The Role of TNF-α in Alzheimer's Disease: A Narrative Review

Interplay of Neuroinflammation and Gut Microbiota Dysbiosis in Alzheimer's Disease Using Diffusion Kurtosis Imaging Biomarker in 3 × Tg-AD Mouse Models

The relationship between alterations in brain microstructure and dysbiosis of gut microbiota in Alzheimer's disease (AD) has garnered increasing attention, although the functional implications of these changes are not yet fully elucidated. This research examines how neuroinflammation, systemic inflammation, and gut microbiota interact in male 3 × Tg-AD and B6129SF1/J wild-type (WT) mice at 6 months-old (6-MO) and 12 months-old (12-MO). Employing a combination of behavioral assessments, diffusion kurtosis imaging (DKI), microbiota profiling, cytokine analysis, short-chain fatty acids (SCFAs), and immunohistochemistry, we explored the progression of AD-related pathology. Significant memory impairments in AD mice at both assessed ages were correlated with altered DKI parameters that suggest neuroinflammation and microstructural damage. We observed elevated levels of pro-inflammatory cytokines, such as IL-1β, IL-6, TNFα, and IFN-γ, in the serum, which were associated with increased activity of microglia and astrocytes in brain regions critical for memory. Although gut microbiota analysis did not reveal significant changes in alpha diversity, it did show notable differences in beta diversity and a diminished Firmicutes/Bacteroidetes (F/B) ratio in AD mice at 12-MO. Furthermore, a reduction in six kinds of SCFAs were identified at two time points of 6-MO and 12-MO, indicating widespread disruption in gut microbial metabolism. These findings underscore a complex bidirectional relationship between systemic inflammation and gut dysbiosis in AD, highlighting the gut-brain axis as a crucial factor in disease progression. This study emphasizes the potential of integrating DKI metrics, microbiota profiling, and SCFA analysis to enhance our understanding of AD pathology and to identify new therapeutic targets.

Targeting the inter-monomeric space of TNFR1 pre-ligand dimers: A novel binding pocket for allosteric modulators

Tumor necrosis factor (TNF) receptor 1 (TNFR1) plays a central role in signal transduction mediating inflammation and cell death associated with autoimmune and neurodegenerative disorders. Inhibition of TNFR1 signaling is a highly sought-after strategy to target these diseases. TNFR1 forms pre-ligand dimers held together by the pre-ligand assembly domain (PLAD), which is essential for receptor signaling. TNFR1 dimers form the crucial points of interaction for the entire receptor signaling complex by connecting TNF ligand bound trimeric receptors. While previous studies have shown the feasibility of disrupting TNFR1 dimeric interactions through competitive mechanism that targets the PLAD, our recent studies have demonstrated that small molecules could also bind PLAD to modulate TNFR1 signaling through an allosteric mechanism. Importantly, these allosteric modulators alter receptor dynamics and propagate long-range conformational perturbation that involves reshuffling of the receptors in the cytosolic domains without disrupting receptor-receptor or receptor-ligand interactions. In this study, we perform molecular docking of previously reported allosteric modulators on the extracellular domain of TNFR1 to understand their binding sites and interacting residues. We identify the inter-monomeric space between TNFR1 pre-ligand dimers as a novel binding pocket for allosteric modulators. We further conduct pharmacological analyses to understand the bioactivity of these compounds and their interacting residues and pharmacological properties. We then provide insights into the structure-activity relationship of these allosteric modulators and the feasibility of targeting TNFR1 conformational dynamics. This paves the way for developing new therapeutic strategies and designing chemical scaffolds to target TNFR1 signaling.

The Role of Inflammatory Markers in Linking Metabolic Syndrome to Cognitive Decline in Middle-Aged Women: A Focus on TNF-α and IL-6

Background: Metabolic syndrome (MetS) and related disorders, such as insulin resistance, pose significant health risks in middle-aged women, including cognitive decline. Chronic inflammation, characterized by elevated levels of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), has been identified as a key mechanism linking metabolic disturbances to neurodegenerative processes. Methods: This study aimed to examine the associations between metabolic disorders, inflammatory markers, and cognitive function among middle-aged women. A cross-sectional study was conducted on 179 non-smoking perimenopausal and postmenopausal women aged 43-73 years. Anthropometric, metabolic, and cognitive parameters were assessed, including body mass index (BMI), waist-to-height ratio (WHtR), fasting glucose (GLU), triglycerides (TG), IL-6, TNF-α, and Mini-Mental State Examination (MMSE) scores. Logistic regression models were applied to evaluate the relationships between inflammation, MetS components, and cognitive impairments. Results: Women with insulin resistance showed significantly worse metabolic profiles and lower MMSE scores (23.98 vs. 24.91, p = 0.032). IL-6 levels were strongly associated with hypertriglyceridemia (OR = 1.096, 95% CI: 1.044-1.151, p < 0.001) and insulin resistance (OR = 1.068, 95% CI: 1.030-1.107, p < 0.001), while TNF-α correlated with abdominal obesity (WHtR OR = 1.429, 95% CI: 1.005-2.031, p = 0.047). Moreover, TNF-α was a significant predictor of cognitive impairments (OR = 1.362, 95% CI: 1.153-1.610, p < 0.001), whereas IL-6 showed no significant association. Conclusions: These findings highlight that TNF-α may be a key inflammatory marker associated with metabolic disturbances and cognitive decline in middle-aged women. IL-6 appears to be more specifically linked to lipid abnormalities and insulin resistance. Targeted interventions to reduce inflammation may moderate metabolic and cognitive risks in this population.

Brivaracitam Ameliorates Increased Inflammation, Oxidative Stress, and Acetylcholinesterase Activity in Ischemic Mice

Objective

Cerebral ischemia is a medical condition that occurs due to poor supply of blood in the brain. Reperfusion being savage further exaggerates the tissue injury causing cerebral ischemia/reperfusion injury (CI/R). CI/R is marked by an impairment in release of neurotransmitter, excitotoxicity, oxidative stress, inflammation, and neuronal apoptosis. The current study has utilized brivaracetam (BRV), a synaptic vesicle protein 2A modulator in experimental model of CI/R injury.

Methods

CI/R injury was induced in Swiss Albino mice by occlusion of common carotid arteries followed by reperfusion. Animals were assessed for learning and memory, motor coordination (Rota rod, lateral push, and inclined beam walking test), cerebral infarction, and histopathological alterations. Biochemical assessments were made for oxidative stress (thiobarbituric acid reactive species, reduced glutathione, catalase, superoxide dismutase), inflammation (tumor necrosis factor-α and interleukin-10), and acetylcholinesterase activity (AChE) in brain supernatants.

Results

CI/R animals showed impairment in learning, memory, and motor coordination, along with increase in cerebral infarction, and histopathological alterations. Furthermore, increase in brain oxidative stress, inflammation, and AChE activity were recorded in CI/R animals. Administration of BRV (10 mg/kg and 20 mg/kg; p.o.) was observed to recuperate CI/R induced impairments in behavioral, biochemical, and histopathological analysis.

Conclusion

It may be concluded that BRV mediates neuroprotection during CI/R via decreasing brain oxidative stress, inflammation, and AChE activity.

Mouse-to-human modeling of microglia single-nuclei transcriptomics identifies immune signaling pathways and potential therapeutic candidates associated with Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and behavior change. Studies have found that dysregulation of microglial cells is pivotal to AD pathology. These mechanisms have been studied in mouse models to uncover potential therapeutic biomarkers. Despite these findings, there are limitations to the translatable biological information from mice to humans due to differences in physiology, timeline of disease, and the heterogeneity of humans. To address the inter-species discrepancies, we developed a novel implementation of the Translatable Components Regression (TransComp-R) framework, which integrated microglia single-nuclei mouse and human transcriptomics data to identify biological pathways in mice predictive of human AD. We compared model variations with sparse and traditional principal component analysis. We found that both dimensionality reduction techniques encoded similar AD disease biology on mouse principal components with limited differences in technical performance. Several mouse sparse principal components explained high amounts of variance in humans and significantly differentiated human AD from control microglial cells. Additionally, we identified FDA-approved medications that induced gene expression profiles correlated with projections of healthy human microglia on mouse principal components. Such medications included cabergoline, selumetinib, and palbociclib. This computational framework may support uncovering cross-species disease insights and candidate pharmacological solutions from single-cell datasets.

Brain interleukins and Alzheimer's disease

The central nervous system (CNS) is immune-privileged by several immuno-modulators as interleukins (ILs). ILs are cytokines secreted by immune cells for cell-cell signaling communications and affect the functions of the CNS. ILs were reported to orchestrate different molecular and cellular mechanisms of both physiological and pathological events, through overproduction or over-expression of their receptors. They interact with numerous receptors mediating pro-inflammatory and/or anti-inflammatory actions. Interleukins have been implicated to participate in neurodegenerative diseases. They play a critical role in Alzheimer's disease (AD) pathology which is characterized by the over-production of pro-inflammatory ILs. These may aggravate neurodegeneration, in addition to their contribution to detrimental mechanisms as oxidative stress, and excitotoxicity. However, recent research on the relation between ILs and AD revealed major discrepancies. Most of the major ILs were shown to play both pro- and anti-inflammatory roles in different experimental settings and models. The interactions between different ILs through shared pathways also add to the difficulty of drawing solid conclusions. In addition, targeting the different ILs has not yielded consistent results. The repeated failures of therapeutic drugs in treating AD necessitate the search for novel agents targeting multiple mechanisms of the disease pathology. In this context, the understanding of interleukins and their roles throughout the disease progression and interaction with other systems in the brain may provide promising therapeutic targets for the prevention or treatment of AD.

Osteopontin in Alzheimer's Disease: A Double-Edged Sword in Neurodegeneration and Neuroprotection-A Systematic Review

BACKGROUND

Osteopontin (OPN) has emerged as a pivotal molecule in Alzheimer's disease (AD), with studies indicating its potential to act as both a neuroprotective agent and a contributor to neurodegeneration. This systematic review aims to elucidate the roles of OPN in AD pathogenesis through inflammatory pathways.

METHODS

We conducted a comprehensive analysis of current literature on OPN's involvement in AD, focusing on its signaling pathways, cellular interactions, and regulatory mechanisms. We searched PubMed, EMBASE, and Scopus databases by the keyword of Alzheimer's Disease and Osteopontin. Our date search was in 1990 until July 1, 2024 with no language limitation.

RESULTS

In a review of 758 studies, a total of 15 reports met the eligibility criteria and were included. Among the findings, four studies provided evidence supporting the protective mechanism of OPN within the context of AD. Eleven studies explain the inflammatory role of OPN. OPN has been shown to play a role in synaptic pruning, microglial activation, and the inflammatory processes associated with AD. Additionally, OPN is implicated in facilitating cellular communication and serves as a chemotactic molecule. It is suggested that the protective effects of OPN are predominantly mediated by the c fragment of the protein and are most prominent in the early stages of AD progression.

CONCLUSION

OPN in AD has dual effects-protecting neurons and contributing to their degeneration. Future research should enhance its protective mechanisms, target specific signaling pathways, and develop therapies to slow AD progression.

Exploring TNFR1: from discovery to targeted therapy development

This review seeks to elucidate the therapeutic potential of tumor necrosis factor receptor 1 (TNFR1) and enhance our comprehension of its role in disease mechanisms. As a critical cell-surface receptor, TNFR1 regulates key signaling pathways, such as nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK), which are associated with pro-inflammatory responses and cell death. The intricate regulatory mechanisms of TNFR1 signaling and its involvement in various diseases, including inflammatory disorders, infectious diseases, cancer, and metabolic syndromes, have attracted increasing scholarly attention. Given the potential risks associated with targeting tumor necrosis factor-alpha (TNF-α), selective inhibition of the TNFR1 signaling pathway has been proposed as a promising strategy to reduce side effects and enhance therapeutic efficacy. This review emphasizes the emerging field of targeted therapies aimed at selectively modulating TNFR1 activity, identifying promising therapeutic strategies that exploit TNFR1 as a drug target through an evaluation of current clinical trials and preclinical studies. In conclusion, this study contributes novel insights into the biological functions of TNFR1 and presents potential therapeutic strategies for clinical application, thereby having substantial scientific and clinical significance.

A Network Pharmacology Study and Experimental Validation to Identify the Potential Mechanism of Heparan Sulfate on Alzheimer's Disease-Related Neuroinflammation

BACKGROUND/OBJECTIVES

Heparan sulfate (HS) is a polysaccharide that is found on the surface of cells and has various biological functions in the body.

METHODS

The purpose of this study was to predict the pharmacological effects and molecular mechanisms of HS on Alzheimer's disease (AD) and neuroinflammation (NI) through a network pharmacology analysis and to experimentally verify them.

RESULTS

We performed functional enrichment analysis of common genes between HS target genes and AD-NI gene sets and obtained items such as the "Cytokine-Mediated Signaling Pathway", "Positive Regulation Of MAPK Cascade", and "MAPK signaling pathway". To confirm the predicted results, the anti-inflammatory effect of HS was investigated using lipopolysaccharide (LPS)-stimulated BV2 microglia cells. HS inhibited the production of nittic oxide, interleukin (IL)-6, and tumor necrosis factor-α in LPS-stimulated BV2 cells, but not IL-1β. In addition, HS inactivated P38 in the MAPK signaling pathway.

CONCLUSIONS

These findings suggest the potential for HS to become a new treatment for AD and NI.

Investigating interleukin-8 in Alzheimer's disease: A comprehensive review

Several studies indicate that the development of Alzheimer's disease (AD) has strong interactions with immune mechanisms within the brain, indicating a close association between inflammation in the central nervous system and the progression of neurodegeneration. Despite considerable progress in understanding the inflammatory aspects of AD, several of them remain unresolved. Pro-inflammatory cytokines and microglia are pivotal components in the inflammatory cascade. Among these, the role of interleukin-8 (IL-8) in neurodegeneration seems complex and multifaceted, involving inflammation, neurotoxicity, blood-brain barrier disruption, and oxidative stress, and is still poorly characterized. We conducted a review to describe the evidence of IL-8 involvement in AD. IL-8 is a cytokine known for its proinflammatory properties and typically produced by macrophages, predominantly functions as a chemotactic signal for attracting neutrophils to inflamed sites in the bloodstream. Interestingly, IL-8 is also present in the brain, where it is primarily released by microglia in response to inflammatory signals. This review aims to provide a comprehensive overview of the structure, function, and regulatory mechanisms of IL-8 relevant to AD pathology.

Decoding paradoxical links of cytokine markers in cognition: Cross talk between physiology, inflammaging, and Alzheimer's disease- related cognitive decline

Recent research has revolutionized our understanding of memory consolidation by emphasizing the critical role of astrocytes, microglia, and immune cells in through cytokine signaling. Cytokines, compact proteins, play pivotal roles in neuronal development, synaptic transmission, and normal aging. This review explores the cellular mechanisms contributing to cognitive decline in inflammaging and Alzheimer's disease, highlighting the paradoxical effects of most studied cytokines (IL-1, IL-6, TNF-α) in brain function, which act as a double-edged sword in brain physiology, acting both as facilitators of healthy cognitive function and as a potential contributor to cognitive decline.

The mTOR Pathway: A Common Link Between Alzheimer's Disease and Down Syndrome

Down syndrome (DS) is a chromosomal condition that causes many systemic dysregulations, leading to several possible age-related diseases including Alzheimer's disease (AD). This may be due to the triplication of the Amyloid precursor protein (APP) gene or other alterations in mechanistic pathways, such as the mTOR pathway. Impairments to upstream regulators of mTOR, such as insulin, PI3K/AKT, AMPK, and amino acid signaling, have been linked to amyloid beta plaques (Aβ) and neurofibrillary tangles (NFT), the most common AD pathologies. However, the mechanisms involved in the progression of pathology in human DS-related AD (DS-AD) are not fully investigated to date. Recent advancements in omics platforms are uncovering new insights into neurodegeneration. Genomics, spatial transcriptomics, proteomics, and metabolomics are novel methodologies that provide more data in greater detail than ever before; however, these methods have not been used to analyze the mTOR pathways in connection to DS-AD. Using these new techniques can unveil unexpected insights into pathological cellular mechanisms through an unbiased approach.

The Association Between Inflammatory Dietary Pattern and Risk of Cognitive Impairment Among Older Adults with Chronic Diseases and Its Multimorbidity: A Cross-Sectional Study

Background

The present study aimed to explore the association between the inflammatory potential of diet, assessed by energy-adjusted dietary inflammatory index (E-DII) and reduced rank regression (RRR)-derived inflammatory dietary pattern, and the risk for cognitive impairment (CI) in community-dwelling older adults, especially in older adults with chronic diseases and multimorbidity.

Methods

A total of 549 older adults from Taiyuan city were included in the present cross-sectional study. The Chinese Version of the Mini-Mental State Examination (CMMSE) was used for the evaluation of cognitive function. E-DII score was calculated based on semi-quantitative food frequency questionnaire (FFQ). Blood samples, including interleukin (IL)-1β, interleukin (IL)-18, tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP), were tested for calculating RRR-derived inflammatory dietary pattern. Logistic regression was used to assess the association between inflammatory dietary pattern and risk of CI. In addition, patients with diabetes, hypertension, hyperlipidemia and multimorbidity were screened for further analysis among 549 older adults.

Results

In those 549 older adults, adjusting for demographic characteristics and chronic disease status, there was no association between E-DII score tertile (OR T3VST1 : 1.357, 95%CI:0.813~2.265, P trend = 0.267), RRR-derived inflammatory dietary pattern score tertile (OR T3VST1 : 1.092, 95%CI:0.679~ 1.758, P trend = 0.737) and risk of CI. However, in older adults with diabetes and multimorbidity, the score tertile of E-DII and RRR-derived inflammatory dietary pattern were positively correlated with risk of CI in a dose-responsive manner (All P trend < 0.05). There is insufficient evidence to reach similar conclusion in patients with hypertension and hyperlipidemia (All P trend > 0.05).

Conclusion

In the present study, pro-inflammatory diet contributed to the increased risk of CI in older adults with diabetes and multimorbidity. These results supplemented vital evidence for the prevention and treatment of CI in older adults with chronic diseases.

mosGraphGPT: a foundation model for multi-omic signaling graphs using generative AI

Generative pretrained models represent a significant advancement in natural language processing and computer vision, which can generate coherent and contextually relevant content based on the pre-training on large general datasets and fine-tune for specific tasks. Building foundation models using large scale omic data is promising to decode and understand the complex signaling language patterns within cells. Different from existing foundation models of omic data, we build a foundation model, mosGraphGPT, for multi-omic signaling (mos) graphs, in which the multi-omic data was integrated and interpreted using a multi-level signaling graph. The model was pretrained using multi-omic data of cancers in The Cancer Genome Atlas (TCGA), and fine-turned for multi-omic data of Alzheimer's Disease (AD). The experimental evaluation results showed that the model can not only improve the disease classification accuracy, but also is interpretable by uncovering disease targets and signaling interactions. And the model code are uploaded via GitHub with link: https://github.com/mosGraph/mosGraphGPT.

Melatonin improves cognitive dysfunction and decreases gliosis in the streptozotocin-induced rat model of sporadic Alzheimer's disease

Introduction

Alzheimer's disease (AD) and other forms of dementia have a devastating effect on the community and healthcare system, as neurodegenerative diseases are causing disability and dependency in older population. Pharmacological treatment options are limited to symptomatic alleviation of cholinergic deficit and accelerated clearance of β-amyloid aggregates, but accessible disease-modifying interventions are needed especially in the early phase of AD. Melatonin was previously demonstrated to improve cognitive function in clinical setting and experimental studies also.

Methods

In this study, the influence of melatonin supplementation was studied on behavioral parameters and morphological aspects of the hippocampus and amygdala of rats. Streptozotocin (STZ) was injected intracerebroventricularly to induce AD-like symptoms in male adult Wistar rats (n = 18) which were compared to age-matched, sham-operated animals (n = 16). Melatonin was administered once daily in a dose of 20 mg/kg body weight by oral route. Behavioral analysis included open-field, novel object recognition, and radial-arm maze tests. TNF-α and MMP-9 levels were determined from blood samples to assess the anti-inflammatory and neuroprotective effects of melatonin. Immunohistological staining of brain sections was performed using anti-NeuN, anti-IBA-1, and anti-GFAP primary antibodies to evaluate the cellular reorganization of hippocampus.

Results and Discussion

The results show that after 40 days of treatment, melatonin improved the cognitive performance of STZ-induced rats and reduced the activation of microglia in both CA1 and CA3 regions of the hippocampus. STZ-injected animals had higher levels of GFAP-labeled astrocytes in the CA1 region, but melatonin treatment reduced this to that of the control group. In conclusion, melatonin may be a potential therapeutic option for treating AD-like cognitive decline and neuroinflammation.

Targeting Microglia in Alzheimer's Disease: Pathogenesis and Potential Therapeutic Strategies

Microglia, as resident macrophages in the central nervous system, play a multifunctional role in the pathogenesis of Alzheimer's disease (AD). Their clustering around amyloid-β (Aβ) deposits is a core pathological feature of AD. Recent advances in single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq) have revealed dynamic changes in microglial phenotypes over time and across different brain regions during aging and AD progression. As AD advances, microglia primarily exhibit impaired phagocytosis of Aβ and tau, along with the release of pro-inflammatory cytokines that damage synapses and neurons. Targeting microglia has emerged as a potential therapeutic approach for AD. Treatment strategies involving microglia can be broadly categorized into two aspects: (1) enhancing microglial function: This involves augmenting their phagocytic ability against Aβ and cellular debris and (2) mitigating neuroinflammation: Strategies include inhibiting TNF-α signaling to reduce the neuroinflammatory response triggered by microglia. Clinical trials exploring microglia-related approaches for AD treatment have garnered attention. Additionally, natural products show promise in enhancing beneficial effects and suppressing inflammatory responses. Clarifying microglial dynamics, understanding their roles, and exploring novel therapeutic approaches will advance our fight against AD.

Decoding the role of the CCL2/CCR2 axis in Alzheimer's disease and innovating therapeutic approaches: Keeping All options open

Alzheimer's disease (AD), as a neurodegenerative disorder, distresses the elderly in large numbers and is characterized by β-amyloid (Aβ) accumulation, elevated tau protein levels, and chronic inflammation. The brain's immune system is aided by microglia and astrocytes, which produce chemokines and cytokines. Nevertheless, dysregulated expression can cause hyperinflammation and lead to neurodegeneration. CCL2/CCR2 chemokines are implicated in neurodegenerative diseases exacerbating. Inflicting damage on nerves and central nervous system (CNS) cells is the function of this axis, which recruits and migrates immune cells, including monocytes and macrophages. It has been shown that targeting the CCL2/CCR2 axis may be a therapeutic option for inflammatory diseases. Using the current knowledge about the involvement of the CCL2/CCR2 axis in the immunopathogenesis of AD, this comprehensive review synthesizes existing information. It also explores potential therapeutic options, including modulation of the CCL2/CCR2 axis as a possible strategy in AD.

From Inhalation to Neurodegeneration: Air Pollution as a Modifiable Risk Factor for Alzheimer's Disease

Air pollution, a growing concern for public health, has been linked to various respiratory and cardiovascular diseases. Emerging evidence also suggests a link between exposure to air pollutants and neurodegenerative diseases, particularly Alzheimer's disease (AD). This review explores the composition and sources of air pollutants, including particulate matter, gases, persistent organic pollutants, and heavy metals. The pathophysiology of AD is briefly discussed, highlighting the role of beta-amyloid plaques, neurofibrillary tangles, and genetic factors. This article also examines how air pollutants reach the brain and exert their detrimental effects, delving into the neurotoxicity of air pollutants. The molecular mechanisms linking air pollution to neurodegeneration are explored in detail, focusing on oxidative stress, neuroinflammation, and protein aggregation. Preclinical studies, including in vitro experiments and animal models, provide evidence for the direct effects of pollutants on neuronal cells, glial cells, and the blood-brain barrier. Epidemiological studies have reported associations between exposure to air pollution and an increased risk of AD and cognitive decline. The growing body of evidence supporting air pollution as a modifiable risk factor for AD underscores the importance of considering environmental factors in the etiology and progression of neurodegenerative diseases, in the face of worsening global air quality.

Effect of total flavonoids of Dracocephalum moldavica L. On neuroinflammation in Alzheimer's disease model amyloid-β (Aβ1-42)-peptide-induced astrocyte activation

One of the main pathological features noted in Alzheimer's disease (AD) is the presence of plagues of aggregated β-amyloid (Aβ1-42)-peptides. Excess deposition of amyloid-β oligomers (AβO) are known to promote neuroinflammation. Sequentially, following neuroinflammation astrocytes become activated with cellular characteristics to initiate activated astrocytes. The purpose of this study was to determine whether total flavonoids derived from Dracocephalum moldavica L. (TFDM) inhibited Aβ1-42-induced damage attributed to activated C8-D1A astrocytes. Western blotting and ELISA were used to determine the expression of glial fibrillary acidic protein (GFAP), and complement C3 to establish the activation status of astrocytes following induction from exposure to Aβ1-42. Data demonstrated that stimulation of C8-D1A astrocytes by treatment with 40 μM Aβ1-42 for 24 hr produced significant elevation in protein expression and protein levels of acidic protein (GFAP) and complement C3 accompanied by increased expression and levels of inflammatory cytokines. Treatment with TFDM or the clinically employed drug donepezil in AD therapy reduced production of inflammatory cytokines, and toxicity initiated following activation of C8-D1A astrocytes following exposure to Aβ1-42. Therefore, TFDM similar to donepezil inhibited inflammatory secretion in reactive astrocytes, suggesting that TFDM may be considered as a potential compound to be utilized in AD therapy.

Aging brain: exploring the interplay between bone marrow aging, immunosenescence, and neuroinflammation

Aging is a complex process characterized by a myriad of physiological changes, including alterations in the immune system termed immunosenescence. It exerts profound effects on both the bone marrow and the central nervous system, with significant implications for immunosenescence in neurological contexts. Our mini-review explores the complex relationship between bone marrow aging and its impact on immunosenescence, specifically within the context of neurological diseases. The bone marrow serves as a crucial hub for hematopoiesis and immune cell production, yet with age, it undergoes significant alterations, including alterations in hematopoietic stem cell function, niche composition, and inflammatory signaling. These age-related shifts in the bone marrow microenvironment contribute to dysregulation of immune cell homeostasis and function, impacting neuroinflammatory processes and neuronal health. In our review, we aim to explore the complex cellular and molecular mechanisms that link bone marrow aging to immunosenescence, inflammaging, and neuroinflammation, with a specific focus on their relevance to the pathophysiology of age-related neurological disorders. By exploring this interplay, we strive to provide a comprehensive understanding of how bone marrow aging impacts immune function and contributes to the progression of neurological diseases in aging individuals. Ultimately, this knowledge can hold substantial promise for the development of innovative therapeutic interventions aimed at preserving immune function and mitigating the progression of neurological disorders in the elderly population.

Review on anti-alzheimer drug development: approaches, challenges and perspectives

Alzheimer is an irreversible progressive neurodegenerative disease that causes failure of cerebral neurons and disability of the affected person to practice normal daily life activities. There is no concrete evidence to identify the exact reason behind the disease, so several relevant hypotheses emerged, highlighting many possible therapeutic targets, such as acetylcholinesterase, cholinergic receptors, N-methyl d-aspartate receptors, phosphodiesterase, amyloid β protein, protein phosphatase 2A, glycogen synthase kinase-3 beta, β-secretase, γ-secretase, α-secretase, serotonergic receptors, glutaminyl cyclase, tumor necrosis factor-α, γ-aminobutyric acid receptors, and mitochondria. All of these targets have been involved in the design of new potential drugs. An extensive number of these drugs have been studied in clinical trials. However, only galantamine, donepezil, and rivastigmine (ChEIs), memantine (NMDA antagonist), and aducanumab and lecanemab (selective anti-Aβ monoclonal antibodies) have been approved for AD treatment. Many drugs failed in the clinical trials to such an extent that questions have been posed about the significance of some of the aforementioned targets. On the contrary, the data of other drugs were promising and shed light on the significance of their targets for the development of new potent anti-alzheimer drugs.

Taming Microglia in Alzheimer's Disease: Exploring Potential Implications of Choline Alphoscerate via α7 nAChR Modulation

Alzheimer's disease (AD), marked by cognitive impairment, predominantly affects the brain regions regulated by cholinergic innervation, such as the cerebral cortex and hippocampus. Cholinergic dysfunction, a key contributor to age-related cognitive decline, has spurred investigations into potential therapeutic interventions. We have previously shown that choline alphoscerate (α-GPC), a cholinergic neurotransmission-enhancing agent, protects from Aβ-mediated neurotoxicity. Herein, we investigated the effects of α-GPC on the microglial phenotype in response to Aβ via modulation of the nicotinic alpha-7 acetylcholine receptor (α7 nAChR). BV2 microglial cells were pre-treated for 1 h with α-GPC and were treated for 24, 48, and 72 h with Aβ1-42 and/or α-BTX, a selective α7nAchR antagonist. Fluorescent immunocytochemistry and Western blot analysis showed that α-GPC was able to antagonize Aβ-induced inflammatory effects. Of note, α-GPC exerted its anti-inflammatory effect by directly activating the α7nAChR receptor, as suggested by the induction of an increase in [Ca2+]i and Ach-like currents. Considering that cholinergic transmission appears crucial in regulating the inflammatory profiles of glial cells, its modulation emerges as a potential pharmaco-therapeutic target to improve outcomes in inflammatory neurodegenerative disorders, such as AD.