Copper coordination modulates prion conversion and infectivity in mammalian prion proteins

Variation in the prion protein gene (PRNP) open reading frame sequence in French cervids

The recent emergence of chronic wasting disease (CWD) in Europe has become a new public health risk for monitoring of wild and farmed cervids. This disease, due to prions, has proliferated in North America in a contagious manner. In several mammalian species, polymorphisms in the prion protein gene (PRNP) play a crucial role in the susceptibility to prions and their spread. To obtain a reliable picture of the distribution of PRNP polymorphisms in the two most common cervid species in France, we sequenced the open reading frame (ORF) of this gene in 2114 animals, 1116 roe deer (Capreolus capreolus) and 998 red deer (Cervus elaphus). Selection criteria such as historical origin, spatial distribution and sex ratio have been integrated to establish this sample collection. Except for one heterozygous animal with a non-synonymous mutation at codon 37 (G37A), all the 1116 French roe deer were monomorphic. Red deer showed greater variation with two non-synonymous substitutions (T98A; Q226E), three synonymous substitutions (codons 21, 78 and 136) and a new 24pb deletion (Δ69-77). We found significant regional variations between French regions in the frequency of the identified substitutions. After cloning of the PRNP ORF from animals presenting multiple non-synonymous polymorphisms, we identified six haplotypes and obtained a total of twelve genotypes. As in other European countries, we highlighted the apparent homogeneity of PRNP in the French roe deer and the existence of a greater diversity in the red deer. These results were in line with European phylogeographic studies on these two species.

Comparing Prion Proteins Across Species: Is Zebrafish a Useful Model?

Despite the considerable body of research dedicated to the field of neurodegeneration, the gap in knowledge on the prion protein and its intricate involvement in brain diseases remains substantial. However, in the past decades, many steps forward have been taken toward a better understanding of the molecular mechanisms underlying both the physiological role of the prion protein and the misfolding event converting it into its pathological counterpart, the prion. This review aims to provide an overview of the main findings regarding this protein, highlighting the advantages of many different animal models that share a conserved amino acid sequence and/or structure with the human prion protein. A particular focus will be given to the species Danio rerio, a compelling research organism for the investigation of prion biology, thanks to its conserved orthologs, ease of genetic manipulation, and cost-effectiveness of high-throughput experimentation. We will explore its potential in filling some of the gaps on physiological and pathological aspects of the prion protein, with the aim of directing the future development of therapeutic interventions.

Unveiling the Effects of Copper Ions in the Aggregation of Amyloidogenic Proteins

Amyloid diseases have become a global concern due to their increasing prevalence. Transition metals, including copper, can affect the aggregation of the pathological proteins involved in these diseases. Copper ions play vital roles in organisms, but the disruption of their homeostasis can negatively impact neuronal function and contribute to amyloid diseases with toxic protein aggregates, oxidative stress, mitochondrial dysfunction, impaired cellular signaling, inflammation, and cell death. Gaining insight into the imbalance of copper ions and its impact on protein folding and aggregation is crucial for developing focused therapies. This review examines the influence of copper ions on significant amyloid proteins/peptides, offering a comprehensive overview of the current understanding in this field.

Bio-Metal Dyshomeostasis-Associated Acceleration of Aging and Cognitive Decline in Down Syndrome

Down syndrome (DS), which is caused by triplication of human chromosome 21 (Hsa21), exhibits some physical signs of accelerated aging, such as graying hair, wrinkles and menopause at an unusually young age. Development of early-onset Alzheimer's disease, which is frequently observed in adults with DS, is also suggested to occur due to accelerated aging of the brain. Several Hsa21 genes are suggested to be responsible for the accelerated aging in DS. In this review, we summarize these candidate genes and possible molecular mechanisms, and discuss the related key factors. In particular, we focus on copper, an essential trace element, as a key factor in the accelerated aging in DS. In addition, the physiological significance of brain copper accumulation in cognitive impairment is discussed. We herein provide our hypothesis on the copper dyshomeostasis-based pathophysiology of DS.