acid oxidation, degradation of amino acids, and biosynthesis of...
Peroxisomes are eukaryotic organelles that are essential for multiple metabolic pathways, including fatty acid oxidation, degradation of amino acids, and biosynthesis of ether lipids. Consequently, peroxisome dysfunction leads to pediatric-onset neurodegenerative conditions, including Peroxisome Biogenesis Disorders (PBD). Due to the dynamic, tissue-specific, and context-dependent nature of their biogenesis and function, live cell imaging of peroxisomes is essential for studying peroxisome regulation, as well as for the diagnosis of PBD-linked abnormalities. However, the peroxisomal imaging toolkit is lacking in many respects, with no reporters for substrate import, nor cell-permeable probes that could stain dysfunctional peroxisomes. Here we report that the BODIPY-C12 fluorescent fatty acid probe stains functional and dysfunctional peroxisomes in live mammalian cells. We then go on to improve BODIPY-C12, generating peroxisome-specific reagents, PeroxiSPY650 and PeroxiSPY555. These probes combine high peroxisome specificity, bright fluorescence in the red and far-red spectrum, and fast non-cytotoxic staining, making them ideal tools for live cell, whole organism, or tissue imaging of peroxisomes. Finally, we demonstrate that PeroxiSPY enables diagnosis of peroxisome abnormalities in the PBD CRISPR/Cas9 cell models and patient-derived cell lines.
Topics: Peroxisomes; Humans; Fatty Acids; Fluorescent Dyes; Boron Compounds; Peroxisomal Disorders; Animals
PubMed: 38773129
DOI: 10.1038/s41467-024-48679-2 -
Brain : a Journal of Neurology Jun 2024The peroxisomal disease adrenoleukodystrophy (X-ALD) is caused by loss of the transporter of very-long-chain fatty acids (VLCFAs), ABCD1. An excess of VLCFAs disrupts...
The peroxisomal disease adrenoleukodystrophy (X-ALD) is caused by loss of the transporter of very-long-chain fatty acids (VLCFAs), ABCD1. An excess of VLCFAs disrupts essential homeostatic functions crucial for axonal maintenance, including redox metabolism, glycolysis and mitochondrial respiration. As mitochondrial function and morphology are intertwined, we set out to investigate the role of mitochondrial dynamics in X-ALD models. Using quantitative 3D transmission electron microscopy, we revealed mitochondrial fragmentation in corticospinal axons in Abcd1- mice. In patient fibroblasts, an excess of VLCFAs triggers mitochondrial fragmentation through the redox-dependent phosphorylation of DRP1 (DRP1S616). The blockade of DRP1-driven fission by the peptide P110 effectively preserved mitochondrial morphology. Furthermore, mRNA inhibition of DRP1 not only prevented mitochondrial fragmentation but also protected axonal health in a Caenorhabditis elegans model of X-ALD, underscoring DRP1 as a potential therapeutic target. Elevated levels of circulating cell-free mtDNA in patients' CSF align this leukodystrophy with primary mitochondrial disorders. Our findings underscore the intricate interplay between peroxisomal dysfunction, mitochondrial dynamics and axonal integrity in X-ALD, shedding light on potential avenues for therapeutic intervention.
Topics: Adrenoleukodystrophy; Animals; Mitochondrial Dynamics; Humans; Mice; Dynamins; ATP Binding Cassette Transporter, Subfamily D, Member 1; Caenorhabditis elegans; Mitochondria; Axons; Fibroblasts; Male; DNA, Mitochondrial; Disease Models, Animal; Pyramidal Tracts; Peptide Fragments; GTP Phosphohydrolases
PubMed: 38763511
DOI: 10.1093/brain/awae038