Neuroinflammation in Alzheimer's disease: Current evidence and future directions

Nanomaterials-mediated lysosomal regulation: a robust protein-clearance approach for the treatment of Alzheimer's disease

Alzheimer's disease is a debilitating, progressive neurodegenerative disorder characterized by the progressive accumulation of abnormal proteins, including amyloid plaques and intracellular tau tangles, primarily within the brain. Lysosomes, crucial intracellular organelles responsible for protein degradation, play a key role in maintaining cellular homeostasis. Some studies have suggested a link between the dysregulation of the lysosomal system and pathogenesis of neurodegenerative diseases, including Alzheimer's disease. Restoring the normal physiological function of lysosomes hold the potential to reduce the pathological burden and improve the symptoms of Alzheimer's disease. Currently, the efficacy of drugs in treating Alzheimer's disease is limited, with major challenges in drug delivery efficiency and targeting. Recently, nanomaterials have gained widespread use in Alzheimer's disease drug research owing to their favorable physical and chemical properties. This review aims to provide a comprehensive overview of recent advances in using nanomaterials (polymeric nanomaterials, nanoemulsions, and carbon-based nanomaterials) to enhance lysosomal function in treating Alzheimer's disease. This review also explores new concepts and potential therapeutic strategies for Alzheimer's disease through the integration of nanomaterials and modulation of lysosomal function. In conclusion, this review emphasizes the potential of nanomaterials in modulating lysosomal function to improve the pathological features of Alzheimer's disease. The application of nanotechnology to the development of Alzheimer's disease drugs brings new ideas and approaches for future treatment of this disease.

Ameliorative potential of ethanol extract of Calyptrochilum emarginatum leaves on scopolamine-induced amnesia in male swiss mice

ETHNOPHARMACOLOGICAL RELEVANCE

Calyptrochilum emarginatum (Afzel. Ex Sw.) Schltr. (Orchidaceae) is a traditional medicinal plant known for its antimicrobial properties and efficacy in managing convulsive fever and menstrual disorders and addressing conditions such as malaria, tuberculosis, and cough.

AIM OF THE STUDY

The study aims to examine the memory-enhancing and neuroprotective properties of ethanol extract of Calyptrochilum emarginatum leaves (EECEL) in scopolamine-induced amnesia mice model.

MATERIALS AND METHODS

Forty-two male mice were divided into six groups (n = 7). Group 1 served as control, administered distilled water (10 mL/kg, p. o), group 2 received scopolamine only (3 mg/kg, i. p.), groups 3 to 6 received pretreatments of EECEL (50, 100, and 200 mg/kg, p. o.) and donepezil (1 mg/kg, p. o.) 30 min before scopolamine (3 mg/kg), for seven days. Following treatments, behavioral (learning and memory) assessments were carried out, while biochemical (acetylcholinesterase activity, oxidative stress markers, inflammatory cytokines markers) and histological evaluations were done after euthanasia.

RESULTS

Scopolamine significantly impaired spatial, long term and recognition memory. Nevertheless, administration of EECEL (50, 100, and 200 mg/kg orally) enhanced memory function in mice, as observed in the Y maze [F (5, 30) = 20.23, p < 0.0001], Morris water maze [F (10, 90) = 3.105, p = 0.0019; [F (5, 30) = 21.13, p < 0.0001]], and novel object recognition tasks [F (5, 30) = 37.22, p < 0.0001)]. Scopolamine-treated mice exhibited significant dysfunction in the cholinergic system, as evidenced by elevated AChE activity [0.099 ± 0.005 vs. 0.063 ± 0.004 mol/min/g] with an elevation in oxidative stress. On the other hand, administration of EECEL counteracted these consequences by reducing AChE activity, mitigating oxidative damage, reducing pro-inflammatory cytokines, and preventing degeneration of neurons.

CONCLUSION

The results demonstrated that EECEL effectively mitigates scopolamine-induced memory impairment via an oxido-inflammatory mechanism and modulation of the central cholinergic system.

Remimazolam attenuates lipopolysaccharide-induced neuroinflammation and cognitive dysfunction

OBJECTIVE

Remimazolam, a novel benzodiazepine, is widely used as an anesthetic in endoscopic procedures; however, its effects on cognitive function remain unclear, limiting its broader application in general anaesthesia. Neuroinflammation is a well-established key factor in the etiology and progression of cognitive dysfunction, including conditions such as Alzheimer's disease, Parkinson's disease, postoperative delirium, and postoperative cognitive dysfunction. Preclinical studies have demonstrated that remimazolam exerts anti-inflammatory and neuroprotective effects, and clinical reports indicate a reduced incidence of postoperative delirium in patients treated with remimazolam. Nevertheless, whether remimazolam improves cognitive function through its anti-inflammatory properties remains uncertain. This study aimed to investigate the neuroprotective effects of remimazolam and its underlying mechanism in a lipopolysaccharide (LPS)-induced model of neuroinflammation, neuronal injury, and cognitive dysfunction METHODS: C57BL/6 J male mice were administered LPS intraperitoneally to establish a model of neuroinflammation-induced cognitive impairment. A subset of mice received remimazolam via intraperitoneal injection 30 minutes prior to LPS administration. Cognitive performance was evaluated using behavioural tests, including the Morris Water Maze (MWM), Novel Object Recognition (NOR) test, and Open Field Test (OFT). Hippocampal tissues were analyzed by haematoxylin-eosin (HE) staining to assess structural changes. Inflammatory markers, including Interleukin (IL)-6, IL-1β, and tumor necrosis factor-α, were quantified using enzyme-linked immunosorbent assay (ELISA) and real-time quantitative PCR. Immunofluorescence was used to detect translocator protein (TSPO) and markers of microglia activation (IBA-1, CD16/32, and CD206).

RESULTS

(1) Remimazolam reversed LPS-induced cognitive deficits, as evidenced by shorter spatial exploration latency and increased platform crossings in the MWM, and an elevated recognition index in the NOR test. (2) Remimazolam improved hippocampal morphology, reducing LPS-induced neuronal damage. (3) Remimazolam significantly decreased levels of hippocampal inflammatory cytokines, inhibited microglial activation, promoted M2-type microglia polarization, and increased TSPO expression.

CONCLUSION

Remimazolam demonstrated neuroprotective and anti-neuroinflammatory effects in a mouse model of LPS-induced cognitive impairment. These effects are likely mediated through the regulation of TSPO, which inhibits microglial activation and promotes the polarization of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype.

Design, synthesis, in vitro and in vivo biological evaluation of pterostilbene derivatives for anti-inflammation therapy

Pterostilbene (PST) is a naturally derived stilbene compound in grapes, blueberries, and other fruits. It is also a natural dietary compound with a wide range of biological activities such as antioxidant, anti-inflammatory, antitumor, and so on. Structural modifications based on the chemical scaffold of the pterostilbene skeleton are of great importance for drug discovery. In this study, pterostilbene skeletons were used to design novel anti-inflammatory compounds with high activity and low toxicity. A total of 30 new were found and synthesised, and their anti-inflammatory activity and safety were screened. Among them, compound E2 was the most active (against NO: IC50 = 0.7 μM) than celecoxib. Further studies showed that compound E2 exerted anti-inflammatory activity by blocking LPS-induced NF-κB/MAPK signalling pathway activation. In vivo experiments revealed that compound E2 had a good alleviating effect on acute colitis in mice. In conclusion, compound E2 may be a promising anti-inflammatory lead compound.

Causal relationship between imaging-derived phenotypes and neurodegenerative diseases: a Mendelian randomization study

Neurodegenerative diseases are incurable conditions that lead to gradual and progressive deterioration of brain function in patients. With the aging population, the prevalence of these diseases is expected to increase, posing a significant economic burden on society. Imaging techniques play a crucial role in the diagnosis and monitoring of neurodegenerative diseases. This study utilized a two-sample Mendelian randomization (MR) analysis to assess the causal relationship between different imaging-derived phenotypes (IDP) in the brain and neurodegenerative diseases. Multiple MR methods were employed to minimize bias and obtain reliable estimates of the potential causal relationship between the variable exposures of interest and the outcomes. The study found potential causal relationships between different IDPs and Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and frontotemporal dementia (FTD). Specifically, the study identified potential causal relationships between 2 different types of IDPs and AD, 8 different types of IDPs and PD, 11 different types of imaging-derived phenotypes and ALS, 1 type of IDP and MS, and 1 type of IDP and FTD. This study provides new insights for the prevention, diagnosis, and treatment of neurodegenerative diseases, offering important clues for understanding the pathogenesis of these diseases and developing relevant intervention strategies.

Unveiling the role of astrogliosis in Alzheimer's disease Pathology: Insights into mechanisms and therapeutic approaches

Alzheimer's disease (AD) is one of the most debilitating age-related disorders that affect people globally. It impacts social and cognitive behavior of the individual and is characterized by phosphorylated tau and Aβ accumulation. Astrocytesmaintain a quiescent, anti-inflammatory state on anatomical level, expressing few cytokines and exhibit phagocytic activity to remove misfolded proteins. But in AD, in response to specific stimuli, astrocytes overstimulate their phagocytic character with overexpressing cytokine gene modules. Upon interaction with generated Aβ and neurofibrillary tangle, astrocytes that are continuously activated release a large number of inflammatory cytokines. This cytokine storm leads to neuroinflammation which is also one of the recognizable features of AD. Astrogliosis eventually promotes cholinergic dysfunction, calcium imbalance, oxidative stress and excitotoxicity. Furthermore, C5aR1, Lcn2/, BDNF/TrkB and PPARα/TFEB signaling dysregulation has a major impact on the disease progression. This review clarifies numerous ways that lead to astrogliosis, which is stimulated by a variety of processes that exacerbate AD pathology and make it a suitable target for AD treatment. Drugs under clinical and preclinical investigations that target several pathways managing astrogliosis and are efficacious in ameliorating the pathology of the disease are also included in this study. D-ALA2GIP, TRAM-34, Genistein, L-serine, MW150 and XPro1595 are examples of few drugs targeting astrogliosis. Therefore, this study may aid in the development of a potent therapeutic agent for ameliorating astrogliosis mediated AD progression.

Advancements in Single-Cell RNA Sequencing Research for Neurological Diseases

Neurological diseases are a major cause of the global burden of disease. Although the mechanisms of the occurrence and development of neurological diseases are not fully clear, most of them are associated with cells mediating neuroinflammation. Yet medications and other therapeutic options to improve treatment are still very limited. Single-cell RNA sequencing (scRNA-seq), as a delightfully potent breakthrough technology, not only identifies various cell types and response states but also uncovers cell-specific gene expression changes, gene regulatory networks, intercellular communication, and cellular movement trajectories, among others, in different cell types. In this review, we describe the technology of scRNA-seq in detail and discuss and summarize the application of scRNA-seq in exploring neurological diseases, elaborating the corresponding specific mechanisms of the diseases as well as providing a reliable basis for new therapeutic approaches. Finally, we affirm that scRNA-seq promotes the development of the neuroscience field and enables us to have a deeper cellular understanding of neurological diseases in the future, which provides strong support for the treatment of neurological diseases and the improvement of patients' prognosis.

Association of Crohn's disease and ulcerative colitis with the risk of neurological diseases: a large-scale Mendelian randomization study

Observational studies suggested increased risks of Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS) in patients with Crohn's disease (CD) and ulcerative colitis (UC). We aimed to assess the causality for the associations of CD and UC with the risks of AD, PD, and MS through a two-sample Mendelian randomization (MR) study. Independent single nucleotide polymorphisms associated with CD (17,897 cases and 33,977 controls) and UC (13,768 cases and 33,977 controls) were identified as genetic instruments based on a European-descent genome-wide association study (GWAS) released by the International Inflammatory Bowel Disease Genetics Consortium. Summary statistics for AD (combined: 25,881 cases and 256,837 controls), PD (combined: 35,836 cases and 665,686 controls), and MS (combined: 48,477 cases and 285,515 controls) were obtained from the largest GWASs and FinnGen study of European ancestry, respectively. MR estimates were generated using the inverse-variance weighted method in the main analysis with a series of sensitivity analyses. MR analyses were conducted per outcome database and were subsequently meta-analyzed to generate combined estimates. Genetically predicted UC was significantly associated with increased risks of AD (combined: OR, 1.03; 95% CI, 1.01-1.05; P = 1.80 × 10-3) and MS (combined: OR, 1.37; 95% CI, 1.23-1.53; P = 1.18 × 10-8), while there was no association between genetically predicted UC and the risk of PD. In contrast, no significant associations were observed for genetically predicted CD with AD, PD, and MS. MR-Egger regression showed no directional pleiotropy for the identified associations, and sensitivity analyses with different MR methods further confirmed these findings. This study suggested significant adverse effects of UC on AD and MS, highlighting that UC patients should receive early intervention with optimal adjunctive medical therapy to reduce the risks of AD and MS.

NLRP3/1-mediated pyroptosis: beneficial clues for the development of novel therapies for Alzheimer's disease

The inflammasome is a multiprotein complex involved in innate immunity that mediates the inflammatory response leading to pyroptosis, which is a lytic, inflammatory form of cell death. There is accumulating evidence that nucleotide-binding domain and leucine-rich repeat pyrin domain containing 3 (NLRP3) inflammasome-mediated microglial pyroptosis and NLRP1 inflammasome-mediated neuronal pyroptosis in the brain are closely associated with the pathogenesis of Alzheimer's disease. In this review, we summarize the possible pathogenic mechanisms of Alzheimer's disease, focusing on neuroinflammation. We also describe the structures of NLRP3 and NLRP1 and the role their activation plays in Alzheimer's disease. Finally, we examine the neuroprotective activity of small-molecule inhibitors, endogenous inhibitor proteins, microRNAs, and natural bioactive molecules that target NLRP3 and NLRP1, based on the rationale that inhibiting NLRP3 and NLRP1 inflammasome-mediated pyroptosis can be an effective therapeutic strategy for Alzheimer's disease.

Dietary selenium intake, hypertension and cognitive function among US adults, NHANES 2011-2014

Dietary selenium intake and hypertension were associated with cognitive function, but it was limitedly understood whether the effect of selenium intake on cognitive function in older adults was modified by hypertension status. A total of 2416 participants aged ≥ 60 years old from the National Health and Nutrition Examination Survey in 2011-2014 were involved in this study. Selenium intake from foods was estimated using two non-consecutive 24-hour dietary recalls. Blood pressure was measured by trained personnel or physicians at a mobile testing center. Cognitive function was measured by Registry for Alzheimer's disease (CERAD), the Animal Fluency test (AFT), and Digit Symbol Substitution Test (DSST). Among 2,416 participants, we found that higher dietary intake of selenium was associated with higher score on most tests (CERAD: Total Score: P for trend = 0.01; AFT: P for trend = 0.01; DSST: P for trend = 0.02) and hypertension was associated with lower score on each test (CEARD: Total Score (β = - 0.87, P = 0.03), CERAD: Delayed Recall Score (β = - 0.37, P = 0.04), AFT (β = - 0.88, P = 0.03), and DSST (β = - 2.72, P = 0.02). The interaction of hypertension status and dietary selenium intake on CERAD-immediate (P for interaction = 0.02) and DSST (P for interaction = 0.04) were statistical significance. In addition, hypertension did not mediate the association between dietary selenium intake and the four dimensions of cognition. The findings suggest that in older adults with hypertension, higher dietary selenium intake is associated with improved cognitive function, implying a potential nutritional strategy for preventing cognitive impairment in this population.

The Relationship Between Alzheimer's Disease and Pyroptosis and the Intervention Progress of Traditional Chinese Medicine

Alzheimer's disease (AD) is a progressive neurodegenerative disease caused by multiple causes. The main pathological features of AD are β-amyloid (Aβ) deposition, hyperphosphorylation of Tau protein, and progressive neuronal loss. Pyroptosis is one of the main forms of neuronal death, which is mainly caused by the activation of Gasdermin protein by upstream signals and the release of its N-terminal domain on the cell membrane. Studies have shown that there is a close relationship between Alzheimer's disease (AD) and pyroptosis. Therefore, this paper summarizes the relationship between pyroptosis and its molecular mechanism and AD, as well as the related research of traditional Chinese medicine in the treatment of AD by regulating pyroptosis, in order to provide a new direction for the study of AD pathogenesis based on pyroptosis pathway.

A Map of Transcriptomic Signatures of Different Brain Areas in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder that progressively involves brain regions with an often-predictable pattern. Damage to the brain appears to spread and worsen with time, but the molecular mechanisms underlying the region-specific distribution of AD pathology at different stages of the disease are still under-investigated. In this study, a whole-transcriptome analysis was carried out on brain samples from the hippocampus (HI), temporal and parietal cortices (TC and PC, respectively), cingulate cortex (CG), and substantia nigra (SN) of six subjects with a definite AD diagnosis and three healthy age-matched controls in duplicate. The transcriptomic results showed a greater number of differentially expressed genes (DEGs) in the TC (1571) and CG (1210) and a smaller number of DEGs in the HI (206), PC (109), and SN (60). Furthermore, the GSEA showed a difference between the group of brain areas affected early (HI and TC) and the group of areas that were subsequently involved (PC, CG, and SN). Notably, in the HI and TC, there was a significant downregulation of shared DEGs primarily involved in synaptic transmission, while in the PC, CG, and SN, there was a significant downregulation of genes primarily involved in protein folding and trafficking. The course of AD could follow a definite time- and severity-related pattern that arises from protein misfolding, as observed in the PC, CG, and SN, and leads to synaptic impairment, as observed in the HI and TC. Therefore, a map of the molecular and biological processes involved in AD pathogenesis may be traced. This could aid in the discovery of novel biological targets in order to develop effective and well-timed therapeutic approaches.

Network Medicine Approach Unravels Endophenotype Signature in Alzheimer's Disease through Large-Scale Comparative Proteomics Analysis: Vascular Dysfunction as a Prime Example

Alzheimer's disease (AD) is the most common neurodegenerative disease burdening public health. We proposed a network-based infrastructure to identify protein signatures for five AD pathological endophenotypes: amyloidosis, tauopathy, vascular dysfunction, lysosomal dysfunction, and neuroinflammation. We analyzed 23 proteomic data sets from AD patients and transgenic mouse models, using network proximity to measure associations between endophenotype modules and differentially expressed proteins (DEPs) in the integrated AD proteome. We focused on the vascular dysfunction signature with 21 DEPs by integrating RNA-seq, single-cell transcriptomics, GWAS, and literature. Experiments on APP/PS1 and MCAO models highlighted three proteins (SEPT5, SNAP25, STXBP1) as novel AD biomarker candidates. This study demonstrates a network medicine framework for deciphering endophenotype signatures in AD.

Prevention and Treatment Strategies for Alzheimer's Disease: Focusing on Microglia and Astrocytes in Neuroinflammation

Alzheimer's disease (AD) is a fatal neurodegenerative disease characterized by its insidious onset and progressive development, making it the most common form of dementia. Despite its prevalence, the exact causes and mechanisms responsible for AD remain unclear. Recent studies have highlighted that inflammation in the central nervous system (CNS) plays a crucial role in both the initiation and progression of AD. Neuroinflammation, an immune response within the CNS triggered by glial cells in response to various stimuli, such as nerve injury, infection, toxins, or autoimmune reactions, has emerged as a significant factor alongside amyloid deposition and neurofibrillary tangles (NFTs) commonly associated with AD. This article aims to provide an overview of the most recent research regarding the involvement of neuroinflammation in AD, with a particular focus on elucidating the specific mechanisms involving microglia and astrocytes. By exploring these intricate processes, a new theoretical framework can be established to further probe the impact of neuroinflammation on the development and progression of AD. Through a deeper understanding of these underlying mechanisms, potential targets for therapeutic interventions and novel treatment strategies can be identified in the ongoing battle against AD.

Microglial responses partially mediate the effect of Aβ on cognition in Alzheimer's disease

INTRODUCTION

Microglial responses are an integral part of Alzheimer's disease (AD) pathology and are associated with amyloid beta (Aβ) deposition. This study aimed to investigate the effects of Aβ and microglial responses on global cognitive impairment.

METHODS

In this longitudinal study, 28 patients with mild cognitive impairment and 11 healthy controls underwent 11C-PK11195 and 11C-Pittsburgh compound B positron emission tomography (PET), structural magnetic resonance imaging scans, and global cognitive ratings at baseline and 2-year follow-up. Correlations between PET uptake and global cognition were assessed. Additionally, the mediation effect of the microglial response on the association between Aβ load and global cognition was assessed.

RESULTS

Aβ load and the microglial response were both independently detrimental to global cognitive performance at baseline; however, at 2-year follow-up the association between Aβ load and global cognitive ratings was partially mediated by the microglial response.

DISCUSSION

As AD progresses, the associated microglial response partially mediates the detrimental effect of aggregated Aβ on cognition.

HIGHLIGHTS

This was a longitudinal study of amyloid beta (Aβ), microglial responses, and global cognitive performance. Aβ and microglial responses both affect cognition in early Alzheimer's disease. Microglial response partially mediates the effect of Aβ on cognition in later stages.

Effects of Leaf Extracts from Genetic Resource of Capsicum spp. on Neuroprotection and Anti-Neuroinflammation in HT22 and in BV2 Cells

To develop functional varieties of Capsicum spp. leaves, 40 genetic resources were collected and extracted with 30% aqueous-fermented ethanol. We investigated the protective effects of extracts from 40 genetic resources of Capsicum spp. on glutamate-induced HT22 and LPS-induced BV2 cells. The results showed that the five extracts exhibited cell-protective activities. We also investigated the anti-inflammatory effects of these five extracts on LPS-induced BV2 cell neuroinflammation and found that 23OM18 exhibited superior anti-inflammatory effects. We further investigated the protective activity and anti-inflammatory mechanisms of 23OM18 in these two cell models. In addition, the profiles of 16 metabolites were compared between the representative accessions and among the five genetic resources using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). The results showed that 23OM18 protected HT22 cells by inhibiting reactive oxygen species generation and regulating the MAPK-JNK signaling pathway, thereby reducing LPS-induced BV2 cell neuroinflammation by regulating the NF-κB and MAPK signaling pathways. Based on these results, 23OM18 has the potential to be developed as a functional food for the treatment of neurodegenerative diseases.

Nanomaterials that Aid in the Diagnosis and Treatment of Alzheimer's Disease, Resolving Blood-Brain Barrier Crossing Ability

As a form of dementia, Alzheimer's disease (AD) suffers from no efficacious cure, yet AD treatment is still imperative, as it ameliorates the symptoms or prevents it from deteriorating or maintains the current status to the longest extent. The human brain is the most sensitive and complex organ in the body, which is protected by the blood-brain barrier (BBB). This yet induces the difficulty in curing AD as the drugs or nanomaterials that are much inhibited from reaching the lesion site. Thus, BBB crossing capability of drug delivery system remains a significant challenge in the development of neurological therapeutics. Fortunately, nano-enabled delivery systems possess promising potential to achieve multifunctional diagnostics/therapeutics against various targets of AD owing to their intriguing advantages of nanocarriers, including easy multifunctionalization on surfaces, high surface-to-volume ratio with large payloads, and potential ability to cross the BBB, making them capable of conquering the limitations of conventional drug candidates. This review, which focuses on the BBB crossing ability of the multifunctional nanomaterials in AD diagnosis and treatment, will provide an insightful vision that is conducive to the development of AD-related nanomaterials.

Magnetic stirring with iron oxide nanospinners accretes neurotoxic Aβ42 oligomers into phagocytic clearable plaques for Alzheimer's disease treatment

An increasing number of medications have been explored to treat the progressive and irreversible Alzheimer's disease (AD) that stands as the predominant form of dementia among neurodegenerative ailments. However, assertions about toxic side effects of these drugs are a significant hurdle to overcome, calling for drug-free nanotherapeutics. Herein, a new therapeutic strategy devoid of conventional drugs or other cytotoxic species was developed. The constructed superparamagnetic iron oxide nanoparticles (SPIONs) nanospinners can accrete neurotoxic β-amyloid 42 oligomers (oAβ42) into aggregated magnetic plaques (mpAβ) by mechanical rotating force via remote interaction between nanoparticles and the applied magnetic field. While the cellular uptake of mpAβ attained from the magnetic stirring treatment by neuronal cells is severely limited, the facile phagocytic uptake of mpAβ by microglial cells leads to the polarization of the brain macrophages to M2 phenotype and thus the increased anti-inflammatory responses to the treatment. The SPION stirring treatment protects the AD mice from memory deterioration and maintain cognitive ability as evidenced from both nesting and Barnes maze tests. The examination of the oAβ42 injected brain tissues with the stirring treatment showed significant amelioration of functional impairment of neurons, microglia, astrocytes and oligodendrocytes alongside no obvious tissue damage caused by stirring meanwhile complete degradation of SPION was observed at day 7 after the treatment. The in vitro and animal data of this work strongly corroborate that this new modality of undruggable stirring treatment with SPIONs provides a new feasible strategy for developing novel AD treatments.

Microglial activation and polarization in type 2 diabetes-related cognitive impairment: A focused review of pathogenesis

Microglia, as immune cells in the central nervous system, are closely related to cognitive impairment associated with type 2 diabetes (T2D). Preliminary explorations have investigated the relationship between T2D-related cognitive impairment and the activation and polarization of microglia. This review summarizes the potential mechanisms of microglial activation and polarization in the context of T2D. It discusses central inflammatory responses, neuronal apoptosis, amyloid-β deposition, and abnormal phosphorylation of Tau protein mediated by microglial activation and polarization, exploring the connections between microglial activation and polarization and T2D-related cognitive impairment from multiple perspectives. Additionally, this review provides references for future treatment targeting microglia in T2D-related cognitive impairment and for clinical translation.

Phosphatidylserine: A comprehensive overview of synthesis, metabolism, and nutrition

Phosphatidylserine (PtdS) is classified as a glycerophospholipid and a primary anionic phospholipid and is particularly abundant in the inner leaflet of the plasma membrane in neural tissues. It is synthesized from phosphatidylcholine or phosphatidylethanolamine by exchanging the base head group with serine, and this reaction is catalyzed by PtdS synthase-1 and PtdS synthase-2 located in the endoplasmic reticulum. PtdS exposure on the outside surface of the cell is essential for eliminating apoptotic cells and initiating the blood clotting cascade. It is also a precursor of phosphatidylethanolamine, produced by PtdS decarboxylase in bacteria, yeast, and mammalian cells. Furthermore, PtdS acts as a cofactor for several necessary enzymes that participate in signaling pathways. Beyond these functions, several studies indicate that PtdS plays a role in various cerebral functions, including activating membrane signaling pathways, neuroinflammation, neurotransmission, and synaptic refinement associated with the central nervous system (CNS). This review discusses the occurrence of PtdS in nature and biosynthesis via enzymes and genes in plants, yeast, prokaryotes, mammalian cells, and the brain, and enzymatic synthesis through phospholipase D (PLD). Furthermore, we discuss metabolism, its role in the CNS, the fortification of foods, and supplementation for improving some memory functions, the results of which remain unclear. PtdS can be a potentially beneficial addition to foods for kids, seniors, athletes, and others, especially with the rising consumer trend favoring functional foods over conventional pills and capsules. Clinical studies have shown that PtdS is safe and well tolerated by patients.

Mitochondria-targeting Cu2-xSe-TPP with dual enzyme activity alleviates Alzheimer's disease by modulating oxidative stress

Mitochondrial dysfunction in microglia has been implicated as a key pathogenesis of most neurodegenerative diseases including Alzheimer's disease (AD). Abnormal production of reactive oxygen species (ROS) and neuroinflammation caused by mitochondrial oxidative stress are important factors leading to neuronal death in AD. Herein, a "dual brake" strategy to synergistically halt mitochondrial dysfunction and neuroinflammation targeting mitochondria in microglia is proposed. To achieve this goal, (3-carboxypropyl) triphenyl-phosphonium bromide (TPP)-modified Cu2-xSe nanozymes (Cu2-xSe-TPP NPs) with dual enzyme-like activities was designed. Cu2-xSe-TPP NPs with superoxide dismutase-mimetic (SOD) and catalase-mimetic (CAT) activities can effectively scavenge ROS in the mitochondria of microglia and relieve mitochondrial oxidative stress. In vivo studies demonstrated that Cu2-xSe-TPP NPs can alleviate oxidative stress and promote neuroprotection in the hippocampus of AD model mice. In addition, Cu2-xSe-TPP NPs can regulate the polarization of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, promote Aβ phagocytosis and reshape the AD inflammatory microenvironment, thus effectively attenuating AD neuropathology and rescuing cognitive deficits in AD model mice. Taken together, this strategy preventing mitochondrial damage and remodeling the inflammatory microenvironment will provide a new perspective for AD therapy.

The Effect of FTY720 on Sphingolipid Imbalance and Cognitive Decline in Aged EFAD Mice

Background

During Alzheimer's disease (AD) progression, there is a decline in the bioactive sphingolipid sphingosine-1-phosphate (S1P). Previous research showed that FTY720, an S1P mimetic, prevented cognitive decline and reduced ceramide levels in transgenic mice with familial AD carrying the human APOE4 gene (E4FAD) at 6-7 months of age.

Objective

The objective of this study is to explore the protective effects of FTY720 at late-stage AD.

Methods

Male mice aged 9.5 to 10.5 months were orally administered FTY720 (0.1 mg/kg) via oral gavage for 6 weeks. A pre-test of water maze was used for evaluating the pathological status. After 4 weeks of administration, memory, locomotion, and anxiety were assessed. Cortex samples were analyzed for amyloid-β (Aβ) and sphingolipid levels.

Results

Compared with APOE3 mice, APOE4, E3FAD and E4FAD mice exhibited significant memory deficits. After 6 weeks administration, FTY720 did not alleviate memory deficits in EFAD mice. Lipid analysis revealed that S1P was significantly reduced in EFAD mice (E3FAD or E4FAD) compared to controls (APOE3 and APOE4). Ceramide level alterations were predominantly dependent on APOE isoforms rather than AD transgenes. Interestingly, Cer (d18 : 1/22 : 1) was elevated in APOE4 mice compared to APOE3, and FTY720 reduced it.

Conclusions

E4FAD and APOE4 mice exhibited significant spatial memory deficits and higher ceramide concentrations compared to APOE3 mice. FTY720 did not reverse memory deficits in E4FAD and APOE4 mice but reduced specific ceramide species. This study provides insights into the association between sphingolipids and APOE4 in advanced AD stages, exploring potential therapeutic targeting of sphingolipid metabolism.

A Peptide-Drug Conjugate-Based Nanoplatform for Immunometabolic Activation and In Situ Nerve Regeneration in Advanced-Stage Alzheimer's Disease

The formidable protection of physiological barriers and unclear pathogenic mechanisms impede drug development for Alzheimer's disease (AD). As defenders of the central nervous system, immune-metabolism function, and stemness of glial cells remain dormant during degeneration, representing a significant challenge for simultaneously targeting and modulating. Here, a modular nanoplatform is presented composed of peptide-drug conjugates and an inflammation-responsive core. The nanoplatform is transported through the blood-brain barrier via transcytosis and disassembles in the oxidative stress microenvironment upon intravenous administration. The released drug-conjugated modules can specifically target and deliver hydroxychloroquine (HCQ) and all-trans retinoic acid (ATRA) to microglia and astrocytes, respectively. The immune function of chronic tolerant microglia is activated by metabolic modulation, and reactive astrocytes trans-differentiate into functional neurons. In a transgenic mouse model, nanoplatform reduces levels of toxic proteins and inflammation while increasing neuronal density. This results in the amelioration of learning and memory decline. The modular nanoplatform provides design principles for multi-cellular targeting and combination nano-therapy for inflammation-related diseases.

Cerebrovascular disease is associated with Alzheimer's plasma biomarker concentrations in adults with Down syndrome

By age 40 years, over 90% of adults with Down syndrome have Alzheimer's disease pathology and most progress to dementia. Despite having few systemic vascular risk factors, individuals with Down syndrome have elevated cerebrovascular disease markers that track with the clinical progression of Alzheimer's disease, suggesting a role of cerebrovascular disease that is hypothesized to be mediated by inflammatory factors. This study examined the pathways through which small vessel cerebrovascular disease contributes to Alzheimer's disease-related pathophysiology and neurodegeneration in adults with Down syndrome. One hundred eighty-five participants from the Alzheimer's Biomarkers Consortium-Down Syndrome [mean (SD) age = 45.2 (9.3) years] with available MRI and plasma biomarker data were included in this study. White matter hyperintensity (WMH) volumes were derived from T2-weighted fluid-attenuated inversion recovery MRI scans, and plasma biomarker concentrations of amyloid beta 42/40, phosphorylated tau 217, astrocytosis (glial fibrillary acidic protein) and neurodegeneration (neurofilament light chain) were measured with ultrasensitive immunoassays. We examined the bivariate relationships of WMH, amyloid beta 42/40, phosphorylated tau 217 and glial fibrillary acidic protein with age-residualized neurofilament light chain across Alzheimer's disease diagnostic groups. A series of mediation and path analyses examined statistical pathways linking WMH and Alzheimer's disease pathophysiology to promote neurodegeneration in the total sample and groups stratified by clinical diagnosis. There was a direct and indirect bidirectional effect through the glial fibrillary acidic protein of WMH on phosphorylated tau 217 concentration, which was associated with neurofilament light chain concentration in the entire sample. Amongst cognitively stable participants, WMH was directly and indirectly, through glial fibrillary acidic protein, associated with phosphorylated tau 217 concentration, and in those with mild cognitive impairment, there was a direct effect of WMH on phosphorylated tau 217 and neurofilament light chain concentrations. There were no associations of WMH with biomarker concentrations among those diagnosed with dementia. The findings from this cross-sectional study suggest that among individuals with Down syndrome, cerebrovascular disease promotes neurodegeneration by increasing astrocytosis and tau pathophysiology in the presymptomatic phases of Alzheimer's disease, but future studies will need to confirm these associations with longitudinal data. This work joins an emerging literature that implicates cerebrovascular disease and its interface with neuroinflammation as a core pathological feature of Alzheimer's disease in adults with Down syndrome.

The Kynurenine Pathway, Aryl Hydrocarbon Receptor, and Alzheimer's Disease

Alzheimer's disease (AD) is the leading cause of dementia, mainly affecting elderly individuals. AD is characterized by β-amyloid plaques, abnormal tau tangles, neuronal loss, and metabolic disruptions. Recent studies have revealed the involvement of the kynurenine (KP) pathway and the aryl hydrocarbon receptor (AhR) in AD development. The KP pathway metabolizes tryptophan to produce neuroactive substances like kynurenine, kynurenic acid, and quinolinic acid. In AD, high levels of kynurenine and the neurotoxic quinolinic acid are associated with increased neuroinflammation and excitotoxicity; conversely, reduced levels of kynurenic acid, which acts as a glutamate receptor antagonist, compromise neuroprotection. Research has indicated elevated KP metabolites and enzymes in the hippocampus of AD patients and other tissues such as blood, cerebrospinal fluid, and urine. However, the finding that KP metabolites are AD biomarkers in blood, cerebrospinal fluid, and urine has been controversial. This controversy, stemming from the lack of consideration of the specific stage of AD, details of the patient's treatment, cognitive deficits, and psychiatric comorbidities, underscores the need for more comprehensive research. AhR, a ligand-activated transcription factor, regulates immune response, oxidative stress, and xenobiotic metabolism. Various ligands, including tryptophan metabolites, can activate it. Some studies suggest that AhR activation contributes to AD, while others propose that it provides neuroprotection. This discrepancy may be explained by the specific ligands that activate AhR, highlighting the complex relationship between the KP pathway, AhR activation, and AD, where the same pathway can produce both neuroprotective and harmful effects.

Association between the systemic immune-inflammation index and hearing loss: A cross-sectional study of NHANES 2005 to 2018

The relationship between systemic inflammation and hearing loss (HL) remains unclear. To investigate the association between the systemic immune-inflammation index (SII) and objective HL, this study was performed. Participants from the National Health and Nutrition Examination Survey (NHANES) spanning from 2005 to 2018 were analyzed. Two types of hearing loss were investigated: speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL). The SII score was constructed using the levels of peripheral neutrophil (N), lymphocyte (L), and platelet (P), and was defined as P multiplied by N/L (in units of 109/L). Weighted multivariable logistic regression and subgroup analysis were used to examine the relationship between HL and high-SII group (≥330 × 109/L). A total of 6428 participants were included in the study. This study found that the high-SII group was positively associated with a higher risk of HL (OR: 1.29, 95% CI: 1.05-1.57, P < .05) and HFHL (OR: 1.24, 95% CI: 1.05-1.46, P < .05), but not significant for SFHL (OR: 1.13, 95% CI: 0.94-1.37, P > .05). Subgroup analysis showed that this association was similar in different age groups. Finally, sensitivity analysis confirmed the robustness of the association. In the full model, increasing SII index per SD was associated with HL (OR: 1.17, 95% CI: 1.09-1.26, P < .001) and HFHL (OR: 1.13, 95% CI: 1.06-1.21, P < .001). The significance of SFHL was not detected with the increasing SII index (OR: 1.13, 95% CI: 0.94-1.37, P > .05). SII score was associated with HL and HFHL in the general adult population of the United States, but was not significantly correlated with SFHL.

Intracranial atherosclerotic disease and neurodegeneration: a narrative review and plausible mechanisms

INTRODUCTION

Intracranial atherosclerotic disease (ICAD) of the large cerebral arteries, a leading cause of stroke worldwide, is increasingly implicated in cognitive impairment and neurodegeneration among the general population; however, the underlying pathophysiologic mechanisms in this relationship remain unknown.

METHODS

In this narrative review, we aim to provide an overview of the epidemiology and pathophysiology of ICAD, the evidence that relates ICAD to neurodegeneration, putative mechanisms, and future research directions. We synthesized available evidence on PubMed up to August 2024.

RESULTS AND CONCLUSIONS

ICAD, a common cause of stroke, is characterized as a chronic, inflammatory, fibroproliferative disease of the cerebral large arteries. Numerous lines of evidence have related ICAD to clinical, neuroimaging, and pathology-based markers of cognitive impairment and Alzheimer's disease; however, little data exists on plausible pathophysiological links. Based on ongoing and adjacent work, we hypothesize hypoperfusion, arterial stiffness, and inflammation to play a role, but further research is needed. Conventional classification of ICAD often infers from symptomatic coronary artery disease and relies on degree of luminal stenosis, but unique anatomic features of the intracranial circulation may be relevant and a more comprehensive description that includes arterial wall features and plaque morphology may be needed to fully understand its relationship with cognitive impairment and neurodegeneration.

p38α Mitogen-Activated Protein Kinase-An Emerging Drug Target for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder, characterized by the formation of amyloid β and tau protein aggregates in the brain, neuroinflammation, impaired cholinergic neurotransmission, and oxidative stress, resulting in the gradual loss of neurons and neuronal function, which leads to cognitive and memory deficits in AD patients. Chronic neuroinflammation plays a particularly important role in the progression of AD since the excessive release of proinflammatory cytokines from glial cells (microglia and astrocytes) induces neuronal damage, which subsequently causes microglial activation, thus facilitating further neurodegenerative changes. Mitogen-activated protein kinase (MAPK) p38α is one of the key enzymes involved in the control of innate immune response. The increased activation of the p38α MAPK pathway, observed in AD, has been for a long time associated not only with the maintenance of excessive inflammatory process but is also linked with pathophysiological hallmarks of this disease, and therefore is currently considered an attractive drug target for novel AD therapeutics. This review aims to summarize the current state of knowledge about the involvement of p38α MAPK in different aspects of AD pathophysiology and also provides insight into the possible therapeutic effects of novel p38α MAPK inhibitors, which are currently studied as potential drug candidates for AD treatment.

Exploring the relationship between lipid metabolism and cognition in individuals living with stable-phase Schizophrenia: a small cross-sectional study using Olink proteomics analysis

BACKGROUND

Cognitive impairment is a core symptom of schizophrenia. Metabolic abnormalities impact cognition, and although the influence of blood lipids on cognition has been documented, it remains unclear. We conducted a small cross-sectional study to investigate the relationship between blood lipids and cognition in patients with stable-phase schizophrenia. Using Olink proteomics, we explored the potential mechanisms through which blood lipids might affect cognition from an inflammatory perspective.

METHODS

A total of 107 patients with stable-phase schizophrenia and cognitive impairment were strictly included. Comprehensive data collection included basic patient information, blood glucose, blood lipids, and body mass index. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and the MATRICS Consensus Cognitive Battery (MCCB). After controlling for confounding factors, we identified differential metabolic indicators between patients with mild and severe cognitive impairment and conducted correlation and regression analyses. Furthermore, we matched two small sample groups of patients with lipid metabolism abnormalities and used Olink proteomics to analyze inflammation-related differential proteins, aiming to further explore the association between lipid metabolism abnormalities and cognition.

RESULTS

The proportion of patients with severe cognitive impairment (SCI) was 34.58%. Compared to patients with mild cognitive impairment (MCI), those with SCI performed worse in the Attention/Alertness (t = 2.668, p = 0.009) and Working Memory (t = 2.496, p = 0.014) cognitive dimensions. Blood lipid metabolism indicators were correlated with cognitive function, specifically showing that higher levels of TG (r = -0.447, p < 0.001), TC (r = -0.307, p = 0.002), and LDL-C (r = -0.607, p < 0.001) were associated with poorer overall cognitive function. Further regression analysis indicated that TG (OR = 5.578, P = 0.003) and LDL-C (OR = 5.425, P = 0.001) may be risk factors for exacerbating cognitive impairment in individuals with stable-phase schizophrenia. Proteomics analysis revealed that, compared to individuals with stable-phase schizophrenia and normal lipid metabolism, those with hyperlipidemia had elevated levels of 10 inflammatory proteins and decreased levels of 2 inflammatory proteins in plasma, with these changes correlating with cognitive function. The differential proteins were primarily involved in pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, and IL-17 signaling pathway.

CONCLUSION

Blood lipids are associated with cognitive function in individuals with stable-phase schizophrenia, with higher levels of TG, TC, and LDL-C correlating with poorer overall cognitive performance. TG and LDL-C may be risk factors for exacerbating cognitive impairment in these patients. From an inflammatory perspective, lipid metabolism abnormalities might influence cognition by activating or downregulating related proteins, or through pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, and IL-17 signaling pathway.

Potential neuroprotective and autophagy-enhancing effects of alogliptin on lithium/pilocarpine-induced seizures in rats: Targeting the AMPK/SIRT1/Nrf2 axis

BACKGROUND

Status epilepticus (SE) as a severe neurodegenerative disease, greatly negatively affects people's health, and there is an urgent need for innovative treatments. The valuable neuroprotective effects of glucagon-like peptide-1 (GLP-1) in several neurodegenerative diseases have raised motivation to investigate the dipeptidyl peptidase-4 (DPP-4) inhibitor; alogliptin (ALO), an oral antidiabetic drug as a potential treatment for SE. ALO has shown promising neuroprotective effects in Alzheimer's and Parkinson's diseases, but its impact on SE has not yet been studied.

AIM

The present study aimed to explore the repurposing potential for ALO in a lithium/pilocarpine (Li/Pil)-induced SE model in rats.

MAIN METHODS

ALO (30 mg/kg/day) was administered via gavage for 14 days, and SE was subsequently induced in the rats using a single dose of Li/Pil (127/60 mg/kg), while levetiracetam was used as a standard antiepileptic drug.

KEY FINDINGS

The results showed that ALO reduced seizure severity and associated hippocampal neurodegeneration. ALO also increased γ-aminobutyric acid (GABA) levels, diminished glutamate spikes, and corrected glial fibrillary acidic protein (GFAP) changes. At the molecular level, ALO increased GLP-1 levels and activated its downstream signaling pathway, AMP-activated protein kinase (AMPK)/sirtuin-1 (SIRT1). ALO also dampened the brain's pro-oxidant response, curbed neuroinflammation, and counteracted hippocampal apoptosis affording neuroprotection. In addition, it activated autophagy as indicated by Beclin1 elevation.

SIGNIFICANCE

This study suggested that the neuroprotective properties and autophagy-enhancing effects of ALO make it a promising treatment for SE and can potentially be used as a management approach for this condition.

Emerging Human Pluripotent Stem Cell-Based Human-Animal Brain Chimeras for Advancing Disease Modeling and Cell Therapy for Neurological Disorders

Human pluripotent stem cell (hPSC) models provide unprecedented opportunities to study human neurological disorders by recapitulating human-specific disease mechanisms. In particular, hPSC-based human-animal brain chimeras enable the study of human cell pathophysiology in vivo. In chimeric brains, human neural and immune cells can maintain human-specific features, undergo maturation, and functionally integrate into host brains, allowing scientists to study how human cells impact neural circuits and animal behaviors. The emerging human-animal brain chimeras hold promise for modeling human brain cells and their interactions in health and disease, elucidating the disease mechanism from molecular and cellular to circuit and behavioral levels, and testing the efficacy of cell therapy interventions. Here, we discuss recent advances in the generation and applications of using human-animal chimeric brain models for the study of neurological disorders, including disease modeling and cell therapy.

The effect and mechanism of patchouli alcohol on cognitive dysfunction in AD mice induced by Aβ1-42 oligomers through AMPK/mTOR pathway

Alzheimer's disease (AD) is a neurodegenerative brain disorder that progressively impairs long-term and working memory. The function and mechanism of PA(Patchouli alcohol) in improving AD in the external treatment of encephalopathy remain unclear. This study aimed to investigate the therapeutic effect of PA on AD using an Aβ1-42 induced AD mouse model with LPS(Lipopolysaccharide) stimulation of BV2 microglial cells. Additionally, we aimed to explore the potential mechanism of PA in enhancing autophagy and reducing neuroinflammation through the AMPK (AMP-activated protein kinase)/mTOR (Mammaliam target of rapamycin) signaling pathway. The Morris water maze was used to assess cognitive function, and cortical and hippocampal tissues were collected for further analysis of the corresponding signaling pathways and inflammatory changes through biological experiments. Our research findings demonstrate that PA has a significant positive impact on cognitive and memory impairments in mice that have been induced with Aβ1-42-induced AD. Additionally, PA was also found to revert the activation of microglia induced by LPS. These effects may be attributed to the reduction of neuroinflammation and enhancement of the AMPK/mTOR autophagy pathway. Therefore, PA may serve as an effective therapeutic option to prevent or delay the progression of AD-associated memory dysfunction.

The Effects of PICALM rs3851179 and Age on Brain Atrophy and Cognition Along the Alzheimer's Disease Continuum

Rs3851179, a variant of PICALM gene, and age are the risk factors of Alzheimer's disease (AD). AD is divided into early-onset AD (EOAD, < 65 years) and late-onset AD (LOAD, ≥ 65 years) by age. The purpose was to investigate the impact of different genotypes of PICALM rs3851179 on brain atrophy and cognitive decline across the AD continuum in different age groups. Four hundred seven cognitive normal (CN) controls, 362 mild cognitive impairment (MCI) patients, and 94 AD patients were enrolled to assess the interaction between AD continuum, age status, and PICALM on gray matter volume (GMV), global cognition, memory function, and executive function using full factorial ANCOVA (3 × 2 × 2). The interaction between AD continuum and PICALM significantly affected the GMV of the left putamen (PUT.L). rs3851179 A-allele carriers did not show a significant decrease in PUT.L GMV from CN to MCI to AD, while GG-allele carriers did. The interaction between AD continuum and age status was significant on GMV of the left angular gyrus (ANG.L) and right superior occipital gyrus (SOG.R). LOAD had higher GMV of ANG.L and SOG.R than EOAD. The interactive effects among AD continuum, age status, and PICALM were not significant on GMV but were significant on global cognition and executive function. The A-allele was found to have a protective effect on global cognition and executive function in EOAD, but not significantly so in LOAD. PICALM rs3851179 A-allele might alleviate the atrophy of PUT.L across the AD continuum than GG-allele. Age status did not affect the interaction between AD continuum and PICALM on brain atrophy. The ANG.L and SOG.R atrophied more severely in EOAD than in LOAD. Rs3851179 A-allele was protective for global cognition and executive function in EOAD.

Potential Inflammatory Markers Related to the Conversion to Alzheimer's Disease in Female Patients With Late-Life Depression

Background

Inflammation has been postulated as a mediating factor in the development of Alzheimer's disease (AD) pathology. We investigated candidate inflammatory markers related to conversion to AD among patients with depression.

Methods

A longitudinal study was conducted with older women with depression who were at least 55 years of age, with a mean follow-up period of 5.73 years. At baseline, 9 inflammatory cytokines were measured using the immunoreactivity method. During follow-up, patients with depression who complained of cognitive impairment were evaluated and diagnosed with AD conversion. Association of the cytokines with conversion to AD was analyzed using multivariable Cox proportional hazards regression with adjusting covariates. For clinical applicability, the optimal cutoff value was determined using the minimum p value approach for the conversion to AD and was used to plot an AD-free survival curve.

Results

Among 132 participants, 34 patients with depression (25.76%) developed AD during their follow-up period. Higher levels of interleukin (IL) 1β at baseline (hazard ratio = 3.30 [95% CI, 1.11-9.78], p = .031) and lower levels of IL-10 (p < .001) were significantly associated with an increased risk of progression to AD. The survival curve plotted by the cutoff value of ≥0.25 pg/mL for IL-1β and ≤0.15 pg/mL for IL-10 suggested adjusted hazard ratios of 8.96 (95% CI, 3.48-23.09; p < .001) for IL-1β and 10.99 (p < .001) for IL-10, respectively.

Conclusions

This study demonstrated that IL-1β and IL-10 were associated with conversion to AD among patients with late-life depression, suggesting their potential as predictive markers of the transition to AD from depression.

GluR2 can Drive Neuroinflammation and Cognitive Impairments Following Peripherally Repeated Lipopolysaccharide Exposures

Neuroinflammation is being increasingly recognized as a vital factor in the development of various neurological and neuropsychiatric diseases. Lipopolysaccharides (LPS), an outer membrane component of gram-negative bacteria, can trigger innate immune responses, resulting in neuroinflammation and subsequent cognitive deficits. The expression of glutamate receptors (GluRs) on glial cells can induce glial activation. Therefore, we hypothesized that repeated LPS exposure can increase GluR levels, promoting microglial activation and ultimately affecting synaptic plasticity and cognitive function. In this study, C57/BL6 mice were repeatedly exposed to LPS to construct a neuroinflammation animal model. The levels of GluRs, inflammatory cytokines, ionized calcium-binding adaptor molecule 1, postsynaptic density protein 95, synaptophysin 38, NMDA receptor 2 A, and NMDA receptor 2B (GluN2B) were measured in the hippocampi. Furthermore, dendritic spine density in the CA1 hippocampal region was determined. Repeated LPS exposure induced cognitive impairments and microglial activation and increased GluR1 and GluR2 levels. This was accompanied by a significant decrease in GluN2B expression and dendritic spine density in the hippocampi. However, CFM-2, an α-amino-3- hydroxy-5-methyl-4-isoxazolepropionate receptor antagonist, reversed these anomalies. Furthermore, minocycline, a microglial inhibitor, reversed these anomalies and downregulated GluR2 but not GluR1 expression. In summary, we demonstrated that GluR2 plays an essential role in microglia-induced neuroinflammation, resulting in synaptic plasticity and cognitive impairment induced by repeated exposure to LPS.

Exploring advancements in early detection of Alzheimer's disease with molecular assays and animal models

Alzheimer's Disease (AD) is a challenging neurodegenerative condition, with overwhelming implications for affected individuals and healthcare systems worldwide. Animal models have played a crucial role in studying AD pathogenesis and testing therapeutic interventions. Remarkably, studies on the genetic factors affecting AD risk, such as APOE and TREM2, have provided valuable insights into disease mechanisms. Early diagnosis has emerged as a crucial factor in effective AD management, as demonstrated by clinical studies emphasizing the benefits of initiating treatment at early stages. Novel diagnostic technologies, including RNA sequencing of microglia, offer promising avenues for early detection and monitoring of AD progression. Therapeutic strategies remain to evolve, with a focus on targeting amyloid beta (Aβ) and tau pathology. Advances in animal models, such as APP-KI mice, and the advancement of anti-Aβ drugs signify progress towards more effective treatments. Therapeutically, the focus has shifted towards intricate approaches targeting multiple pathological pathways simultaneously. Strategies aimed at reducing Aβ plaque accumulation, inhibiting tau hyperphosphorylation, and modulating neuroinflammation are actively being explored, both in preclinical models and clinical trials. While challenges continue in developing validated animal models and translating preclinical findings to clinical success, the continuing efforts in understanding AD at molecular, cellular, and clinical levels offer hope for improved management and eventual prevention of this devastating disease.

EXAMINING THE IMPACT OF PERMISSIBILITY HYPERCAPNIA ON POSTOPERATIVE DELIRIUM AMONG ELDERLY PATIENTS UNDERGOING THORACOSCOPIC-LAPAROSCOPIC ESOPHAGECTOMY: A SINGLE-CENTER INVESTIGATIVE STUDY

ABSTRACT

Objective: This study explores how permissive hypercapnia, a key aspect of lung-protective ventilation, impacts postoperative delirium in elderly patients following thoracic surgery. Methods: A single-center trial at The Second Hospital of Anhui Medical University involved 136 elderly patients undergoing thoracoscopic esophageal cancer resection. Randomly assigned to maintain PaCO 2 35-45 mm Hg (group N) or 46-55 mm Hg (group H). Primary outcome: postoperative delirium (POD) incidence 1-3 days post-surgery. Secondary endpoints included monitoring rSO 2 , cardiovascular parameters (MAP, HR), pH, OI, and respiratory parameters (VT, RR, Cdyn, PIP) at specific time points. Perioperative tests assessed CRP/ALB ratio (CAR) and systemic inflammatory index (SII). VAS scores were documented for 3 postoperative days. Results: Postoperatively, group H showed significantly lower POD incidence than group N (7.4% vs. 19.1%, P = 0.043). Group H exhibited higher PaCO 2 and rSO 2 during surgery ( P < 0.05). Patients in group H maintained better cardiovascular stability with higher blood pressure and lower heart rate on T2-4 ( P < 0.05). Respiratory parameters were more stable in group H with lower TV, RR, and PIP, and higher Cdyn during OLV ( P < 0.05). Group H had lower pH and higher OI at T2-4 ( P < 0.05). CRP and CAR levels rose less in group H on the first day and 1 week later ( P < 0.05). Conclusions: Maintaining PaCO 2 at 46-55 mm Hg reduces POD incidence, possibly by enhancing rSO 2 levels and stabilizing intraoperative respiration/circulation.

Yishen Huazhuo decoction regulates microglial polarization to reduce Alzheimer's disease-related neuroinflammation through TREM2

Background

Aging is the primary risk factor for the onset of Alzheimer's disease (AD). Inflamma-aging is a major feature in the process of aging, and the chronic neuroinflammation caused by inflamma-aging is closely related to AD. As the main participant of neuroinflammation, the polarization of microglia (MG) could influence the development of neuroinflammation.

Objective

This study aims to observe the impact of YHD on microglia (MG) polarization and neuroinflammation to delay the onset and progression of AD.

Methods

In vivo experiment, four-month senescence accelerated mouse prone 8 (SAMP8) were used as the model group, the SAMR1 mice of the same age were used as the control group. In YHD group, 6.24 g/kg YHD was intragastrically administrated continuously for 12 weeks, and Ibuprofen 0.026 g/kg in positive control group. Morris Water Maze test was used to evaluate the learning and memory ability, Nissl's staining and immunofluorescence double staining for neuron damage and MG M1/M2 polarization, Enzyme-Linked Immunosorbent Assay (ELISA) for neuroinflammation biomarkers in hippocampus, Western blot for key protein expression of TREM2/NF-κB signaling pathway. In vitro experiments, 10 μM/l Aβ1-42 induced BV-2 cell model was used to re-verify the effect of YHD regulating MG polarization to reduce neuroinflammation. Also, TREM2 small interfering RNA (siRNA) was used to clarify the key target of YHD.

Results

YHD could improve the learning and memory ability of SAMP8 mice evaluated by the Morris Water Maze test. Like Ibuprofen, YHD could regulate the M1/M2 polarization of MG and the levels of neuroinflammatory markers TNF-α and IL-10 in hippocampus, and relieve neuroinflammation and neuron loss. In addition, YHD could also regulate the expression of PU.1, TREM2, p-NF-κB P65 in the TREM2/NF-κB signaling pathway. Further in vitro experiments, we found that YHD had a significant regulatory effect on Aβ1-42-induced BV-2 cell polarization, and it could significantly increase PU.1, TREM2, decrease p-NF-κB P65, p-IKKβ, TNF-α, IL-6, IL-1β. At the same time, using siRNA to inhibit TREM2, it proved that TREM2 was a key target for YHD to promote Aβ1-42-induced BV-2 cell M2 polarization to reduce neuroinflammation.

Conclusions

YHD could regulate the TREM2/NF-κB signaling pathway through TREM2, thereby to adjust MG polarization and reduce AD-related neuroinflammation.

Common molecular and pathophysiological underpinnings of delirium and Alzheimer's disease: molecular signatures and therapeutic indications

BACKGROUND

Delirium and Alzheimer's disease (AD) are common causes of cognitive dysfunction among older adults. These neurodegenerative diseases share a common and complex relationship, and can occur individually or concurrently, increasing the chance of permanent mental dysfunction. However, the common molecular pathophysiology, key proteomic biomarkers, and functional pathways are largely unknown, whereby delirium is superimposed on AD and dementia.

METHODS

We employed an integrated bioinformatics and system biology analysis approach to decipher such common key proteomic signatures, pathophysiological links between delirium and AD by analyzing the gene expression data of AD-affected human brain samples and comparing them with delirium-associated proteins. The present study identified the common drug target hub-proteins examining the protein-protein interaction (PPI) and gene regulatory network analysis. The functional enrichment and pathway analysis was conducted to reveal the common pathophysiological relationship. Finally, the molecular docking and dynamic simulation was used to computationally identify and validate the potential drug target and repurposable drugs for delirium and AD.

RESULTS

We detected 99 shared differentially expressed genes (sDEGs) associated with AD and delirium. The sDEGs-set enrichment analysis detected the transmission across chemical synapses, neurodegeneration pathways, neuroinflammation and glutamatergic signaling pathway, oxidative stress, and BDNF signaling pathway as the most significant signaling pathways shared by delirium and AD. The disease-sDEGs interaction analysis highlighted the other disease risk factors with delirium and AD development and progression. Among the sDEGs of delirium and AD, the top 10 hub-proteins including ALB, APP, BDNF, CREB1, DLG4, GAD1, GAD2, GFAP, GRIN2B and GRIN2A were found by the PPI network analysis. Based on the maximum molecular docking binding affinities and molecular dynamic simulation (100 ns) results, the ALB and GAD2 were found as prominent drug target proteins when tacrine and donepezil were identified as potential drug candidates for delirium and AD.

CONCLUSION

The study outlined the common key biomolecules and biological pathways shared by delirium and AD. The computationally reported potential drug molecules need a deeper investigation including clinical trials to validate their effectiveness. The outcomes from this study will help to understand the typical pathophysiological relationship between delirium and AD and flag future therapeutic development research for delirium.

Longitudinal associations of cardiovascular health and vascular events with incident dementia

INTRODUCTION

Evidence supporting cardiovascular diseases could increase the risk of dementia remains fragmented. A comprehensive study to illuminate the distinctive associations across different dementia types is still lacking. This study is sought to: (1) determine the clinical validity of Framingham General Cardiovascular Risk Score (FGCRS) for dementia assessment and (2) examine the associations between cardiovascular diseases and the risk of dementia.

METHODS

A total of 432 079 dementia-free individuals at baseline from UK Biobank were included. Multivariable Cox proportional hazard models were used to investigate the prospective associations for FGCRS and a series of cardiovascular diseases with all-cause dementia (ACD) and its major components, Alzheimer's disease (AD) and vascular dementia (VaD).

RESULTS

During a median follow-up of 110.1 months, 4711 individuals were diagnosed with dementia. FGCRS was associated with increased risks across the dementia spectrum. In stratification analysis, high-risk groups have demonstrated the greatest dementia burdens, particularly to VaD. Over 74 traits, 9 adverse associations, such as chronic ischaemic heart disease (ACD: HR=1.354; AD: HR=1.269; VaD: HR=1.768), atrioventricular block (ACD: HR=1.562; AD: HR=1.556; VaD: HR=2.069), heart failure (ACD: HR=1.639; AD: HR=1.543; VaD: HR=2.141) and hypotension (ACD: HR=2.912; AD: HR=2.361; VaD: HR=3.315) were observed. Several distinctions were also found, with atrial fibrillation, cerebral infarction, and haemorrhage only associated with greater risks of ACD and VaD.

DISCUSSION

By identifying distinctive associations between cardiovascular diseases and dementia, this study has established a comprehensive 'mapping' that may untangle the long-standing discrepancy. FGCRS has demonstrated its predictivity beyond cardiovascular diseases burdens, suggesting potential opportunities for implantation.

Recent advances in Alzheimer's disease: Mechanisms, clinical trials and new drug development strategies

Alzheimer's disease (AD) stands as the predominant form of dementia, presenting significant and escalating global challenges. Its etiology is intricate and diverse, stemming from a combination of factors such as aging, genetics, and environment. Our current understanding of AD pathologies involves various hypotheses, such as the cholinergic, amyloid, tau protein, inflammatory, oxidative stress, metal ion, glutamate excitotoxicity, microbiota-gut-brain axis, and abnormal autophagy. Nonetheless, unraveling the interplay among these pathological aspects and pinpointing the primary initiators of AD require further elucidation and validation. In the past decades, most clinical drugs have been discontinued due to limited effectiveness or adverse effects. Presently, available drugs primarily offer symptomatic relief and often accompanied by undesirable side effects. However, recent approvals of aducanumab (1) and lecanemab (2) by the Food and Drug Administration (FDA) present the potential in disrease-modifying effects. Nevertheless, the long-term efficacy and safety of these drugs need further validation. Consequently, the quest for safer and more effective AD drugs persists as a formidable and pressing task. This review discusses the current understanding of AD pathogenesis, advances in diagnostic biomarkers, the latest updates of clinical trials, and emerging technologies for AD drug development. We highlight recent progress in the discovery of selective inhibitors, dual-target inhibitors, allosteric modulators, covalent inhibitors, proteolysis-targeting chimeras (PROTACs), and protein-protein interaction (PPI) modulators. Our goal is to provide insights into the prospective development and clinical application of novel AD drugs.

Bartonella spp. infection in people with Mild Cognitive Impairment: A pilot study

Mild Cognitive Impairment (MCI) is a neurological disorder at the transition between normal cognitive decline and dementia. Despite the potential role of neuroinflammation in the pathogenesis of MCI, infectious triggers remain mostly unknown. Infection with Bartonella spp., a zoonotic bacterium, has recently been associated with diffuse neurological and psychiatric symptoms. Given the preferential endothelial localization of Bartonella spp. and the role of vascular changes in neurocognitive decline, we hypothesized that there is an association between Bartonella spp. infection and pathologically accelerated decline in cognitive function in aging. To test this hypothesis, we collected serological and molecular markers of past and present Bartonella spp. infection in a sample of older people with and without MCI. Samples were processed in a blinded way to exclude laboratory biases. Contrary to our hypothesis, people with MCI were not more likely than people without MCI to have an active Bartonella spp. infection as measured by droplet digital PCR (p = 0.735) and quantitative PCR (p = 1). In addition, there was no significant difference in positive serological results between cases and controls (p = 0.461). Overall, higher-than-expected active Bartonella spp. infection (37% by ddPCR) and seroreactivity (71% by indirect fluorescent antibody assay) were found in people without MCI. Conclusions require caution, as our study was limited by the small number of cases with MCI. Overall, our results identified a higher than previously recognized rate of exposure and infection with Bartonella spp. in this older study population but does not support a specific role for such infection in MCI.

Biomimetic engineering of a neuroinflammation-targeted MOF nanozyme scaffolded with photo-trigger released CO for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is one of the most fatal and irreversible neurodegenerative diseases, which causes a huge emotional and financial burden on families and society. Despite the progress made with recent clinical use of inhibitors of acetylcholinesterase and amyloid-β (Aβ) antibodies, the curative effects of AD treatment remain unsatisfactory, which is probably due to the complexity of pathogenesis and the multiplicity of therapeutic targets. Thus, modulating complex pathological networks could be an alternative approach to treat AD. Here, a neutrophil membrane-coated MOF nanozyme (denoted as Neu-MOF/Fla) is biomimetically engineered to disturb the malignant Aβ deposition-inflammation cycle and ameliorate the pathological network for effective AD treatment. Neu-MOF/Fla could recognize the pathological inflammatory signals of AD, and deliver the photo-triggered anti-inflammatory CO and MOF based hydrolytic nanozymes to the lesion area of the brain in a spontaneous manner. Based on the in vitro and in vivo studies, Neu-MOF/Fla significantly suppresses neuroinflammation, mitigates the Aβ burden, beneficially modulates the pro-inflammatory microglial phenotypes and improves the cognitive defects of AD mice models. Our work presents a good example for developing biomimetic multifunctional nanotherapeutics against AD by means of amelioration of multiple symptoms and improvement of cognitive defects.

Leukotriene signaling in neurodegeneration: implications for treatment strategies

Leukotrienes (LTs) are a group of substances that cause inflammation. They are produced by the enzyme 5-lipoxygenase (5-LOX) from arachidonic acid. Cysteinyl LTs are a group of lipid molecules that have a prominent role in inflammatory signaling in the allergic diseases. Although they are traditionally known for their role in allergic disease, current advancements in bio-medical research have shed light on the involvement of these inflammatory mediators in diseases such as in the inflammation related to central nervous system (CNS) disorders. Among the CNS diseases, LTs, along with 5-LOX and their receptors, have been shown to be associated with multiple sclerosis (MS), Alzheimer's disease (AD), and Parkinson's disease (PD). Through a comprehensive review of current research and experimentation, this investigation provides an insight on the biosynthesis, receptors, and biological effects of LTs in the body. Furthermore, implications of leukotriene signaling in CNS and its intricate role in neurodegeneration are also studied. Through the revelation of these insights, our aim is to establish a foundation for the development of enhanced and focused therapeutic approaches in the continuous endeavor to combat neurodegeneration. Furthermore, the pharmacological inhibition of leukotriene signaling with selective inhibitors offers promising prospects for future interventions and treatments for neurodegenerative diseases.

A review of the roles of pathogens in Alzheimer's disease

Alzheimer's disease (AD) is one of the leading causes of dementia and is characterized by memory loss, mental and behavioral abnormalities, and impaired ability to perform daily activities. Even as a global disease that threatens human health, effective treatments to slow the progression of AD have not been found, despite intensive research and significant investment. In recent years, the role of infections in the etiology of AD has sparked intense debate. Pathogens invade the central nervous system through a damaged blood-brain barrier or nerve trunk and disrupt the neuronal structure and function as well as homeostasis of the brain microenvironment through a series of molecular biological events. In this review, we summarize the various pathogens involved in AD pathology, discuss potential interactions between pathogens and AD, and provide an overview of the promising future of anti-pathogenic therapies for AD.

Blood Astrocyte Biomarkers in Alzheimer Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Neuroinflammation, particularly early astrocyte reactivity, is a significant driver of Alzheimer disease (AD) pathogenesis. It is unclear how the levels of astrocyte biomarkers change in patients across the AD continuum and which best reflect AD-related change. We performed a systematic review and meta-analysis of 3 blood astrocyte biomarkers (glial fibrillary acidic protein [GFAP], chitinase-3-like protein 1 [YKL-40], and S100B) in patients clinically diagnosed with AD.

METHODS

MEDLINE and Web of Science were searched on March 23, 2023, without restrictions on language, time, or study design, for studies reporting blood levels of the astrocyte biomarkers GFAP, YKL-40, or S100B in patients on the AD continuum (including those with mild cognitive impairment [MCI] and dementia) and a cognitively unimpaired (CU) control population. AD diagnosis was based on established diagnostic criteria and/or comprehensive multidisciplinary clinical consensus. Studies reporting indirect biomarker measures (e.g., levels of biomarker autoantibodies) were excluded. Risk of bias assessment was performed using the revised Quality Assessment of Diagnostic Accuracy Studies tool. Pooled effect sizes were determined using the Hedge g method with a random-effects model. The review was prospectively registered on PROSPERO (registration number CRD42023458305).

RESULTS

The search identified 1,186 studies; 36 met inclusion criteria (AD continuum n = 3,366, CU n = 4,115). No study was assessed to have a high risk of bias. Compared with CU individuals, patients on the AD continuum had higher GFAP and YKL-40 levels (GFAP effect size 1.15, 95% CI 0.94-1.36, p < 0.0001; YKL-40 effect size 0.38, 95% CI 0.28-0.49, p < 0.0001). Both biomarkers were elevated in more advanced clinical stages of the disease (i.e., in AD dementia compared with MCI due to AD: GFAP effect size 0.48, 95% CI 0.19-0.76, p = 0.0009; YKL-40 effect size 0.34, 95% CI 0.10-0.57, p = 0.0048). No significant differences in blood S100B levels were identified.

DISCUSSION

We demonstrated significant elevations in blood GFAP and YKL-40 levels in patients on the AD continuum compared with CU individuals. Furthermore, within the AD clinical spectrum, significant elevation correlated with more advanced disease stage. Our findings suggest that both biomarkers reflect AD-related pathology. Our findings are limited by the lack of cultural and linguistic diversity in the study populations meta-analyzed. Future meta-analyses using a biomarker-defined AD population are warranted.

Danggui Shaoyao San and disassembled prescription: neuroprotective effects via AMPK/mTOR-mediated autophagy in mice

BACKGROUND

Danggui Shaoyao San (DSS), a frequently prescribed Chinese medicine formula, has demonstrated clinical efficacy in the treatment of Alzheimer's disease (AD). This study aims to explore the differences in therapeutic effects of DSS and its disassembled prescriptions, Suangan (SG) and Xingan (XG), in treating Alzheimer's Disease and the mechanism of DSS recovering autophagy in AD.

METHODS

A network pharmacology strategy was employed to delineate the bioactive constituents, associated targets, and regulatory mechanisms of DSS in AD, encompassing in silico target forecasting, the generation and scrutiny of PPI networks, alongside GO and KEGG-based pathway elucidation. An AD mouse model, induced by intracerebroventricular injection of Aβ1-42, was used to evaluate the therapeutic effects of DSS and its disassembled prescriptions on AD. Cognitive function was evaluated using the Morris water maze. Expression levels of inflammatory cytokines were quantified via RT-qPCR and ELISA. Western blotting was used to detect the expression of proteins related to AD pathological markers and the AMPK/mTOR signaling pathway.

RESULTS

50 active compounds and 718 HUB genes were screened from relevant databases and literature. KEGG and GO analyses indicated that DSS's potential mechanisms against AD involved the AMPK/mTOR signaling pathway and mitophagy. In vivo animal model, the results demonstrated that DSS, SG, and XG treatments improved cognitive function and ameliorated neuroinflammation in mice. Additionally, they alleviated the pathological changes of neuronal cells. These treatments also increased the protein level of PSD-95, and decreased levels of APP and p-Tau. Among them, DSS exhibited the best efficacy. Furthermore, DSS, SG, and XG upregulated the expression of LC3, Beclin1, and p-AMPK, while decreasing the expression of P62 and p-mTOR.

CONCLUSIONS

DSS, SG, and XG were found to ameliorate AD-related pathological symptoms in Aβ1-42-injected mice, likely through the AMPK/mTOR autophagy signaling pathway.

Kojic acid reverses LPS-induced neuroinflammation and cognitive impairment by regulating the TLR4/NF-κB signaling pathway

Intense neuroinflammation contributes to neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Lipopolysaccharides (LPSs) are an integral part of the cell wall of Gram-negative bacteria that act as pathogen-associated molecular patterns (PAMPs) and potentially activate the central nervous system's (CNS) immune system. Microglial cells are the local macrophages of the CNS and have the potential to induce and control neuroinflammation. This study aims to evaluate the anti-inflammatory and antioxidant effect of kojic acid against the toxic effects of LPSs, such as neuroinflammation-induced neurodegeneration and cognitive decline. The C57BL/6N mice were subjected to LPS injection for 2 weeks on alternate days (each mouse received 0.25 mg/kg/i.p. for a total of seven doses), and kojic acid was administered orally for 3 weeks consecutively (50 mg/kg/mouse, p. o). Bacterial endotoxins, or LPSs, are directly attached to TLR4 surface receptors of microglia and astrocytes and alter the cellular metabolism of immune cells. Intraperitoneal injection of LPS triggers the toll-like receptor 4 (TLR4), phospho-nuclear factor kappa B (p-NFκB), and phospho-c-Jun n-terminal kinase (p-JNK) protein expressions in the LPS-treated group, but these expression levels were significantly downregulated in the LPS + KA-treated mice brains. Prolong neuroinflammation leads to the generation of reactive oxygen species (ROS) followed by a decrease in nuclear factor erythroid-2-related factor 2 (Nrf2) and the enzyme hemeoxygenase 1 (HO-1) expression in LPS-subjected mouse brains. Interestingly, the levels of both Nrf-2 and HO-1 increased in the LPS + KA-treated mice group. In addition, kojic acid inhibited LPS-induced TNF-α and IL-1β production in mouse brains. These results indicated that kojic acid may suppress LPS-induced neuroinflammation and oxidative stress in male wild-type mice brains (in both the cortex and the hippocampus) by regulating the TLR4/NF-κB signaling pathway.

Signaling pathways in the treatment of Alzheimer's disease with acupuncture: a narrative review

BACKGROUND

To date, there is no effective treatment for Alzheimer's disease (AD), a progressive neurodegenerative disorder that is increasing in prevalence worldwide. The objective of this review was to summarize the core targets and signaling pathways involved in acupuncture treatment for AD.

METHODS

We reviewed numerous signaling pathways, including mammalian target of rapamycin (mTOR), phosphatidylinositol 3-kinase-protein kinase B (PI3 K/Akt), adenosine monophosphate-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK), nuclear factor (NF)-kB, p53, Wnt, nitric oxide (NO), Janus kinase / signal transducer and activator of transcription (JAK/ STAT), RhoA/ROCK (Rho-associated protein kinase) and Ca2+/ calmodulin-dependent protein kinase II (CaMKII) / cyclic adenosine monophosphate-response element-binding protein (CREB). The relevant data were obtained from PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI) and Wanfang databases.

RESULTS

In summary, the effects of acupuncture are mediated by multiple targets and pathways. Furthermore, acupuncture can improve pathological changes associated with AD (such as abnormal deposition of amyloid (A)β, tau hyperphosphorylation, synaptic dysfunction and neuronal apoptosis) through multiple signaling pathways.

CONCLUSION

Overall, our findings provide a basis for future research into the effects of acupuncture on AD.