Neurexin 2 p.G849D variant, implicated in Parkinson's disease, increases reactive oxygen species, and reduces cell viability and mitochondrial membrane potential in SH-SY5Y cells

Nitrogen doped carbon quantum dots: a multifaceted carbon nanomaterial that interferes in an amyloid-forming trajectory

Carbon quantum dots (CQDs) are a versatile class of carbon-based nanomaterial frameworks that have previously been used as a diagnostic device, in sensing for environmental applications, in bioimaging, and for drug delivery systems. Their versatility stems from their ability to be chemically tailored via functionalization to optimize properties for specific applications. In this study, we have synthesized lactic acid-derived nitrogen doped carbon quantum dots (LAdN-CQDs) and examined their ability to intervene in the conversion of soluble, monomeric hen egg-white lysozyme (HEWL) into mature fibrils. Our data indicate that LAdN-CQDs inhibit HEWL fibril formation in a dose-dependent manner (achieving up to 50% inhibition at 2.5 mg mL-1). Furthermore, in a neuroblastoma-derived cell line, LAdN-CQDs were found not to disrupt mitochondrial membrane potential or trigger apoptosis at the same concentration range, suggesting that they are biocompatible. LAdN-CQDs effectively neutralized reactive oxygen species (ROS), with a 50% decrease in ROS levels at just 100 μg mL-1 when challenged with an established free radical generator and protected the cell line from rotenone-induced apoptosis. The ability of LadN-CQDs to inhibit the soluble-to-toxic transformation of HEWL, the tolerance of SHSY-5Y cells to LAdN-CQDs, and their ability to restitute cells from rotenone-induced apoptosis, combined with the biocompatibility findings, suggest that LAdN-CQDs are potentially neuroprotective. The findings indicate that LAdN-CQDs represent a versatile, carbon-based, sustainable nanoplatform that bridges nanotechnology and neuroprotection, promoting the development of green chemistry-based healthcare solutions.

Graphene acid quantum dots: A highly active multifunctional carbon nano material that intervene in the trajectory towards neurodegeneration

Carbon dots (CDs) are carbon nano materials (CNMs) that find use across several biological applications because of their water solubility, biocompatible nature, eco-friendliness, and ease of synthesis. Additionally, their physiochemical properties can be chemically tuned for further optimization towards specific applications. Here, we investigate the efficacy of C70-derived Graphene Acid Quantum Dots (GAQDs) in mitigating the transformation of soluble, monomeric Hen Egg-White Lysozyme (HEWL) to mature fibrils during its amyloidogenic trajectory. Our findings reveal that GAQDs exhibit dose-dependent inhibition of HEWL fibril formation (up to 70 % at 5 mg/mL) without affecting mitochondrial membrane potential or inducing apoptosis at the same density. Furthermore, GAQDs scavenged reactive oxygen species (ROS); achieving a 50 % reduction in ROS levels at a mere 100 µg/mL when exposed to a standard free radical generator. GAQDs were not only found to be biocompatible with a human neuroblastoma-derived SHSY-5Y cell line but also rescued the cells from rotenone-induced apoptosis. The GAQD-tolerance of SHSY-5Y cells coupled with their ability to restitute cells from rotenone-dependent apoptosis, when taken in conjunction with the biocompatibility data, indicate that GAQDs possess neuroprotective potential. The data position this class of CNMs as promising candidates for resolving aberrant cellular outputs that associate with the advent and progress of multifactorial neurodegenerative disorders including Parkinson's (PD) and Alzheimer's diseases (AD) wherein environmental causes are implicated (95 % etiology). The data suggest that GAQDs are a multifunctional carbon-based sustainable nano-platform at the intersection of nanotechnology and neuroprotection for advancing green chemistry-derived, sustainable healthcare solutions.

Oxidative Stress in Age-Related Neurodegenerative Diseases: An Overview of Recent Tools and Findings

Reactive oxygen species (ROS) have been described to induce a broad range of redox-dependent signaling reactions in physiological conditions. Nevertheless, an excessive accumulation of ROS leads to oxidative stress, which was traditionally considered as detrimental for cells and organisms, due to the oxidative damage they cause to biomolecules. During ageing, elevated ROS levels result in the accumulation of damaged proteins, which may exhibit altered enzymatic function or physical properties (e.g., aggregation propensity). Emerging evidence also highlights the relationship between oxidative stress and age-related pathologies, such as protein misfolding-based neurodegenerative diseases (e.g., Parkinson's (PD), Alzheimer's (AD) and Huntington's (HD) diseases). In this review we aim to introduce the role of oxidative stress in physiology and pathology and then focus on the state-of-the-art techniques available to detect and quantify ROS and oxidized proteins in live cells and in vivo, providing a guide to those aiming to characterize the role of oxidative stress in ageing and neurodegenerative diseases. Lastly, we discuss recently published data on the role of oxidative stress in neurological disorders.