Study on different pathogenic factors in different disease stages of patients with Wilson disease

Extracellular Acidosis, Cysteine, and Glutathione Enhance the Toxic Effect of Copper Ions in Cultures of Cerebellar Granule Neurons

We studied the effect of extracellular acidosis, cysteine, glutathione, and iron ions (Fe3+) on the neurocytotoxic effect of copper ions (Cu2+) in vitro. At acidic pH of the culture medium (pH 6.8), the toxic effect of copper on cultured neurons significantly increased in comparison with that at neutral pH 7.3. In the presence of 25 μM Cu2+ in the culture medium at pH 7.3 and 6.8, the neuronal survival was 89±2 and 63±4%, respectively. In the presence of glutathione or cysteine (1 μM) in the culture medium, even 0.5 μM Cu2+ caused 100% death of cultured neurons, while the presence of Fe3+ (10-50 μM) had no effect on the toxicity of Cu2+. In general, acidosis or the presence of glutathione or cysteine increases the cytotoxicity of copper ions.

Cerebral Iron Deposition in Neurodegeneration

Disruption of cerebral iron regulation appears to have a role in aging and in the pathogenesis of various neurodegenerative disorders. Possible unfavorable impacts of iron accumulation include reactive oxygen species generation, induction of ferroptosis, and acceleration of inflammatory changes. Whole-brain iron-sensitive magnetic resonance imaging (MRI) techniques allow the examination of macroscopic patterns of brain iron deposits in vivo, while modern analytical methods ex vivo enable the determination of metal-specific content inside individual cell-types, sometimes also within specific cellular compartments. The present review summarizes the whole brain, cellular, and subcellular patterns of iron accumulation in neurodegenerative diseases of genetic and sporadic origin. We also provide an update on mechanisms, biomarkers, and effects of brain iron accumulation in these disorders, focusing on recent publications. In Parkinson’s disease, Friedreich’s disease, and several disorders within the neurodegeneration with brain iron accumulation group, there is a focal siderosis, typically in regions with the most pronounced neuropathological changes. The second group of disorders including multiple sclerosis, Alzheimer’s disease, and amyotrophic lateral sclerosis shows iron accumulation in the globus pallidus, caudate, and putamen, and in specific cortical regions. Yet, other disorders such as aceruloplasminemia, neuroferritinopathy, or Wilson disease manifest with diffuse iron accumulation in the deep gray matter in a pattern comparable to or even more extensive than that observed during normal aging. On the microscopic level, brain iron deposits are present mostly in dystrophic microglia variably accompanied by iron-laden macrophages and in astrocytes, implicating a role of inflammatory changes and blood–brain barrier disturbance in iron accumulation. Options and potential benefits of iron reducing strategies in neurodegeneration are discussed. Future research investigating whether genetic predispositions play a role in brain Fe accumulation is necessary. If confirmed, the prevention of further brain Fe uptake in individuals at risk may be key for preventing neurodegenerative disorders.