Ferroptosis, a regulated form of cell death characterized by iron-dependent lipid peroxide accumulation, plays a pivotal role in various pathological conditions, including neurodegenerative diseases. While reasonable evidence for ferroptosis exist e.g. in Parkinson’s disease or Alzheimer’s disease, there are only few reports on amyotrophic lateral sclerosis (ALS), a fast progressive and incurable neurodegenerative disorder characterized by progressive motor neuron degeneration. Initial studies, however, highlight that ferroptosis might be significantly involved in ALS. Key features of ferroptosis include oxidative stress, glutathione depletion, mitochondrial and dysfunction alterations in mitochondrial morphology, mediated by proteins such as GPX4, xCT, ACSL4 FSP1, Nrf2 and TfR1. Induction of ferroptosis involves small molecule compounds like erastin and RSL3, which disrupt system Xc- and GPX4 activity, respectively, yielding in lipid peroxidation and cellular demise. Mutations in Fused in Sarcoma (FUS) are associated with familial ALS. Pathophysiological hallmarks of FUS-ALS involve mitochondrial dysfunction and oxidative damage, implicating ferroptosis as putative cell death pathway in motor neuron demise. However, mechanistic understanding of ferroptosis in ALS, particularly FUS-ALS, remains limited. Here, we investigated ferroptosis vulnerability in a FUS-ALS cell model, revealing mitochondrial disturbance and increased susceptibility for ferroptosis in cells harboring the mutant FUS variant. This was accompanied by altered expression of ferroptosis-associated proteins, particularly by dramatic reduction of xCT expression, leading to cellular imbalance of the redox system and increased lipid peroxidation. Iron chelation with deferoxamine as well as inhibition of the mitochondrial calcium uniporter (MCU) significantly alleviated ferroptotic cell death and lipid peroxidation. These findings suggest a link between ferroptosis and FUS-ALS, offering potential therapeutic targets.

Macroautophagy/autophagy plays an important role in cellular copper clearance. The means by which the copper metabolism and autophagy pathways interact mechanistically is vastly unexplored. Dysfunctional ATP7B, a copper-transporting ATPase, is involved in the development of monogenic Wilson disease, a disorder characterized by disturbed copper transport. Using in silico prediction, we found that ATP7B contains a number of potential binding sites for LC3, a central protein in autophagy pathway, so-called LC3 interaction regions (LIRs). The conserved LIR3, located at the C-terminal end of ATP7B, was found to directly interact with LC3B in vitro. Replacing the two conserved hydrophobic residues W1452 and L1455 of LIR3 significantly reduced interaction. Furthermore, autophagy was induced in normal human hepatocellular carcinoma cells (HepG2) leading to enhanced colocalization of ATP7B and LC3B on the autophagosome membranes. By contrast, HepG2 cells deficient of ATP7B (HepG2 ATP7B-/-) showed autophagy deficiency at elevated copper condition. This phenotype was complemented by heterologous ATP7B expression. These findings suggest a cooperative role of ATP7B and LC3B in autophagy-mediated copper clearance.