Functional interaction of peroxisomal ABC proteins and acyl-CoA sythesis in glial cells

神经胶质细胞中过氧化物酶体 ABC 蛋白与酰基辅酶 A 合成的功能相互作用

基本信息

批准号：
16590044
负责人：
MORITA Masashi
金额：
$ 2.18万
依托单位：
University of Toyama (2005)Toyama Medical and Pharmaceutical University (2004)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

1.X-linked adrenoleukodystorophy (ALD) is a neurodegenerative disorder characterized by an abnormal accumulation of very long chain fatty acid (VLCFA). It is caused by a defect in the gene ABCD1 which encodes the peroxisomal membrane ABC protein, ALDP. However, the function of ALDP in CNS and the mechanism of the neurodegeneration in X-ALD were still unclear. In the present study, we have analyzed lipid metabolisms in ALDP-knockdown glioblastoma cells. In the ALDP-knockdown cells, the VLCFA β-oxidation activity was decreased by 〜70%. In addition, incorporation of [1-^<14>C]lignoceric acid into cholesterol ester fractions was increased in these cells. Furthermore, the incorporation of [2-^<14>C]acetic acid into cholesterol was significantly decreased and the cholesterol mass was increased in the ALDP-knockdown cells. These results indicate that in glial cells dysfunction of ALDP leads to the disruption of cholesterol metabolism as well as VLCFA metabolisms.2.We analyzed the lipid metabolisms of primary microglia and astrocyte prepared from ALD-KO mouse. The VLCFA β-oxidation activity was significantly decreased when compared with that from wild mouse. These glial cells are reported to have important roles in neuronal functions. Disruption of VLCFA metabolisms in these cells could lead to the neurodegeneration in X-ALD.3.We found that baicalein 5,6,7-trimethyl ether, a flavonoid derivative, have an ability to normalize the abnormal VLCFA metabolisms in X-ALD fibroblasts. This flavonoid derivative stimulated the peroxisomal VLCFA β-oxidation but inhibited the mitochondrial fatty acid β-oxidation. The flavonoid activated the acyl-CoA synthetase activities, suggesting that up-regulation of acyl-CoA synthetases could result in the stimulation of the VLCFA β-oxidation.4.A novel medium-chain acyl-CoA synthetase was cloned and characterized. This enzyme was expressed in brain, adrenal gland, ovary and testis.

1.X连锁肾上腺脑白质营养不良（ALD）是一种神经退行性疾病，其特征是极长链脂肪酸（VLCFA）的异常积累，它是由编码过氧化物酶体膜ABC蛋白ALDP的基因ABCD1缺陷引起的。 ALDP 在 CNS 中的功能以及 X-ALD 中神经变性的机制仍不清楚。在本研究中，我们分析了 ALDP 敲低中的脂质代谢。在ALDP敲低的细胞中，VLCFA β-氧化活性降低了约70％。此外，这些细胞中[1-^ 14 C]木蜡酸的掺入增加。在ALDP敲低细胞中，[2-14C]乙酸掺入胆固醇显着减少并且胆固醇质量增加。这些结果表明在神经胶质细胞中。 ALDP功能障碍导致胆固醇代谢和VLCFA代谢紊乱。2.我们分析了ALD-KO小鼠原代小胶质细胞和星形胶质细胞的脂质代谢，与野生相比，VLCFAβ氧化活性显着降低。据报道，这些神经胶质细胞在神经元功能中具有重要作用，这些细胞中 VLCFA 代谢的破坏可能导致 X-ALD 的神经变性。3。我们发现黄芩素。 5,6,7-三甲醚是一种黄酮衍生物，能够使 X-ALD 成纤维细胞中异常的 VLCFA 代谢正常化。这种黄酮衍生物刺激过氧化物酶体 VLCFA β-氧化，但抑制线粒体脂肪酸 β-氧化。酰基辅酶A合成酶活性，表明酰基辅酶A合成酶的上调可能导致刺激4.克隆并表征了一种新型中链酰基辅酶A合成酶，该酶在脑、肾上腺、卵巢和睾丸中表达。