Special Issue: Alzheimer's disease

Evaluating serum CXCL12, sCD22, Lp-PLA2 levels and ratios as biomarkers for diagnosis of Alzheimer's disease

BACKGROUND

Grasping the underlying mechanisms of Alzheimer's disease (AD) is still a work in progress, and existing diagnostic techniques encounter various obstacles. Therefore, the discovery of dependable biomarkers is essential for early detection, tracking the disease's advancement, and steering treatment strategies.

AIM

To explore the diagnostic potential of serum CXCL12, sCD22, Lp-PLA2, and their ratios in AD, aiming to enhance early detection and inform targeted treatment strategies.

METHODS

The study was conducted in Dongying people's Hospital from January 2021 to December 2022. Participants included 60 AD patients (AD group) and 60 healthy people (control group). Using a prospective case-control design, the levels of CXCL12, sCD22 and Lp-PLA2 and their ratios were detected by enzyme-linked immunosorbent assay kit in the diagnosis of AD. The differences between the two groups were analyzed by statistical methods, and the corresponding ratio was constructed to improve the specificity and sensitivity of diagnosis.

RESULTS

Serum CXCL12 levels were higher in the AD group (47.2 ± 8.5 ng/mL) than the control group (32.8 ± 5.7 ng/mL, P < 0.001), while sCD22 levels were lower (14.3 ± 2.1 ng/mL vs 18.9 ± 3.4 ng/mL, P < 0.01). Lp-PLA2 levels were also higher in the AD group (112.5 ± 20.6 ng/mL vs 89.7 ± 15.2 ng/mL, P < 0.05). Significant differences were noted in CXCL12/sCD22 (3.3 vs 1.7, P < 0.001) and Lp-PLA2/sCD22 ratios (8.0 vs 5.2, P < 0.05) between the groups. Receiver operating characteristic analysis confirmed high sensitivity and specificity of these markers and their ratios in distinguishing AD, with area under the curves ranging from 0.568 to 0.787.

CONCLUSION

Serum CXCL12 and Lp-PLA2 levels were significantly increased, while sCD22 were significantly decreased, as well as increases in the ratios of CXCL12/sCD22 and Lp-PLA2/sCD22, are closely related to the onset of AD. These biomarkers and their ratios can be used as potential diagnostic indicators for AD, providing an important clinical reference for early intervention and treatment.

Potential mechanisms underlying lithium treatment for Alzheimer's disease and COVID-19

Disruption of intracellular Ca2+ homeostasis plays an important role as an upstream pathology in Alzheimer's disease (AD), and correction of Ca2+ dysregulation has been increasingly proposed as a target of future effective disease-modified drugs for treating AD. Calcium dysregulation is also an upstream pathology for the COVID-19 virus SARS-CoV-2 infection and replication, leading to host cell damage. Clinically available drugs that can inhibit the disturbed intracellular Ca2+ homeostasis have been repurposed to treat COVID-19 patients. This narrative review aims at exploring the underlying mechanism by which lithium, a first line drug for the treatment of bipolar disorder, inhibits Ca2+ dysregulation and associated downstream pathology in both AD and COVID-19. It is suggested that lithium can be repurposed to treat AD patients, especially those afflicted with COVID-19.

Effects of a Personalized Music Intervention for Persons with Dementia and their Caregivers

Background: Given the challenges of developing disease-modifying treatments for Alzheimer’s disease and related disorders, non-pharmacological interventions represent an increasingly promising approach in long-term care settings. Music-based interventions have been effective in improving the quality of life by influencing biopsychosocial factors that play a role in the progression of illnesses such as depression and anxiety. However, approaches have tended to focus exclusively on the person with dementia rather than integrating caregivers. Objective: This study aimed to determine the impact of a music-based intervention on the quality of life of persons with dementia and their caregivers. Methods: A mixed-methods study was conducted with seven dyads consisting of residents (aged 76–92) with diagnoses of dementia and their caregivers (aged 53–84) at a skilled nursing facility in Pennsylvania. Eight music intervention sessions were completed in the presence of the resident and caregiver using personalized playlists created for the dyad. Pre- and post-intervention questionnaires were administered during each session, and observational data for both residents and caregivers were collected. Results: Caregivers reported feeling less overwhelmed after the intervention with a mean difference of –0.24±0.14, p = 0.016. Mean difference in the other 5 responses showed that listening to music had a beneficial impact for resident/caregiver dyads. Observations of interpersonal behavior supported the benefit of the intervention for these dyads. Conclusion: Quantitative analysis of a personalized music intervention for residents/caregivers showed positive trends in increasing personal connection, and qualitative data identified greater appreciation of the relationship and increased bonding.

Anti-PrP monoclonal antibody as a novel treatment for neurogenesis in mouse model of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is the most common degenerative disease characterized by cognitive impairment, memory decline, and language disorder for which there is no effective treatment. Neurogenesis has been indicated in AD and may play an important role in the pathogenesis of AD. Targeting this pathway is a new idea for the treatment of the disease. A recent study reveals that the cellular prion protein (PrP), a receptor for Aβ oligomers, regulates neurogenesis, and its elevated expression is related to cell differentiation. The aim of the present study was to investigate the neuroprotective effects of 6D11 (PrP monoclonal antibody) via neurogenesis promotion in APP/PS1 transgenic mice and Aβ-induced cell model of AD.

METHODS

In the present study, 9-month-old male APP/PS1 mice were injected with 6D11. Then, the Morris water maze was used to examine the spatial learning and memory abilities of the mice in both groups, and immunostained was used to assess the level of Aβ, neurogenesis, and neural stem cells (NSCs) differentiation.

RESULTS

6D11 attenuated cognitive deficits in APP/PS1 transgenic mice, which was accompanied by a decrease of the deposition of Aβ. In addition, 6D11 treatment promoted differentiation of the existing hippocampal cells to neurons.

CONCLUSIONS

Our findings confirmed that 6D11 has a therapeutic effect in APP/PS1 transgenic AD mouse model and Aβ-induced AD cell model, and the effect exerted via increase of neurogenesis and cell differentiation by transduction of Aβ peptide signal.

Novel Mannich bases with strong carbonic anhydrases and acetylcholinesterase inhibition effects: 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2(3H)-benzoxazolones

In this study, a new series of Mannich bases, 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2( 3H )-benzoxazolones ( 1a-g ), were synthesized by the Mannich reaction. Inhibitory effects of the newly synthesized compounds towards carbonic anhydrases (CAs) and acetylcholinesterase (AChE) enzymes were evaluated to find out new potential drug candidate compounds. According to the inhibitory activity results, Ki values of the compounds 1 and 1a-g were in the range of 12.3 ± 1.2 to 154.0 ± 9.3 nM against hCA I, and they were in the range of 8.6 ± 1.9 to 41.0 ± 5.5 nM against hCA II. Ki values of acetazolamide (AZA) that was used as a reference compound were 84.4 ± 8.4 nM towards hCA I and 59.2 ± 4.8 nM towards hCA II. Ki values of the compounds 1 and 1a-g were in the range of 35.2 ± 2.0 to 158.9 ± 33.5 nM towards AChE. Ki value of Tacrine (TAC), the reference compound, was 68.6 ± 3.8 nM towards AChE. Furthermore, docking studies were done with the most potent compounds 1d , 1g , and 1f (in terms of hCA I, hCA II, and AChE inhibition effects, respectively) to determine the binding profiles of the series with these enzymes. Additionally, the prediction of ADME profiles of the compounds pointed out that the newly synthesized compounds had desirable physicochemical properties as lead compounds for further studies.

Animal and Cellular Models of Alzheimer's Disease: Progress, Promise, and Future Approaches

Alzheimer's disease (AD) is an incurable neurodegenerative disease affecting over 45 million people worldwide. Transgenic mouse models have made remarkable contributions toward clarifying the pathophysiological mechanisms behind the clinical manifestations of AD. However, the limited ability of these in vivo models to accurately replicate the biology of the human disease have precluded the translation of promising preclinical therapies to the clinic. In this review, we highlight several major pathogenic mechanisms of AD that were discovered using transgenic mouse models. Moreover, we discuss the shortcomings of current animal models and the need to develop reliable models for the sporadic form of the disease, which accounts for the majority of AD cases, as well as human cellular models to improve success in translating results into human treatments.

Synthesis and in silico studies of triazene-substituted sulfamerazine derivatives as acetylcholinesterase and carbonic anhydrases inhibitors

A novel series of sulfonamides, 4-(3-phenyltriaz-1-en-1-yl)-N-(4-methyl-2-pyrimidinyl)benzenesulfonamides (1-9), was designed and synthesized by the diazo reaction between sulfamerazine and substituted aromatic amines for the first time. Their chemical structures were characterized by ¹ H nuclear magnetic resonance (NMR), ¹³ C NMR, and high-resolution mass spectra. The newly synthesized compounds were evaluated in terms of acetylcholineasterase (AChE) and human carbonic anhydrases (hCA) I and II isoenzymes inhibitory activities. According to the AChE inhibition results, the K_i values of the compounds 1-9 were in the range of 19.9 ± 1.5 to 96.5 ± 20.7 nM against AChE. Tacrine was used as the reference drug and its K_i value was 49.2 ± 2.7 nM against AChE. The K_i values of the compounds 1-9 were in the range of 10.2 ± 2.6 to 101.4 ± 27.8 nM against hCA I, whereas they were 18.3 ± 4.4 to 48.1 ± 4.5 nM against hCA II. Acetazolamide was used as a reference drug and its K_i values were 72.2 ± 5.4 and 52.2 ± 5.7 nM against hCA I and hCA II, respectively. The most active compounds, 1 (nonsubstituted) against AChE, 5 (4-ethoxy-substituted) against hCA I, and 8 (4-bromo-substituted) against hCA II, were chosen and docked at the binding sites of these enzymes to explain the inhibitory activities of the series. The newly synthesized compounds presented satisfactory pharmacokinetic properties via the estimation of ADME properties.

β-Amyloid precursor protein (APP) and the human diseases

Several pathophysiological functions of the human β-amyloid precursor protein (APP) have been recently proposed in different human diseases such as neurodevelopmental and neurodegenerative disorders including rare diseases such as autism, fragile X syndrome, amyotrophic lateral sclerosis, multiple sclerosis, Lesch-Nyhan disease; common and complex disorders such as Alzheimer's disease; metabolic disorders such as diabetes; and also cancer. APP as well as all of its proteolytic fragments including the amyloid-β (Aβ) peptide, are part of normal physiology. The targeting of the components of APP proteolytic processing as a pharmacologic strategy will not be without consequences. Recent research results highlight the impact of alternative splicing (AS) process on human disease, and may provide new directions for the research on the impact of the human APP on human diseases. The identification of molecules capable of correcting and/or inhibiting pathological splicing events is therefore an important issue for future therapeutic approaches. To this end, the defective APP-mRNA isoform responsible for the disease in cells and tissues appears as an ideal target for epigenetic therapeutic intervention and antisense drugs are potential treatment.