衰退的MECR病原体变异会导致类似于LHON的视神经病变
Claudio Fiorini1, Andrea Degiorgi2, Maria Lucia Cascavilla3
1Programma di Neurogenetica, IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy.
Journal of medical genetics
|September 21, 2023
概括
MECR基因变异会导致类似于勒伯遗传性视神经病 (LHON) 的症状. 这项研究揭示了 mitochondrial 脂肪酸合成受损作为一个新的 LHON 机制.
科学领域:
- 遗传学 遗传学是一种遗传学.
- 线粒体生物学 线粒体生物学
- 神经眼科 神经眼科
背景情况:
- 勒伯遗传性光神经病 (LHON) 是一种线粒体疾病,导致视网膜质细胞退化,通常与线粒体DNA突变有关.
- 此外,LHON也与核基因变异有关,包括参与线粒体脂肪酸合成 (mtFAS) 的MCAT.
- 编码 mitochondrial trans-2-enoyl-CoA 减少酶的 MECR 对于 mtFAS 是至关重要的;它的突变会导致儿童发病的光学缩疾病.
研究的目的:
- 为了研究两个突然视力丧失的姐妹的LHON类视神经病变的遗传基础.
- 阐明候选MECR变异对线粒体功能和细胞应激反应的功能后果.
主要方法:
- 整体外基因组测序在受影响的姐妹中发现了一种同卵性MECR变异.
- 确定的MECR变体在酵母中建模,以评估线粒体功能障碍,包括氧化生长,氧气消耗和蛋白质水平.
- 在酵母模型中评估了蛋白质化,对氧化应激 (H2O2) 的反应,以及酸补充剂的效果.
主要成果:
- 这两位姐妹都携带一种同卵性致病性MECR变异 (p.Arg258Trp).
- 酵母中的MECR-R258W突变导致生长减少,氧气消耗减少,MECR蛋白水平显著降低,这表明结构不稳定.
- 酵母突变体表现出受损的脂化和增加对氧化应激的敏感性,部分通过脂酸进行救援.
结论:
- 这项研究报告了第一个具有同卵性MECR变异导致LHON类视神经病变的家族.
- 这些发现将MECR突变与LHON联系起来,加强了线粒体脂肪酸合成受损的作用,作为LHON的新型致病机制.
- 这扩大了LHON的遗传谱,并突出了mtFAS缺陷作为视觉神经病变的潜在原因.
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