ABSTRACT
Intermittent theta burst stimulation (iTBS), a time-saving and cost-effective repetitive transcranial magnetic stimulation regime, has been shown to improve cognition in patients with Alzheimer's disease (AD). However, the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown. Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation. Here, we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1 (ISCA1, an essential regulatory factor for mitochondrial respiration) in the brain of APP/PS1 mice. In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function, which is required for ISCA1. Moreover, iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice. The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD. We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.
Subject(s)
Humans , Mice , Animals , Transcranial Magnetic Stimulation , Alzheimer Disease/therapy , Cognitive Dysfunction/therapy , Cognition , Sulfur , Iron , Iron-Sulfur Proteins , Mitochondrial ProteinsABSTRACT
The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.
Subject(s)
Mice , Animals , Alzheimer Disease/pathology , Receptor, Nerve Growth Factor , Amyloid beta-Peptides , Autoantibodies , Mice, TransgenicABSTRACT
Deficiencies in the clearance of peripheral amyloid β (Aβ) play a crucial role in the progression of Alzheimer's disease (AD). Previous studies have shown that the ability of blood monocytes to phagocytose Aβ is decreased in AD. However, the exact mechanism of Aβ clearance dysfunction in AD monocytes remains unclear. In the present study, we found that blood monocytes in AD mice exhibited decreases in energy metabolism, which was accompanied by cellular senescence, a senescence-associated secretory phenotype, and dysfunctional phagocytosis of Aβ. Improving energy metabolism rejuvenated monocytes and enhanced their ability to phagocytose Aβ in vivo and in vitro. Moreover, enhancing blood monocyte Aβ phagocytosis by improving energy metabolism alleviated brain Aβ deposition and neuroinflammation and eventually improved cognitive function in AD mice. This study reveals a new mechanism of impaired Aβ phagocytosis in monocytes and provides evidence that restoring their energy metabolism may be a novel therapeutic strategy for AD.
Subject(s)
Animals , Mice , Alzheimer Disease , Amyloid beta-Peptides , Monocytes , Cognition , Energy Metabolism , PhagocytosisABSTRACT
Deficits in the clearance of amyloid β protein (Aβ) by the peripheral system play a critical role in the pathogenesis of sporadic Alzheimer's disease (AD). Impaired uptake of Aβ by dysfunctional monocytes is deemed to be one of the major mechanisms underlying deficient peripheral Aβ clearance in AD. In the current study, flow cytometry and biochemical and behavioral techniques were applied to investigate the effects of polysaccharide krestin (PSK) on AD-related pathology in vitro and in vivo. We found that PSK, widely used in therapy for various cancers, has the potential to enhance Aβ uptake and intracellular processing by human monocytes in vitro. After administration of PSK by intraperitoneal injection, APP/PS1 mice performed better in behavioral tests, along with reduced Aβ deposition, neuroinflammation, neuronal loss, and tau hyperphosphorylation. These results suggest that PSK holds promise as a preventive agent for AD by strengthening the Aβ clearance by blood monocytes and alleviating AD-like pathology.
Subject(s)
Animals , Mice , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/metabolism , Cognition , Disease Models, Animal , Mice, Transgenic , Monocytes/pathology , Polysaccharides/therapeutic use , ProteoglycansABSTRACT
Since the establishment of the biomarker-based A-T-N (Amyloid/Tau/Neurodegeneration) framework in Alzheimer's disease (AD), the diagnosis of AD has become more precise, and cerebrospinal fluid tests and positron emission tomography examinations based on this framework have become widely accepted. However, the A-T-N framework does not encompass the whole spectrum of AD pathologies, and problems with invasiveness and high cost limit the application of the above diagnostic methods aimed at the central nervous system. Therefore, we suggest the addition of an "X" to the A-T-N framework and a focus on peripheral biomarkers in the diagnosis of AD. In this review, we retrospectively describe the recent progress in biomarkers based on the A-T-N-X framework, analyze the problems, and present our perspectives on the diagnosis of AD.
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Objective: To investigate the functional changes of key gut microbiota (GM) that produce lipopolysaccharide (LPS) in atrial fibrillation (AF) patients and to explore their potential role in the pathogenesis of AF. Methods: This was a prospective cross-sectional study. Patients with AF admitted to Beijing Chaoyang Hospital of Capital Medical University were enrolled from March 2016 to December 2018. Subjects with matched genetic backgrounds undergoing physical examination during the same period were selected as controls. Clinical baseline data and fecal samples were collected. Bacterial DNA was extracted and metagenomic sequencing was performed by using Illumina Novaseq. Based on metagenomic data, the relative abundances of KEGG Orthology (KO), enzymatic genes and species that harbored enzymatic genes were acquired. The key features were selected via the least absolute shrinkage and selection operator (LASSO) analysis. The role of GM-derived LPS biosynthetic feature in the development of AF was assessed by receiver operating characteristic (ROC) curve, partial least squares structural equation modeling (PLS-SEM) and logistic regression analysis. Results: Fifty nonvalvular AF patients (mean age: 66.0 (57.0, 71.3), 32 males(64%)) were enrolled as AF group. Fifty individuals (mean age 55.0 (50.5, 57.5), 41 males(82%)) were recruited as controls. Compared with the controls, AF patients showed a marked difference in the GM genes underlying LPS-biosynthesis, including 20 potential LPS-synthesis KO, 7 LPS-biosynthesis enzymatic genes and 89 species that were assigned as taxa harbored nine LPS-enzymatic genes. LASSO regression analysis showed that 5 KO, 3 enzymatic genes and 9 species could be selected to construct the KO, enzyme and species scoring system. Genes enriched in AF group included 2 KO (K02851 and K00972), 3 enzymatic genes (LpxH, LpxC and LpxK) and 7 species (Intestinibacter bartlettii、Ruminococcus sp. JC304、Coprococcus catus、uncultured Eubacterium sp.、Eubacterium sp. CAG:251、Anaerostipes hadrus、Dorea longicatena). ROC curve analysis revealed the predictive capacity of differential GM-derived LPS signatures to distinguish AF patients in terms of above KO, enzymatic and species scores: area under curve (AUC)=0.957, 95%CI: 0.918-0.995, AUC=0.940, 95%CI 0.889-0.991, AUC=0.972, 95%CI 0.948-0.997. PLS-SEM showed that changes in lipopolysaccharide-producing bacteria could be involved in the pathogenesis of AF. The key KO mediated 35.17% of the total effect of key bacteria on AF. After incorporating the clinical factors of AF, the KO score was positively associated with the significantly increased risk of AF (OR<0.001, 95%CI:<0.001-0.021, P<0.001). Conclusion: Microbes involved in LPS synthesis are enriched in the gut of AF patients, accompanied with up-regulated LPS synthesis function by encoding the LPS-enzymatic biosynthesis gene.
Subject(s)
Aged , Humans , Male , Middle Aged , Atrial Fibrillation/complications , Cross-Sectional Studies , Gastrointestinal Microbiome , Lipopolysaccharides , Prospective StudiesABSTRACT
BACKGROUND@#Recent studies suggest that a healthy diet helps to prevent the development of Alzheimer disease (AD). This study aimed to investigate whether spicy food consumption is associated with cognition and cerebrospinal fluid (CSF) biomarkers of AD in the Chinese population.@*METHODS@#We enrolled 55 AD patients and 55 age- and gender-matched cognitively normal (CN) subjects in a case-control study, as well as a cohort of 131 participants without subjective cognitive decline (non-AD) in a cross-sectional study. Spicy food consumption was assessed using the Food Frequency Questionnaire (FFQ). Associations of FFQ scores with cognition and CSF biomarkers of AD were analyzed.@*RESULTS@#In the case-control study, spicy food consumption was lower in AD patients than that in CNs (4.0 [4.0-8.0] vs. 8.0 [4.5-10.0], P < 0.001); FFQ scores were positively associated with Mini-Mental Status Examination scores in the total sample (r = 0.218, P = 0.014). In the cross-sectional study, the association between spicy food consumption and cognition levels was verified in non-AD subjects (r = 0.264, P = 0.0023). Moreover, higher FFQ scores were significantly associated with higher β-Amyloid (1-42) (Aβ42) levels and lower phospho-tau/Aβ42 and total tau/Aβ42 ratios in the CSF of non-AD subjects (P < 0.05).@*CONCLUSION@#Spicy food consumption is closely related to higher cognition levels and reversed AD biomarkers in the CSF, suggesting that a capsaicin-rich diet might have the potential to modify the cognitive status and cerebral pathologies associated with AD.
Subject(s)
Humans , Alzheimer Disease , Amyloid beta-Peptides , Biomarkers , Case-Control Studies , Cognition , Cross-Sectional Studies , Peptide Fragments , tau ProteinsABSTRACT
To evaluate whether the polygenic profile modifies the development of sporadic Alzheimer's disease (sAD) and pathological biomarkers in cerebrospinal fluid (CSF), 462 sAD patients and 463 age-matched cognitively normal (CN) controls were genotyped for 35 single-nucleotide polymorphisms (SNPs) that are significantly associated with sAD. Then, the alleles found to be associated with sAD were used to build polygenic risk score (PRS) models to represent the genetic risk. Receiver operating characteristic (ROC) analyses and the Cox proportional hazards model were used to evaluate the predictive value of PRS for the sAD risk and age at onset. We measured the CSF levels of Aβ42, Aβ42/Aβ40, total tau (T-tau), and phosphorylated tau (P-tau) in a subgroup (60 sAD and 200 CN participants), and analyzed their relationships with the PRSs. We found that 14 SNPs, including SNPs in the APOE, BIN1, CD33, EPHA1, SORL1, and TOMM40 genes, were associated with sAD risk in our cohort. The PRS models built with these SNPs showed potential for discriminating sAD patients from CN controls, and were able to predict the incidence rate of sAD and age at onset. Furthermore, the PRSs were correlated with the CSF levels of Aβ42, Aβ42/Aβ40, T-tau, and P-tau. Our study suggests that PRS models hold promise for assessing the genetic risk and development of AD. As genetic risk profiles vary among populations, large-scale genome-wide sequencing studies are urgently needed to identify the genetic risk loci of sAD in Chinese populations to build accurate PRS models for clinical practice.
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Objective To explore the treatment effect of group cognitive behavioral therapy (GCBT) for patients with insomnia.Methods Two hundred and forty-one cases of insomnia were collected in the department of Sleep and Neurology Psychological in D aping Hospital and Field Surgery Research Institute of Army Medical University from March 2016 to June 2017.They were randomly divided into GCBT group (n=128) and pharmacotherapy group (n=113),and the treatment last for 8 weeks for each group.Then the differences of the sleep parameters,Insomnia Severity Index (ISI) scores,Hamilton Depression Scale (HAMD)scores and Hamilton Anxiety Scale (HAMA) scores were compared in two groups at per-treatment,four-week treatment time point and eight-week treatment time point.Results At the four week treatment time point,the differences of sleep onset latency (SOL),total sleep time (TST),time in bed (TIB),number of awakenings (NOA) and insomnia severity index (ISI) in GCBT group compared to pharmacotherapy group were statistically significant (P<0.05).While the differences of sleep efficiency (SE),HAMA and HAMD were of no statistically significant difference (P>0.05).At the eight week treatment time point,the differences of SOL,SE,NOA,HAMA,HAMD and ISI in GCBT group compared to pharmacotherapy group were statistically significant (P<0.05),and there is no significant difference in TST and TIB (P>0.05).Conclusion GCBT and pharmacotherapy can improve insomnia symptoms,reduce the level of anxiety and insomnia severity.GCBT can also reduce the level of depression,although GCBT improve insomnia symptoms were slower than pharmacotherapy,but curative cffect is superior to pharmacotherapy,and it should be popularized in clinic.
ABSTRACT
Alzheimer's disease (AD), the most common type of dementia, is becoming a major challenge for global health and social care. However, the current understanding of AD pathogenesis is limited, and no early diagnosis and disease-modifying therapy are currently available. During the past year, significant progress has been made in clinical research on the diagnosis, prevention, and treatment of AD. In this review, we summarize the latest achievements, including diagnostic biomarkers, polygenic hazard score, amyloid and tau PET imaging, clinical trials targeting amyloid-beta (Aβ), tau, and neurotransmitters, early intervention, and primary prevention and systemic intervention approaches, and provide novel perspectives for further efforts to understand and cure the disease.
Subject(s)
Animals , Humans , Alzheimer Disease , Diagnosis , Therapeutics , Biomarkers , Blood , Biomedical Research , Methods , Disease Progression , Magnetic Resonance ImagingABSTRACT
<p><b>OBJECTIVE</b>To observe the efficacy of Yangxue Qingnao granule (YXQN) in treating cerebral arteriosclerosis and to explore its mechanisms.</p><p><b>METHODS</b>One hundred and sixty-seven patients with arteriosclerosis were randomly divided into the treated group treated with conventional medical treatment plus YXQN and the control group treated with conventional medical treatment alone, to observe the changes before and after treatment in scores of chief symptoms, mean velocity of cerebral blood flow (VM), plasma nitric oxide (NO), calcitonin gene related peptide (CGRP) and endothelin (ET) levels.</p><p><b>RESULTS</b>(1) After treatment in treated group, the scores of chief symptoms such as vertigo, headache and tinnitus were significantly lower than those in the control group (P < 0.05 or P < 0.01); (2) NO and CGRP level in the treated group after treatment obviously elevated, and ET and VM markedly reduced (P < 0.01), while no evident change of these parameters was found in the control group (P < 0.01).</p><p><b>CONCLUSION</b>The efficacy of YXQN in treating cerebral arteriosclerosis is definite, modulating the level of vasoactive factors was its important mechanism.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Blood Flow Velocity , Calcitonin Gene-Related Peptide , Blood , Cerebral Arteries , Drugs, Chinese Herbal , Therapeutic Uses , Endothelins , Blood , Intracranial Arteriosclerosis , Drug Therapy , Nitric Oxide , Blood , PhytotherapyABSTRACT
Objective To investigate the diagnostic accuracy of 64-slice spiral computed tomography(MSCT)in detecting coronary artery lesions and to analyze the impacts of coronary artery calcium on its diagnostic accuracy.Methods Sixty patients underwent 64-MSCT coronary angiography and conventional coronary angiography(CCA).Calcium scoring was estimated on plain scans.The diagnostic accuracy of MSCT to detect significant lesions(≥50%)was evaluated referring to quantitative coronary angiography(QCA).The impacts of coronary artery calcium on the diagnostic accuracy was analyzed.Results A total of 797 segments were diagnositc.The overall sensitivity,specificity,positive predictive value and negative predictive value of 64-MSCT were 96%(174/182),98%(601/615),93% (174/188),and 99%(601/609),respectively.When calcium score ≥100(Agatston score),the specificity and positive predictive value of 64-MSCT was 63%(12/19)and 81%(30/37), respectively.Conclusion In patients with no or mild coronary calcification,the 64-MSCT coronary angiography had a reliable detection of coronary artery stenoses.But severe calcification in coronary artery may degrade diagnostic specificity and positive predictive value of MSCT coronary angiography.