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1.
ACS Chem Neurosci ; 2024 Jul 27.
Article in English | MEDLINE | ID: mdl-39066700

ABSTRACT

Amyloid-ß (Aß) aggregates are recognized as initiators of Alzheimer's disease, and their interaction with the nervous system contributes to the progression of neurodegeneration. Herein, we investigated the frequency at which neuropeptides interact with Aß and affect the aggregation kinetics and cytotoxicity of Aß. To this end, we established a native mass spectrometry (MS)-centric workflow for screening Aß-interacting neuropeptides, and six out of 12 neuropeptides formed noncovalent complexes with Aß species in the MS gas phase. Thioflavin-T fluorescence assays and gel separation indicated that leptin and cerebellin decreased Aß aggregation, whereas kisspeptin increased this process. In addition, leptin and cerebellin attenuated Aß-induced cytotoxicity, which was independent of the influence of metal ions. Leptin can chelate copper from copper-bound Aß species, reducing the cytotoxicity caused by the aggregation of Aß and metal ion complexes. Overall, our study demonstrated that neuropeptides frequently interact with Aß and revealed that leptin and cerebellin are potential inhibitors of Aß aggregation, providing great insight into understanding the molecular mechanism of Aß interacting with the nervous system and facilitating drug development.

2.
J Adv Res ; 2024 Jul 28.
Article in English | MEDLINE | ID: mdl-39079584

ABSTRACT

INTRODUCTION: Nav1.6 is closely related to the pathology of Alzheimer's Disease (AD), and astrocytes have recently been identified as a significant source of ß-amyloid (Aß). However, little is known about the connection between Nav1.6 and astrocyte-derived Aß. OBJECTIVE: This study explored the crucial role of Nav1.6 in mediated astrocyte-derived Aß in AD and knockdown astrocytic Nav1.6 alleviates AD progression by promoting autophagy and lysosome-APP fusion. METHODS: A mouse model for astrocytic Nav1.6 knockdown was constructed to study the effects of astrocytic Nav1.6 on amyloidosis. The role of astrocytic Nav1.6 on autophagy and lysosome-APP(amyloid precursor protein) fusion was used by transmission electron microscope, immunostaining, western blot and patch clamp. Glial cell activation was detected using immunostaining. Neuroplasticity and neural network were assessed using patch-clamp, Golgi stain and EEG recording. Behavioral experiments were performed to evaluate cognitive defects. RESULTS: Astrocytic Nav1.6 knockdown reduces amyloidosis, alleviates glial cell activation and morphological complexity, improves neuroplasticity and abnormal neural networks, as well as promotes learning and memory abilities in APP/PS1 mice. Astrocytic Nav1.6 knockdown reduces itself-derived Aß by promoting lysosome- APP fusion, which is related to attenuating reverse Na+-Ca2+ exchange current thus reducing intracellular Ca2+ to facilitate autophagic through AKT/mTOR/ULK pathway. CONCLUSION: Our findings unveil the crucial role of astrocyte-specific Nav1.6 in reducing astrocyte-derived Aß, highlighting its potential as a cell-specific target for modulating AD progression.

3.
Int J Biol Macromol ; 276(Pt 1): 133862, 2024 Jul 14.
Article in English | MEDLINE | ID: mdl-39013512

ABSTRACT

Amyloid beta (Aß) aggregation is one of the distinctive pathological hallmarks of Alzheimer's disease (AD). Therefore, the development of effective inhibitors against Aß aggregate formation offers great promise for the treatment of AD. In this study, we designed a novel negatively charged functionalized conjugate aimed at inhibiting Aß42 aggregation and attenuating neurotoxicity by grafting polysialic acid with mannuronate oligosaccharide, a biocompatible glycan extracted from seaweeds, designated as polysialic acid-mannan conjugate (PSA-MOS). ThT, biological microscopy, TEM and CD confirmed the inhibition of Aß42 aggregation by PSA-MOS, as well as its ability to inhibit the conformational transition of Aß42 to ß-sheet. CCK-8 assay demonstrated that PSA-MOS was not cytotoxic to SH-SY5Y (p < 0.05) and promoted cell proliferation. In the Aß42-induced SH-SY5Y injury models, PSA-MOS dose-dependently ameliorated cytotoxicity (p < 0.0001) and significantly reduced the levels of inflammatory factors of IL-1ß (p < 0.0001), IL-6 (p < 0.0001) and TNF-α (p < 0.05). MD simulations demonstrated that PSA-MOS effectively impeded the α-helix to ß-sheet transition of the Aß42 monomer via electrostatic interactions with its CTR and NTR regions. These findings demonstrate the therapeutic potential of PSA-MOS as promising glycoconjugate for the treatment of AD.

4.
Sleep Med ; 121: 303-314, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39047304

ABSTRACT

Sleep is considered closely related to cognitive function, and cognitive impairment is the main clinical manifestation of Alzheimer's disease (AD). Sleep disturbance in AD patients is more severe than that in healthy elderly individuals. Additionally, sleep deprivation reportedly increases the activity of the hypothalamic orexin system and the risk of AD. To investigate whether intervention with the orexin system can improve sleep disturbance in AD and its impact on AD pathology. In this study, six-month-old amyloid precursor protein/presenilin 1 mice were subjected to six weeks of chronic sleep deprivation and injected intraperitoneally with almorexant, a dual orexin receptor antagonist (DORA), to investigate the effects and mechanisms of sleep deprivation and almorexant intervention on learning and memory in mice with AD. We found that sleep deprivation aggravated learning and memory impairment and increased brain ß-amyloid (Aß) deposition in mice with AD. The application of almorexant can increase the total sleep time of sleep-deprived mice and reduce cognitive impairment and Aß deposition, which is related to the improvement in Aquaporin-4 polarity. Thus, DORA may be an effective strategy for delaying the progression of AD patients by improving the sleep disturbances.

5.
J Prev Alzheimers Dis ; 11(4): 881-888, 2024.
Article in English | MEDLINE | ID: mdl-39044497

ABSTRACT

BACKGROUND: Stronger resting-state functional connectivity of the default mode and frontoparietal control networks has been associated with cognitive resilience to Alzheimer's disease related pathology and neurodegeneration in smaller cohort studies. OBJECTIVES: We investigated whether these networks are associated with longitudinal CR to AD biomarkers of beta-amyloid (Aß). DESIGN: Longitudinal mixed. SETTING: The Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study and its natural history observation arm, the Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) study. PARTICIPANTS: A sample of 1,021 cognitively unimpaired older adults (mean age = 71.2 years [SD = 4.7 years], 61% women, 42% APOEε4 carriers, 52% Aß positive). MEASUREMENTS: Global cognitive performance (Preclinical Alzheimer's Cognitive Composite) was assessed over an average 5.4 year follow-up period (SD = 2 years). Cortical Aß and functional connectivity (left and right frontoparietal control and default mode networks) were estimated from fMRI and PET, respectively, at baseline. Covariates included baseline age, APOEε4 carrier status, years of education, adjusted gray matter volume, head motion, study group, cumulative treatment exposure, and cognitive test version. RESULTS: Mixed effects models revealed that functional connectivity of the left frontoparietal control network moderated the negative effect of Aß on cognitive change (p = .025) such that stronger connectivity was associated with reduced Aß-related cognitive decline. CONCLUSIONS: Our results demonstrate a potential protective effect of functional connectivity in preclinical AD, such that stronger connectivity in this network is associated with slower Aß-related cognitive decline.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Cognitive Dysfunction , Frontal Lobe , Magnetic Resonance Imaging , Parietal Lobe , Humans , Female , Male , Aged , Amyloid beta-Peptides/metabolism , Parietal Lobe/diagnostic imaging , Longitudinal Studies , Frontal Lobe/diagnostic imaging , Positron-Emission Tomography , Prodromal Symptoms , Nerve Net/diagnostic imaging , Nerve Net/physiopathology
6.
Neurosci Lett ; 837: 137914, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39032802

ABSTRACT

ß-amyloid42 (Aß42) in Alzheimer's disease (AD) and orexin in narcolepsy are considered crucial biomarkers for diagnosis and therapeutic targets. Recently, orexin and Aß cerebral dynamics have been studied in both pathologies, but how they interact with each other remains further to be known. In this study, we investigated the reliability of using the correlation between orexin-A and Aß42 CSF levels as a candidate marker to explain the chain of events leading to narcolepsy or AD pathology. In order to test the correlation between these biomarkers, patients diagnosed with AD (n = 76), narcolepsy type 1 (NT1, n = 17), narcolepsy type 2 (NT2, n = 23) and healthy subjects (n = 91) were examined. Patients and healthy subjects underwent lumbar puncture between 8:00 and 10:00 am at the Neurology Unit of the University Hospital of Rome "Tor Vergata". CSF levels of Aß42, total-tau, phosphorylated-tau, and orexin-A were assessed. The results showed that CSF levels of Aß42 were significantly lower (p < 0.001) in AD (332.28 ± 237.36 pg/mL) compared to NT1 (569.88 ± 187.00 pg/mL), NT2 (691.00 ± 292.63 pg/mL) and healthy subjects (943.68 ± 198.12 pg/mL). CSF orexin-A levels were statistically different (p < 0.001) between AD (148.01 ± 29.49 pg/mL), NT1 (45.94 ± 13.63 pg/mL), NT2 (104.92 ± 25.55 pg/mL) and healthy subjects (145.18 ± 27.01 pg/mL). Moderate-severe AD patients (mini mental state examination < 21) showed the highest CSF orexin-A levels, whereas NT1 patients showed the lowest CSF orexin-A levels. Correlation between CSF levels of Aß42 and orexin-A was found only in healthy subjects (r = 0.26; p = 0.01), and not in narcolepsy or AD patients. This lack of correlation in both diseases may be explained by the pathology itself since the correlation between these two biomarkers is evident only in the healthy subjects. This study adds to the present literature by further documenting the interplay between orexinergic neurotransmission and cerebral Aß dynamics, possibly sustained by sleep.

7.
Anal Chim Acta ; 1317: 342894, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-39030021

ABSTRACT

BACKGROUND: The formation of amyloid-ß (Aß) plaques is one of the key neuropathological hallmarks of Alzheimer's disease (AD). Near-infrared (NIR) probes show great potential for imaging of Aß plaques in vivo and in vitro. Dicyanoisophorone (DCIP) based Aß probes have attracted considerable attention due to their exceptional properties. However, DCIP probes still has some drawbacks, such as short emission wavelength (<650 nm) and low fluorescence intensity after binding to Aß. It is clear that further modification is needed to improve their luminescence efficiency and sensitivity. RESULTS: We designed and synthesize four novel pyrrolidine-alkylamino-substituted DCIP derivatives (6a-d) as imaging agents for ß-amyloid (Aß) aggregates. Compound 6c responds better to Aß aggregates than the other three compounds (6a, 6b and 6d) and its precursor DCIP. The calculated detection limit is to be as low as 0.23 µM. Compound 6c shows no cytotoxicity in the tested concentration for SH-SY5Y and HL-7702 cells. Additionally, compound 6c is successfully applied to monitor Aß aggregates in live SH-SY5Y cells and APP/PS1 transgenic mice. The retention time in the transgenic mice brain is much longer than that of age-matched wild-type mice. SIGNIFICANCE: The results indicates that compound 6c had an excellent ability to penetrate the blood-brain barrier and it could effectively distinguish APP/PS1 transgenic mice and wide-type mice. This represents its promising applications for Aß detection in basic and biomedical research.


Subject(s)
Cyclohexanones , Humans , Cell Line , Amyloid beta-Protein Precursor/analysis , Amyloid beta-Protein Precursor/chemistry , Amyloid beta-Protein Precursor/metabolism , Pyrrolidines/chemistry , Cyclohexanones/chemical synthesis , Cyclohexanones/chemistry , Cyclohexanones/pharmacology , Spectroscopy, Near-Infrared , Molecular Structure , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/chemistry , Fluorescent Dyes/pharmacology , Spectrometry, Fluorescence , Models, Molecular , Protein Structure, Tertiary , Molecular Docking Simulation , Cell Survival/drug effects , Animals , Mice , Male , Mice, Inbred C57BL , Brain/metabolism , Amination , Alkylation
8.
Ageing Res Rev ; 99: 102383, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38955264

ABSTRACT

Globally, Alzheimer's disease (AD) is the most widespread chronic neurodegenerative disorder, leading to cognitive impairment, such as aphasia and agnosia, as well as mental symptoms, like behavioral abnormalities, that place a heavy psychological and financial burden on the families of the afflicted. Unfortunately, no particular medications exist to treat AD, as the current treatments only impede its progression.The link between AD and type 2 diabetes (T2D) has been increasingly revealed by research; the danger of developing both AD and T2D rises exponentially with age, with T2D being especially prone to AD. This has propelled researchers to investigate the mechanism(s) underlying this connection. A critical review of the relationship between insulin resistance, Aß, oxidative stress, mitochondrial hypothesis, abnormal phosphorylation of Tau protein, inflammatory response, high blood glucose levels, neurotransmitters and signaling pathways, vascular issues in AD and diabetes, and the similarities between the two diseases, is presented in this review. Grasping the essential mechanisms behind this detrimental interaction may offer chances to devise successful therapeutic strategies.


Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/therapy , Alzheimer Disease/metabolism , Alzheimer Disease/diagnosis , Diabetes Mellitus, Type 2/therapy , Diabetes Mellitus, Type 2/complications , Animals , Oxidative Stress/physiology
9.
Appl Radiat Isot ; 211: 111424, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38970986

ABSTRACT

Naturally Occurring Radioactive Materials (NORM) contribute to everyone's natural background radiation dose. The technologically advanced activities of the gas and oil sectors produce considerable amounts of radioactive materials as industrial by-products or waste products. The goal of the current study is to estimate the danger of long-term liability to Technologically Enhanced Naturally Occurring Radioactive Materials (TE-NORM) on blood indices, neurotransmitters, oxidative stress markers, and ß-amyloid in the cerebral cortex of rats' brains. Twenty adult male albino rats were divided into two equal groups (n = 10): control and irradiated. Irradiated rats were exposed to a total dose of 0.016 Gy of TE-NORM as a whole-body chronic exposure over a period of two months. It should be ''The results showed no significant changes in RBC count, Hb concentration, hematocrit percentage (HCT%), and Mean Corpuscular Hemoglobin Concentration (MCHC). However, there was a significant increase in the Mean Corpuscular Volume of RBCs (MCV) and a significant decrease in cell distribution width (RDW%) compared to the control. Alteration in neurotransmitters is noticeable by a significant increase in glutamic acid and significant decreases in serotonin and dopamine. Increased lipid peroxidation, decreased glutathione content, superoxide dismutase, catalase, and glutathione peroxidase activities indicating oxidative stress were accompanied by increased ß-amyloid in the cerebral cortex of rats' brains. The findings of the present study showed that chronic radiation liability has some harmful effects, that may predict the risks of future health problems in occupational radiation exposure in the oil industries. Therefore, the control of exposure and application of sample dosimetry is recommended for health and safety.


Subject(s)
Oxidative Stress , Animals , Male , Rats , Oxidative Stress/radiation effects , Background Radiation , Neurotransmitter Agents/metabolism , Neurotransmitter Agents/blood , Brain/radiation effects , Brain/metabolism , Lipid Peroxidation/radiation effects , Amyloid beta-Peptides/metabolism
10.
Neurochem Int ; 178: 105799, 2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38950625

ABSTRACT

Alumunium usage and toxicity has been a global concern especially an increased use of nanoparticulated aluminum (Al-NPs) products from the environment and the workplace. Al degrades in to nanoparticulate form in the environment due to the routine process of bioremediation in human body. Al-NPs toxicity plays key role in the pathophysiology of neurodegeneration which is characterised by the development of neurofibrillary tangles and neuritic plaques which correlates to the Alzheimer's disease. This study evaluated the Al-NPs induced neurodegeneration and causative behavioral alterations due to oxidative stress, inflammation, DNA damage, ß-amyloid aggregation, and histopathological changes in mice. Furthermore, the preventive effect of naringenin (NAR) as a potent neuroprotective flavonoid against Al-NPs induced neurodegeneration was assessed. Al-NPs were synthesized and examined using FTIR, XRD, TEM, and particle size analyzer. Mice were orally administered with Al-NPs (6 mg/kg b.w.) followed by NAR treatment (10 mg/kg b.w. per day) for 66 days. The spatial working memory was determined by novel object recognition, T-maze, Y-maze, and Morris Water Maze tests. We measured nitric oxide, advanced oxidation of protein products, protein carbonylation, lipid peroxidation, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced glutathione, oxidised glutathione, and acetylcholine esterase, as well as cytokines analysis, immunohistochemistry, and DNA damage. Al-NPs significantly reduced the learning memory power, increased oxidative stress, reduced antioxidant enzymatic activity, increased DNA damage, altered the levels of cytokines, and increased ß-amyloid aggregation in the cortex and hippocampus regions of the mice brain. These neurobehavioral impairments, neuronal oxidative stress, and histopathological alterations were significantly attenuated by NAR supplementation. In conclusion, Al-NPs may be potent neurotoxic upon exposure and that NAR could serve as a potential preventive measure in the treatment and management of neuronal degeneration.

11.
Exp Gerontol ; 194: 112514, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38971132

ABSTRACT

Mitochondrial dysfunction is a prominent hallmark of Alzheimer's disease (AD). The transcriptional coactivator PPARγ coactivator 1 (PGC-1a) has been identified as a key regulator of mitochondrial biogenesis and function. However, the precise structure/function relationship between PGC-1a and mitochondrial quality control remains incompletely understood. In this study, we investigated the impact of PGC-1a on AD pathology and its underlying mechanisms with a specific focus on mitochondrial axonal transport. Additionally, we generated two PGC-1α mutants by substituting leucine residues at positions 148 and 149 within the LKKLL motif or at positions 209 and 210 within the LLKYL motif with alanine. Subsequently, we examined the effects of these mutants on mutAPP-induced abnormalities in anterograde and retrograde axonal transport, disrupted mitochondrial distribution, and impaired mitophagy. Mutagenesis studies revealed that the LLKYL motif at amino acid position 209-210 within PGC-1α plays an essential role in its interaction with estrogen-related receptors (ERRα), which is necessary for restoring normal mitochondrial anterograde axonal transport, maintaining proper mitochondrial distribution, and ultimately preventing neuronal apoptosis. Furthermore, it was found that the Leu-rich motif at amino acids 209-210 within PGC-1α is crucial for rescuing mutAPP-induced impairment in mitophagy and loss of membrane potential by restoring normal mitochondrial retrograde axonal transport. Conversely, mutation of residues 148 and 149 in the LKKLL motif does not compromise the effectiveness of PGC-1α. These findings provide valuable insights into the molecular determinants governing specificity of action for PGC-1α involved in regulating mutAPP-induced deficits in mitochondrial axonal trafficking. Moreover, they suggest a potential therapeutic target for addressing Alzheimer's disease.


Subject(s)
Alzheimer Disease , Axonal Transport , Mitochondria , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/genetics , Alzheimer Disease/metabolism , Mitochondria/metabolism , Animals , Humans , Amino Acid Motifs , Mice , Mitophagy , Apoptosis , Amyloid beta-Protein Precursor/metabolism , Amyloid beta-Protein Precursor/genetics , Mutation , Neurons/metabolism
12.
Article in English | MEDLINE | ID: mdl-39076087

ABSTRACT

BACKGROUND: The low effectiveness of existing pharmacotherapy strategies for Alzheimer's disease (AD) makes it necessary to develop a new concept for the treatment of this type of dementia. This search is promising to be carried out within the framework of the paradigm of targeting intracellular signaling pathways in Regenerative-Competent Cells (RCCs). OBJECTIVE: The purpose of the research is to study the impact of adenylate cyclase (AC) inhibitor on disorders of the psychoemotional status in aged male C57BL/6 mice, as well as on the dynamics of the content and functioning of RCCs nervous tissue. METHODS: We examined the effect of the AC inhibitor (2',5'-Dideoxyadenosine) on conditioned reflex activity, behavioral and emotional profile in a mouse AD model (16-month-old (aged) male C57BL/6 mice), as well as the functioning of neural stem cells (NSCs), neuronal-committed progenitors (NCPs), and neuroglial cells in the subventricular zone of the cerebral hemispheres (SVZ). RESULTS: In aged C57BL/6 mice, we found impairments in exploratory behavior, emotional reactivity, and memory, which are the characteristics of senile dementia. Therapy based on AC inhibition led to an increase in the number of NSCs and NPCs in the SVZ due to an increase in their proliferative activity. These changes were more pronounced in NCPs. At the same time, a decrease in the specialization intensity was recorded in NSCs. These phenomena developed against the background of increased secretion of neurotrophic growth factors by oligodendrocytes and microglial cells. The neuroregenerative effects of 2',5'-dideoxyadenosine correlated with the correction of age-related disorders of the psychoemotional status in aged mice. CONCLUSION: The results provide the basis for the development of targeted drugs based on AC inhibitors to stimulate neurogenesis as an approach for the effective treatment of AD.

13.
Eur J Med Res ; 29(1): 313, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38849950

ABSTRACT

Alzheimer's disease (AD) is a diverse disease with a complex pathophysiology. The presence of extracellular ß-amyloid deposition as neuritic plaques and intracellular accumulation of hyper-phosphorylated tau as neurofibrillary tangles remain the core neuropathologic criteria for diagnosing Alzheimer's disease. Nonetheless, several recent basic discoveries have revealed significant pathogenic roles for other essential cellular and molecular processes. Previously, there were not so many disease-modifying medications (DMT) available as drug distribution through the blood-brain barrier (BBB) is difficult due to its nature, especially drugs of polypeptides nature and proteins. Recently FDA has approved lecanemab as DMT for its proven efficacy. It is also complicated to deliver drugs for diseases like epilepsy or any brain tumor due to the limitations of the BBB. After the advancements in the drug delivery system, different techniques are used to transport the medication across the BBB. Other methods are used, like enhancement of brain blood vessel fluidity by liposomes, infusion of hyperosmotic solutions, and local intracerebral implants, but these are invasive approaches. Non-invasive approaches include the formulation of nanoparticles and their coating with polymers. This review article emphasizes all the above-mentioned techniques, procedures, and challenges to transporting medicines across the BBB. It summarizes the most recent literature dealing with drug delivery across the BBB.


Subject(s)
Alzheimer Disease , Blood-Brain Barrier , Drug Delivery Systems , Humans , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/drug effects , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Drug Delivery Systems/methods , Animals , Biological Transport
14.
J Inorg Biochem ; 259: 112636, 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38943843

ABSTRACT

The dyshomeostasis of metal ions in the brain leads to the accumulation of excess metals in extracellular and inter-neuronal locations and the Amyloid ß peptide (Aß) binds these transition metals, which ultimately cause the Aß aggregation and severe oxidative stress in the brain. The aggregation of Aß and oxidative stress are important factors to trigger Alzheimer's disease (AD). Metal chelation therapy is a promising approach to removing metals from Aß-M species and relieve the oxidative stress. Therefore, 4 tetrahydrosalens containing benzothiazole moiety were designed and synthesized. Their biological activities for Alzheimer's disease therapy in vitro were determined by Turbidity assay, BCA protein assay, MTT assay and fluorescent probe of DCFH-DA. The results were comparing with that of non-specific chelator (cliquinol, CQ) and non-benzothiazole functionalized tetrahydrosalens, the results demonstrated that benzothiazole functionalized chelators had more efficient bio-activities in preventing Cu2+-induced Aß aggregation, attenuating cytotoxicity mediated by Aß-Cu2+ species and decrease the level of reactive oxygen species (ROS) in Cu2+-Aß treated PC12 cells than that of cliquinol and non-benzothiazole functionalized analogues.

15.
Am J Transl Res ; 16(5): 1962-1968, 2024.
Article in English | MEDLINE | ID: mdl-38883359

ABSTRACT

OBJECTIVE: To investigate the clinical significance of plasma p-amyloid 1-40 (Aß1-40) in patients with Alzheimer's disease (AD). METHODS: In this retrospective study, the clinical data of 305 patients, with or without Alzheimer's disease (AD), who were treated at the Affiliated Hospital of Youjiang Medical University for Nationalities and the People's Hospital of Baise between January 2018 and December 2021 were analyzed. Patients were divided into two groups: an AD group (n=147) and a non-AD group (without AD, n=158 cases). Blood test indices, including serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE), high-sensitivity C-reactive protein (hsCRP), and plasma ß-amyloid 1-40 were collected and compared between the two groups. RESULTS: The plasma ß-amyloid 1-40 in the AD group was (3.71±3.45) mol/L, which was significantly higher than (2.8±1.35) mmol/L in the non-AD group (P<0.05). Similarly, hsCRP expression was significantly higher in the AD group than that in the non-AD group (P<0.05). There were no significant differences in AST, ALT, UA, T-tau, NFL or Cr levels between the two groups (all P>0.05). Moreover, univariate regression analysis showed that plasma ß-amyloid 1-40 and hsCRP were significantly correlated with AD. Multiple regression analysis demonstrated that plasma p-amyloid 1-40 (P<0.0001) and hsCRP (P=0.002) were independent predictors of AD. CONCLUSION: Plasma p-amyloid 1-40 and hsCRP are closely related to AD, and may serve as important clinical predictors of AD.

16.
Int J Mol Sci ; 25(11)2024 May 29.
Article in English | MEDLINE | ID: mdl-38892154

ABSTRACT

A plethora of pathophysiological events have been shown to play a synergistic role in neurodegeneration, revealing multiple potential targets for the pharmacological modulation of Alzheimer's disease (AD). In continuation to our previous work on new indole- and/or donepezil-based hybrids as neuroprotective agents, the present study reports on the beneficial effects of lead compounds of the series on key pathognomonic features of AD in both cellular and in vivo models. An enzyme-linked immunosorbent assay (ELISA) was used to evaluate the anti-fibrillogenic properties of 15 selected derivatives and identify quantitative changes in the formation of neurotoxic ß-amyloid (Aß42) species in human neuronal cells in response to treatment. Among the most promising compounds were 3a and 3c, which have recently shown excellent antioxidant and anticholinesterase activities, and, therefore, have been subjected to further in vivo investigation in mice. An acute toxicity study was performed after intraperitoneal (i.p.) administration of both compounds, and 1/10 of the LD50 (35 mg/kg) was selected for subacute treatment (14 days) with scopolamine in mice. Donepezil (DNPZ) and/or galantamine (GAL) were used as reference drugs, aiming to establish any pharmacological superiority of the multifaceted approach in battling hallmark features of neurodegeneration. Our promising results give first insights into emerging disease-modifying strategies to combine multiple synergistic activities in a single molecule.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Donepezil , Melatonin , Neuroprotective Agents , Donepezil/pharmacology , Donepezil/therapeutic use , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Animals , Humans , Mice , Melatonin/pharmacology , Amyloid beta-Peptides/metabolism , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Male , Antioxidants/pharmacology , Cholinesterase Inhibitors/pharmacology , Indans/pharmacology , Indans/therapeutic use , Disease Models, Animal , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Piperidines/pharmacology , Piperidines/therapeutic use
17.
Int J Mol Sci ; 25(11)2024 May 31.
Article in English | MEDLINE | ID: mdl-38892278

ABSTRACT

Alzheimer's disease (AD) presents a significant challenge due to its multifaceted nature, characterized by cognitive decline, memory loss, and neuroinflammation. Though AD is an extensively researched topic, effective pharmacological interventions remain elusive, prompting explorations into non-pharmacological approaches. Microcurrent (MC) therapy, which utilizes imperceptible currents, has emerged as a potent clinical protocol. While previous studies have focused on its therapeutic effects, this study investigates the impact of MC on neuronal damage and neuroinflammation in an AD mouse model, specifically addressing potential side effects. Utilizing 5xFAD transgenic mice, we examined the effects of MC therapy on neuronal integrity and inflammation. Our findings suggest that MC therapy attenuates memory impairment and reduces neurodegeneration, as evidenced by improved performance in memory tests and the preservation of the neuronal structure. Additionally, MC therapy significantly decreases amyloid-beta (Aß) plaque deposition and inhibits apoptosis, indicating its potential to mitigate AD pathology. This study determined that glial activation is effectively reduced by using MC therapy to suppress the TLR4-MyD88-NFκB pathway, which consequently causes the levels of inflammatory factors TNF-α, IL-1ß, and IL-6 to decrease, thus implicating TLR4 in neurodegenerative disease-related neuroinflammation. Furthermore, while our study did not observe significant adverse effects, a further clinical trial into potential side effects and neuroinflammatory responses associated with MC therapy is warranted.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Disease Models, Animal , Mice, Transgenic , Neurons , Animals , Alzheimer Disease/therapy , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Mice , Cognitive Dysfunction/therapy , Cognitive Dysfunction/etiology , Cognitive Dysfunction/metabolism , Neurons/metabolism , Neurons/pathology , Myeloid Differentiation Factor 88/metabolism , Myeloid Differentiation Factor 88/genetics , Toll-Like Receptor 4/metabolism , Amyloid beta-Peptides/metabolism , Neuroinflammatory Diseases/metabolism , Neuroinflammatory Diseases/etiology , Neuroinflammatory Diseases/pathology , Plaque, Amyloid/pathology , Plaque, Amyloid/metabolism , NF-kappa B/metabolism , Apoptosis
18.
Int J Mol Sci ; 25(12)2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38928107

ABSTRACT

Aß peptides are known to bind neural plasma membranes in a process leading to the deposit of Aß-enriched plaques. These extracellular structures are characteristic of Alzheimer's disease, the major cause of late-age dementia. The mechanisms of Aß plaque formation and deposition are far from being understood. A vast number of studies in the literature describe the efforts to analyze those mechanisms using a variety of tools. The present review focuses on biophysical studies mostly carried out with model membranes or with computational tools. This review starts by describing basic physical aspects of lipid phases and commonly used model membranes (monolayers and bilayers). This is followed by a discussion of the biophysical techniques applied to these systems, mainly but not exclusively Langmuir monolayers, isothermal calorimetry, density-gradient ultracentrifugation, and molecular dynamics. The Methodological Section is followed by the core of the review, which includes a summary of important results obtained with each technique. The last section is devoted to an overall reflection and an effort to understand Aß-bilayer binding. Concepts such as Aß peptide membrane binding, adsorption, and insertion are defined and differentiated. The roles of membrane lipid order, nanodomain formation, and electrostatic forces in Aß-membrane interaction are separately identified and discussed.


Subject(s)
Amyloid beta-Peptides , Lipid Bilayers , Membrane Lipids , Amyloid beta-Peptides/metabolism , Amyloid beta-Peptides/chemistry , Humans , Lipid Bilayers/metabolism , Lipid Bilayers/chemistry , Membrane Lipids/metabolism , Membrane Lipids/chemistry , Protein Binding , Cell Membrane/metabolism , Alzheimer Disease/metabolism , Animals , Biophysical Phenomena , Molecular Dynamics Simulation
19.
J Colloid Interface Sci ; 672: 53-62, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-38830318

ABSTRACT

Increasing evidence suggests that the accumulations of reactive oxygen species (ROS), ß-amyloid (Aß), and neuroinflammation are crucial pathological hallmarks for the onset of Alzheimer's disease (AD), yet there are few effective treatment strategies. Therefore, design of nanomaterials capable of simultaneously elimination of ROS and inhibition of Aß aggregation and neuroinflammation is urgently needed for AD treatment. Herein, we designed human serum albumin (HSA)-embedded ultrasmall copper nanoclusters (CuNCs@HSA) via an HSA-mediated fabrication strategy. The as-prepared CuNCs@HSA exhibited outstanding multiple enzyme-like properties, including superoxide dismutase (>5000 U/mg), catalase, and glutathione peroxidase activities as well as hydroxyl radicals scavenging ability. Besides, CuNCs@HSA prominently inhibited Aß fibrillization, and its inhibitory potency was 2.5-fold higher than native HSA. Moreover, CuNCs@HSA could significantly increase the viability of Aß-treated cells from 60 % to over 96 % at 40 µg/mL and mitigate Aß-induced oxidative stresses. The secretion of neuroinflammatory cytokines by lipopolysaccharide-induced BV-2 cells, including tumor necrosis factor-α and interleukin-6, was alleviated by CuNCs@HSA. In vivo studies manifested that CuNCs@HSA effectively suppressed the formation of plaques in transgenic C. elegans, reduced ROS levels, and extended C. elegans lifespan by 5 d. This work, using HSA as a template to mediate the fabrication of copper nanoclusters with robust ROS scavenging capability, exhibited promising potentials in inhibiting Aß aggregation and neuroinflammation for AD treatment.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Copper , Metal Nanoparticles , Copper/chemistry , Copper/pharmacology , Amyloid beta-Peptides/metabolism , Amyloid beta-Peptides/antagonists & inhibitors , Amyloid beta-Peptides/chemistry , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Humans , Animals , Metal Nanoparticles/chemistry , Mice , Reactive Oxygen Species/metabolism , Neuroinflammatory Diseases/drug therapy , Serum Albumin, Human/chemistry , Caenorhabditis elegans/metabolism , Particle Size , Oxidative Stress/drug effects , Cell Survival/drug effects , Cell Line , Serum Albumin/chemistry , Serum Albumin/pharmacology , Surface Properties
20.
Brain ; 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38915268

ABSTRACT

Considering the growing age of the world population, the incidence of epilepsy in older adults is expected to increase significantly. It has been suggested that late-onset temporal lobe epilepsy (LO-TLE) may be neurodegenerative in origin and overlap with Alzheimer's Disease (AD). Herein, we aimed to characterize the pattern of cortical atrophy and cerebrospinal fluid (CSF) biomarkers of AD (total and phosphorylated tau, and ß-amyloid) in a selected population of LO-TLE of unknown origin. We prospectively enrolled individuals with temporal lobe epilepsy onset after the age of 50 and no cognitive impairment. They underwent a structural MRI scan and CSF biomarkers measurement. Imaging and biomarkers data were compared to three retrospectively collected groups: (i) age-sex-matched healthy controls, (ii) patients with Mild Cognitive Impairment (MCI) and abnormal CSF AD biomarkers (MCI-AD), and (iii) patients with MCI and normal CSF AD biomarkers (MCI-noAD). From a pool of 52 patients, twenty consecutive eligible LO-TLE patients with a mean disease duration of 1.8 years were recruited. As control populations, 25 patients with MCI-AD, 25 patients with MCI-noAD, and 25 healthy controls were enrolled. CSF biomarkers returned normal values in LO-TLE, significantly different from patients with MCI due to AD. There were no differences in cortico-subcortical atrophy between epilepsy patients and healthy controls, while patients with MCI demonstrated widespread injuries of cortico-subcortical structures. Individuals with a late-onset form of temporal lobe epilepsy, characterized by short disease duration and normal CSF ß-amyloid and tau protein levels, showed patterns of cortical thickness and subcortical volumes not significantly different from healthy controls, but highly different from patients with MCI, either due to Alzheimer's Disease or not.

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