MicroRNA-125b induces tau hyperphosphorylation and cognitive deficits in Alzheimer's disease

A review on the lncRNA-miRNA-mRNA regulatory networks involved in inflammatory processes in Alzheimer's disease

Alzheimer's disease is a progressive neurodegenerative condition that is the most frequent reason for dementia. Due to the increasing trend of aging in societies, it will place a large social and financial burden on society. Although beta amyloid plaques and the formation of neurofibrillary tangles are mentioned as the main events in this disorder, the exact molecular pathology and inflammatory regulatory networks involved in neuroinflammatory events, as a fundamental pathogenic mechanism remain unknown. Understanding these molecular network pathways in addition to helping to understand the pathogenesis of Alzheimer's disease, can also help in the early diagnosis as well as the control of inflammatory processes that are involved in its progression. So, in this study, we intend to have an overview on the regulatory lncRNAs of Alzheimer's disease and their related miRNA and mRNAs, as well as the relationship of these regulatory pathways with inflammatory processes, so that we can provide a perspective for future studies in the field of diagnosis and possibly treatment of this disorder.

Exercise-induced modulation of miRNAs and gut microbiome: a holistic approach to neuroprotection in Alzheimer's disease

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is marked by cognitive decline, neuroinflammation, and neuronal loss. MicroRNAs (miRNAs) have emerged as critical regulators of gene expression, influencing key pathways involved in neuroinflammation and neurodegeneration in AD. This review delves into the multifaceted role of exercise in modulating miRNA expression and its interplay with the gut microbiome, proposing a comprehensive framework for neuroprotection in AD. By synthesizing current research, we elucidate how exercise-induced changes in miRNA profiles can mitigate inflammatory responses, promote neurogenesis, and reduce amyloid-beta and tau pathologies. Additionally, we explore the gut-brain axis, highlighting how exercise-driven alterations in gut microbiota composition can further influence miRNA expression, thereby enhancing cognitive function and reducing neuroinflammatory markers. This holistic approach underscores the potential of targeting exercise-regulated miRNAs and gut microbiome interactions as a novel, noninvasive therapeutic strategy to decelerate AD progression and improve quality of life for patients. This approach aims to decelerate disease progression and improve patient outcomes, offering a promising avenue for enhancing the effectiveness of AD management.

MicroRNAs modulation by curcumin, catalpol, and other natural products in Alzheimer's disease: a review

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with limited pharmacological treatment options, necessitating the exploration of alternative therapeutic strategies. Emerging evidence suggests that microRNAs (miRNAs), such as miR-132, miR-34a, and miR-124, play crucial roles in AD pathogenesis, influencing amyloid-beta (Aβ) aggregation, tau phosphorylation, neuroinflammation, and oxidative stress. Natural products have been identified as potential modulators of miRNA expression, offering neuroprotective benefits through multi-target mechanisms. This review systematically examines the impact of curcumin, catalpol, Allium jesdianum, Tanshinone IIA (Tan IIA), and Tiaoxin Recipe (TXR) on miRNA regulation in AD, summarizing their molecular targets and therapeutic potential. Furthermore, we discuss challenges related to bioavailability and clinical translation, highlighting the need for advanced delivery systems and personalized medicine approaches. By integrating recent findings, this review provides a comprehensive perspective on the role of miRNA modulation in AD therapy and underscores the potential of natural products as novel therapeutic agents.

The neuroinflammatory role of microRNAs in Alzheimer's disease: pathological insights to therapeutic potential

Alzheimer's disease (AD) is a neurodegenerative disease and the most common cause of dementia, contributing to around 60-80% of cases. The main pathophysiology of AD is characterized by an abnormal accumulation of protein aggregates extracellularly (beta-amyloid plaques) and intracellularly (neurofibrillary tangles of hyperphosphorylated tau). However, an increasing number of studies have also suggested neuroinflammation may have a crucial role in precipitating the cascade reactions that result in the development of AD neuropathology. In particular, several studies indicate microRNAs (miRNAs) can act as regulatory factors for neuroinflammation in AD, with potential to affect the occurrence and/or progression of AD inflammation by targeting the expression of multiple genes. Therefore, miRNAs may have potential as therapeutic targets for AD, which requires more research. This article will review the existing studies on miRNAs that have been identified to regulate neuroinflammation, aiming to gain further insights into the specific regulatory processes of miRNAs, highlight the diagnostic and therapeutic potential of miRNAs as biomarkers in AD, as well as current challenges, and suggest the further work to bridge the gap in knowledge to utilize miRNAs as therapeutic targets for AD.

Value of blood neural cell-derived small extracellular vesicles in the diagnosis and prediction of Alzheimer's disease: A systematic revie

Blood neural cell-derived small extracellular vesicles (sEVs) can directly reflect changes in brain tissue and are easier to obtain than cerebrospinal fluid. This article systematically reviews the alterations of proteins and miRNAs from neural cell-derived sEVs in patients with Alzheimer's disease (AD), and summarizes the biomarkers with clinical diagnostic and predictive value. PubMed, Web of Science, Embase, and Cochrane Library were searched for studies in blood neural cell-derived sEVs in AD patients up to May 2024. According to the inclusion and exclusion criteria, the literature was screened, the information was extracted and the quality was evaluated. Proteins and miRNAs from neural cell-derived sEVs were classified and summarized, focusing on target molecules with high diagnostic and predictive values for AD. A final 34 articles reporting 5601 participants were included. In cross-sectional studies, Aβ- and Tau-related proteins (Aβ42, Aβ42/40, p-S396-Tau, p-Tau181), p-S312-IRS-1, and cathepsin D were increased, conversely, synaptic proteins (neurogranin, synaptotagmin, synaptophysin, synaptopodin, NMDAR2A) and REST were decreased in blood neuron-derived sEVs (NDsEVs) of patients with AD. While miR-29c-3p was increased in blood NDsEVs and glial cell-derived sEVs. Each of these proteins and miRNAs demonstrated high AD diagnostic value. Additionally, blood astrocyte-derived sEVs (ADsEVs) showed increased complement effector proteins and decreased complement regulatory proteins with a moderate diagnostic value. In longitudinal cohort studies, three composite models displayed high predictive efficacy for early AD prediction, and could predict the occurrence of AD within 1-10 years. Therefore, Aβ- and Tau-related proteins, synaptic proteins, and miRNA in blood neural cell-derived sEVs demonstrate high AD diagnostic and predictive values serving as important biomarkers. Especially, synaptic proteins showed significant changes in the early clinical stage, which has early predictive value.

Role of mitogen-activated protein kinase inhibitors in Alzheimer's disease: Rouge of brain kinases

Alzheimer's disease (AD) is the chief cause of dementia and related mortality worldwide due to progressive accumulation of amyloid peptide (Aβ) and hyperphosphorylated tau protein. These neuropathological changes lead to cognitive impairment and memory dysfunction. Notably, most Food drug Administration (FDA) approved anti-AD medications such as tacrine and donepezil are engaged with symptomatic relief of cognitive impairment but do not reverse the underlying AD neuropathology. Therefore, searching for new anti-AD is advisable. It has been shown that the inflammatory signaling pathways such as mitogen-activated protein kinases (MAPK) are intricate with the Aβ and tau protein neuropathology in AD. In addition, inhibition of brain MAPK plays a critical role in mitigating cognitive dysfunction in early-onset AD. Though, the fundamental mechanisms for the beneficial effects of MAPK inhibitors were not fully explained. Therefore, this review aims to discuss the potential molecular mechanisms of MAPK inhibitors in AD.

Unlocking the therapeutic promise of miRNAs in promoting amyloid-β clearance for Alzheimer's disease

Alzheimer's disease (AD) is a neurological disorder that affects cognition and behavior, accounting for 60-70 % of dementia cases. Its mechanisms involve amyloid aggregates, hyperphosphorylated tau tangles, and loss of neural connections. Current treatments have limited efficacy due to a lack of specific targets. Recently, microRNAs (miRNAs) have emerged as key modulators in AD, regulating gene expression through interactions with mRNA. Dysregulation of specific miRNAs contributes to disease progression by disrupting clearance pathways. Antisense oligonucleotide (ASO)-based therapies show promise for AD treatment, particularly when combined with miRNA mimics or antagonists, targeting complex regulatory networks. However, miRNAs can interact with each other, complicating cellular processes and potentially leading to side effects. Our review emphasizes the role of miRNAs in regulating amyloid-beta (Aβ) clearance and highlights their potential as therapeutic targets and early biomarkers for AD, underscoring the need for further research to enhance their efficacy and safety.

Exploring the Role of microRNAs as Blood Biomarkers in Alzheimer's Disease and Frontotemporal Dementia

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common forms of dementia globally. AD is characterized by the accumulation of amyloid-β (Aβ) plaques and hyperphosphorylated tau in the brain, leading to progressive memory loss and cognitive decline, significantly impairing daily life. In contrast, FTD is marked by selective degeneration of the frontal and/or temporal lobes, typically resulting in profound changes in personality and social behavior, speech disorders, and psychiatric symptoms. Numerous studies have found microRNAs (miRNAs)-small, non-coding RNA molecules that regulate gene expression post-transcriptionally-to be dysregulated in AD and FTD. As a result, miRNAs have emerged as promising novel biomarkers for these diseases. This review examines the current understanding of miRNAs in AD and FTD, emphasizing their potential as accessible, noninvasive biomarkers for diagnosing these prevalent neurodegenerative disorders.

Whole Transcriptome RNA-Seq Reveals Drivers of Pathological Dysfunction in a Transgenic Model of Alzheimer's Disease

Alzheimer's disease (AD) affects more than 55 million people worldwide, yet current theories cannot fully explain its aetiology. Accordingly, gene expression profiling has been used to provide a holistic view of the biology underpinning AD. Focusing primarily on protein-coding genes, such approaches have highlighted a critical involvement of microglia-related inflammatory processes. Simultaneous investigation of transcriptional regulators and noncoding RNA (ncRNA) can offer further insight into AD biology and inform the development of disease-modifying therapies. We previously described a method for whole transcriptome sampling to simultaneously investigate protein-coding genes and ncRNA. Here, we use this technique to explore transcriptional changes in a murine model of AD (15-month-old APP/PS1 mice). We confirmed the extensive involvement of microglia-associated genes and gene networks, consistent with literature. We also report a wealth of differentially-expressed non-coding RNA - including microRNA, long non-coding RNA, small nuclear and small nucleolar RNA, and pseudogenes - many of which have been overlooked previously. Transcription factor analysis determined that six transcription factors likely regulate gene expression changes in this model (Irf8, Junb, c-Fos, Lmo2, Runx1, and Nfe2l2). We then utilised validated miRNA-target interactions, finding 60 interactions between 15 miRNA and 42 mRNA (messenger RNA) with largely consistent directionality. Furthermore, we found that eight transcription factors (Clock, Lmo2, Runx1, Nfe2l2, Egr2, c-Fos, Junb, and Nr4a1) are likely responsible for the regulation of miRNA expression. Taken together, these data indicate a complex interplay of coding and non-coding RNA, driven by a small number of specific transcription factors, contributing to transcriptional changes in 15-month-old APP/PS1 mice.

Effects of memantine and donepezil on social memory, anxiety-like behavior and the expression levels of microRNA-124, microRNA-125b, and microRNA-132 in scopolamine-induced memory impairment in rats

INTRODUCTION

Almost all physiological processes are modulated by microRNAs, therefore, dysregulation of these small regulatory RNAs is observed in a variety of diseases, including cognitive impairments.

METHODS

In this study, 40 male Wistar rats were randomly divided into five groups of control, scopolamine, donepezil, memantine, and combined administration of donepezil + memantine. Rats in scopolamine, donepezil, memantine, and combined administration of donepezil + memantine groups received scopolamine (1 mg/kg-intraperitoneal) for 7 days. After the last administration of scopolamine, was started injecting donepezil (3 mg/kg-i.p.), memantine (10 mg/kg-i.p.), and combined administration of Donepezil + Memantine (0.5 mg/kg and 5 mg/kg-i.p., respectively), up to 21 days. Twenty-four hours after the last injection, elevated plus-maze, social interaction, open field tests, and gene expression analysis of miR-124, miR-125b, and miR-132 in the hippocampus were carried out.

RESULTS

The results of the behavioral tests indicate that donepezil and memantine significantly prevented Scopolamine-induced anxiety, sociability, and social memory decline. The gene expression of selected microRNAs did not significantly differ between the groups.

DISCUSSION

This study revealed that donepezil and memantine effectively prevent synaptic plasticity disruption and cognitive decline induced by scopolamine. Findings indicated that this treatment is unrelated to the expression of the selected microRNAs. The positive effects of memantine and donepezil depend on age, dosages, cognitive task demands, and possibly the length and timing of the treatment.

Therapeutic potential and microRNA regulating properties of phytochemicals in Alzheimer's disease

Alzheimer's disease (AD) is the leading cause of dementia in the elderly and is characterized by the aggregation of Aβ (peptide) and neurofibrillary tangles along with inflammatory processes. Aging is a significant driver of these alterations, and dementia is a major cause of disability and mortality. Despite extensive clinical trials over the past two decades, no effective drug has been developed to improve AD symptoms or slow its progression, indicating the inefficiency of current treatment targets. In AD development, the molecular microenvironment plays a significant role. MicroRNAs (miRNAs) are a key component of this microenvironment, regulate post-transcriptional gene expression, and are expressed more abundantly in the brain than in other tissues. Several dysregulated miRNAs in AD have been linked to neuropathological changes, such as plaque and tangle accrual, as well as altered expression of notorious molecules. Preclinical studies have confirmed the efficacy of phytochemicals/food bioactive compounds (PCs/FBCs) in regulating miRNA expression, which makes them immensely beneficial for targeting miRNA-altered expression patterns in neuronal diseases. This review highlights the potential of miRNAs in driving AD pathology and its development. Furthermore, it discusses the therapeutic efficacy of PCs/FBCs and their miRNA-regulatory properties, especially focusing on antiinflammatory and antioxidant capacities for their development as effective AD agents.

MicroRNA-based recent research developments in Alzheimer's disease

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is characterized by memory and physical impairment in aged individuals. microRNAs (miRNAs) are small, single-stranded noncoding RNAs that induce translational repression by binding to the 3' UTR of a target mRNA. miRNAs play a crucial role in neurological activity by mediating cellular proliferation, synaptic plasticity, apoptosis and more. Ongoing research in patents and clinical trials have called attention to promising miRNAs as biomarkers and therapeutics in AD. Recent research has shown that miRNAs are aberrantly expressed in AD brain, blood, cerebrospinal fluid and serum. Attenuated miRNA expressions have diagnostic potential in AD by interacting with amyloid-β synthesis, phosphorylated tau, and neurofibrillary tangles. In this study, miRNA-29a, miRNA-125b, miRNA-34a, miRNA-146a, and miRNA-155 have shown promise as potential biomarker candidates for AD. Improving cognitive symptoms can be traced to restoring the endogenous miRNA activity by synthesizing miRNA mimics and miRNA antisense oligonucleotides. miRNA-483-5p, miRNA-188-5p, miRNA-219, miRNA135a/5p, miRNA-23/23b-3p, miRNA-124, and miRNA-455-3p are growing therapeutics for AD. However, miRNA-based therapeutics struggle outside of preclinical testing. miRNA-107, miRNA-206, miRNA-30/7, and miRNA-142-3p face bottlenecks in clinical trials due to a lack of experimental design, transparency and volunteer size. Patenting recent miRNA-based developments demonstrates the commitment in identifying a new biomarker and/or therapeutic for AD.

Identification of adipose tissue-derived exosomal microRNA as a novel causal biomarker for cognitive impairment in type 2 diabetes mellitus: Triangulating evidence from Mendelian randomization and multicentre population studies

AIMS

To explore serum exosomal microRNAs (miRNAs) as risk biomarkers for early detection of cognitive impairment in type 2 diabetes mellitus (T2DM) patients.

MATERIALS AND METHODS

This study included two phases: a discovery phase and a validation phase. To detect adipose tissue exosomal biomarkers for T2DM patients, small RNA sequencing was conducted on a discovery population consisting of six T2DM patients and five subjects with normal glucose tolerance. To identify miRNAs with causal effects on cognitive impairment, Mendelian randomization (MR) analysis using publicly available genome wide association studies (GWAS) datasets was performed. Relationships between serum exosomal miRNAs and cognitive impairment were evaluated in a training population of 207 T2DM patients, and further validated in an external population of 101 T2DM patients from multiple centres.

RESULTS

In the discovery phase, 13 exosomal miRNAs were significantly upregulated in adipose tissue of T2DM patients. MR analyses identified that increased miR-125a-5p was causally associated with increased Alzheimer's disease (AD) risk (OR = 1.231, 95% CI 1.062-1.426). In the validation phase, higher serum exosomal miR-125a-5p levels were related to increased amnestic mild cognitive impairment (aMCI) risk (OR = 1.066, 95% CI 1.030-1.103) and reduced left hippocampal body volume (r = -0.189, p < 0.05), achieving an area under the curve (AUC) of 0.728 for identifying aMCI in T2DM patients. External validation confirmed a diagnostic AUC of 0.738.

CONCLUSIONS

Serum exosomal miR-125a-5p derived from adipose tissue can serve as a causal biomarker for cognitive impairment in T2DM patients.

Plant-derived nanovesicles: Promising therapeutics and drug delivery nanoplatforms for brain disorders

Plant-derived nanovesicles (PDNVs), including plant extracellular vesicles (EVs) and plant exosome-like nanovesicles (ELNs), are natural nano-sized membranous vesicles containing bioactive molecules. PDNVs consist of a bilayer of lipids that can effectively encapsulate hydrophilic and lipophilic drugs, improving drug stability and solubility as well as providing increased bioavailability, reduced systemic toxicity, and enhanced target accumulation. Bioengineering strategies can also be exploited to modify the PDNVs to achieve precise targeting, controlled drug release, and massive production. Meanwhile, they are capable of crossing the blood-brain barrier (BBB) to transport the cargo to the lesion sites without harboring human pathogens, making them excellent therapeutic agents and drug delivery nanoplatform candidates for brain diseases. Herein, this article provides an initial exposition on the fundamental characteristics of PDNVs, including biogenesis, uptake process, isolation, purification, characterization methods, and source. Additionally, it sheds light on the investigation of PDNVs' utilization in brain diseases while also presenting novel perspectives on the obstacles and clinical advancements associated with PDNVs.

RNA helicase MOV10 suppresses fear memory and dendritic arborization and regulates microtubule dynamics in hippocampal neurons

BACKGROUND

RNA helicase MOV10 is highly expressed in postnatal brain and associates with FMRP and AGO2, suggesting a role in translation regulation in learning and memory.

RESULTS

We generated a brain-specific knockout mouse (Mov10 Deletion) with greatly reduced MOV10 expression in cortex and hippocampus. Behavior testing revealed enhanced fear memory, similar to that observed in a mouse with reduced brain microRNA production, supporting MOV10's reported role as an AGO2 cofactor. Cultured hippocampal neurons have elongated distal dendrites, a reported feature of augmin/HAUS over-expression in Drosophila da sensory neurons. In mitotic spindle formation, HAUS is antagonized by the microtubule bundling protein NUMA1. Numa1 mRNA is a MOV10 CLIP target and is among the genes significantly decreased in Mov10 Deletion hippocampus. Restoration of NUMA1 expression and knockdown of HAUS rescued phenotypes of the Mov10 Deletion hippocampal neurons.

CONCLUSIONS

This is the first evidence of translation regulation of NUMA1 by MOV10 as a control point in dendritogenesis.

Posterior cingulate cortex microRNA dysregulation differentiates cognitive resilience, mild cognitive impairment, and Alzheimer's disease

INTRODUCTION

MicroRNA (miRNA) activity is increasingly appreciated as a key regulator of pathophysiologic pathways in Alzheimer's disease (AD). However, the role of miRNAs during the progression of AD, including resilience and prodromal syndromes such as mild cognitive impairment (MCI), remains underexplored.

METHODS

We performed miRNA-sequencing on samples of posterior cingulate cortex (PCC) obtained post mortem from Rush Religious Orders Study participants diagnosed ante mortem with no cognitive impairment (NCI), MCI, or AD. NCI subjects were subdivided as low pathology (Braak stage I/II) or high pathology (Braak stage III/IV), suggestive of resilience. Bioinformatics approaches included differential expression, messenger RNA (mRNA) target prediction, interactome modeling, functional enrichment, and AD risk modeling.

RESULTS

We identified specific miRNA groups, mRNA targets, and signaling pathways distinguishing AD, MCI, resilience, ante mortem neuropsychological test performance, post mortem neuropathological burden, and AD risk.

DISCUSSION

These findings highlight the potential of harnessing miRNA activity to manipulate disease-modifying pathways in AD, with implications for precision medicine.

HIGHLIGHTS

MicroRNA (MiRNA) dysregulation is a well-established feature of Alzheimer's disease (AD). Novel miRNAs also distinguish subjects with mild cognitive impairment and putative resilience. MiRNAs correlate with cognitive performance and neuropathological burden. Select miRNAs are associated with AD risk with age as a significant covariate. MiRNA pathways include insulin, prolactin, kinases, and neurite plasticity.

Non-coding RNAs in the pathogenesis of Alzheimer's disease: β-amyloid aggregation, Tau phosphorylation and neuroinflammation

Alzheimer's disease is a progressive neurodegenerative disorder primarily affecting individuals aged 65 and older, characterized by cognitive decline and diminished quality of life. The molecular hallmarks of AD include extracellular β-amyloid plaques, intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein, and chronic neuroinflammation. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have emerged as potential therapeutic targets due to their regulatory roles in AD pathogenesis. For example, miR-124 has been shown to modulate Aβ levels, while lncRNAs such as BACE1-AS regulate the expression of BACE1, a crucial enzyme in Aβ production. Transcriptomic studies of AD patients have revealed dysregulation of ncRNA expression, further supporting their involvement in disease progression. This review examines the regulatory functions of ncRNAs in AD, focusing on their impact on Aβ, tau hyperphosphorylation, and neuroinflammation. Additionally, we discuss the emerging role of ncRNAs in liquid-liquid phase separation and the formation of protein aggregates, key processes contributing to AD pathology.

The regulation of miRNAs using curcumin and other polyphenols during the prevention and treatment of Alzheimer's disease

Alzheimer's disease (AD), a prevalent neurodegenerative disorder, predominantly affects individuals over the age of 65 and poses significant challenges in terms of effective management and treatment. The disease's pathogenesis involves complex molecular pathways including misfolded proteins accumulation, neuroinflammation, and synaptic dysfunction. Recent insights have highlighted the role of microRNAs (miRNAs) as critical regulators within these pathways, where they influence gene expression and contribute to the pathophysiological landscape of AD. Notably, emerging research has demonstrated that polyphenols, including curcumin, might modulate miRNA activity, thus offering a novel approach to mitigate AD symptoms and progression. This review explores the potential mechanisms through which polyphenols regulate miRNA expression and activity, specifically focusing on autophagy enhancement and inflammation reduction in the context of AD. We provide a detailed examination of key studies linking miRNA dysregulation to AD pathogenesis and discuss how polyphenols might correct these aberrations. The findings presented here underscore the therapeutic potential of polyphenols in AD treatment via miRNA modulation, pointing to new directions in disease management strategies and highlighting the need for targeted research into miRNA-based interventions.

Fluorescent Particles Based on Aggregation-Induced Emission for Optical Diagnostics of the Central Nervous System

In 2001, Tang's team discovered a unique type of luminogens with substantial enhanced fluorescence upon aggregation and introduced the concept of "aggregation-induced emission (AIE)". Unlike conventional fluorescent materials, AIE luminogens (AIEgens) emit weak or no fluorescence in solution but become highly fluorescent in aggregated or solid states, due to a mechanism known as restriction of intramolecular motions (RIM). Initially considered a purely inorganic chemical phenomenon, AIE was later applied in biomedicine to improve the sensitivity of immunoassays. Subsequently, AIE has been extensively explored in various biomedical applications, especially in cell imaging. Early studies achieved nonspecific cell imaging using nontargeted AIEgens, and later, specific cellular imaging was realized through the design of targeted AIEgens. These advancements have enabled the visualization of various biomacromolecules and intracellular organelles, providing valuable insights into cellular microenvironments and statuses. Neurological disorders affect over 3 billion people worldwide, highlighting the urgent need for advanced diagnostic and therapeutic tools. AIEgens offer promising opportunities for imaging the central nervous system (CNS), including nerve cells, neural tissues, and blood vessels. This review focuses on the application of AIEgens in CNS imaging, exploring their roles in the diagnosis of various neurological diseases. We will discuss the evolution and conclude with an outlook on the future challenges and opportunities for AIEgens in clinical diagnostics and therapeutics of CNS disorders.

Mitochondrial microRNAs: Key Drivers in Unraveling Neurodegenerative Diseases

MicroRNAs (miRNAs) are a class of small non-coding RNAs (ncRNAs) crucial for regulating gene expression at the post-transcriptional level. Recent evidence has shown that miRNAs are also found in mitochondria, organelles that produce energy in the cell. These mitochondrial miRNAs, also known as mitomiRs, are essential for regulating mitochondrial function and metabolism. MitomiRs can originate from the nucleus, following traditional miRNA biogenesis pathways, or potentially from mitochondrial DNA, allowing them to directly affect gene expression and cellular energy dynamics within the mitochondrion. While miRNAs have been extensively investigated, the function and involvement of mitomiRs in the development of neurodegenerative disorders like Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis remain to be elucidated. This review aims to discuss findings on the role of mitomiRs in such diseases and their potential as therapeutic targets, as well as to highlight future research directions.

Effects of MicroRNAs and Long Non-coding RNAs on Beneficial Action of Exercise on Cognition in Degenerative Diseases: A Review

Recent research has exposed a growing body of proof underscoring the importance of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in maintaining the physical composition of neurons and influencing cognitive functioning in both standard and atypical circumstances. Extensive research has been conducted on the possible application of miRNAs and lncRNAs as biomarkers for various diseases, with a particular focus on brain disorders, as they possess remarkable durability in cell-free surroundings and can endure repeated freezing and thawing processes. It is intriguing to note that miRNAs and lncRNAs have the ability to function through paracrine mechanisms, thereby playing a role in communication between different organs. Recent research has proposed that the improvement of cognitive abilities through physical exercise in mentally healthy individuals is a valuable method for uncovering potential connections between miRNAs, or microRNAs, and lncRNAs, and human cognitive function. The process of cross-correlating data from disease models and patients with existing data will be crucial in identifying essential miRNAs and lncRNAs, which can potentially act as biomarkers or drug targets in the treatment of cognitive disorders. By combining this method with additional research in animal models, we can determine the function of these molecules and their potential impact on therapy. This article discusses the latest research about the primary miRNAs, lncRNAs, and their exosomes that are affected by physical activity in terms of human cognitive function.

Mapping the current trends and hotspots of extracellular vesicles in Alzheimer's disease: a bibliometric analysis

Background

Extracellular vesicles (EVs) have garnered significant attention in Alzheimer's disease (AD) research over the past decade, largely due to their potential in diagnostics and therapeutics. Although the investigation of EVs in AD is a relatively recent endeavor, a comprehensive bibliometric analysis of this rapidly growing field has yet to be conducted.

Methods

This study aims to elucidate and synthesize the relationship between EVs and AD, offering critical insights to guide future research and expand therapeutic possibilities. Over the past 10-15 years, substantial progress has been made in this domain. Through bibliometric techniques, this analysis assesses research performance by examining scientific publications and metrics, including productivity indicators, impact measurements, data mining, and visualization tools.

Results

A total of 602 publications were analyzed using various online platforms for bibliometric analysis. Notably, the number of publications began to increase rapidly in 2018, with China and the United States emerging as leaders in this research area. The National Institute on Aging produced the highest number of publications among institutions. The Journal of Molecular Sciences and the Journal of Biological Chemistry were the most prolific and most frequently cited journals, respectively. Among individual contributors, Dimitrios Kapogiannis was identified as the most productive author, while Edward J. Goetzl was the most co-cited. The most prevalent keywords included "neurodegenerative diseases," "exosomes," "blood biomarkers," "amyloid beta," "microglia," and "tau protein." Current research hotspots involve microRNA dysregulation, oxidative stress, carboxyl-terminal fragments, small EVs, and mesenchymal stem cell-derived EVs, indicating key areas for future research.

Conclusion

Research on microRNA dysregulation, oxidative stress, carboxyl-terminal fragments, small EVs, and mesenchymal stem cell-derived EVs represents a critical frontier in the study of Alzheimer's disease. The role of EV-mediated neuroinflammation in AD is a focal point of ongoing investigation and will likely shape future developments in the field.

Role of Redox Homeostasis in the Communication Between Brain and Liver Through Extracellular Vesicles

Extracellular vesicles (EVs) are small, membrane-bound particles secreted by cells into the extracellular environment, playing an increasingly recognized role in inter-organ communication and the regulation of various physiological processes. Regarding the redox homeostasis context, EVs play a pivotal role in propagating and mitigating oxidative stress signals across different organs. Cells under oxidative stress release EVs containing signaling molecules that can influence the redox status of distant cells and tissues. EVs are starting to be recognized as contributors to brain-liver communication. Therefore, in this review, we show how redox imbalance can affect the release of EVs in the brain and liver. We propose EVs as mediators of redox homeostasis in the brain-liver axis.

Exploring the role of miR-125b-5p as a pro-inflammatory factor in Alzheimer's disease pathology

BACKGROUND

Alzheimer's disease (AD) is a common neurodegenerative disease, where neuroinflammation significantly influences its pathophysiology by driving the disease's pathological cascade. As a pro-inflammatory regulator, miR-125b-5p contributes to AD progression, though its precise role and mechanisms remain unclear.

OBJECTIVE

We aims to identify mRNAs significantly regulated by pro-inflammatory miR-125b-5p in AD and uncover key neuroinflammatory pathways.

METHODS

Target mRNAs regulated by miR-125b-5p were predicted using online databases and analyzed with two mRNA datasets to identify differentially expressed mRNAs (DEmRNAs). Enrichment analysis was conducted to explore their biological functions and pathways. The significance of DEmRNAs expression in AD-related inflammatory pathways was verified by the Wilcoxon test, predictive accuracy was assessed via area under the curves (AUCs), and novel mRNAs were identified through positive control analysis.

RESULTS

A total of 613 miR-125b-5p target mRNAs were identified, and 44 DEmRNAs were detected to be regulated by miR-125b-5p in two datasets. The 44 target DEmRNAs associated with AD include three key pathways: insulin signaling (EXOC7, FLOT2, MKNK2), phosphatidylinositol signaling (IP6K1, MTMR3), and phospholipase D signaling (CYTH1, GAB2). Correlation analysis indicated strong correlations among 7 mRNAs, all showing significant differential expression, with AUCs above 0.5, confirming their predictive value. Three mRNAs (EXOC7, IP6K1, CYTH1) were identified as novel AD-related genes. MiR-125b-5p binding sites in the 3'-UTRs of these 7 mRNAs suggest their potential roles in AD-related inflammation and signaling pathways.

CONCLUSIONS

This study investigates the pro-inflammatory miR-125b-5p's role in the pathological processes of AD, highlighting its regulation of key target mRNAs and critical pathways.

Exosomal MicroRNAs in Alzheimer's Disease: Unveiling Their Role and Pioneering Tools for Diagnosis and Treatment

Alzheimer's disease (AD) is a common neurodegenerative disorder that presents a significant health concern, often leading to substantial cognitive decline among older adults. A prominent feature of AD is progressive dementia, which eventually disrupts daily functioning and the ability to live independently. A major challenge in addressing AD is its prolonged pre-symptomatic phase, which makes early detection difficult. Moreover, the disease's complexity and the inefficiency of current diagnostic methods impede the development of targeted therapies. Therefore, there is an urgent need to enhance diagnostic methodologies for detection and treating AD even before clinical symptoms appear. Exosomes are nanoscale biovesicles secreted by cells, including nerve cells, into biofluids. These exosomes play essential roles in the central nervous system (CNS) by facilitating neuronal communication and thus influencing major physiological and pathological processes. Exosomal cargo, particularly microRNAs (miRNAs), are critical mediators in this cellular communication, and their dysregulation affects various pathological pathways related to neurodegenerative diseases, including AD. This review discusses the significant roles of exosomal miRNAs in the pathological mechanisms related to AD, focusing on the promising use of exosomal miRNAs as diagnostic biomarkers and targeted therapeutic interventions for this devastating disease.

The plasma miRNAome in ADNI: Signatures to aid the detection of at-risk individuals

INTRODUCTION

MicroRNAs are short non-coding RNAs that control proteostasis at the systems level and are emerging as potential prognostic and diagnostic biomarkers for Alzheimer's disease (AD).

METHODS

We performed small RNA sequencing on plasma samples from 847 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants.

RESULTS

We identified microRNA signatures that correlate with AD diagnoses and help predict the conversion from mild cognitive impairment (MCI) to AD.

DISCUSSION

Our data demonstrate that plasma microRNA signatures can be used to not only diagnose MCI, but also, critically, predict the conversion from MCI to AD. Moreover, combined with neuropsychological testing, plasma microRNAome evaluation helps predict MCI to AD conversion. These findings are of considerable public interest because they provide a path toward reducing indiscriminate utilization of costly and invasive testing by defining the at-risk segment of the aging population.

HIGHLIGHTS

We provide the first analysis of the plasma microRNAome for the ADNI study. The levels of several microRNAs can be used as biomarkers for the prediction of conversion from MCI to AD. Adding the evaluation of plasma microRNA levels to neuropsychological testing in a clinical setting increases the accuracy of MCI to AD conversion prediction.

A Comprehensive Review of Membrane Transporters and MicroRNA Regulation in Alzheimer's Disease

Alzheimer's disease (AD) is a distressing neurodegenerative condition characterized by the accumulation of amyloid-beta (Aβ) plaques and tau tangles within the brain. The interconnectedness between membrane transporters (SLCs) and microRNAs (miRNAs) in AD pathogenesis has gained increasing attention. This review explores the localization, substrates, and functions of SLC transporters in the brain, emphasizing the roles of transporters for glutamate, glucose, nucleosides, and other essential compounds. The examination delves into the significance of SLCs in AD, their potential for drug development, and the intricate realm of miRNAs, encompassing their transcription, processing, functions, and regulation. MiRNAs have emerged as significant players in AD, including those associated with mitochondria and synapses. Furthermore, this review discusses the intriguing nexus of miRNAs targeting SLC transporters and their potential as therapeutic targets in AD. Finally, the review underscores the interaction between SLC transporters and miRNA regulation within the context of Alzheimer's disease, underscoring the need for further research in this area. This comprehensive review aims to shed light on the complex mechanisms underlying the causation of AD and provides insights into potential therapeutic approaches.

Unveiling the multifaceted pathogenesis and therapeutic drugs of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is a severe neurodegenerative disorder characterized by the accumulation of β-amyloid (Aβ) plaques and tau phosphorylation-induced neurofibrillary tangles. This review comprehensively summarizes AD pathogenesis and related factors, drawing on a wealth of authoritative reports and research findings. Specifically, we delve into the intricate mechanisms underlying AD pathology, including Aβ deposition, tau protein phosphorylation, cholinergic dysfunction, neuroinflammation, mitochondrial oxidative stress, ferroptosis, imbalance in the gut microbiota, and microRNA dysregulation. We also explored the effects of these factors on the brain, including synaptic damage and cognitive impairment. Moreover, our review highlights the associations between the pathogenesis of AD and inflammatory cytokines in the peripheral blood and cerebrospinal fluid, dysbiosis of the gut microbiota, and changes in microRNA expression. Overall, we provided a systematic and illustrative overview of the pathogenesis and therapeutic drugs for AD, offering help in the prevention and treatment of this condition.

Blood-derived microRNAs are related to cognitive domains in the general population

INTRODUCTION

Blood-derived microRNAs (miRNAs) are potential candidates for detecting and preventing subclinical cognitive dysfunction. However, replication of previous findings and identification of novel miRNAs associated with cognitive domains, including their relation to brain structure and the pathways they regulate, are still lacking.

METHODS

We examined blood-derived miRNAs and miRNA co-expression clusters in relation to cognitive domains, structural magnetic resonance imaging measures, target gene expression, and genetic variants in 2869 participants of a population-based cohort.

RESULTS

Five previously identified and 14 novel miRNAs were associated with cognitive domains. Eleven of these were also associated with cortical thickness and two with hippocampal volume. Multi-omics analysis showed that certain identified miRNAs were genetically influenced and regulated genes in pathways like neurogenesis and synapse assembly.

DISCUSSION

We identified miRNAs associated with cognitive domains, brain regions, and neuronal processes affected by aging and neurodegeneration, making them promising candidate blood-based biomarkers or therapeutic targets of subclinical cognitive dysfunction.

HIGHLIGHTS

We investigated the association of blood-derived microRNAs with cognitive domains. Five previously identified and 14 novel microRNAs were associated with cognition. Eleven cognition-related microRNAs were also associated with cortical thickness. Identified microRNAs were linked to genes associated with neuronal functions. Results provide putative biomarkers or therapeutic targets of cognitive aging.

Novel insights into minipuberty and GnRH: Implications on neurodevelopment, cognition, and COVID-19 therapeutics

In humans, the first 1000 days of life are pivotal for brain and organism development. Shortly after birth, gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus are activated, a phenomenon known as minipuberty. This phenomenon, observed in all mammals studied, influences the postnatal development of the hypothalamic-pituitary-gonadal (HPG) axis and reproductive function. This review will put into perspective the results of recent studies showing that the impact of minipuberty extends beyond reproductive function, influencing sensory and cognitive maturation. Studies in mice have revealed the role of nitric oxide (NO) in regulating minipuberty amplitude, with NO deficiency linked to cognitive and olfactory deficits. Additionally, findings indicate that cognitive and sensory defects in adulthood in a mouse model of Down syndrome are associated with an age-dependent decline of GnRH production, whose origin can be traced back to minipuberty, and point to the potential therapeutic role of pulsatile GnRH administration in cognitive disorders. Furthermore, this review delves into the repercussions of COVID-19 on GnRH production, emphasizing potential consequences for neurodevelopment and cognitive function in infected individuals. Notably, GnRH neurons appear susceptible to SARS-CoV-2 infection, raising concerns about potential long-term effects on brain development and function. In conclusion, the intricate interplay between GnRH neurons, GnRH release, and the activity of various extrahypothalamic brain circuits reveals an unexpected role for these neuroendocrine neurons in the development and maintenance of sensory and cognitive functions, supplementing their established function in reproduction. Therapeutic interventions targeting the HPG axis, such as inhaled NO therapy in infancy and pulsatile GnRH administration in adults, emerge as promising approaches for addressing neurodevelopmental cognitive disorders and pathological aging.

Insights into the Role of microRNAs as Clinical Tools for Diagnosis, Prognosis, and as Therapeutic Targets in Alzheimer's Disease

Neurodegenerative diseases (NDDs) are a diverse group of neurological disorders characterized by alterations in the structure and function of the central nervous system. Alzheimer's disease (AD), characterized by impaired memory and cognitive abilities, is the most prevalent type of senile dementia. Loss of synapses, intracellular aggregation of hyperphosphorylated tau protein, and extracellular amyloid-β peptide (Aβ) plaques are the hallmarks of AD. MicroRNAs (miRNAs/miRs) are single-stranded ribonucleic acid (RNA) molecules that bind to the 3' and 5' untranslated regions of target genes to cause post-transcriptional gene silencing. The brain expresses over 70% of all experimentally detected miRNAs, and these miRNAs are crucial for synaptic function and particular signals during memory formation. Increasing evidence suggests that miRNAs play a role in AD pathogenesis and we provide an overview of the role of miRNAs in synapse formation, Aβ synthesis, tau protein accumulation, and brain-derived neurotrophic factor-associated AD pathogenesis. We further summarize and discuss the role of miRNAs as potential therapeutic targets and biomarkers for AD detection and differentiation between early- and late-stage AD, based on recent research. In conclusion, altered expression of miRNAs in the brain and peripheral circulation demonstrates their potential as biomarkers and therapeutic targets in AD.

Unlocking early detection of Alzheimer's disease: The emerging role of nanomaterial-based optical sensors

Alzheimer's disease (AD) is a chronic and progressive neurodegenerative disorder that affects millions of individuals worldwide. Researchers have conducted numerous studies to find accurate biomarkers for early AD diagnosis and develop more effective treatments. The main pathological hallmarks of AD are amyloid beta and Tau proteins. Other biomarkers, such as DNA, RNA, and proteins, can also be helpful in early AD diagnosis. To diagnose and treat AD promptly, it is essential to accurately measure the concentration of biomarkers in the cerebrospinal fluid or blood. However, due to the low concentrations of these biomarkers in the body, highly sensitive analytical techniques are required. To date, sensors have become increasingly important due to their high sensitivity, swift detection, and adaptable manipulation features. These qualities make them an excellent substitute for conventional instruments. Nanomaterials are commonly employed in sensors to amplify signals and improve sensitivity. This review paper summarized the integration of nanomaterials in optical sensor systems, including colorimetric, fluorescent, and surface-enhanced Raman scattering sensors for AD biomarkers detection.

Spatiotemporal Dysregulation of Neuron-Glia Related Genes and Pro-/Anti-Inflammatory miRNAs in the 5xFAD Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD), the leading cause of dementia, is a multifactorial disease influenced by aging, genetics, and environmental factors. miRNAs are crucial regulators of gene expression and play significant roles in AD onset and progression. This exploratory study analyzed the expression levels of 28 genes and 5 miRNAs (miR-124-3p, miR-125b-5p, miR-21-5p, miR-146a-5p, and miR-155-5p) related to AD pathology and neuroimmune responses using RT-qPCR. Analyses were conducted in the prefrontal cortex (PFC) and the hippocampus (HPC) of the 5xFAD mouse AD model at 6 and 9 months old. Data highlighted upregulated genes encoding for glial fibrillary acidic protein (Gfap), triggering receptor expressed on myeloid cells (Trem2) and cystatin F (Cst7), in the 5xFAD mice at both regions and ages highlighting their roles as critical disease players and potential biomarkers. Overexpression of genes encoding for CCAAT enhancer-binding protein alpha (Cebpa) and myelin proteolipid protein (Plp) in the PFC, as well as for BCL2 apoptosis regulator (Bcl2) and purinergic receptor P2Y12 (P2yr12) in the HPC, together with upregulated microRNA(miR)-146a-5p in the PFC, prevailed in 9-month-old animals. miR-155 positively correlated with miR-146a and miR-21 in the PFC, and miR-125b positively correlated with miR-155, miR-21, while miR-146a in the HPC. Correlations between genes and miRNAs were dynamic, varying by genotype, region, and age, suggesting an intricate, disease-modulated interaction between miRNAs and target pathways. These findings contribute to our understanding of miRNAs as therapeutic targets for AD, given their multifaceted effects on neurons and glial cells.

Rosuvastatin attenuates total-tau serum levels and increases expression of miR-124-3p in dyslipidemic Alzheimer's patients: a historic cohort study

microRNAs are candidate diagnostic biomarkers for Alzheimer's disease. This study aimed to compare Silymarin with Rosuvastatin and placebo on total-Tau protein level and expression levels of microRNAs and TGF-β and COX-2 in Alzheimer's patients with secondary dyslipidemia. 36 mild AD patients with dyslipidemia were divided into three groups of 12. The first group received silymarin (140mg), the second group received placebo (140mg), and the third group recieved Rosuvastatin (10mg). Tablets were administered three times a day for Six months. The blood samples of the patients were collected before and after the intervention and the serum was separated. Using the RT-qPCR method, the expression levels of miR-124-3p and miR-125b-5p were assessed, and the serum levels of total-Tau, TGF-β, and COX-2 enzyme were measured using the ELISA method. Data were analyzed with SPSS software. In this study, the level of Δtotal-Tau was significantly lower in the Rosuvastatin group compared to the placebo (P = 0.038). Also, a significant reduction in the level of ΔTGF-β was observed in the Silymarin to Rosuvastatin group (p = 0.046) and ΔmiR-124-3p was significantly increased in the Rosuvastatin compared to the placebo group (p = 0.044). Rosuvastatin outperformed silymarin in decreasing Δtotal-Tau serum levels and enhancing expression of ΔmiR-124-3p, attributed to Rosuvastatin's capacity to lower cholesterol levels and inflammation concurrently. Conversely, silymarin was more effective than Rosuvastatin in reducing levels of ΔTGF-β. Serum miR-124-3p could serve as a promising diagnostic biomarker and a new therapeutic focus in AD.

MicroRNA (miRNA) as a biomarker for diagnosis, prognosis, and therapeutics molecules in neurodegenerative disease

Neurodegenerative diseases that include Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), Huntington's disease (HD), and multiple sclerosis (MS) that arise due to numerous causes like protein accumulation and autoimmunity characterized by neurologic depletion which lead to incapacity in normal physiological function such as thinking and movement in these patients. Glial cells perform an important role in protective neuronal function; in the case of neuroinflammation, glial cell dysfunction can promote the development of neurodegenerative diseases. miRNA that participates in gene regulation and plays a vital role in many biological processes in the body; in the central nervous system (CNS), it can play an essential part in neural maturation and differentiation. In neurodegenerative diseases, miRNA dysregulation occurs, enhancing the development of these diseases. In this review, we discuss neurodegenerative disease (Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS)) and how miRNA is preserved as a diagnostic biomarker or therapeutic agent in these disorders. Finally, we highlight miRNA as therapy.

Induced pluripotent stem cell models as a tool to investigate and test fluid biomarkers in Alzheimer's disease and frontotemporal dementia

Neurodegenerative diseases are increasing in prevalence and comprise a large socioeconomic burden on patients and their caretakers. The need for effective therapies and avenues for disease prevention and monitoring is of paramount importance. Fluid biomarkers for neurodegenerative diseases have gained a variety of uses, including informing participant selection for clinical trials, lending confidence to clinical diagnosis and disease staging, determining prognosis, and monitoring therapeutic response. Their role is expected to grow as disease-modifying therapies start to be available to a broader range of patients and as prevention strategies become established. Many of the underlying molecular mechanisms of currently used biomarkers are incompletely understood. Animal models and in vitro systems using cell lines have been extensively employed but face important translatability limitations. Induced pluripotent stem cell (iPSC) technology, where a theoretically unlimited range of cell types can be reprogrammed from peripheral cells sampled from patients or healthy individuals, has gained prominence over the last decade. It is a promising avenue to study physiological and pathological biomarker function and response to experimental therapeutics. Such systems are amenable to high-throughput drug screening or multiomics readouts such as transcriptomics, lipidomics, and proteomics for biomarker discovery, investigation, and validation. The present review describes the current state of biomarkers in the clinical context of neurodegenerative diseases, with a focus on Alzheimer's disease and frontotemporal dementia. We include a discussion of how iPSC models have been used to investigate and test biomarkers such as amyloid-β, phosphorylated tau, neurofilament light chain or complement proteins, and even nominate novel biomarkers. We discuss the limitations of current iPSC methods, mentioning alternatives such as coculture systems and three-dimensional organoids which address some of these concerns. Finally, we propose exciting prospects for stem cell transplantation paradigms using animal models as a preclinical tool to study biomarkers in the in vivo context.

Methylglyoxal Affects the Expression of miR-125b, miR-107, and Oxidative Stress Pathway-associated Genes in the SH-SY5Y Cell Line

Purpose

Alzhеimеr's disеasе (AD) is thе most prеvalеnt form of dеmеntia globally. Rеsеarch links thе incrеasе of rеactivе oxidativе spеciеs (ROS) to thе pathogеnеsis of AD; thus, this study invеstigatеd thе impact of mеthylglyoxal (MGO) on thе еxprеssion of miR-125b, miR-107, and gеnеs involvеd in oxidativе strеss signaling in SH-SY5Y cеlls.

Methods

Thе MTT assay assеssеd MGO's еffеcts on SH-SY5Y viability. miR-125b and miR-107 еxprеssion was analyzеd via rеal-timе PCR. Additionally, thе Human Oxidativе Strеss Pathway Plus RT2 Profilеr PCR array quantifiеd oxidativе pathway gеnе еxprеssion.

Results

MGO concеntrations undеr 700μM did not significantly rеducе SH-SY5Y viability. MiR-125b and miR-107 еxprеssion in SH-SY5Y cеlls incrеasеd and dеcrеasеd rеspеctivеly (P<0.05). Cеlls trеatеd with 700μM MGO еxhibitеd incrеasеd CCS, CYBB, PRDX3, SPINK1, CYGB, DHCR24 and BAG2 еxprеssion (P<0.05). Thosе trеatеd with 1400μM MGO showеd incrеasеd CCS, CYBB, PRDX3, SPINK1, DUSP1, EPHX2, EPX, FOXM1, and GPX3 еxprеssion (P<0.05).

Conclusion

MGO altеrs oxidativе strеss pathway gеnе, miR-125b, and miR-107 еxprеssion in SH-SY5Y cеlls. Targеting MGO or miR-125b and miR-107 may providе novеl AD thеrapеutic stratеgiеs or improvе sеvеrе symptoms. Furthеr rеsеarch should еlucidatе thе prеcisе mеchanisms.

Non-Coding RNAs and Neurodegenerative Diseases: Information of their Roles in Apoptosis

Apoptosis can be known as a key factor in the pathogenesis of neurodegenerative disorders. In disease conditions, the rate of apoptosis expands and tissue damage may become apparent. Recently, the scientific studies of the non-coding RNAs (ncRNAs) has provided new information of the molecular mechanisms that contribute to neurodegenerative disorders. Numerous reports have documented that ncRNAs have important contributions to several biological processes associated with the increase of neurodegenerative disorders. In addition, microRNAs (miRNAs), circular RNAs (circRNAs), as well as, long ncRNAs (lncRNAs) represent ncRNAs subtypes with the usual dysregulation in neurodegenerative disorders. Dysregulating ncRNAs has been associated with inhibiting or stimulating apoptosis in neurodegenerative disorders. Therefore, this review highlighted several ncRNAs linked to apoptosis in neurodegenerative disorders. CircRNAs, lncRNAs, and miRNAs were also illustrated completely regarding the respective signaling pathways of apoptosis.

Dual-specificity protein phosphatase 6 (DUSP6) overexpression reduces amyloid load and improves memory deficits in male 5xFAD mice

Introduction

Dual specificity protein phosphatase 6 (DUSP6) was recently identified as a key hub gene in a causal VGF gene network that regulates late-onset Alzheimer's disease (AD). Importantly, decreased DUSP6 levels are correlated with an increased clinical dementia rating (CDR) in human subjects, and DUSP6 levels are additionally decreased in the 5xFAD amyloidopathy mouse model.

Methods

To investigate the role of DUSP6 in AD, we stereotactically injected AAV5-DUSP6 or AAV5-GFP (control) into the dorsal hippocampus (dHc) of both female and male 5xFAD or wild type mice, to induce overexpression of DUSP6 or GFP.

Results

Barnes maze testing indicated that DUSP6 overexpression in the dHc of 5xFAD mice improved memory deficits and was associated with reduced amyloid plaque load, Aß1-40 and Aß1-42 levels, and amyloid precursor protein processing enzyme BACE1, in male but not in female mice. Microglial activation, which was increased in 5xFAD mice, was significantly reduced by dHc DUSP6 overexpression in both males and females, as was the number of "microglial clusters," which correlated with reduced amyloid plaque size. Transcriptomic profiling of female 5xFAD hippocampus revealed upregulation of inflammatory and extracellular signal-regulated kinase pathways, while dHc DUSP6 overexpression in female 5xFAD mice downregulated a subset of genes in these pathways. Gene ontology analysis of DEGs (p < 0.05) identified a greater number of synaptic pathways that were regulated by DUSP6 overexpression in male compared to female 5xFAD.

Discussion

In summary, DUSP6 overexpression in dHc reduced amyloid deposition and memory deficits in male but not female 5xFAD mice, whereas reduced neuroinflammation and microglial activation were observed in both males and females, suggesting that DUSP6-induced reduction of microglial activation did not contribute to sex-dependent improvement in memory deficits. The sex-dependent regulation of synaptic pathways by DUSP6 overexpression, however, correlated with the improvement of spatial memory deficits in male but not female 5xFAD.

miRNAs in cerebrospinal fluid associated with Alzheimer's disease: A systematic review and pathway analysis using a data mining and machine learning approach

Alzheimer's disease (AD) is the most common type and accounts for 60%-70% of the reported cases of dementia. MicroRNAs (miRNAs) are small non-coding RNAs that play a crucial role in gene expression regulation. Although the diagnosis of AD is primarily clinical, several miRNAs have been associated with AD and considered as potential markers for diagnosis and progression of AD. We sought to match AD-related miRNAs in cerebrospinal fluid (CSF) found in the GeoDataSets, evaluated by machine learning, with miRNAs listed in a systematic review, and a pathway analysis. Using machine learning approaches, we identified most differentially expressed miRNAs in Gene Expression Omnibus (GEO), which were validated by the systematic review, using the acronym PECO-Population (P): Patients with AD, Exposure (E): expression of miRNAs, Comparison (C): Healthy individuals, and Objective (O): miRNAs differentially expressed in CSF. Additionally, pathway enrichment analysis was performed to identify the main pathways involving at least four miRNAs selected. Four miRNAs were identified for differentiating between patients with and without AD in machine learning combined to systematic review, and followed the pathways analysis: miRNA-30a-3p, miRNA-193a-5p, miRNA-143-3p, miRNA-145-5p. The pathways epidermal growth factor, MAPK, TGF-beta and ATM-dependent DNA damage response, were regulated by these miRNAs, but only the MAPK pathway presented higher relevance after a randomic pathway analysis. These findings have the potential to assist in the development of diagnostic tests for AD using miRNAs as biomarkers, as well as provide understanding of the relationship between different pathophysiological mechanisms of AD.

MicroRNA biomarkers as next-generation diagnostic tools for neurodegenerative diseases: a comprehensive review

Neurodegenerative diseases (NDs) are characterized by abnormalities within neurons of the brain or spinal cord that gradually lose function, eventually leading to cell death. Upon examination of affected tissue, pathological changes reveal a loss of synapses, misfolded proteins, and activation of immune cells-all indicative of disease progression-before severe clinical symptoms become apparent. Early detection of NDs is crucial for potentially administering targeted medications that may delay disease advancement. Given their complex pathophysiological features and diverse clinical symptoms, there is a pressing need for sensitive and effective diagnostic methods for NDs. Biomarkers such as microRNAs (miRNAs) have been identified as potential tools for detecting these diseases. We explore the pivotal role of miRNAs in the context of NDs, focusing on Alzheimer's disease, Parkinson's disease, Multiple sclerosis, Huntington's disease, and Amyotrophic Lateral Sclerosis. The review delves into the intricate relationship between aging and NDs, highlighting structural and functional alterations in the aging brain and their implications for disease development. It elucidates how miRNAs and RNA-binding proteins are implicated in the pathogenesis of NDs and underscores the importance of investigating their expression and function in aging. Significantly, miRNAs exert substantial influence on post-translational modifications (PTMs), impacting not just the nervous system but a wide array of tissues and cell types as well. Specific miRNAs have been found to target proteins involved in ubiquitination or de-ubiquitination processes, which play a significant role in regulating protein function and stability. We discuss the link between miRNA, PTM, and NDs. Additionally, the review discusses the significance of miRNAs as biomarkers for early disease detection, offering insights into diagnostic strategies.

Serum Exosomal miRNA-125b and miRNA-451a are Potential Diagnostic Biomarker for Alzheimer's Diseases

Aim

To explore the diagnostic value of serum-derived exosomal miRNAs and predict the roles of their target genes in Alzheimer's disease (AD) based on the expression of miRNAs in AD patients.

Methods

We determined the relative concentration of exosomal miRNAs by High-throughput Second-generation Sequencing and real-time quantitative real-time PCR.

Results

71 AD patients and 71 ND subjects were collected. The study demonstrated that hsa-miR-125b-1-3p, hsa-miR-193a-5p, hsa-miR-378a-3p, hsa-miR-378i and hsa-miR-451a are differentially expressed in the serum-derived exosomes of AD patients compared with healthy subjects. According to ROC analysis, hsa-miR-125b-1-3p has an AUC of 0.765 in the AD group compared to the healthy group with a sensitivity and specificity of 82.1-67.7%, respectively. Enrichment analysis of its target genes showed that they were related to neuroactive ligand-receptor interactions, the PI3K-Akt signaling pathway, the Hippo signaling pathway and nervous system-related pathways. And, hsa-miR-451a had an AUC of 0.728 that differentiated the AD group from the healthy group with a sensitivity and specificity of 67.9% and 72.6%, respectively. Enrichment analysis of its target genes showed a relationship with cytokine-cytokine receptor interactions and the PI3K-Akt signaling pathway.

Conclusion

The dysregulation of serum exosomal microRNAs in patients with AD may promote the diagnosis of AD. The target genes of miRNAs may be involved in the occurrence and development of AD through various pathways.

Micro-RNA profiles of pathology and resilience in posterior cingulate cortex of cognitively intact elders

The posterior cingulate cortex (PCC) is a key hub of the default mode network underlying autobiographical memory retrieval, which falters early in the progression of Alzheimer's disease (AD). We recently performed RNA sequencing of post-mortem PCC tissue samples from 26 elderly Rush Religious Orders Study participants who came to autopsy with an ante-mortem diagnosis of no cognitive impairment but who collectively displayed a range of Braak I-IV neurofibrillary tangle stages. Notably, cognitively unimpaired subjects displaying high Braak stages may represent cognitive resilience to AD pathology. Transcriptomic data revealed elevated synaptic and ATP-related gene expression in Braak Stages III/IV compared with Stages I/II, suggesting these pathways may be related to PCC resilience. We also mined expression profiles for small non-coding micro-RNAs (miRNAs), which regulate mRNA stability and may represent an underexplored potential mechanism of resilience through the fine-tuning of gene expression within complex cellular networks. Twelve miRNAs were identified as differentially expressed between Braak Stages I/II and III/IV. However, the extent to which the levels of all identified miRNAs were associated with subject demographics, neuropsychological test performance and/or neuropathological diagnostic criteria within this cohort was not explored. Here, we report that a total of 667 miRNAs are significantly associated (rho > 0.38, P < 0.05) with subject variables. There were significant positive correlations between miRNA expression levels and age, perceptual orientation and perceptual speed. By contrast, higher miRNA levels correlated negatively with semantic and episodic memory. Higher expression of 15 miRNAs associated with lower Braak Stages I-II and 47 miRNAs were associated with higher Braak Stages III-IV, suggesting additional mechanistic influences of PCC miRNA expression with resilience. Pathway analysis showed enrichment for miRNAs operating in pathways related to lysine degradation and fatty acid synthesis and metabolism. Finally, we demonstrated that the 12 resilience-related miRNAs differentially expressed in Braak Stages I/II versus Braak Stages III/IV were predicted to regulate mRNAs related to amyloid processing, tau and inflammation. In summary, we demonstrate a dynamic state wherein differential PCC miRNA levels are associated with cognitive performance and post-mortem neuropathological AD diagnostic criteria in cognitively intact elders. We posit these relationships may inform miRNA transcriptional alterations within the PCC relevant to potential early protective (resilience) or pathogenic (pre-clinical or prodromal) responses to disease pathogenesis and thus may be therapeutic targets.

Non-coding RNAs and neuroinflammation: implications for neurological disorders

Neuroinflammation is considered a balanced inflammatory response important in the intrinsic repair process after injury or infection. Under chronic states of disease, injury, or infection, persistent neuroinflammation results in a heightened presence of cytokines, chemokines, and reactive oxygen species that result in tissue damage. In the CNS, the surrounding microglia normally contain macrophages and other innate immune cells that perform active immune surveillance. The resulting cytokines produced by these macrophages affect the growth, development, and responsiveness of the microglia present in both white and gray matter regions of the CNS. Controlling the levels of these cytokines ultimately improves neurocognitive function and results in the repair of lesions associated with neurologic disease. MicroRNAs (miRNAs) are master regulators of the genome and subsequently control the activity of inflammatory responses crucial in sustaining a robust and acute immunological response towards an acute infection while dampening pathways that result in heightened levels of cytokines and chemokines associated with chronic neuroinflammation. Numerous reports have directly implicated miRNAs in controlling the abundance and activity of interleukins, TGF-B, NF-kB, and toll-like receptor-signaling intrinsically linked with the development of neurological disorders such as Parkinson's, ALS, epilepsy, Alzheimer's, and neuromuscular degeneration. This review is focused on discussing the role miRNAs play in regulating or initiating these chronic neurological states, many of which maintain the level and/or activity of neuron-specific secondary messengers. Dysregulated miRNAs present in the microglia, astrocytes, oligodendrocytes, and epididymal cells, contribute to an overall glial-specific inflammatory niche that impacts the activity of neuronal conductivity, signaling action potentials, neurotransmitter robustness, neuron-neuron specific communication, and neuron-muscular connections. Understanding which miRNAs regulate microglial activation is a crucial step forward in developing non-coding RNA-based therapeutics to treat and potentially correct the behavioral and cognitive deficits typically found in patients suffering from chronic neuroinflammation.

Mesenchymal Stem Cells from Familial Alzheimer's Patients Express MicroRNA Differently

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the predominant form of dementia globally. No reliable diagnostic, predictive techniques, or curative interventions are available. MicroRNAs (miRNAs) are vital to controlling gene expression, making them valuable biomarkers for diagnosis and prognosis. This study examines the transcriptome of olfactory ecto-mesenchymal stem cells (MSCs) derived from individuals with the PSEN1(A431E) mutation (Jalisco mutation). The aim is to determine whether this mutation affects the transcriptome and expression profile of miRNAs and their target genes at different stages of asymptomatic, presymptomatic, and symptomatic conditions. Expression microarrays compare the MSCs from mutation carriers with those from healthy donors. The results indicate a distinct variation in the expression of miRNAs and mRNAs among different symptomatologic groups and between individuals with the mutation. Using bioinformatics tools allows us to identify target genes for miRNAs, which in turn affect various biological processes and pathways. These include the cell cycle, senescence, transcription, and pathways involved in regulating the pluripotency of stem cells. These processes are closely linked to inter- and intracellular communication, vital for cellular functioning. These findings can enhance our comprehension and monitoring of the disease's physiological processes, identify new disorder indicators, and develop innovative treatments and diagnostic tools for preventing or treating AD.

Understanding the multifaceted role of miRNAs in Alzheimer's disease pathology

Small non-coding RNAs (miRNAs) regulate gene expression by binding to mRNA and mediating its degradation or inhibiting translation. Since miRNAs can regulate the expression of several genes, they have multiple roles to play in biological processes and human diseases. The majority of miRNAs are known to be expressed in the brain and are involved in synaptic functions, thus marking their presence and role in major neurodegenerative disorders, including Alzheimer's disease (AD). In AD, amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are known to be the major hallmarks. The clearance of Aβ and tau is known to be associated with miRNA dysregulation. In addition, the β-site APP cleaving enzyme (BACE 1), which cleaves APP to form Aβ, is also found to be regulated by miRNAs, thus directly affecting Aβ accumulation. Growing evidences suggest that neuroinflammation can be an initial event in AD pathology, and miRNAs have been linked with the regulation of neuroinflammation. Inflammatory disorders have also been associated with AD pathology, and exosomes associated with miRNAs are known to regulate brain inflammation, suggesting for the role of systemic miRNAs in AD pathology. Several miRNAs have been related in AD, years before the clinical symptoms appear, most of which are associated with regulating the cell cycle, immune system, stress responses, cellular senescence, nerve growth factor (NGF) signaling, and synaptic regulation. Phytochemicals, especially polyphenols, alter the expression of various miRNAs by binding to miRNAs or binding to the transcriptional activators of miRNAs, thus control/alter various metabolic pathways. Awing to the sundry biological processes being regulated by miRNAs in the brain and regulation of expression of miRNAs via phytochemicals, miRNAs and the regulatory bioactive phytochemicals can serve as therapeutic agents in the treatment and management of AD.

The Clinical Aspects of COVID and Alzheimer's Disease: A Round-Up of Where Things Stand and Are Headed

 The link between long COVID-19 and brain/cognitive impairments is concerning and may foster a worrisome worldwide emergence of novel cases of neurodegenerative diseases with aging. This review aims to update the knowledge, crosstalk, and possible intersections between the Post-COVID Syndrome (PCS) and Alzheimer's disease (AD). References included in this review were obtained from PubMed searches conducted between October 2023 and November 2023. PCS is a very heterogenous and poorly understood disease with recent evidence of a possible association with chronic diseases such as AD. However, more scientific data is required to establish the link between PCS and AD.

Adipose Tissue Exosome circ_sxc Mediates the Modulatory of Adiposomes on Brain Aging by Inhibiting Brain dme-miR-87-3p

Aging of the brain usually leads to the decline of neurological processes and is a major risk factor for various neurodegenerative diseases, including sleep disturbances and cognitive decline. Adipose tissue exosomes, as adipocyte-derived vesicles, may mediate the regulatory processes of adipose tissue on other organs, including the brain; however, the regulatory mechanisms remain unclear. We analyzed the sleep-wake behavior of young (10 days) and old (40 days) Drosophila and found that older Drosophila showed increased sleep fragmentation, which is similar to mammalian aging characteristics. To investigate the cross-tissue regulatory mechanisms of adiposity on brain aging, we extracted 10-day and 40-day Drosophila adipose tissue exosomes and identified circRNAs with age-dependent expression differences by RNA-seq and differential analysis. Furthermore, by combining data from 3 datasets of the GEO database (GSE130158, GSE24992, and GSE184559), circ_sxc that was significantly downregulated with age was finally screened out. Moreover, dme-miR-87-3p, a conserved target of circ_sxc, accumulates in the brain with age and exhibits inhibitory effects in predicted binding relationships with neuroreceptor ligand genes. In summary, the current study showed that the Drosophila brain could obtain circ_sxc by uptake of adipose tissue exosomes which crossed the blood-brain barrier. And circ_sxc suppressed brain miR-87-3p expression through sponge adsorption, which in turn regulated the expression of neurological receptor ligand proteins (5-HT1B, GABA-B-R1, Rdl, Rh7, qvr, NaCP60E) and ensured brain neuronal synaptic signaling normal function of synaptic signaling. However, with aging, this regulatory mechanism is dysregulated by the downregulation of the adipose exosome circ_sxc, which contributes to the brain exhibiting sleep disturbances and other "aging" features.

Noncoding RNAs in Alzheimer's Disease: Overview of Functional and Therapeutic Significance

Alzheimer's disease (AD) is a multifactorial disorder resulting from the complex interaction between genetic, epigenetic, and environmental factors. It represents an impending epidemic and lacks effective pharmacological interventions. The emergence of high throughput sequencing techniques and comprehensive genome evaluation has uncovered a diverse spectrum of noncoding RNA (ncRNA) families. ncRNAs are the critical modulators of an eclectic array of biological processes and are now transpiring as imperative players in diagnosing and treating various diseases, including neurodegenerative disorders. Several ncRNAs are explicitly augmented in the brain, wherein they potentially regulate cognitive abilities and other functions of the central nervous system. Growing evidence suggests the substantial role of ncRNAs as modulators of tau phosphorylation, Aβ production, neuroinflammation, and neuronal survival. It indicates their therapeutic relevance as a biomarker and druggable targets against AD. The current review summarizes the existing literature on the functional significance of ncRNAs in AD pathogenesis and its imminent implications in clinics.

Non-coding RNAs in Regulation of Protein Aggregation and Clearance Pathways: Current Perspectives Towards Alzheimer's Research and Therapy

Alzheimer's disease (AD) is the leading cause of dementia, affecting approximately 45.0 million people worldwide and ranking as the fifth leading cause of mortality. AD is identified by neurofibrillary tangles (NFTs), which include abnormally phosphorylated tau-protein and amyloid protein (amyloid plaques). Peptide dysregulation is caused by an imbalance between the production and clearance of the amyloid-beta (Aβ) and NFT. AD begins to develop when these peptides are not cleared from the body. As a result, understanding the processes that control both normal and pathological protein recycling in neuronal cells is critical. Insufficient Aβ and NFT clearance are important factors in the development of AD. Autophagy, lysosomal dysfunction, and ubiquitin-proteasome dysfunction have potential roles in the pathogenesis of many neurodegenerative disorders, particularly in AD. Modulation of these pathways may provide a novel treatment strategy for AD. Non-coding RNAs (ncRNAs) have recently emerged as important biological regulators, with particular relevance to the emergence and development of neurodegenerative disorders such as AD. ncRNAs can be used as potential therapeutic targets and diagnostic biomarkers due to their critical regulatory functions in several biological processes involved in disease development, such as the aggregation and accumulation of Aβ and NFT. It is evident that ncRNAs play a role in the pathophysiology of AD. In this communication, we explored the link between ncRNAs and AD and their regulatory mechanisms that may help in finding new therapeutic targets and AD medications.