Synaptic basis of Alzheimer's disease: Focus on synaptic amyloid beta, P-tau and mitochondria

The complex effects of miR-146a in the pathogenesis of Alzheimer's disease

Alzheimer's disease is a neurodegenerative disorder characterized by cognitive dysfunction and behavioral abnormalities. Neuroinflammatory plaques formed through the extracellular deposition of amyloid-β proteins, as well as neurofibrillary tangles formed by the intracellular deposition of hyperphosphorylated tau proteins, comprise two typical pathological features of Alzheimer's disease. Besides symptomatic treatment, there are no effective therapies for delaying Alzheimer's disease progression. MicroRNAs (miR) are small, non-coding RNAs that negatively regulate gene expression at the transcriptional and translational levels and play important roles in multiple physiological and pathological processes. Indeed, miR-146a, a NF-κB-regulated gene, has been extensively implicated in the development of Alzheimer's disease through several pathways. Research has demonstrated substantial dysregulation of miR-146a both during the initial phases and throughout the progression of this disorder. MiR-146a is believed to reduce amyloid-β deposition and tau protein hyperphosphorylation through the TLR/IRAK1/TRAF6 pathway; however, there is also evidence supporting that it can promote these processes through many other pathways, thus exacerbating the pathological manifestations of Alzheimer's disease. It has been widely reported that miR-146a mediates synaptic dysfunction, mitochondrial dysfunction, and neuronal death by targeting mRNAs encoding synaptic-related proteins, mitochondrial-related proteins, and membrane proteins, as well as other mRNAs. Regarding the impact on glial cells, miR-146a also exhibits differential effects. On one hand, it causes widespread and sustained inflammation through certain pathways, while on the other hand, it can reverse the polarization of astrocytes and microglia, alleviate neuroinflammation, and promote oligodendrocyte progenitor cell differentiation, thus maintaining the normal function of the myelin sheath and exerting a protective effect on neurons. In this review, we provide a comprehensive analysis of the involvement of miR-146a in the pathogenesis of Alzheimer's disease. We aim to elucidate the relationship between miR-146a and the key pathological manifestations of Alzheimer's disease, such as amyloid-β deposition, tau protein hyperphosphorylation, neuronal death, mitochondrial dysfunction, synaptic dysfunction, and glial cell dysfunction, as well as summarize recent relevant studies that have highlighted the potential of miR-146a as a clinical diagnostic marker and therapeutic target for Alzheimer's disease.

Review of the therapeutic effects of traditional Chinese medicine in sepsis-associated encephalopathy

ETHNOPHARMACOLOGICAL RELEVANCE

Sepsis-associated encephalopathy (SAE) is a common and serious complication during the acute phase of and after recovery from sepsis that seriously affects the quality of life of patients. Traditional Chinese medicine (TCM) has been widely used in modern medicine for neurological anomalies and has become a therapeutic tool for the treatment of SAE due to its multitargeting effects and low toxicity and side effects.

AIMS OF THE STUDY

This review provides insights into the pathogenesis and treatments of SAE, focusing on the clinical and experimental impacts of TCM formulations and their single components.

METHODS

Several known databases such as PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure (CNKI), and others were extensively explored with keywords and phrases such as "sepsis-associated encephalopathy", "traditional Chinese medicine", "herbs", "SAE", "sepsis", "cerebral" or other relevant terms to obtain literature between 2018 and 2024.

RESULTS

Extensive evidence indicated that TCM could decrease mortality and normalize neurological function in patients with sepsis; these effects might be associated with factors such as reduced oxidative stress and downregulated expression of inflammatory factors.

CONCLUSIONS

TCM shows notable efficacy in treating SAE, warranting deeper mechanistic studies to optimize its clinical application.

Corilagin improves cognitive impairment in APP/PS1 mice by reducing Aβ generation and enhancing synaptic plasticity

Alzheimer's disease (AD) is closely associated with the neurotoxic effects of amyloid-β (Aβ), leading to synaptic damage, neuronal loss and cognitive dysfunction. Previous in vitro studies have demonstrated the potential of corilagin to counteract Aβ-induced oxidative stress, inflammatory injury, and β-site amyloid precursor protein cleaving enzyme-1 (BACE1) activity in Aβ production. However, the in vivo protective effects of corilagin on Alzheimer's disease remain unexplored. The purpose of this study was to investigate the protective effects of corilagin on APP/PS1 mice and the underlying mechanisms. The cognitive function of the mice was assessed by step-through passive avoidance and Morris water maze tests. Nissl staining was used to evaluate neuronal damage in the hippocampus. ELISA and Western blotting analyses were used to determine the associated protein expression. Transmission electron microscopy was utilized to observe the synaptic ultrastructure of hippocampal neurons. Golgi staining was applied to assess dendritic morphology and dendritic spine density in hippocampal pyramidal neurons. Immunohistochemistry and Western blotting were performed to examine the expression of synaptic-associated proteins. The results showed that corilagin improves learning and memory in APP/PS1 mice, reduces hippocampal neuron damage, inhibits BACE1 and reduces Aβ generation. It also improves synaptic plasticity and the expression of synaptic-associated proteins. Corilagin effectively reduces Aβ generation by inhibiting BACE1, ultimately reducing neuronal loss and enhancing synaptic plasticity to improve synaptic transmission. This study sheds light on the potential therapeutic role of corilagin in Alzheimer's disease.

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.

Single-Nucleus Landscape of Glial Cells and Neurons in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disease with a projected significant increase in incidence. Therefore, this study analyzed single-nucleus AD data to provide a theoretical basis for the clinical development and treatment of AD. We downloaded AD-related monocyte data from the Gene Expression Omnibus database, annotated cells, compared cell abundance between groups, and investigated glial and neuronal cell biological processes and pathways through functional enrichment analysis. Furthermore, we constructed a global regulatory network for AD based on cell communication and ecological analyses. Our findings revealed increased abundance of Capping Protein Regulator And Myosin 1 linker 1 (CARMIL1)+ astrocytes (AST), Immunoglobulin Superfamily Member 21 (IGSF21)+ microglia (MIC), SRY-Box Transcription Factor 6 (SOX6)+ inhibitory neurons (InNeu), and laminin alpha-2 chain (LAMA2)+ oligodendrocytes (OLI) cell subgroups in tissues of patients with AD, while prostaglandin D2 synthase (PTGDS)+ AST, Src Family Tyrosine Kinase (FYN)+ MIC, and Proteolipid Protein 1 (PLP1)+ InNeu subgroups specifically decreased. We found that the cell phenotype of patients with AD shifted from a simpler to a more complex state compared to the control group. Cell communication analysis revealed strong communication between MIC and NEU. Furthermore, AST, MIC, NEU, and OLI were involved in oxidative stress- and inflammation-related pathways, potentially contributing to disease development. This study provides a theoretical basis for further exploring the specific mechanisms underlying AD.

MicroRNA-455-3P as a peripheral biomarker and therapeutic target for mild cognitive impairment and Alzheimer's disease

MicroRNAs are small non-coding RNAs evolutionary conserved molecules. They regulate cellular processes, including RNA silencing, post-translational gene expression and neurodegeneration. MicroRNAs are involved with human diseases such as cancer, Alzheimer's disease (AD) and others. Interestingly, cerebrospinal fluids (CSF) and the blood of AD patients have altered expressions of many RNAs, which may serve as potential peripheral biomarkers. The intensive investigation from our lab revealed that microRNA-455-3 P (miR-455-3p) is a strong candidate as a potential biomarker and therapeutic target for AD. Several genes implicated in the pathogenesis of AD are directly targeted by miR-455-3p. Several years of our lab research revealed that miR-455-3p regulates important physiological processes associated with AD, such as the processing of the amyloid precursor protein (APP), TGF-β signaling, the regulation of oxidative stress, mitochondrial biogenesis, and synaptic damages. The expression of miR-455-3p in mild cognitive impaired subjects and AD patients pointed out its involvement in AD progression. Recently, our lab generated both transgenic and knockout mice for miR-455-3p. Interestingly miR-455-3p transgenic mice showed superior cognitive learning, improved memory and extended lifespan compared to age matched wild-type mice, whereas miR-455-3-p knockout mice showed cognitive decline and reduced lifespan. Information derived from mouse models further demonstrated the advantageous impact of miR-455-3p on dendritic growth, synaptogenesis, and mitochondrial biogenesis in preventing the onset and progression of AD. The identification of miR-455-3p as a biomarker was suggested by its presence in postmortem AD brains, B-lymphocytes, and fibroblasts. Our hypothesis that miR-455-3p could be a peripheral biomarker and therapeutic target for AD.

Electroacupuncture activates AMPKα1 to improve learning and memory in the APP/PS1 mouse model of early Alzheimer's disease by regulating hippocampal mitochondrial dynamics

OBJECTIVE

Studies have shown that electroacupuncture (EA) can alleviate cognitive impairments from Alzheimer's disease (AD) by regulating the expression of adenosine monophosphate-activated protein kinase (AMPK), but the specific mechanism involved remains to be elucidated. Therefore, this study explores the potential mechanism by which EA improves cognitive function from the perspective of mitochondrial dynamics.

METHODS

The four-month-old transgenic mice with amyloid precursor protein (APP)/presenilin 1 (PS1) and AMPKα1-subunit conditional knockout (AMPKα1-cKO) were used for experiments. To evaluate the effects of EA treatment on cognitive function, the T-maze and Morris water maze were used. In addition, chemical exchange saturation transfer, thioflavin staining, transmission electron microscopy, mitochondrial membrane potential, and Western blotting were used to examine the potential mechanisms underlying the effects of EA on APP/PS1 mice.

RESULTS

Both APP/PS1 mice and AMPKα1-cKO mice exhibited dysfunction in mitochondrial dynamics accompanied by learning and memory impairment. Inactivation of the AMPK/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) pathway increased pathological amyloid-β (Aβ) deposition and aggravated the dysfunction in mitochondrial dynamics. In addition, EA rescued learning and memory deficits in APP/PS1 mice by activating the AMPK/PGC-1α pathway, specifically by reducing pathological Aβ deposition, normalizing energy metabolism, protecting the structure and function of mitochondria, increasing the levels of mitochondrial fusion proteins, and downregulating the expression of fission proteins. However, the therapeutic effect of EA on cognition in APP/PS1 mice was hindered by AMPKα1 knockout.

CONCLUSION

The regulation of hippocampal mitochondrial dynamics and reduction in Aβ deposition via the AMPK/PGC-1α pathway are critical for the ability of EA to ameliorate cognitive impairment in APP/PS1 mice. Please cite this article as: Jia WW, Lin HW, Yang MG, Dai YL, Ding YY, Xu WS, Wang SN, Cao YJ, Liang SX, Wang ZF, Chen C, Liu WL. Electroacupuncture activates AMPKα1 to improve learning and memory in the APP/PS1 mouse model of early Alzheimer's disease by regulating hippocampal mitochondrial dynamics. J Integr Med. 2024; Epub ahead of print.

Excitotoxicity, Oxytosis/Ferroptosis, and Neurodegeneration: Emerging Insights into Mitochondrial Mechanisms

Mitochondrial dysfunction plays a pivotal role in the development of age-related diseases, particularly neurodegenerative disorders. The etiology of mitochondrial dysfunction involves a multitude of factors that remain elusive. This review centers on elucidating the role(s) of excitotoxicity, oxytosis/ferroptosis and neurodegeneration within the context of mitochondrial bioenergetics, biogenesis, mitophagy and oxidative stress and explores their intricate interplay in the pathogenesis of neurodegenerative diseases. The effective coordination of mitochondrial turnover processes, notably mitophagy and biogenesis, is assumed to be critically important for cellular resilience and longevity. However, the age-associated decrease in mitophagy impedes the elimination of dysfunctional mitochondria, consequently impairing mitochondrial biogenesis. This deleterious cascade results in the accumulation of damaged mitochondria and deterioration of cellular functions. Both excitotoxicity and oxytosis/ferroptosis have been demonstrated to contribute significantly to the pathophysiology of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's Disease (HD), Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS). Excitotoxicity, characterized by excessive glutamate signaling, initiates a cascade of events involving calcium dysregulation, energy depletion, and oxidative stress and is intricately linked to mitochondrial dysfunction. Furthermore, emerging concepts surrounding oxytosis/ferroptosis underscore the importance of iron-dependent lipid peroxidation and mitochondrial engagement in the pathogenesis of neurodegeneration. This review not only discusses the individual contributions of excitotoxicity and ferroptosis but also emphasizes their convergence with mitochondrial dysfunction, a key driver of neurodegenerative diseases. Understanding the intricate crosstalk between excitotoxicity, oxytosis/ferroptosis, and mitochondrial dysfunction holds potential to pave the way for mitochondrion-targeted therapeutic strategies. Such strategies, with a focus on bioenergetics, biogenesis, mitophagy, and oxidative stress, emerge as promising avenues for therapeutic intervention.

Mitochondria in Aging and Alzheimer's Disease: Focus on Mitophagy

Alzheimer's disease (AD) is characterized by the accumulation of amyloid β and phosphorylated τ protein aggregates in the brain, which leads to the loss of neurons. Under the microscope, the function of mitochondria is uniquely primed to play a pivotal role in neuronal cell survival, energy metabolism, and cell death. Research studies indicate that mitochondrial dysfunction, excessive oxidative damage, and defective mitophagy in neurons are early indicators of AD. This review article summarizes the latest development of mitochondria in AD: 1) disease mechanism pathways, 2) the importance of mitochondria in neuronal functions, 3) metabolic pathways and functions, 4) the link between mitochondrial dysfunction and mitophagy mechanisms in AD, and 5) the development of potential mitochondrial-targeted therapeutics and interventions to treat patients with AD.

Establishment of a novel cellular model for Alzheimer's disease in vitro studies

Alzheimer's disease (AD) is a neurodegenerative disease characterized by memory loss, cognitive impairment, and behavioral and psychological symptoms of dementia. The limited efficacy of drugs for the treatment of neurodegenerative diseases reflects their complex etiology and pathogenesis. A novel in vitro model may help to bridge the gap between existing preclinical animal models and human clinical trials, thus identifying promising therapeutic targets that can be explored in upcoming clinical trials. By assisting in the identification of the mechanism of action and potential dangers, in vitro testing can also shorten the time and expense of translation.

AIM

As a result of these factors, our objective is to develop a powerful and informative cellular model of AD within a short period of time. Through triggering the MAPK and NF-κβ signaling pathways with the aid of small chemical compounds (PAF C-16 and BetA), respectively, in mouse microglial (SIM-A9) and neuroblast Neuro-2a (N2a) cell lines.

RESULTS

PAF C-16, initiated an activation effect at a concentration of 3.12 nM to 25 nM in the SIM-A9 and N2a cell lines after 72 h. BetA, activated the NF-κβ pathway with a concentration of 12.5 nM to 25 nM in the SIM-A9 and N2a cell lines after 72 h. The combination of the activator chemicals provided suitable activation for MEK1/2-ERK and NF-κβ in more than three subcultures. Activators significantly initiate APP and MAPT gene expression, as well as the expression of proteins APP, β. Amyloid, tau, and p-tau. The activation of the targeted pathways leads to significant morphological changes.

CONCLUSION

We can infer that the MEK1/2-ERK and NF-κβ pathways, respectively, are directly activated by the PAF C-16 and BetA chemicals. The activation of MEK1/2-ERK pathway results in the activation of the APP gene, which in turn activates the β. Amyloid protein, which in turn results in plaque. Furthermore, NF-κβ activation results in the activation of the MAPT gene, which leads to Tau and p-Tau protein activation, which ultimately results in tangles. This can be put into practice in just three days, with a high level of activity and stability that is passed down to the next three generations (subculture), with significant morphological changes. In microglial and neuroblast cell lines, we were successful in creating a novel AD-cell model.

Role of astrocytes in Alzheimer's disease pathogenesis and the impact of exercise-induced remodeling

Alzheimer's disease (AD) is a prevalent and debilitating brain disorder that worsens progressively with age, characterized by cognitive decline and memory impairment. The accumulation of amyloid-beta (Aβ) leading to amyloid plaques and hyperphosphorylation of Tau, resulting in intracellular neurofibrillary tangles (NFTs), are primary pathological features of AD. Despite significant research investment and effort, therapies targeting Aβ and NFTs have proven limited in efficacy for treating or slowing AD progression. Consequently, there is a growing interest in non-invasive therapeutic strategies for AD prevention. Exercise, a low-cost and non-invasive intervention, has demonstrated promising neuroprotective potential in AD prevention. Astrocytes, among the most abundant glial cells in the brain, play essential roles in various physiological processes and are implicated in AD initiation and progression. Exercise delays pathological progression and mitigates cognitive dysfunction in AD by modulating astrocyte morphological and phenotypic changes and fostering crosstalk with other glial cells. This review aims to consolidate the current understanding of how exercise influences astrocyte dynamics in AD, with a focus on elucidating the molecular and cellular mechanisms underlying astrocyte remodeling. The review begins with an overview of the neuropathological changes observed in AD, followed by an examination of astrocyte dysfunction as a feature of the disease. Lastly, the review explores the potential therapeutic implications of exercise-induced astrocyte remodeling in the context of AD.

Systems genetics identifies methionine as a high risk factor for Alzheimer's disease

As a dietary strategy, methionine restriction has been reported to promote longevity and regulate metabolic disorders. However, the role and possible regulatory mechanisms underlying methionine in neurodegenerative diseases such as Alzheimer's disease (AD), remain unexplored. This study utilized the data from BXD recombinant inbred (RI) mice to establish a correlation between the AD phenotype in mice and methionine level. Gene enrichment analysis indicated that the genes associated with the concentration of methionine in the midbrain are involved in the dopaminergic synaptic signaling pathway. Protein interaction network analysis revealed that glycogen synthase kinase 3 beta (GSK-3β) was a key regulator of the dopaminergic synaptic pathway and its expression level was significantly correlated with the AD phenotype. Finally, in vitro experiments demonstrated that methionine deprivation could reduce the expression of Aβ and phosphorylated Tau, suggesting that lowering methionine levels in humans may be a preventive or therapeutic strategy for AD. In conclusion, our findings support that methionine is a high risk factor for AD. These findings predict potential regulatory network, theoretically supporting methionine restriction to prevent AD.

Progress in mitochondrial and omics studies in Alzheimer's disease research: from molecular mechanisms to therapeutic interventions

Alzheimer's disease (Alzheimer's disease, AD) is a progressive neurological disorder characterized by memory loss and cognitive impairment. It is characterized by the formation of tau protein neurofibrillary tangles and β-amyloid plaques. Recent studies have found that mitochondria in neuronal cells of AD patients exhibit various dysfunctions, including reduced numbers, ultrastructural changes, reduced enzyme activity, and abnormal kinetics. These abnormal mitochondria not only lead to the loss of normal neuronal cell function, but are also a major driver of AD progression. In this review, we will focus on the advances of mitochondria and their multi-omics in AD research, with particular emphasis on how mitochondrial dysfunction in AD drives disease progression. At the same time, we will focus on summarizing how mitochondrial genomics technologies have revealed specific details of these dysfunctions and how therapeutic strategies targeting mitochondria may provide new directions for future AD treatments. By delving into the key mechanisms of mitochondria in AD related to energy metabolism, altered kinetics, regulation of cell death, and dysregulation of calcium-ion homeostasis, and how mitochondrial multi-omics technologies can be utilized to provide us with a better understanding of these processes. In the future, mitochondria-centered therapeutic strategies will be a key idea in the treatment of AD.

Intranasal insulin treatment ameliorates spatial memory, muscular strength, and frailty deficits in 5xFAD mice

The 5xFAD mouse model shows age-related weight loss as well as cognitive and motor deficits. Metabolic dysregulation, especially impaired insulin signaling, is also present in AD. This study examined whether intranasal delivery of insulin (INI) at low (0.875 U) or high (1.750 U) doses would ameliorate these deficits compared to saline in 10-month-old female 5xFAD and B6SJL wildtype (WT) mice. INI increased forelimb grip strength in the wire hang test in 5xFAD mice in a dose-dependent manner but did not improve the performance of 5xFAD mice on the balance beam. High INI doses reduced frailty scores in 5xFAD mice and improved spatial memory in both acquisition and reversal probe trials in the Morris water maze. INI increased swim speed in 5xFAD mice but had no effect on object recognition memory or working memory in the spontaneous alternation task, nor did it improve memory in the contextual or cued fear memory tasks. High doses of insulin increased the liver, spleen, and kidney weights and reduced brown adipose tissue weights. P-Akt signaling in the hippocampus was increased by insulin in a dose-dependent manner. Altogether, INI increased strength, reduced frailty scores, and improved visual spatial memory. Hypoglycemia was not present after INI, however alterations in tissue and organ weights were present. These results are novel and important as they indicate that intra-nasal insulin can reverse cognitive, motor and frailty deficits found in this mouse model of AD.

Regulatory roles of microRNAs in modulating mitochondrial dynamics, amyloid beta fibrillation, microglial activation, and cholinergic signaling: Implications for alzheimer's disease pathogenesis

Alzheimer's Disease (AD) remains a formidable challenge due to its complex pathology, notably involving mitochondrial dysfunction and dysregulated microRNA (miRNA) signaling. This study delves into the underexplored realm of miRNAs' impact on mitochondrial dynamics and their interplay with amyloid-beta (Aβ) aggregation and tau pathology in AD. Addressing identified gaps, our research utilizes advanced molecular techniques and AD models, alongside patient miRNA profiles, to uncover miRNAs pivotal in mitochondrial regulation. We illuminate novel miRNAs influencing mitochondrial dynamics, Aβ, and tau, offering insights into their mechanistic roles in AD progression. Our findings not only enhance understanding of AD's molecular underpinnings but also spotlight miRNAs as promising therapeutic targets. By elucidating miRNAs' roles in mitochondrial dysfunction and their interactions with hallmark AD pathologies, our work proposes innovative strategies for AD therapy, aiming to mitigate disease progression through targeted miRNA modulation. This contribution marks a significant step toward novel AD treatments, emphasizing the potential of miRNAs in addressing this complex disease.

Historical review: The golden age of the Golgi method in human neuropathology

Golgi methods were used to study human neuropathology in the 1970s, 1980s, and 1990s of the last century. Although a relatively small number of laboratories applied these methods, their impact was crucial by increasing knowledge about: (1) the morphology, orientation, and localization of neurons in human cerebral and cerebellar malformations and ganglionic tumors, and (2) the presence of abnormal structures including large and thin spines (spine dysgenesis) in several disorders linked to mental retardation, focal enlargements of the axon hillock and dendrites (meganeurites) in neuronal storage diseases, growth cone-like appendages in Alzheimer disease, as well as abnormal structures in other dementias. Although there were initial concerns about their reliability, reduced dendritic branches and dendritic spines were identified as common alterations in mental retardation, dementia, and other pathological conditions. Similar observations in appropriate experimental models have supported many abnormalities that were first identified using Golgi methods in human material. Moreover, electron microscopy, immunohistochemistry, fluorescent tracers, and combined methods have proven the accuracy of pioneering observations uniquely visualized as 3D images of fully stained individual neurons. Although Golgi methods had their golden age many years ago, these methods may still be useful complementary tools in human neuropathology.

Potential Application of MicroRNAs and Some Other Molecular Biomarkers in Alzheimer's Disease

Alzheimer's disease (AD) is the world's most common neurodegenerative disease, expected to affect up to one-third of the elderly population in the near future. Among the major challenges in combating AD are the inability to reverse the damage caused by the disease, expensive diagnostic tools, and the lack of specific markers for the early detection of AD. This paper highlights promising research directions for molecular markers in AD diagnosis, including the diagnostic potential of microRNAs. The latest molecular methods for diagnosing AD are discussed, with particular emphasis on diagnostic techniques prior to the appearance of full AD symptoms and markers detectable in human body fluids. A collection of recent studies demonstrates the promising potential of molecular methods in AD diagnosis, using miRNAs as biomarkers. Up- or downregulation in neurodegenerative diseases may not only provide a new diagnostic tool but also serve as a marker for differentiating neurodegenerative diseases. However, further research in this direction is needed.

P2X7 Receptor: an Emerging Target in Alzheimer's Disease

Alzheimer's disease (AD) is a major cause of age-related dementia, which is becoming a global health crisis. However, the pathogenesis and etiology of AD are still not fully understood. And there are no valid treatment methods or precise diagnostic tools for AD. There is increasing evidence that P2X7R expression is upregulated in AD and is involved in multiple related pathological processes such as Aβ plaques, neurogenic fiber tangles, oxidative stress, and chronic neuroinflammation. This suggests that P2X7R may be a key player in the development of AD. P2X7R is a member of the ligand-gated purinergic receptor (P2X) family. It has received attention in neuroscience due to its role in a wide range of aging and age-related neurological disorders. In this review, we summarize current information on the roles of P2X7R in AD and suggest potential pharmacological interventions to slow down AD progression.

Latest advances and clinical application prospects of resveratrol therapy for neurocognitive disorders

Neurocognitive disorders, such as Alzheimer's disease, vascular dementia, and postoperative cognitive dysfunction, are non-psychiatric brain syndromes in which a significant decline in cognitive function causes great trauma to the mental status of the patient. The lack of effective treatments for neurocognitive disorders imposes a considerable burden on society, including a substantial economic impact. Over the past few decades, the identification of resveratrol, a natural plant compound, has provided researchers with an opportunity to formulate novel strategies for the treatment of neurocognitive disorders. This is because resveratrol effectively protects the brain of those with neurocognitive disorders by targeting some mechanisms such as inflammation and oxidative stress. This article reviews the status of recent research investigating the use of resveratrol for the treatment of different neurocognitive disorders. By examining the possible mechanisms of action of resveratrol and the shared mechanisms of different neurocognitive disorders, treatments for neurocognitive disorders may be further clarified.

Targeting SIK3 to modulate hippocampal synaptic plasticity and cognitive function by regulating the transcription of HDAC4 in a mouse model of Alzheimer's disease

Cognitive deterioration and memory decline associated with the progression of Alzheimer's disease (AD) primarily results from synaptic failure. However, current understanding of the upstream regulatory mechanisms controlling synaptic plasticity remains limited. Salt-inducible kinase 3 (SIK3) is central to the signal pathway and is involved in neuronal regulation of sleep duration in mice. We speculated that the SIK3 cascade signaling pathway might contribute to the pathogenesis of AD. Thus, the present study employed AD transgenic mouse models, Morris Water Maze, virus-mediated gene transfer, electrophysiology, co-immunoprecipitation, western blotting, quantitative polymerase chain reaction, immunofluorescence, ChIP-qPCR, Golgi-Cox staining and dendritic spine analysis to investigate this connection. Our results revealed that SIK3 mRNA/protein expression was significantly reduced in middle-aged AD transgenic mouse models and AD patients. Conditional deletion of SIK3 gene in dorsal hippocampal neurons of 5×FAD mice further accelerated cognitive deterioration and impaired synaptic plasticity. In hippocampal neuronal cultures, SIK3 formed a complex with HDAC4, directly phosphorylated HDAC4 and regulated its nuclear cytoplasmic shuttle. Overexpression of SIK3 could facilitate the expression of synaptic plasticity-related genes by directly repressing mef2c or involving the recruitment of histone deacetylase to promoter regions of target genes through regulation of p-HDAC4, and vice versa. Moreover, up-regulation of SLP-S, the truncated fragment of SIK3, in dorsal hippocampal neurons, restored the synaptic plasticity and alleviates the cognitive impairment in 5×FAD mice. Collectively, these findings revealed a novel and important role of SIK3-HDAC4 regulation of synaptic plasticity and propose a new target for therapeutic approaches of cognitive deficits associated with AD.

Cross-Talking Pathways of Rapidly Accelerated Fibrosarcoma-1 (RAF-1) in Alzheimer's Disease

Alzheimer's disease (AD) becomes one of the main global burden diseases with the aging population. This study was to investigate the potential molecular mechanisms of rapidly accelerated fibrosarcoma-1 (RAF-1) in AD through bioinformatics analysis. Differential gene expression analysis was performed in GSE132903 dataset. We used weight gene correlation network analysis (WGCNA) to evaluate the relations among co-expression modules and construct global regulatory network. Cross-talking pathways of RAF-1 in AD were identified by functional enrichment analysis. Totally, 2700 differentially expressed genes (DEGs) were selected between AD versus non-dementia control and RAF-1-high versus low group. Among them, DEGs in turquoise module strongly associated with AD and high expression of RAF-1 were enriched in vascular endothelial growth factor (VEGF), neurotrophin, mitogen-activated protein kinase (MAPK) signaling pathway, oxidative phosphorylation, GABAergic synapse, and axon guidance. Moreover, cross-talking pathways of RAF-1, including MAPK, VEGF, neurotrophin signaling pathways, and axon guidance, were identified by global regulatory network. The performance evaluation of AUC was 84.2%. The gene set enrichment analysis (GSEA) indicated that oxidative phosphorylation and synapse-related biological processes were enriched in RAF-1-high and AD group. Our findings strengthened the potential roles of high RAF-1 level in AD pathogenesis, which were mediated by MAPK, VEGF, neurotrophin signaling pathways, and axon guidance.

Potential value of serum prealbumin and serum albumin in the identification of postoperative delirium in patients undergoing knee/hip replacement: an observational study and internal validation study

Background

Postoperative delirium (POD) is a common postoperative neurological complication that can lead to a variety of postoperative complications. At present, the pathogenesis of POD is unclear. This study aims to explore the relationship between serum prealbumin and serum albumin and POD and whether serum prealbumin and serum albumin influence POD through POD core pathology.

Objective

We enrolled 500 Chinese Han patients between September 2020 to January 2023. We analyzed the risk and protective factors of POD using the multivariate logistic regression. We also assessed the predictive power of serum prealbumin, serum albumin, and both in combination with CSF POD biomarkers. We used Stata MP16.0. to examine whether the association between serum prealbumin and serum albumin and POD was mediated by CSF POD biomarkers, and conducted an internal validation study to verify the accuracy of the combination of serum prealbumin + serum albumin + CSF POD biomarkers for predicting POD. The model was visualized using ROC curve and decision curve analysis (DCA). DynNom and Shiny packages were used to create an online calculator. Ten patients who had POD occurring from February 2023 to October 2023 were selected for internal verification.

Results

Finally, a total of 364 patients were included in our study. Levels of serum prealbumin, serum albumin in the POD group were lower than those in the NPOD group. The lever of serum prealbumin, serum albumin were protective factors for POD. The relationship between serum prealbumin, serum albumin and POD was partially mediated by T-tau (12.28%) and P-tau (20.61%). The model combining serum prealbumin and serum albumin and POD biomarkers exhibited a relatively better discriminatory ability to predict POD. DCA also showed that the combination of serum prealbumin and serum albumin and POD biomarkers brought high predictive benefits to patients. The dynamic online calculator can accurately predict the occurrence of POD in the internal validation study.

Conclusion

Preoperative low serum prealbumin and serum albumin levels were the preoperative risk factors for POD, which is partly mediated by T-tau and P-tau. The model combining serum prealbumin and serum albumin and CSF POD biomarkers can accurately predict the occurrence of POD.

Clinical trial registration

http://www.clinicaltrials.gov, identifier ChiCTR2000033439.

Data-driven Stochastic Model for Quantifying the Interplay Between Amyloid-beta and Calcium Levels in Alzheimer's Disease

The abnormal aggregation of extracellular amyloid-β ( A β ) in senile plaques resulting in calcium C a + 2 dyshomeostasis is one of the primary symptoms of Alzheimer's disease (AD). Significant research efforts have been devoted in the past to better understand the underlying molecular mechanisms driving A β deposition and C a + 2 dysregulation. Importantly, synaptic impairments, neuronal loss, and cognitive failure in AD patients are all related to the buildup of intraneuronal A β accumulation. Moreover, increasing evidence show a feed-forward loop between A β and C a + 2 levels, i.e. A β disrupts neuronal C a + 2 levels, which in turn affects the formation of A β . To better understand this interaction, we report a novel stochastic model where we analyze the positive feedback loop between A β and C a + 2 using ADNI data. A good therapeutic treatment plan for AD requires precise predictions. Stochastic models offer an appropriate framework for modelling AD since AD studies are observational in nature and involve regular patient visits. The etiology of AD may be described as a multi-state disease process using the approximate Bayesian computation method. So, utilizing ADNI data from 2-year visits for AD patients, we employ this method to investigate the interplay between A β and C a + 2 levels at various disease development phases. Incorporating the ADNI data in our physics-based Bayesian model, we discovered that a sufficiently large disruption in either A β metabolism or intracellular C a + 2 homeostasis causes the relative growth rate in both C a + 2 and A β , which corresponds to the development of AD. The imbalance of C a + 2 ions causes A β disorders by directly or indirectly affecting a variety of cellular and subcellular processes, and the altered homeostasis may worsen the abnormalities of C a + 2 ion transportation and deposition. This suggests that altering the C a + 2 balance or the balance between A β and C a + 2 by chelating them may be able to reduce disorders associated with AD and open up new research possibilities for AD therapy.

Somatostatin and the pathophysiology of Alzheimer's disease

Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap in the brain. Conversely, chronic stimulation of postsynaptic SST2/4 on gulutamatergic neurons by hyperactive SST-INs promotes intense Mitogen-Activated Protein Kinase (MAPK) p38 activity, leading to somatodendritic p-tau staining and apoptosis/neurodegeneration - in agreement with a near complete overlap between p38 and neurofibrillary tangles. This model is suitable to explain some of the principal risk factors and markers of AD progression, including mitochondrial dysfunction, APOE4 genotype, sex-dependent vulnerability, overactive glial cells, dystrophic neurites, synaptic/spine losses, inter alia. Finally, the model can also shed light on qualitative aspects of AD neuropsychology, especially within the domains of spatial and declarative (episodic, semantic) memory, under an overlying pattern of contextual indiscrimination, ensemble instability, interference and generalisation.

Up-regulation of GPR139 in the medial septum ameliorates cognitive impairment in two mouse models of Alzheimer's disease

G-protein coupled receptors (GPCRs) constitute the largest class of cell surface receptors and present prominent drug targets. GPR139 is an orphan GPCR detected in the septum of the brain. However, its roles in cognition are still unclear. Here we first established a mouse model of cognitive impairment by a single intracerebroventricular injection of aggregated amyloid-beta peptide 1-42 (Aβ1-42). RNA-sequencing data analysis showed that Aβ1-42 induced a significant decrease of GPR139 mRNA in the basal forebrain. Using GPR139 agonist JNJ-63533054 and behavioral tests, we found that GPR139 activation in the brain ameliorated Aβ1-42-induced cognitive impairment. Using western blot, TUNEL apoptosis and Golgi staining assays, we showed that GPR139 activation alleviated Aβ1-42-induced apoptosis and synaptotoxicity in the basal forebrain rather than prefrontal cortex and hippocampus. The further study identified that GPR139 was widely expressed in cholinergic neurons of the medial septum (MS). Using the overexpression virus and transgenic animal model, we showed that up-regulation of GPR139 in MS cholinergic neurons ameliorated cognitive impairment, apoptosis and synaptotoxicity in APP/PS1 transgenic mice. These findings reveal that GPR139 of MS cholinergic neurons could be a critical node in cognition and potentially provides insight into the pathogenesis of Alzheimer's disease.

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family in physiological and pathophysiological process and diseases

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family (PGC-1s), consisting of three members encompassing PGC-1α, PGC-1β, and PGC-1-related coactivator (PRC), was discovered more than a quarter-century ago. PGC-1s are essential coordinators of many vital cellular events, including mitochondrial functions, oxidative stress, endoplasmic reticulum homeostasis, and inflammation. Accumulating evidence has shown that PGC-1s are implicated in many diseases, such as cancers, cardiac diseases and cardiovascular diseases, neurological disorders, kidney diseases, motor system diseases, and metabolic disorders. Examining the upstream modulators and co-activated partners of PGC-1s and identifying critical biological events modulated by downstream effectors of PGC-1s contribute to the presentation of the elaborate network of PGC-1s. Furthermore, discussing the correlation between PGC-1s and diseases as well as summarizing the therapy targeting PGC-1s helps make individualized and precise intervention methods. In this review, we summarize basic knowledge regarding the PGC-1s family as well as the molecular regulatory network, discuss the physio-pathological roles of PGC-1s in human diseases, review the application of PGC-1s, including the diagnostic and prognostic value of PGC-1s and several therapies in pre-clinical studies, and suggest several directions for future investigations. This review presents the immense potential of targeting PGC-1s in the treatment of diseases and hopefully facilitates the promotion of PGC-1s as new therapeutic targets.

Identifying potential genetic epistasis implicated in Alzheimer's disease via detection of SNP-SNP interaction on quantitative trait CSF Aβ42

Although genome-wide association studies have identified multiple Alzheimer's disease (AD)-associated loci by selecting the main effects of individual single-nucleotide polymorphisms (SNPs), the interpretation of genetic variance in AD is limited. Based on the linear regression method, we performed genome-wide SNP-SNP interaction on cerebrospinal fluid Aβ42 to identify potential genetic epistasis implicated in AD, with age, gender, and diagnosis as covariates. A GPU-based method was used to address the computational challenges posed by the analysis of epistasis. We found 368 SNP pairs to be statistically significant, and highly significant SNP-SNP interactions were identified between the marginal main effects of SNP pairs, which explained a relatively high variance at the Aβ42 level. Our results replicated 100 previously reported AD-related genes and 5 gene-gene interaction pairs of the protein-protein interaction network. Our bioinformatics analyses provided preliminary evidence that the 5-overlapping gene-gene interaction pairs play critical roles in inducing synaptic loss and dysfunction, thereby leading to memory decline and cognitive impairment in AD-affected brains.

The role of RLIP76 in oxidative stress and mitochondrial dysfunction: Evidence based on autopsy brains from Alzheimer's disease patients

Several converging lines of evidence from our group support a potential role of RLIP76 (AKA Rlip) in neurodegenerative disorders, including Alzheimer's Disease (AD). However, the role of Rlip in Alzheimer's and other neurodegenerative diseases is not well understood. The purpose of the present study is to determine the role of Rlip in the brains of AD patients and control subjects. To achieve our goals, we used frozen tissues and formalin-fixed paraffin-embedded postmortem brains from AD patients of different Braak stages and age-matched control subjects. Our immunohistology and immunoblotting blotting analysis revealed that expression of Rlip protein gradually and significantly decreased (p = 0.0001) with AD progression, being lowest in Braak stage IV-V. Rlip was colocalized with Amyloid beta (Aβ) and phosphorylated tau (p-Tau) as observed by IHC staining and co-immunoprecipitation studies. Lipid peroxidation (4-HNE generation) and H2O2 production were significantly higher (p = 0.004 and 0.0001 respectively) in AD patients compared to controls, and this was accompanied by lower ATP production in AD (p = 0.0009). Oxidative DNA damage was measured by 8-Hydroxyguanosine (8-OHdG) in tissue lysates by ELISA and COMET assay. AD 8-OHdG levels were significantly higher (p = 0.0001) compared to controls. COMET assay was performed in brain cells, isolated from frozen postmortem samples. The control samples showed minimal DNA in comets representing few DNA strand breaks (<20 %), (score-0-1). However, the AD group showed an average of 50 % to 65 % of DNA in comet tails (score-4-5) indicating numerous DNA strand breaks. The difference between the two groups was significant (p = 0.001), as analyzed by Open Comet by ImageJ. Elevated DNA damage was further examined by western blot analysis for phosphorylated histone variant H2AX (γH2AX). Induction of γH2AX was very significant (p < 0.0001) and confirmed the presence of double-strand breaks in DNA. Overall, our results indicate an important role for Rlip in maintaining neuronal health and homeostasis by suppressing cellular oxidative stress and DNA damage. Based on our findings, we cautiously conclude that Rlip is a promising therapeutic target for Alzheimer's disease.

A drug cocktail of rapamycin, acarbose, and phenylbutyrate enhances resilience to features of early-stage Alzheimer's disease in aging mice

The process of aging is defined by the breakdown of critical maintenance pathways leading to an accumulation of damage and its associated phenotypes. Aging affects many systems and is considered the greatest risk factor for a number of diseases. Therefore, interventions aimed at establishing resilience to aging should delay or prevent the onset of age-related diseases. Recent studies have shown a three-drug cocktail consisting of rapamycin, acarbose, and phenylbutyrate delayed the onset of physical, cognitive, and biological aging phenotypes in old mice. To test the ability of this drug cocktail to impact Alzheimer's disease (AD), an adeno-associated-viral vector model of AD was created. Mice were fed the drug cocktail 2 months prior to injection and allowed 3 months for phenotypic development. Cognitive phenotypes were evaluated through a spatial navigation learning task. To quantify neuropathology, immunohistochemistry was performed for AD proteins and pathways of aging. Results suggested the drug cocktail was able to increase resilience to cognitive impairment, inflammation, and AD protein aggregation while enhancing autophagy and synaptic integrity, preferentially in female cohorts. In conclusion, female mice were more susceptible to the development of early stage AD neuropathology and learning impairment, and more responsive to treatment with the drug cocktail in comparison to male mice. Translationally, a model of AD where females are more susceptible would have greater value as women have a greater burden and incidence of disease compared to men. These findings validate past results and provide the rationale for further investigations into enhancing resilience to early-stage AD by enhancing resilience to aging.

Effect of Human Milk Oligosaccharides on Learning and Memory in Mice with Alzheimer's Disease

Alzheimer's disease (AD) is distinguished by cognitive dysfunction and neuroinflammation in the brain. 2'-Fucosyllactose (2'-FL) is a major human milk oligosaccharide (HMO) that is abundantly present in breast milk and has been demonstrated to exhibit immunomodulatory effects. However, the role of 2'-FL and HMO in gut microbiota modulation in relation to AD remains insufficiently investigated. This study aimed to elucidate the preventive effect of the 2'-FL and HMO impact of AD and the relevant mechanism involved. Here, the behavioral results showed that 2'-FL and HMO intervention decreased the expression of Tau phosphorylation and amyloid-β (Aβ), inhibited neuroinflammation, and restored cognitive impairment in AD mice. The metagenomic analysis proved that 2'-FL and HMO intervention restored the dysbiosis of the gut microbiota in AD. Notably, 2'-FL and HMO intervention significantly enhanced the relative abundance of Clostridium and Akkermansia. The metabolomics results showed that 2'-FL and HMO enhanced the oleoyl-l-carnitine metabolism as potential drivers. More importantly, the levels of oleoyl-l-carnitine were positively correlated with the abundances of Clostridium and Akkermansia. These results indicated that 2'-FL and HMO had therapeutic potential to prevent AD-induced cognitive impairment, which is of great significance for the treatment of AD.

Qingxin Kaiqiao Fang decreases Tau hyperphosphorylation in Alzheimer's disease via the PI3K/Akt/GSK3β pathway in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD) belongs to the category of "senile dementia" in traditional Chinese medicine. AD is associated with brain emptiness or collaterals blocked by phlegm-heat. "Fumanjian" from Jingyue Quanshu treats dementia by promoting qi circulation, alleviating depression, eliminating turbidity, cultivating positivity, and dispelling evil spirits. Qingxin Kaiqiao Fang (QKF), derived from Fumanjian, is effective in treating AD owing to previously mentioned clinical effects. Elucidating the mechanism(s) of action of QKF on AD associated with phlegm-heat may be beneficial for therapeutic management; however, further research is needed.

AIM OF THE STUDY

This study aimed to determine the role of the PI3K/Akt pathway in AD, especially the specific effector protein involved, and explore the efficacy of QKF in treating AD by modulating the PI3K/Akt signal.

MATERIALS AND METHODS

High-performance liquid chromatography-Q-orbitrap-mass spectrometry was used to analyze the chemical components of QKF. Subsequently, APP/PS1 double-transgenic mice were used for behavioral tests, and hematoxylin-eosin and Nissl staining were used to assess the neuroprotective and cognitive effects of QKF. Cerebrospinal fluid pharmacology was used in in vitro validation, and Aβ25-35 was used to induce PC12 cells to establish the AD cell model. Various methods, including immunohistochemistry, Western blotting, quantitative real-time polymerase chain reaction, morphological assay, cell counting kit-8(CCK-8) assay, and terminal deoxynucleotide transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)staining, were used to evaluate the effect of QKF on Tau hyperphosphorylation and anti-apoptosis. These methods also assessed the influence of QKF on the PI3K/Akt/GSK3β pathway involving the mRNA and protein expressions. Finally, the inhibitor - LY294002 was used for reverse validation.

RESULTS

We identified 295 chemical components in the water extract of QKF.QKF improved spatial cognition and learning memory in APP/PS1 mice, protected PC12 cell morphology, improved cell survival, reduced Aβ25-35-induced apoptosis, and inhibited the hyperphosphorylation of Tau protein via the PI3k/Akt/GSK3β signaling pathway. Furthermore, this protective effect of QKF was reduced by LY294002 in vitro.

CONCLUSIONS

QKF can improve spatial cognition, learning, and memory abilities in APP/PS1 mice and protect PC12 cells. Decreasing the Tau hyperphosphorylation in AD exhibits curative efficacy on AD via the PI3K/Akt/GSK3β pathway in vitro and in vivo.

The Compartmentalization of Amyloid-β in Idiopathic Normal Pressure Hydrocephalus Brain Biopsies

Background

Amyloid-β (Aβ) is one of the hallmark lesions of Alzheimer's disease (AD). During the disease process, Aβ undergoes biochemical changes, producing toxic Aβ variants, proposed to be detected within the neurons. Idiopathic normal pressure hydrocephalus (iNPH) causes cognitive impairment, gait, and urinary symptoms in elderly, that can be reversed by a ventriculo-peritoneal shunt. Majority of iNPH subjects display different Aβ variants in their brain biopsies, obtained during shunting.

Objective

To study the cellular compartmentalization of different Aβ variants in brain biopsies from iNPH subjects.

Methods

We studied the cellular localization of different proteoforms of Aβ using antibodies towards different amino acid sequences or post-translational modifications of Aβ, including clones 4G8, 6F/3D, unmodified- (7H3D6), pyroglutamylated- (N3pE), phosphorylated-(1E4E11) Aβ and Aβ protein precursor (AβPP), in brain biopsies from 3 iNPH subjects, using immunohistochemistry and light microscopy (LM), light microscopy on semi-thin sections (LMst), and electron microscopy (EM).

Results

In LM all Aβ variants were detected. In LMst and EM, the Aβ 4G8, 6F/3D, and the pyroglutamylated Aβ were detected. The AβPP was visualized by all methods. The Aβ labelling was located extracellularly with no specific signal within the intracellular compartment, whereas the AβPP was seen both intra- and extracellularly.

Conclusions

The Aβ markers displayed extracellular localization when visualized by three assessment techniques, reflecting the pathological extracellular accumulation of Aβ in the human brain. No intracellular Aβ pathology was seen. AβPP was visualized in intra- and extracellularly, which corresponds to the localization of the protein in the membranes of cells and organelles.

Gut microbiota-driven metabolic alterations reveal gut-brain communication in Alzheimer's disease model mice

The gut microbiota (GM) and its metabolites affect the host nervous system and are involved in the pathogeneses of various neurological diseases. However, the specific GM alterations under pathogenetic pressure and their contributions to the "microbiota - metabolite - brain axis" in Alzheimer's disease (AD) remain unclear. Here, we investigated the GM and the fecal, serum, cortical metabolomes in APP/PS1 and wild-type (WT) mice, revealing distinct hub bacteria in AD mice within scale-free GM networks shared by both groups. Moreover, we identified diverse peripheral - central metabolic landscapes between AD and WT mice that featured bile acids (e.g. deoxycholic and isodeoxycholic acid) and unsaturated fatty acids (e.g. 11Z-eicosenoic and palmitoleic acid). Machine-learning models revealed the relationships between the differential/hub bacteria and these metabolic signatures from the periphery to the brain. Notably, AD-enriched Dubosiella affected AD occurrence via cortical palmitoleic acid and vice versa. Considering the transgenic background of the AD mice, we propose that Dubosiella enrichment impedes AD progression via the synthesis of palmitoleic acid, which has protective properties against inflammation and metabolic disorders. We identified another association involving fecal deoxycholic acid-mediated interactions between the AD hub bacteria Erysipelatoclostridium and AD occurrence, which was corroborated by the correlation between deoxycholate levels and cognitive scores in humans. Overall, this study elucidated the GM network alterations, contributions of the GM to peripheral - central metabolic landscapes, and mediatory roles of metabolites between the GM and AD occurrence, thus revealing the critical roles of bacteria in AD pathogenesis and gut - brain communications under pathogenetic pressure.

Oxidative damage in neurodegeneration: roles in the pathogenesis and progression of Alzheimer disease

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particularly vulnerable to oxidative damage, mainly because of its unique lipid composition, resulting in an amplified cascade of redox reactions that target several cellular components/functions ultimately leading to neurodegeneration. The present review highlights the "OS hypothesis of AD," including amyloid beta-peptide-associated mechanisms, the role of lipid and protein oxidation unraveled by redox proteomics, and the antioxidant strategies that have been investigated to modulate the progression of AD. Collected studies from our groups and others have contributed to unraveling the close relationships between perturbation of redox homeostasis in the brain and AD neuropathology by elucidating redox-regulated events potentially involved in both the pathogenesis and progression of AD. However, the complexity of AD pathological mechanisms requires an in-depth understanding of several major intracellular pathways affecting redox homeostasis and relevant for brain functions. This understanding is crucial to developing pharmacological strategies targeting OS-mediated toxicity that may potentially contribute to slow AD progression as well as improve the quality of life of persons with this severe dementing disorder.

Urolithin A Inhibits Anterior Basolateral Amygdala to Ventral Hippocampal CA1 Circuit to Ameliorate Amyloid-β-Impaired Social Ability

Background

Anxiety and social withdrawal are highly prevalent among patients with Alzheimer's disease (AD). However, the neural circuit mechanisms underlying these symptoms remain elusive, and there is a need for effective prevention strategies.

Objective

This study aims to elucidate the neural circuitry mechanisms underlying social anxiety in AD.

Methods

We utilized 5xFAD mice and conducted a series of experiments including optogenetic manipulation, Tandem Mass Tag-labeled proteome analysis, behavioral assessments, and immunofluorescence staining.

Results

In 5xFAD mice, we observed significant amyloid-β (Aβ) accumulation in the anterior part of basolateral amygdala (aBLA). Behaviorally, 6-month-old 5xFAD mice displayed excessive social avoidance during social interaction. Concurrently, the pathway from aBLA to ventral hippocampal CA1 (vCA1) was significantly activated and exhibited a disorganized firing patterns during social interaction. By optogenetically inhibiting the aBLA-vCA1 pathway, we effectively improved the social ability of 5xFAD mice. In the presence of Aβ accumulation, we identified distinct changes in the protein network within the aBLA. Following one month of administration of Urolithin A (UA), we observed significant restoration of the abnormal protein network within the aBLA. UA treatment also attenuated the disorganized firings of the aBLA-vCA1 pathway, leading to an improvement in social ability.

Conclusions

The aBLA-vCA1 circuit is a vulnerable pathway in response to Aβ accumulation during the progression of AD and plays a crucial role in Aβ-induced social anxiety. Targeting the aBLA-vCA1 circuit and UA administration are both effective strategies for improving the Aβ-impaired social ability.

Utilities of Isolated Nerve Terminals in Ex Vivo Analyses of Protein Translation in (Patho)physiological Brain States: Focus on Alzheimer's Disease

Synapses are the cellular substrates of higher-order brain functions, and their dysfunction is an early and primary pathogenic mechanism across several neurological disorders. In particular, Alzheimer's disease (AD) is categorized by prodromal structural and functional synaptic deficits, prior to the advent of classical behavioral and pathological features. Recent research has shown that the development, maintenance, and plasticity of synapses depend on localized protein translation. Synaptosomes and synaptoneurosomes are biochemically isolated synaptic terminal preparations which have long been used to examine a variety of synaptic processes ex vivo in both healthy and pathological conditions. These ex vivo preparations preserve the mRNA species and the protein translational machinery. Hence, they are excellent in organello tools for the study of alterations in mRNA levels and protein translation in neuropathologies. Evaluation of synapse-specific basal and activity-driven de novo protein translation activity can be conveniently performed in synaptosomal/synaptoneurosomal preparations from both rodent and human brain tissue samples. This review gives a quick overview of the methods for isolating synaptosomes and synaptoneurosomes before discussing the studies that have utilized these preparations to study localized synapse-specific protein translation in (patho)physiological situations, with an emphasis on AD. While the review is not an exhaustive accumulation of all the studies evaluating synaptic protein translation using the synaptosomal model, the aim is to assemble the most relevant studies that have done so. The hope is to provide a suitable research platform to aid neuroscientists to utilize the synaptosomal/synaptoneurosomal models to evaluate the molecular mechanisms of synaptic dysfunction within the specific confines of mRNA localization and protein translation research.

Injection of exogenous amyloid-β oligomers aggravated cognitive deficits, and activated necroptosis, in APP23 transgenic mice

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by the loss of synapses and neurons in the brain, and the accumulation of amyloid plaques. Aβ oligomers (AβO) play a critical role in the pathogenesis of AD. Although there is increasing evidence to support the involvement of necroptosis in the pathogenesis of AD, the exact mechanism remains elusive. In the present study, we explored the effect of exogenous AβO injection on cell necroptosis and cognitive deficits in APP23 transgenic mice. We found that intrahippocampal injection of AβO accelerated the development of AD pathology and caused cognitive impairment in APP23 mice. Specifically, AβO injection significantly accelerated the accumulation of AβO and increased the expression level of phosphorylated-tau, and also induced necroptosis. Behavioral tests showed that AβO injection was associated with cognitive impairment. Furthermore, necroptosis induced by AβO injection occurred predominantly in microglia of the AD brain. We speculate that AβO increased necroptosis by activating microglia, resulting in cognitive deficits. Our results may aid in an understanding of the role played by AβO in AD from an alternative perspective and provide new ideas and evidence for necroptosis as a potential intervention and therapeutic target for AD.

Novel harmine derivatives as potent acetylcholinesterase and amyloid beta aggregation dual inhibitors for management of Alzheimer's disease

In this study, a series of potential ligands for the treatment of AD were synthesised and characterised as novel harmine derivatives modified at position 9 with benzyl piperazinyl. In vitro studies revealed that the majority of the derivatives exhibited moderate to potent inhibition against hAChE and Aβ1 - 42 aggregation. Notably, compounds 13 and 17d displayed potent drug - likeness and ADMET properties, demonstrating remarkable inhibitory activities towards AChE (IC50 = 58.76 nM and 89.38 nM, respectively) as well as Aβ aggregation (IC50 = 9.31 μM and 13.82 μM, respectively). More importantly, compounds 13 and 17d showed exceptional neuroprotective effects against Aβ1 - 42-induced SH - SY5Y damage, while maintaining low toxicity in SH - SY5Y cells. Further exploration of the mechanism through kinetic studies and molecular modelling confirmed that compound 13 could interact with both the CAS and the PAS of AChE. These findings suggested that harmine derivatives hold great potential as dual - targeted candidates for treating AD.

Bezafibrate confers neuroprotection in the 5xFAD mouse model of Alzheimer's disease

Mitochondrial dysfunction plays an important role in the pathogenesis of Alzheimer's disease (AD), the most common neurodegenerative disease. Prior studies suggested impaired mitochondrial biogenesis likely contributes to mitochondrial dysfunction in AD. Bezafibrate, a peroxisome proliferator-activated receptor (PPAR) pan-agonist, has been shown to enhance mitochondrial biogenesis and increase oxidative phosphorylation capacity. In the present study, we investigated whether bezafibrate could rescue mitochondrial dysfunction and other AD-related deficits in 5xFAD mice. Bezafibrate was well tolerated by 5xFAD mice. Indeed, it rescued the expression of key mitochondrial proteins as well as mitochondrial dynamics and function in the brain of 5xFAD mice. Importantly, bezafibrate treatment led to significant improvement of cognitive/memory function in 5xFAD mice accompanied by alleviation of amyloid pathology and neuronal loss as well as reduced oxidative stress and neuroinflammation. Overall, this study suggests that bezafibrate improves mitochondrial function, mitigates neuroinflammation and improves cognitive functions in 5xFAD mice, thus supporting the notion that enhancing mitochondrial biogenesis/function is a promising therapeutic strategy for AD.

Simulation of neuroplasticity in a CNN-based in-silico model of neurodegeneration of the visual system

The aim of this work was to enhance the biological feasibility of a deep convolutional neural network-based in-silico model of neurodegeneration of the visual system by equipping it with a mechanism to simulate neuroplasticity. Therefore, deep convolutional networks of multiple sizes were trained for object recognition tasks and progressively lesioned to simulate neurodegeneration of the visual cortex. More specifically, the injured parts of the network remained injured while we investigated how the added retraining steps were able to recover some of the model's object recognition baseline performance. The results showed with retraining, model object recognition abilities are subject to a smoother and more gradual decline with increasing injury levels than without retraining and, therefore, more similar to the longitudinal cognition impairments of patients diagnosed with Alzheimer's disease (AD). Moreover, with retraining, the injured model exhibits internal activation patterns similar to those of the healthy baseline model when compared to the injured model without retraining. Furthermore, we conducted this analysis on a network that had been extensively pruned, resulting in an optimized number of parameters or synapses. Our findings show that this network exhibited remarkably similar capability to recover task performance with decreasingly viable pathways through the network. In conclusion, adding a retraining step to the in-silico setup that simulates neuroplasticity improves the model's biological feasibility considerably and could prove valuable to test different rehabilitation approaches in-silico.

Evaluation and targeting of amyloid precursor protein (APP)/amyloid beta (Aβ) axis in amyloidogenic and non-amyloidogenic pathways: A time outside the tunnel

In Alzheimer disease (AD), amyloid precursor protein (APP) and production of amyloid beta (Aβ) which is generated by amyloidogenic pathway is implicated in neurotoxicity and neuronal cell deaths. However, physiological Aβ level is essential to improves neuronal survival, attenuates neuronal apoptosis and has neuroprotective effect. In addition, physiological APP level has neurotrophic effect on the central nervous system (CNS). APP has a critical role in the brain growth and development via activation of long-term potentiation (LTP) and acceleration of neurite outgrowth. Moreover, APP is cleaved by α secretase to form a neuroprotective soluble APP alpha (sAPPα) in non-amyloidogenic pathway. Consequently, this mini-review purposes to highlight the possible beneficial role of APP and Aβ. In addition, this mini-review discussed the modulation of APP processing and Aβ production.

Cyanidin-3-O-glucoside protects the brain and improves cognitive function in APPswe/PS1ΔE9 transgenic mice model

Cyanidin-3-O-glucoside (C3G) is a natural anthocyanin with antioxidant, anti-inflammatory, and antitumor properties. However, as the effects of C3G on the amyloidogenic pathway, autophagy, tau phosphorylation, neuronal cell death, and synaptic plasticity in Alzheimer's disease models have not been reported, we attempted to investigate the same in the brains of APPswe/PS1ΔE9 mice were analyzed. After oral administration of C3G (30 mg/kg/day) for 16 weeks, the cortical and hippocampal regions in the brains of APPswe/PS1ΔE9 mice were analyzed. C3G treatment reduced the levels of soluble and insoluble Aβ (Aβ40 and Aβ42) peptides and reduced the protein expression of the amyloid precursor protein, presenilin-1, and β-secretase in the cortical and hippocampal regions. And C3G treatment upregulated the expression of autophagy-related markers, LC3B-II, LAMP-1, TFEB, and PPAR-α and downregulated that of SQSTM1/p62, improving the autophagy of Aβ plaques and neurofibrillary tangles. In addition, C3G increased the protein expression of phosphorylated-AMPK/AMPK and Sirtuin 1 and decreased that of mitogen-activated protein kinases, such as phosphorylated-Akt/Akt and phosphorylated-ERK/ERK, thus demonstrating its neuroprotective effects. Furthermore, C3G regulated the PI3K/Akt/GSK3β signaling by upregulating phosphorylated-Akt/Akt and phosphorylated-GSK3β/GSK3β expression. C3G administration mitigated tau phosphorylation and improved synaptic function and plasticity by upregulating the expression of synapse-associated proteins synaptophysin and postsynaptic density protein-95. Although the potential of C3G in the APPswe/PS1ΔE9 mouse models has not yet been reported, oral administration of the C3G is shown to protect the brain and improve cognitive behavior.

Advances in the Study of the Pathology and Treatment of Alzheimer's Disease and Its Association with Periodontitis

Alzheimer's disease (AD) has become one of the leading causes of health problems in the elderly, and studying its causes and treatments remains a serious challenge for researchers worldwide. The two main pathological features of Alzheimer's disease are the extracellular deposition of β-amyloid (Aβ) to form senile plaques and the intracellular aggregation of hyperphosphorylated Tau protein to form neurofibrillary tangles (NFTs). Researchers have proposed several hypotheses to elucidate the pathogenesis of AD, but due to the complexity of the pathophysiologic factors involved in the development of AD, no effective drugs have been found to stop the progression of the disease. Currently, the mainstay drugs used to treat AD can only alleviate the patient's symptoms and do not have a therapeutic effect. As researchers explore interactions among diseases, much evidence suggests that there is a close link between periodontitis and AD, and that periodontal pathogenic bacteria can exacerbate Aβ deposition and Tau protein hyperphosphorylation through neuroinflammatory mechanisms, thereby advancing the pathogenesis of AD. This article reviews recent advances in the pathogenesis of AD, available therapeutic agents, the relevance of periodontitis to AD, and mechanisms of action.

Role of diet and exercise in aging, Alzheimer's disease, and other chronic diseases

Alzheimer's disease (AD) is a progressive neurodegenerative disease, characterized by memory loss and multiple cognitive impairments. Genetic mutations cause a small proportion (1-2%) of early-onset AD, with mutations in amyloid precursor protein (APP), presenilin 1 (PS1) and presenilin 2 (PS2). Major contributing factors of late-onset AD are ApoE4 genotype, traumatic brain injury, diabetes, obesity, hypertension, cardiovascular conditions, in addition to lifestyle factors, such as unhealthy diet and lack of physical exercise. Disease progression can be delayed and/or prevented to a greater extent by adopting healthy lifestyle with balanced and antioxidant enriched diet and daily exercise. The interaction and interplay of diet, exercise, age, and pharmacological interventions holds a crucial role in the progression, pathogenesis and management of AD and its comorbidities, including diabetes, obesity, hypertension and cardiovascular conditions. Antioxidant enriched diet contributes to brain health, glucose control, weight management, and cardiovascular well-being. Regular exercise removes toxins including free radicals and enhances insulin sensitivity, and supports cardiovascular function. In the current article, we discussed, the role of diet, and exercise in aging, AD and other conditions including diabetes, obesity, hypertension, cardiovascular conditions. This article also highlights the impact of medication, socioeconomic and lifestyle factors, and pharmacological interventions. These aspects were discussed in different races and ethnic groups in Texas, and the US.

Alzheimer's disease: an axonal injury disease?

Alzheimer's disease (AD) is the primary cause of dementia and is anticipated to impose a substantial economic burden in the future. Over a significant period, the widely accepted amyloid cascade hypothesis has guided research efforts, and the recent FDA approval of an anti- amyloid-beta (Aβ) protofibrils antibody, believed to decelerate AD progression, has further solidified its significance. However, the excessive emphasis placed on the amyloid cascade hypothesis has overshadowed the physiological nature of Aβ and tau proteins within axons. Axons, specialized neuronal structures, sustain damage during the early stages of AD, exerting a pivotal influence on disease progression. In this review, we present a comprehensive summary of the relationship between axonal damage and AD pathology, amalgamating the physiological roles of Aβ and tau proteins, along with the impact of AD risk genes such as APOE and TREM2. Furthermore, we underscore the exceptional significance of axonal damage in the context of AD.

Unveiling the Molecular Footprint: Proteome-Based Biomarkers for Alzheimer's Disease

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and memory loss. Early and accurate diagnosis of AD is crucial for implementing timely interventions and developing effective therapeutic strategies. Proteome-based biomarkers have emerged as promising tools for AD diagnosis and prognosis due to their ability to reflect disease-specific molecular alterations. There is of great significance for biomarkers in AD diagnosis and management. It emphasizes the limitations of existing diagnostic approaches and the need for reliable and accessible biomarkers. Proteomics, a field that comprehensively analyzes the entire protein complement of cells, tissues, or bio fluids, is presented as a powerful tool for identifying AD biomarkers. There is a diverse range of proteomic approaches employed in AD research, including mass spectrometry, two-dimensional gel electrophoresis, and protein microarrays. The challenges associated with identifying reliable biomarkers, such as sample heterogeneity and the dynamic nature of the disease. There are well-known proteins implicated in AD pathogenesis, such as amyloid-beta peptides, tau protein, Apo lipoprotein E, and clusterin, as well as inflammatory markers and complement proteins. Validation and clinical utility of proteome-based biomarkers are addressing the challenges involved in validation studies and the diagnostic accuracy of these biomarkers. There is great potential in monitoring disease progression and response to treatment, thereby aiding in personalized medicine approaches for AD patients. There is a great role for bioinformatics and data analysis in proteomics for AD biomarker research and the importance of data preprocessing, statistical analysis, pathway analysis, and integration of multi-omics data for a comprehensive understanding of AD pathophysiology. In conclusion, proteome-based biomarkers hold great promise in the field of AD research. They provide valuable insights into disease mechanisms, aid in early diagnosis, and facilitate personalized treatment strategies. However, further research and validation studies are necessary to harness the full potential of proteome-based biomarkers in clinical practice.

Roles of ApoE4 on the Pathogenesis in Alzheimer's Disease and the Potential Therapeutic Approaches

The Apolipoprotein E ε4 (ApoE ε4) allele, encoding ApoE4, is the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD). Emerging epidemiological evidence indicated that ApoE4 contributes to AD through influencing β-amyloid (Aβ) deposition and clearance. However, the molecular mechanisms of ApoE4 involved in AD pathogenesis remains unclear. Here, we introduced the structure and functions of ApoE isoforms, and then we reviewed the potential mechanisms of ApoE4 in the AD pathogenesis, including the effect of ApoE4 on Aβ pathology, and tau phosphorylation, oxidative stress; synaptic function, cholesterol transport, and mitochondrial dysfunction; sleep disturbances and cerebrovascular integrity in the AD brains. Furthermore, we discussed the available strategies for AD treatments that target to ApoE4. In general, this review overviews the potential roles of ApoE4 in the AD development and suggests some therapeutic approaches for AD. ApoE4 is genetic risk of AD. ApoE4 is involved in the AD pathogenesis. Aβ deposition, NFT, oxidative stress, abnormal cholesterol, mitochondrial dysfunction and neuroinflammation could be observed in the brains with ApoE4. Targeting the interaction of ApoE4 with the AD pathology is available strategy for AD treatments.

Rlip overexpression reduces oxidative stress and mitochondrial dysfunction in Alzheimer's disease: Mechanistic insights

Alzheimer's disease (AD) is a neurodegenerative disease that affects a large proportion of the aging population. RalBP1 (Rlip) is a stress-activated protein that plays a crucial role in oxidative stress and mitochondrial dysfunction in aging and neurodegenerative diseases but its precise role in the progression of AD is unclear. The purpose of our study is to understand the role of Rlip in the progression and pathogenesis of AD in mutant APP/amyloid beta (Aβ)-expressed mouse primary hippocampal (HT22) hippocampal neurons. In the current study, we used HT22 neurons that express mAPP, transfected with Rlip-cDNA and/or RNA silenced, and studied cell survival, mitochondrial respiration, mitochondrial function, immunoblotting & immunofluorescence analysis of synaptic and mitophagy protein's and colocalization of Rlip and mutant APP/Aβ proteins and mitochondrial length and number. We also assessed Rlip levels in autopsy brains from AD patients and control subjects. We found cell survival was decreased in mAPP-HT22 cells and RNA-silenced HT22 cells. However, cell survival was increased in Rlip-overexpressed mAPP-HT22 cells. Oxygen consumption rate (OCR) was decreased in mAPP-HT22 cells and RNA-silenced Rlip-HT22 cells. OCR was increased in Rlip-overexpressed in mAPP-HT22 cells. Mitochondrial function was defective in mAPP-HT22 cells and RNA silenced Rlip in HT22 cells, however, it was rescued in Rlip overexpressed mAPP-HT22 cells. Synaptic and mitophagy proteins were decreased in mAPP-HT22 cells, further reducing RNA-silenced Rlip-HT22 cells. However, these were increased in mAPP+Rlip-HT22 cells. Colocalization analysis revealed Rlip is colocalized with mAPP/Aβ. An increased number of mitochondria and decreased mitochondrial length were found in mAPP-HT22 cells. These were rescued in Rlip overexpressed mAPP-HT22 cells. Reduced Rlip levels were found in autopsy brains from AD patients. These observations strongly suggest that Rlip deficiency causes oxidative stress/mitochondrial dysfunction and Rlip overexpression reduced these defects.

Exosomes in multiple sclerosis and Alzheimer's disease - Adversary and ally

Neuroinflammation and the resulting neurodegeneration is a big challenge for the healthcare system, especially with the aging population. Neuroinflammation can result from a variety of insults to the central nervous system leading to an interplay between immune and brain cells that sustains chronic inflammation and injures neural cells. One facilitator of this toxic interplay are exosomes. Exosomes are nano-sized, bilayer lipid vesicles secreted by cells containing proteins, nucleic acids and lipids. Because exosomes can be internalized by other cells, their contents can elicit inflammatory responses and trigger toxicities in recipient cells. On the flip side, exosomes can act as therapeutic vehicles carrying protective cargo to maintain homeostasis. This review discusses exosome biogenesis, composition, and its role in neuroinflammation and neurodegeneration in the context of multiple sclerosis and Alzheimer's disease. The emerging roles of exosomes as biomarkers of neurologic diseases and as therapeutic delivery vehicles are also discussed. With all of these varying roles, interest and excitement in exosomes continue to grow exponentially and their promise as brain therapeutics is only beginning to be explored and harnessed.

Co-administration of dl-3-n-butylphthalide and neprilysin is neuroprotective in Alzheimer disease associated with mild traumatic brain injury

dl-3-n-Butylphthalide is a potent synthetic Chinese celery extract that is highly efficient in inducing neuroprotection in concussive head injury (CHI), Parkinson's disease, Alzheimer's disease, stroke as well as depression, dementia, anxiety and other neurological diseases. Thus, there are reasons to believe that dl-3-n-butylphthalide could effectively prevent Alzheimer's disease brain pathology. Military personnel during combat operation or veterans are often the victims of brain injury that is a major risk factor for developing Alzheimer's disease in their later lives. In our laboratory we have shown that CHI exacerbates Alzheimer's disease brain pathology and reduces the amyloid beta peptide (AβP) inactivating enzyme neprilysin. We have used TiO2 nanowired-dl-3-n-butylphthalide in attenuating Parkinson's disease brain pathology exacerbated by CHI. Nanodelivery of dl-3-n-butylphthalide appears to be more potent as compared to the conventional delivery of the compound. Thus, it would be interesting to examine the effects of nanowired dl-3-n-butylphthalide together with nanowired delivery of neprilysin in Alzheimer's disease model on brain pathology. In this investigation we found that nanowired delivery of dl-3-n-butylphthalide together with nanowired neprilysin significantly attenuated brain pathology in Alzheimer's disease model with CHI, not reported earlier. The possible mechanism and clinical significance is discussed based on the current literature.