Exposure to CuO Nanoparticles Mediates NFκB Activation and Enhances Amyloid Precursor Protein Expression

Nanoparticles and neurodegeneration: Insights on multiple pathways of programmed cell death regulated by nanoparticles

Currently, nanoparticles (NPs) are extensively applied in the diagnosis and treatment of neurodegenerative diseases (NDs). With the rapid development and increasing exposure to the public, the potential neurotoxicity associated with NDs caused by NPs has attracted the researchers' attentions but their biosafety assessments are still far behind relevant application studies. Based on recent research, this review aims to conduct a comprehensive and systematic analysis of neurotoxicity induced by NPs. The 191 studies selected according to inclusion and exclusion criteria were imported into the software, and the co-citations and keywords of the included literatures were analyzed to find the breakthrough point of previous studies. According to the available studies, the routes of NPs entering into the normal and injured brain were various, and then to be distributed and accumulated in living bodies. When analyzing the adverse effects induced by NPs, we focused on multiple programmed cell deaths (PCDs), especially ferroptosis triggered by NPs and their tight connection and crosstalk that have been found playing critical roles in the pathogenesis of NDs and their underlying toxic mechanisms. The activation of multiple PCD pathways by NPs provides a scientific basis for the occurrence and development of NDs. Furthermore, the adoption of new methodologies for evaluating the biosafety of NPs would benefit the next generation risk assessment (NGRA) of NPs and their toxic interventions. This would help ensure their safe application and sustainable development in the field of medical neurobiology.

Revisiting the smart metallic nanomaterials: advances in nanotechnology-based antimicrobials

Despite significant advancements in diagnostics and treatments over the years, the problem of antimicrobial drug resistance remains a pressing issue in public health. The reduced effectiveness of existing antimicrobial drugs has prompted efforts to seek alternative treatments for microbial pathogens or develop new drug candidates. Interestingly, nanomaterials are currently gaining global attention as a possible next-generation antibiotics. Nanotechnology holds significant importance, particularly when addressing infections caused by multi-drug-resistant organisms. Alternatively, these biomaterials can also be combined with antibiotics and other potent biomaterials, providing excellent synergistic effects. Over the past two decades, nanoparticles have gained significant attention among research communities. Despite the complexity of some of their synthesis strategies and chemistry, unrelenting efforts have been recorded in synthesizing potent and highly effective nanomaterials using different approaches. With the ongoing advancements in nanotechnology, integrating it into medical procedures presents novel approaches for improving the standard of patient healthcare. Although the field of nanotechnology offers promises, much remains to be learned to overcome the several inherent issues limiting their full translation to clinics. Here, we comprehensively discussed nanotechnology-based materials, focusing exclusively on metallic nanomaterials and highlighting the advances in their synthesis, chemistry, and mechanisms of action against bacterial pathogens. Importantly, we delve into the current challenges and prospects associated with the technology.

Self-Therapeutic Nanomaterials: Applications in Biology and Medicine

Over past decades, nanotechnology has contributed to the biomedical field in areas including detection, diagnosis, and drug delivery via opto-electronic properties or enhancement of biological effects. Though generally considered inert delivery vehicles, a plethora of past and present evidence demonstrates that nanomaterials also exude unique intrinsic biological activity based on composition, shape, and surface functionalization. These intrinsic biological activities, termed self-therapeutic properties, take several forms, including mediation of cell-cell interactions, modulation of interactions between biomolecules, catalytic amplification of biochemical reactions, and alteration of biological signal transduction events. Moreover, study of biomolecule-nanomaterial interactions offers a promising avenue for uncovering the molecular mechanisms of biology and the evolution of disease. In this review, we observe the historical development, synthesis, and characterization of self-therapeutic nanomaterials. Next, we discuss nanomaterial interactions with biological systems, starting with administration and concluding with elimination. Finally, we apply this materials perspective to advances in intrinsic nanotherapies across the biomedical field, from cancer therapy to treatment of microbial infections and tissue regeneration. We conclude with a description of self-therapeutic nanomaterials in clinical trials and share our perspective on the direction of the field in upcoming years.

The effect of the use of copper carbonate and copper nanoparticles in the diet of rats on the level of β-amyloid and acetylcholinesterase in selected organs

BACKGROUND

Copper has an important role in nervous system function, as a cofactor of many enzymes and in the synthesis of neurotransmitters. Both the dose and the chemical form of copper can determine the impact of this element on metabolism, the neurological system and the immune system.

AIMS

The aim of the study was to determine whether and in what form the addition of copper changes the level of amyloid beta and acetylcholinesterase level in selected rat tissues.

METHODS

Thirty, healthy, male, albino Wistar rats aged 7 weeks were randomly divided into 3 groups. Three experimental treatments were used to evaluate the effects of different levels and sources of Cu (6.5 mg kg of diet) in the diet: Cu₀ - rats fed a diet without Cu supplementation; Cu_salt - rats fed a diet with CuCO₃ (6.5 mg kg of diet) during two months of feeding; Cu_NPs - rats fed a diet with Cu nanoparticles (6.5 mg kg of diet) during two months of feeding. In blood serum and tissue homogenates there rated the indicators proving the potential neurodegenerative effect and epigenetic DNA damage induced by chemical form of copper or lack of additional copper supplementation in diet were determined. There were analysed: level of acetylcholinesterase, β-amyloid, low-density lipoprotein receptor-related protein 1, apyrimidinic endonuclease, thymidine glycosidase, alkylpurine-DNA-N-glycosylase and glycosylated acetylcholinesterase.

RESULTS

Irrespective of the form of copper added, it was found to increase acetylcholinesterase level in the brain, spleen and liver, as well as in the blood plasma of the rats. Copper in the form of CuCO₃ was found to increase acetylcholinesterase level in the kidneys. The addition of both forms of copper caused a marked increase in the plasma concentration of β-amyloid in comparison with the diet with no added Cu. The addition of both forms of copper caused a marked increase in the plasma concentration of β-amyloid in comparison with the diet with no added Cu.

CONCLUSIONS

A lack of added Cu in the diet of rats reduces the concentration of amyloid-β in the blood, whereas administration of copper, in the form of either CuNPs or CuCO₃, increases the level of this peptide in the blood. The use of copper in the form of CuNPs in the diet of rats does not increase the level of β-amyloid more than the use of the carbonate form of this element. The use of CuNPs or CuCO₃ in the diet of rats increases acetylcholinesterase level in the brain, spleen, liver, and blood. CuNPs in the diet of rats were not found to increase acetylcholinesterase level to a greater extent than Cu⁺² carbonate.

How can exposure to engineered nanomaterials influence our epigenetic code? A review of the mechanisms and molecular targets

Evidence suggests that engineered nanomaterials (ENM) can induce epigenetic modifications. In this review, we provide an overview of the epigenetic modulation of gene expression induced by ENM used in a variety of applications: titanium dioxide (TiO₂), silver (Ag), gold (Au), silica (SiO₂) nanoparticles and carbon-based nanomaterials (CNM). Exposure to these ENM can trigger alterations in cell patterns of DNA methylation, post-transcriptional histone modifications and expression of non-coding RNA. Such effects are dependent on ENM dose and physicochemical properties including size, shape and surface chemistry, as well as on the cell/organism sensitivity. The genes affected are mostly involved in the regulation of the epigenetic machinery itself, as well as in apoptosis, cell cycle, DNA repair and inflammation related pathways, whose long-term alterations might lead to the onset or progression of certain pathologies. In addition, some DNA methylation patterns may be retained as a form of epigenetic memory. Prenatal exposure to ENM may impair the normal development of the offspring by transplacental effects and/or putative transmission of epimutations in imprinting genes. Thus, understanding the impact of ENM on the epigenome is of paramount importance and epigenetic evaluation must be considered when assessing the risk of ENM to human health.

Pulmonary Exposure to Copper Oxide Nanoparticles Leads to Neurotoxicity via Oxidative Damage and Mitochondrial Dysfunction

Copper oxide nanoparticles (CuONPs) are widely used in pharmaceutical, food, and textile industries. They have been shown to cause lung, liver, and kidney damage. However, whether an intratracheal instillation of CuONPs would affect the brain and its underlying mechanisms remain poorly studied. In this study, healthy C57BL/6J male mice were equally subdivided into control group, low-dose (30 μg/animal), medium-dose (50 μg/animal), and high-dose (100 μg/animal) CuONPs-treated groups. Mice were subjected to acute exposure of CuONPs via intratracheal instillation. Brain histopathology, inflammatory factors, oxidative stress markers, and mitochondrial function-related protein expression were determined. Our results demonstrated that CuONPs caused a dose-dependent brain damage in mice. Histopathological changes in the brain, elevation of inflammatory factors (Tnf, Il-6), and significant alterations in oxidative stress markers were also observed after treatment with CuONPs. Intriguingly, we did not observe infiltration of macrophage cell. Moreover, Tim23, TFAM, and MFN2 protein expression levels showed the decreasing trend after treatment with CuONPs. Taken together, these results indicate that pulmonary exposure to CuONPs induces pathological damage, inflammation, oxidative stress, and mitochondrial dysfunction in the cerebral cortex, suggesting that neurotoxicity caused by pulmonary exposure of CuONPs needs more attention from the public and relevant departments.

Acceleration of α-synuclein fibril formation and associated cytotoxicity stimulated by silica nanoparticles as a model of neurodegenerative diseases

A wide range of biophysical and theoretical analysis were employed to explore the formation of (α-syn) amyloid fibril formation as a model of Parkinson's disease in the presence of silica oxide nanoparticles (SiO₂ NPs). Also, different cellular and molecular assays such as MTT, LDH, caspase, ROS, and qPCR were performed to reveal the α-syn amyloid fibrils-associated cytotoxicity against SH-SY5Y cells. Fluorescence measurements showed that SiO₂ NPs accelerate the α-syn aggregation and exposure of hydrophobic moieties. Congo red absorbance, circular dichroism (CD), and transmission electron microscopy (TEM) analysis depicted the SiO₂ NPs accelerated the formation of α-syn amyloid fibrils. Molecular docking study showed that SiO₂ clusters preferably bind to the N-terminal of α-syn as the helix folding site. We also realized that SiO₂ NPs increase the cytotoxicity of α-syn amyloid fibrils through a significant decrease in cell viability, increase in membrane leakage, activation of caspase-9 and -3, elevation of ROS, and increase in the ratio of Bax/Bcl2 mRNA. The cellular assay indicated that α-syn amyloid fibrils formed in the presence of SiO₂ NPs induce their cytotoxic effects through the mitochondrial-mediated intrinsic apoptosis pathway. We concluded that these data may reveal some adverse effects of NPs on the progression of Parkinson's disease.

Environmental Nanoparticles, SARS-CoV-2 Brain Involvement, and Potential Acceleration of Alzheimer's and Parkinson's Diseases in Young Urbanites Exposed to Air Pollution

Alzheimer's and Parkinson's diseases (AD, PD) have a pediatric and young adult onset in Metropolitan Mexico City (MMC). The SARS-CoV-2 neurotropic RNA virus is triggering neurological complications and deep concern regarding acceleration of neuroinflammatory and neurodegenerative processes already in progress. This review, based on our MMC experience, will discuss two major issues: 1) why residents chronically exposed to air pollution are likely to be more susceptible to SARS-CoV-2 systemic and brain effects and 2) why young people with AD and PD already in progress will accelerate neurodegenerative processes. Secondary mental consequences of social distancing and isolation, fear, financial insecurity, violence, poor health support, and lack of understanding of the complex crisis are expected in MMC residents infected or free of SARS-CoV-2. MMC residents with pre-SARS-CoV-2 accumulation of misfolded proteins diagnostic of AD and PD and metal-rich, magnetic nanoparticles damaging key neural organelles are an ideal host for neurotropic SARS-CoV-2 RNA virus invading the body through the same portals damaged by nanoparticles: nasal olfactory epithelium, the gastrointestinal tract, and the alveolar-capillary portal. We urgently need MMC multicenter retrospective-prospective neurological and psychiatric population follow-up and intervention strategies in place in case of acceleration of neurodegenerative processes, increased risk of suicide, and mental disease worsening. Identification of vulnerable populations and continuous effort to lower air pollution ought to be critical steps.

Iron-responsive-like elements and neurodegenerative ferroptosis

A set of common-acting iron-responsive 5′untranslated region (5′UTR) motifs can fold into RNA stem loops that appear significant to the biology of cognitive declines of Parkinson's disease dementia (PDD), Lewy body dementia (LDD), and Alzheimer's disease (AD). Neurodegenerative diseases exhibit perturbations of iron homeostasis in defined brain subregions over characteristic time intervals of progression. While misfolding of Aβ from the amyloid-precursor-protein (APP), alpha-synuclein, prion protein (PrP) each cause neuropathic protein inclusions in the brain subregions, iron-responsive-like element (IRE-like) RNA stem–loops reside in their transcripts. APP and αsyn have a role in iron transport while gene duplications elevate the expression of their products to cause rare familial cases of AD and PDD. Of note, IRE-like sequences are responsive to excesses of brain iron in a potential feedback loop to accelerate neuronal ferroptosis and cognitive declines as well as amyloidosis. This pathogenic feedback is consistent with the translational control of the iron storage protein ferritin. We discuss how the IRE-like RNA motifs in the 5′UTRs of APP, alpha-synuclein and PrP mRNAs represent uniquely folded drug targets for therapies to prevent perturbed iron homeostasis that accelerates AD, PD, PD dementia (PDD) and Lewy body dementia, thus preventing cognitive deficits. Inhibition of alpha-synuclein translation is an option to block manganese toxicity associated with early childhood cognitive problems and manganism while Pb toxicity is epigenetically associated with attention deficit and later-stage AD. Pathologies of heavy metal toxicity centered on an embargo of iron export may be treated with activators of APP and ferritin and inhibitors of alpha-synuclein translation.