Baarine Mauhamad, Beeson Craig, Singh Avtar, Singh Inderjit
Department of Pediatrics, Darby Children's Research Institute, Medical University of South Carolina, Charleston, South Carolina, USA.
J Neurochem. 2015 May;133(3):380-96. doi: 10.1111/jnc.12992. Epub 2015 Jan 13.
X-linked Adrenoleukodystrophy (X-ALD), an inherited peroxisomal metabolic neurodegenerative disorder, is caused by mutations/deletions in the ATP-binding cassette transporter (ABCD1) gene encoding peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). Metabolic dysfunction in X-ALD is characterized by the accumulation of very long chain fatty acids ≥ C22:0) in the tissues and plasma of patients. Here, we investigated the mitochondrial status following deletion of ABCD1 in B12 oligodendrocytes and U87 astrocytes. This study provides evidence that silencing of peroxisomal protein ABCD1 produces structural and functional perturbations in mitochondria. Activities of electron transport chain-related enzymes and of citric acid cycle (TCA cycle) were reduced; mitochondrial redox status was dysregulated and the mitochondrial membrane potential was disrupted following ABCD1 silencing. A greater reduction in ATP levels and citrate synthase activities was observed in oligodendrocytes as compared to astrocytes. Furthermore, most of the mitochondrial perturbations induced by ABCD1 silencing were corrected by treating cells with suberoylanilide hydroxamic acid, an Histone deacetylase inhibitor. These observations indicate a novel relationship between peroxisomes and mitochondria in cellular homeostasis and the importance of intact peroxisomes in relation to mitochondrial integrity and function in the cell types that participate in the pathobiology of X-ALD. These observations suggest suberoylanilide hydroxamic acid as a potential therapy for X-ALD. Schematic description of the effects of loss of peroxisomal ATP-binding cassette transporter D1 (ABCD1) gene on cellular Redox and mitochondrial activities and their correction by suberoylanilide hydroxamic acid (SAHA) treatment. Pathogenomic accumulation of very long chain fatty acids (VLCFA) as a result of loss of ABCD1 leads to dysfunctions of mitochondrial biogenesis and its activities. Treatment with SAHA corrects mitochondrial dysfunctions. These studies describe unique cooperation between mitochondria and peroxisome for cellular activities.
X连锁肾上腺脑白质营养不良(X-ALD)是一种遗传性过氧化物酶体代谢性神经退行性疾病,由编码过氧化物酶体ABC转运蛋白肾上腺脑白质营养不良蛋白(ALDP)的ATP结合盒转运体(ABCD1)基因突变/缺失引起。X-ALD的代谢功能障碍表现为患者组织和血浆中极长链脂肪酸(≥C22:0)的积累。在此,我们研究了B12少突胶质细胞和U87星形胶质细胞中ABCD1缺失后的线粒体状态。本研究提供了证据,表明过氧化物酶体蛋白ABCD1的沉默会导致线粒体的结构和功能扰动。电子传递链相关酶和柠檬酸循环(TCA循环)的活性降低;ABCD1沉默后,线粒体氧化还原状态失调,线粒体膜电位被破坏。与星形胶质细胞相比,少突胶质细胞中ATP水平和柠檬酸合酶活性的降低更为明显。此外,用组蛋白脱乙酰酶抑制剂辛二酰苯胺异羟肟酸处理细胞可纠正ABCD1沉默诱导的大多数线粒体扰动。这些观察结果表明,过氧化物酶体与线粒体在细胞内稳态中存在新的关系,完整的过氧化物酶体对于参与X-ALD病理生物学的细胞类型中线粒体的完整性和功能具有重要意义。这些观察结果表明辛二酰苯胺异羟肟酸可能是X-ALD的一种潜在治疗方法。过氧化物酶体ATP结合盒转运体D1(ABCD1)基因缺失对细胞氧化还原和线粒体活性的影响及其通过辛二酰苯胺异羟肟酸(SAHA)处理的纠正示意图。由于ABCD1缺失导致的极长链脂肪酸(VLCFA)的致病基因组积累导致线粒体生物发生及其活性的功能障碍。SAHA处理可纠正线粒体功能障碍。这些研究描述了线粒体与过氧化物酶体在细胞活动中的独特协作。