From zinc homeostasis to disease progression: Unveiling the neurodegenerative puzzle.

Zinc is a crucial trace element in the human body, playing a role in various physiological processes such as oxidative stress, neurotransmission, protein synthesis, and DNA repair. The zinc transporters (ZnTs) family members are responsible for exporting intracellular zinc, while Zrt- and Irt-like proteins (ZIPs) are involved in importing extracellular zinc. These processes are essential for maintaining cellular zinc homeostasis. Imbalances in zinc metabolism have been linked to the development of neurodegenerative diseases. Disruptions in zinc levels can impact the survival and activity of neurons, thereby contributing to the progression of neurodegenerative diseases through mechanisms like cell apoptosis regulation, protein phase separation, ferroptosis, oxidative stress, and neuroinflammation. Therefore, conducting a systematic review of the regulatory network of zinc and investigating the relationship between zinc dysmetabolism and neurodegenerative diseases can enhance our understanding of the pathogenesis of these diseases. Additionally, it may offer new insights and approaches for the treatment of neurodegenerative diseases.

The metal ion hypothesis of Alzheimer's disease and the anti-neuroinflammatory effect of metal chelators.

Alzheimer's disease (AD), characterized by the ß-amyloid protein (Aß) deposition and tau hyperphosphorylation, is the most common dementia with uncertain etiology. The clinical trials of Aß monoclonal antibody drugs have almost failed, giving rise to great attention on the other etiologic hypothesis regarding AD such as metal ions dysmetabolism and chronic neuroinflammation. Mounting evidence revealed that the metal ions (iron, copper, and zinc) were dysregulated in the susceptible brain regions of AD patients, which was highly associated with Aß deposition, tau hyperphosphorylation, neuronal loss, as well as neuroinflammation. Further studies uncovered that iron, copper and zinc could not only enhance the production of Aß but also directly bind to Aß and tau to promote their aggregations. In addition, the accumulation of iron and copper could respectively promote ferroptosis and cuproptosis. Therefore, the metal ion chelators were recognized as promising agents for treating AD. This review comprehensively summarized the effects of metal ions on the Aß dynamics and tau phosphorylation in the progression of AD. Furthermore, taking chronic neuroinflammation contributes to the progression of AD, we also provided a summary of the mechanisms concerning metal ions on neuroinflammation and highlighted the metal ion chelators may be potential agents to alleviate neuroinflammation under the condition of AD. Nevertheless, more investigations regarding metal ions on neuroinflammation should be taken into practice, and the effects of metal ion chelators on neuroinflammation should gain more attention. Running title: Metal chelators against neuroinflammation.

Potential Application Prospects of Biomolecule-Modified Two-Dimensional Chiral Nanomaterials in Biomedicine.

Chirality, one of the most fundamental properties of natural molecules, plays a significant role in biochemical reactions. Nanomaterials with chiral characteristics have superior properties, such as catalytic properties, optoelectronic properties, and photothermal properties, which have significant potential for specific applications in nanomedicine. Biomolecular modifications such as nucleic acids, peptides, proteins, and polysaccharides are sources of chirality for nanomaterials with great potential for application in addition to intrinsic chirality, artificial macromolecules, and metals. Two-dimensional (2D) nanomaterials, as opposed to other dimensions, due to proper surface area, extensive modification sites, drug loading potential, and simplicity of preparation, are prepared and utilized in diagnostic applications, drug delivery research, and tumor therapy. Current advanced studies on 2D chiral nanomaterials for biomedicine are focused on novel chiral development, structural control, and materials sustainability applications. However, despite the advances in biomedical research, chiral 2D nanomaterials still confront challenges such as the difficulty of synthesis, quality control, batch preparation, chiral stability, and chiral recognition and selectivity. This review aims to provide a comprehensive overview of the origins, synthesis, applications, and challenges of 2D chiral nanomaterials with biomolecules as cargo and chiral modifications and highlight their potential roles in biomedicine.

Astrocyte-derived lactoferrin reduces ß-amyloid burden by promoting the interaction between p38 kinase and PP2A phosphatase in male APP/PS1 transgenic mice.

BACKGROUND AND PURPOSE: Overexpression of astrocytic lactoferrin (Lf) was observed in the brain of Alzheimer's disease (AD) patients, whereas the role of astrocytic Lf in AD progression remains unexplored. In this study, we aimed to evaluate the effects of astrocytic Lf on AD progression. EXPERIMENTAL APPROACH: Male APP/PS1 mice with astrocytes overexpressing human Lf were developed to evaluate the effects of astrocytic Lf on AD progression. N2a-sw cells also were employed to further uncover the mechanism of astrocytic Lf on ß-amyloid (Aß) production. KEY RESULTS: Astrocytic Lf overexpression increased protein phosphatase 2A (PP2A) activity and reduced amyloid precursor protein (APP) phosphorylation, Aß burden and tau hyperphosphorylation in APP/PS1 mice. Mechanistically, astrocytic Lf overexpression promoted the uptake of astrocytic Lf into neurons in APP/PS1 mice, and conditional medium from astrocytes overexpressing Lf inhibited p-APP (Thr668) expression in N2a-sw cells. Furthermore, recombinant human Lf (hLf) significantly enhanced PP2A activity and inhibited p-APP expression, whereas inhibition of p38 or PP2A activities abrogated the hLf-induced p-APP down-regulation in N2a-sw cells. Additionally, hLf promoted the interaction of p38 and PP2A via p38 activation, thereby enhancing PP2A activity, and low-density lipoprotein receptor-related protein 1 (LRP1) knockdown significantly reversed the hLf-induced p38 activation and p-APP down-regulation. CONCLUSIONS AND IMPLICATIONS: Our data suggested that astrocytic Lf promoted neuronal p38 activation, via targeting to LRP1, subsequently promoting p38 binding to PP2A to enhance PP2A enzyme activity, which finally inhibited Aß production via APP dephosphorylation. In conclusion, promoting astrocytic Lf expression may be a potential strategy against AD. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.

Graphdiyne nanoplatforms for photothermal-ferroptosis combination therapy against glioblastoma.

Glioblastoma (GBM) is one of the most malignant tumors of the central nervous system and has a poor prognosis. GBM cells are highly sensitive to ferroptosis and heat, suggesting thermotherapy-ferroptosis as a new strategy for GBM treatment. With its biocompatibility and photothermal conversion efficiency, graphdiyne (GDY) has become a high-profile nanomaterial. Here, the ferroptosis inducer FIN56 was employed to construct GDY-FIN56-RAP (GFR) polymer self-assembled nanoplatforms against GBM. GDY could effectively load FIN56 and FIN56 released from GFR in a pH-dependent manner. The GFR nanoplatforms possessed the advantages of penetrating the BBB and acidic environment-induced in situ FIN56 release. Moreover, GFR nanoplatforms induced GBM cell ferroptosis by inhibiting GPX4 expression, and 808 nm irradiation reinforced GFR-mediated ferroptosis by elevating the temperature and promoting FIN56 release from GFR. In addition, the GFR nanoplatforms were inclined to locate in tumor tissue, inhibit GBM growth, and prolong lifespan by inducing GPX4-mediated ferroptosis in an orthotopic xenograft mouse model of GBM; meanwhile, 808 nm irradiation further improved these GFR-mediated effects. Hence, GFR may be a potential nanomedicine for cancer therapy, and GFR combined with photothermal therapy may be a promising strategy against GBM.

Activation of vitamin D receptor inhibits Tau phosphorylation is associated with reduction of iron accumulation in APP/PS1 transgenic mice.

Vitamin D deficiency and iron accumulation are prevalent in the brains of Alzheimer's disease (AD) patients, however, whether Vitamin D has a role in the regulations of iron metabolism in the condition of AD remains unknown. Our previous studies revealed that vitamin D deficiency promotes ß-amyloid (Aß) deposition in the APP/PS1 mouse brains, while supplemented with a specific agonist of vitamin D receptor (VDR), paricalcitol (PAL), significantly reduced Aß production via promoting the lysosomal degradation of ß-site APP cleavage enzyme 1 (BACE1). In this study, our data suggested that activation of VDR by PAL significantly reduced the iron accumulation in the cortex and hippocampus of APP/PS1 mice through downregulation of Transferrin receptor (TFR) by reducing iron-regulatory protein 2 (IRP2) expression. Furthermore, activation of VDR effectively reduced the phosphorylations of Tau at Ser396 and Thr181 sites via inhibiting the GSK3ß phosphorylation (Tyr216). Taken together, our data suggest that activation of VDR could inhibit the phosphorylations of Tau possibly by repressing the iron accumulation-induced upregulation of GSK3ß activity in the brains of APP/PS1 mice. Thus, activation of VDR may be an effective strategy for treating AD.

Spontaneous Formation of a Superconductor-Topological Insulator-Normal Metal Layered Heterostructure.

2D materials with heterolayered structures beyond graphene are explored. A theoretically predicted superconductor-topological insulator-normal metal heterolayered structure is realized experimentally. The generated hybrid structure HfTe3 /HfTe5 /Hf has potential applications in both quantum-spin Hall effect-based and Majorana-based devices.