SLC2A3 rs12842 polymorphism and risk for Alzheimer’s disease

A non-targeting magnetic metal-organic framework probe for highly specific peptide-mediated precise disease monitoring

Alzheimer's disease (AD) is a universal neurodegenerative disease in older adults with incurable and progressive properties, urging for precise monitoring to perform timely treatment to delay its progression. Herein, we introduced a non-targeting magnetic metal-organic framework probe coupled with high-throughput mass spectrometry, creating a rapid screening strategy for highly specific peptides associated with AD. Notably, an elution-free extraction process was proposed, significantly reducing sample preprocessing time while simultaneously ensuring the efficient detection of captured peptides. Using this elution-free extraction process, high-quality peptide profiles were rapidly extracted from the hundreds of samples from both diseased and healthy individuals. By integrating machine learning algorithms, LC-MS/MS, and Uniprot database searching, we identified three specific serum endogenous peptides (m/z = 4215.41, 2884.77 and 2704.61) closely associated with AD. Remarkably, with the use of any single specific peptide, the AUC (Area Under the Curve) values can reach approximately 0.9 during monitoring AD. Moreover, integrating three specific biomarkers provides a robust basis for machine learning algorithms to build monitoring models, with AUC value up to 1.000. This work represents a substantial advancement in the development of peptide-specific precise monitoring approaches for complex diseases, serving as a catalyst for increased dedication to the molecular detection field.

Attention-Deficit/Hyperactivity Disorder as a Potential Risk Factor for Dementia and Other Neurocognitive Disorders: A Systematic Review

Background

Attention-deficit/hyperactivity disorder (ADHD), a common neurodevelopmental condition now recognized to persist into older adulthood, has been postulated to be a risk factor for neurocognitive disorders given the overlap in clinical features and neurobiology, as well as the complex interplay between ADHD and known risk factors for dementia. Studies have emerged assessing this relationship, but there has not yet been a comprehensive systematic review addressing this topic.

Objective

To assess whether ADHD is a risk factor for neurocognitive disorders and to explore possible mechanisms for such an association.

Methods

A systematic review of the literature was conducted using Medline, Embase, and PsycINFO from inception until June 4, 2023. Studies were included if they assessed whether or how ADHD may be a risk factor for neurocognitive disorders. Studies were excluded if they were not primary literature, not published in a peer-reviewed journal, not in English, and/or used non-human subjects. Study quality was assessed using the QualSyst tool.

Results

Sixteen studies met inclusion criteria. Seven studies found a positive association between ADHD and neurocognitive disorders (all-cause dementia in four studies, Alzheimer's disease in three studies, Lewy body dementia in two studies, and mild cognitive impairment in one study). Four studies did not find an association. Five studies pertained to possible mechanisms for an association, including genetics, with minimal significant findings.

Conclusions

ADHD may be a risk factor for certain neurocognitive disorders, although the evidence base is limited, and the absolute risk is small. Possible explanations include genetic and lifestyle factors.

Recent Development in the Understanding of Molecular and Cellular Mechanisms Underlying the Etiopathogenesis of Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that leads to dementia and patient death. AD is characterized by intracellular neurofibrillary tangles, extracellular amyloid beta (Aβ) plaque deposition, and neurodegeneration. Diverse alterations have been associated with AD progression, including genetic mutations, neuroinflammation, blood-brain barrier (BBB) impairment, mitochondrial dysfunction, oxidative stress, and metal ion imbalance.Additionally, recent studies have shown an association between altered heme metabolism and AD. Unfortunately, decades of research and drug development have not produced any effective treatments for AD. Therefore, understanding the cellular and molecular mechanisms underlying AD pathology and identifying potential therapeutic targets are crucial for AD drug development. This review discusses the most common alterations associated with AD and promising therapeutic targets for AD drug discovery. Furthermore, it highlights the role of heme in AD development and summarizes mathematical models of AD, including a stochastic mathematical model of AD and mathematical models of the effect of Aβ on AD. We also summarize the potential treatment strategies that these models can offer in clinical trials.

Magnetic transferrin nanoparticles (MTNs) assay as a novel isolation approach for exosomal biomarkers in neurological diseases

BACKGROUND

Brain-derived exosomes released into the blood are considered a liquid biopsy to investigate the pathophysiological state, reflecting the aberrant heterogeneous pathways of pathological progression of the brain in neurological diseases. Brain-derived blood exosomes provide promising prospects for the diagnosis of neurological diseases, with exciting possibilities for the early and sensitive diagnosis of such diseases. However, the capability of traditional exosome isolation assays to specifically isolate blood exosomes and to characterize the brain-derived blood exosomal proteins by high-throughput proteomics for clinical specimens from patients with neurological diseases cannot be assured. We report a magnetic transferrin nanoparticles (MTNs) assay, which combined transferrin and magnetic nanoparticles to isolate brain-derived blood exosomes from clinical samples.

METHODS

The principle of the MTNs assay is a ligand-receptor interaction through transferrin on MTNs and transferrin receptor on exosomes, and electrostatic interaction via positively charged MTNs and negatively charged exosomes to isolate brain-derived blood exosomes. In addition, the MTNs assay is simple and rapid (< 35 min) and does not require any large instrument. We confirmed that the MTNs assay accurately and efficiently isolated exosomes from serum samples of humans with neurodegenerative diseases, such as dementia, Parkinson's disease (PD), and multiple sclerosis (MS). Moreover, we isolated exosomes from serum samples of 30 patients with three distinct neurodegenerative diseases and performed unbiased proteomic analysis to explore the pilot value of brain-derived blood protein profiles as biomarkers.

RESULTS

Using comparative statistical analysis, we found 21 candidate protein biomarkers that were significantly different among three groups of neurodegenerative diseases.

CONCLUSION

The MTNs assay is a convenient approach for the specific and affordable isolation of extracellular vesicles from body fluids for minimally-invasive diagnosis of neurological diseases.

Analysis of ADORA2A rs5760423 and CYP1A2 rs762551 Genetic Variants in Patients with Alzheimer's Disease

Various studies have been conducted, exploring the genetic susceptibility of Alzheimer's disease (AD). Adenosine receptor subtype A2a (ADORA2A) and cytochrome P450 1A2 (CYP1A2) are implicated in pathways such as oxidative stress and caffeine metabolism, which are associated with AD. The aim of this study was to explore for any potential association between the ADORA2A rs5760423 and the CYP1A2 rs762551 genetic variants and AD. A case-control study was performed with a total of 654 subjects (327 healthy controls and 327 patients with AD). Five genetic models were assumed. We also examined the allele-allele combination of both variants. The value of 0.05 was considered as the statistical significance threshold. A statistically significant association was found between ADORA2A rs5760423 and AD, as the "T" allele was associated with increased AD risk in recessive (OR = 1.51 (1.03-2.21)) and log-additive (OR = 1.30 (1.04-1.62)) genetic modes. In the codominant model, the TT genotype was more prevalent compared to the GG genotype (OR = 1.71 (1.09-2.66)). The statistical significance was maintained after adjustment for sex. No association between CYP1A2 rs762551 or allele-allele combination and AD was detected. We provide preliminary indication for a possible association between the ADORA2A rs5760423 genetic polymorphism and AD.

Analysis of SOD2 rs4880 Genetic Variant in Patients with Alzheimer's Disease

A few gene loci that contribute to Alzheimer's Disease (AD) onset have been identified. Few studies have been published about the relationship between SOD2 rs4880 single nucleotide variant and AD, revealing inconsistent results. Therefore, the aim of the current study is to further examine the role of the SOD2 rs4880 in AD. We performed a case-control study with a total of 641 subjects (320 patients with probable AD, and 321 healthy controls). The statistical analysis was performed assuming five genetic models. The threshold for statistical significance was set at 0.05. The results revealed no association between SOD2 rs4880 and AD in any of the assumed genetic models that were examined [log-additive OR = 0.95 (0.76-1.19), over-dominant OR = 1.15 (0.85-1.57), recessive OR = 0.85 (0.59-1.22), dominant OR = 1.03 (0.72-1.47), and co-dominant OR1 = 1.10 (0.75-1.60) and OR2 = 0.90 (0.58-1.40)]. Adjustment for sex and subgroup analyses based on sex did not reveal any statistically significant results either. Based on our findings, SOD2 rs4880 does not appear to play a determining role in the risk of developing AD. Larger studies are warranted to elucidate the connection between rs4880 and AD.

Myelin-associated oligodendrocyte basic protein rs616147 polymorphism as a risk factor for Parkinson's disease

BACKGROUND

The rs616147 polymorphism of the myelin-associated oligodendrocyte basic protein (MOBP) gene locus has been associated with amyotrophic lateral sclerosis (ALS). ALS and Parkinson's disease (PD) are two common neurodegenerative disorders that share features regarding their etiology, pathophysiology, and genetic backgrounds. While the MOBP rs616147 polymorphism has been associated with ALS, little is known about its role in PD.

OBJECTIVE

To assess the role of MOBP rs616147 on PD risk.

METHODS

This case-control comparison study consists of 358 PD-affected cases and 358 controls from the Neurology Clinic of the University Hospital of Larissa, University of Thessaly, Faculty of Medicine, in Greece. The diagnosis of PD was made by a specialist neurologist according to the UK Parkinson's Disease Society Brain Bank's clinical criteria. All the participants were genotyped for the MOBP rs616147. Furthermore, in order to validate our results, we genotyped 327 patients with Alzheimer's disease (AD) for MOBP rs616147 and compared them with the control group.

RESULTS

According to the univariate analysis, there was a significant association between rs616147 and PD in the dominant (OR [95% C.I.] = 0.70 [0.52-0.94], p = .018), the overdominant (OR [95% C.I.] = 0.68 [0.50-0.92], p = .011), and in the codominant (G/A VS G/G; OR [95% C.I.] = 0.66 [0.48-0.91], p = .035) modes of inheritance. In contrast, there was no association between the MOBP rs616147 polymorphism and AD.

CONCLUSIONS

We provide preliminary results associating MOBP rs616147 genetic variant with PD.

Glucose transporter 3 in neuronal glucose metabolism: Health and diseases

Neurons obtain glucose from extracellular environment for energy production mainly depending on glucose transporter 3 (GLUT3). GLUT3 uptakes glucose with high affinity and great transport capacity, and is important for neuronal energy metabolism. This review summarized the role of neuronal GLUT3 in brain metabolism, function and development under both physiological conditions and in diseases, aiming to provide insights into neuronal glucose metabolism and its effect on brain. GLUT3 stabilizes neuronal glucose uptake and utilization, influences brain development and function, and ameliorates aging-related manifestations. Neuronal GLUT3 is regulated by synaptic activity, hormones, nutrition, insulin and insulin-like growth factor 1 in physiological conditions, and is also upregulated by hypoxia-ischemia. GLUT3-related neuronal glucose and energy metabolism is possibly involved in the pathogenesis, pathophysiological mechanism, progression or prognosis of brain diseases, including Alzheimer's disease, Huntington's disease, attention-deficit/hyperactivity disorder and epilepsy. GLUT3 may be a promising therapeutic target of these diseases. This review also briefly discussed the role of other glucose transporters in neuronal glucose metabolism, which work together with GLUT3 to sustain and stabilize glucose and energy supply for neurons. Deficiency in these glucose transporters may also participate in brain diseases, especially GLUT1 and GLUT4.