Department of Pathology, Case Western Reserve University, Cleveland, OH, USA.
Department of Pathology, Case Western Reserve University, Cleveland, OH, USA; Hathaway Brown School, Shaker Heights, OH, USA.
Free Radic Biol Med. 2022 Mar;182:23-33. doi: 10.1016/j.freeradbiomed.2022.02.006. Epub 2022 Feb 17.
Mitochondrial membrane protein-associated with neurodegeneration (MPAN) is a rare genetic disease characterized by aggressive neurodegeneration and massive iron accumulation in patients' brains. Genetics studies identified defects in C19orf12 locus being associated with MPAN which likely caused loss of function although underlying pathogenic mechanism(s) remain elusive. In the present study, we investigated C19orf12 knockout (KO) M17 neuronal cells and primary skin fibroblasts from MPAN patients with C19orf12 homozygous G58S or heterozygous C19orf12 p99fs*102 mutations as cellular models of MPAN. C19orf12 KO cells and MPAN fibroblast cells demonstrated mitochondrial fragmentation and dysfunction, iron overload and increased oxidative damage. Antioxidant NAC and iron chelator DFO rescued both oxidative stress and mitochondrial deficits. Moreover, C19orf12 KO cells and MPAN fibroblast cells were susceptible to erastin- or RSL3-induced ferroptosis which could be almost completely prevented by pretreatment of iron chelator DFO. Importantly, we also found mitochondrial fragmentation and increased ferroptosis related oxidative damage in neurons in the biopsied cortical tissues from an MPAN patient. Collectively, these results supported the notion that iron overload and ferroptosis likely play an important role in the pathogenesis of MPAN.
线粒体膜蛋白相关神经退行性变(MPAN)是一种罕见的遗传性疾病,其特征是患者大脑中的神经退行性变迅速和大量铁积累。遗传学研究发现,C19orf12 基因座的缺陷与 MPAN 相关,尽管潜在的发病机制尚不清楚,但可能导致功能丧失。在本研究中,我们以 C19orf12 纯合 G58S 或杂合 C19orf12 p99fs*102 突变的 MPAN 患者的 C19orf12 敲除(KO)M17 神经元细胞和原代皮肤成纤维细胞为细胞模型,研究了 C19orf12 敲除细胞和 MPAN 成纤维细胞。C19orf12 KO 细胞和 MPAN 成纤维细胞表现出线粒体碎片化和功能障碍、铁过载和氧化损伤增加。抗氧化剂 NAC 和铁螯合剂 DFO 挽救了氧化应激和线粒体缺陷。此外,C19orf12 KO 细胞和 MPAN 成纤维细胞易发生 erastin 或 RSL3 诱导的铁死亡,铁螯合剂 DFO 的预处理几乎可以完全阻止铁死亡。重要的是,我们还发现一名 MPAN 患者活检皮质组织中的神经元存在线粒体碎片化和增加的与铁死亡相关的氧化损伤。总之,这些结果支持了铁过载和铁死亡可能在 MPAN 发病机制中起重要作用的观点。