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1.
Acta Neuropathol ; 145(6): 717-731, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36964213

RESUMO

Cerebral amyloid-ß (Aß) accumulation due to impaired Aß clearance is a pivotal event in the pathogenesis of Alzheimer's disease (AD). Considerable brain-derived Aß is cleared via transporting to the periphery. The liver is the largest organ responsible for the clearance of metabolites in the periphery. Whether the liver physiologically clears circulating Aß and its therapeutic potential for AD remains unclear. Here, we found that about 13.9% of Aß42 and 8.9% of Aß40 were removed from the blood when flowing through the liver, and this capacity was decreased with Aß receptor LRP-1 expression down-regulated in hepatocytes in the aged animals. Partial blockage of hepatic blood flow increased Aß levels in both blood and brain interstitial fluid. The chronic decline in hepatic Aß clearance via LRP-1 knockdown specific in hepatocytes aggravated cerebral Aß burden and cognitive deficits, while enhancing hepatic Aß clearance via LRP-1 overexpression attenuated cerebral Aß deposition and cognitive impairments in APP/PS1 mice. Our findings demonstrate that the liver physiologically clears blood Aß and regulates brain Aß levels, suggesting that a decline of hepatic Aß clearance during aging could be involved in AD development, and hepatic Aß clearance is a novel therapeutic approach for AD.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/patologia , Fígado/metabolismo , Fígado/patologia , Camundongos Transgênicos , Modelos Animais de Doenças
2.
Langmuir ; 39(24): 8532-8539, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37290000

RESUMO

Understanding molecular transport in polyelectrolyte brushes (PEBs) is crucial for applications such as separations, drug delivery, anti-fouling, and biosensors, where structural features of the polymer control intermolecular interactions. The complex structure and local heterogeneity of PEBs, while theoretically predicted, are not easily accessed with conventional experimental methods. In this work, we use 3D single-molecule tracking to understand transport behavior within a cationic poly(2-(N,N-dimethylamino)ethyl acrylate) (PDMAEA) brush using an anionic dye, Alexa Fluor 546, as the probe. The analysis is done by a parallelized, unbiased 3D tracking algorithm. Our results explicitly demonstrate that spatial heterogeneity within the brush manifests as heterogeneity of single-molecule displacements. Two distinct populations of probe motion are identified, with anticorrelated axial and lateral transport confinement, which we believe to correspond to intra- vs inter-chain probe motion.

3.
Mol Psychiatry ; 26(10): 5568-5577, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32681097

RESUMO

It is traditionally believed that cerebral amyloid-beta (Aß) deposits are derived from the brain itself in Alzheimer's disease (AD). Peripheral cells such as blood cells also produce Aß. The role of peripherally produced Aß in the pathogenesis of AD remains unknown. In this study, we established a bone marrow transplantation model to investigate the contribution of blood cell-produced Aß to AD pathogenesis. We found that bone marrow cells (BMCs) transplanted from APPswe/PS1dE9 transgenic mice into wild-type (Wt) mice at 3 months of age continuously expressed human Aß in the blood, and caused AD phenotypes including Aß plaques, cerebral amyloid angiopathy (CAA), tau hyperphosphorylation, neuronal degeneration, neuroinflammation, and behavioral deficits in the Wt recipient mice at 12 months after transplantation. Bone marrow reconstitution in APPswe/PS1dE9 mice with Wt-BMCs at 3 months of age reduced blood Aß levels, and alleviated brain Aß burden, neuronal degeneration, neuroinflammation, and behavioral deficits in the AD model mice at 12 months after transplantation. Our study demonstrated that blood cell-produced Aß plays a significant role in AD pathogenesis, and the elimination of peripheral production of Aß can decrease brain Aß deposition and represents a novel therapeutic approach for AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Células Sanguíneas/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos
4.
Mol Psychiatry ; 26(10): 6074-6082, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33828237

RESUMO

Amyloid-ß (Aß) accumulation in the brain is a pivotal event in the pathogenesis of Alzheimer's disease (AD), and its clearance from the brain is impaired in sporadic AD. Previous studies suggest that approximately half of the Aß produced in the brain is cleared by transport into the periphery. However, the mechanism and pathophysiological significance of peripheral Aß clearance remain largely unknown. The kidney is thought to be responsible for Aß clearance, but direct evidence is lacking. In this study, we investigated the impact of unilateral nephrectomy on the dynamic changes in Aß in the blood and brain in both humans and animals and on behavioural deficits and AD pathologies in animals. Furthermore, the therapeutic effects of the diuretic furosemide on Aß clearance via the kidney were assessed. We detected Aß in the kidneys and urine of both humans and animals and found that the Aß level in the blood of the renal artery was higher than that in the blood of the renal vein. Unilateral nephrectomy increased brain Aß deposition; aggravated AD pathologies, including Tau hyperphosphorylation, glial activation, neuroinflammation, and neuronal loss; and aggravated cognitive deficits in APP/PS1 mice. In addition, chronic furosemide treatment reduced blood and brain Aß levels and attenuated AD pathologies and cognitive deficits in APP/PS1 mice. Our findings demonstrate that the kidney physiologically clears Aß from the blood, suggesting that facilitation of Aß clearance via the kidney represents a novel potential therapeutic approach for AD.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Rim/metabolismo , Camundongos , Camundongos Transgênicos , Presenilina-1/metabolismo
5.
Bioorg Chem ; 119: 105577, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34959178

RESUMO

Phallus rubrovolvatus is an important commercially cultivated mushroom species in China. However, the volva of P. rubrovolvatus usually discarded as a by-product due to the unpleasant flavor and difficulty in processing. In this study, we investigated the chemical constituents and bioactivities of the volva of P. rubrovolvatus. As a result, fifteen rare aniline derivatives, including twelve new compounds (1-11, 14) and three new natural products (12, 13, 15) were isolated from the volva. Their structures were determined using 1D and 2D NMR data and HR-ESI-MS data, while the relative and absolute configurations were confirmed by NOESY correlations and comparison between experimental and calculated ECD spectra. In addition, compounds 1-15 were tested for anti-inflammatory activity against lipopolysaccharide (LPS)-induced NO production in RAW264.7 macrophages. Compounds 4, 9 and 10 exhibited anti-inflammatory activity with IC50 values ranging from 12.5 to 15.6 µM.


Assuntos
Compostos de Anilina/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Basidiomycota/química , Óxido Nítrico/antagonistas & inibidores , Extratos Vegetais/farmacologia , Resíduos/análise , Compostos de Anilina/química , Compostos de Anilina/isolamento & purificação , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Relação Dose-Resposta a Droga , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , Óxido Nítrico/biossíntese , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Células RAW 264.7 , Relação Estrutura-Atividade
6.
Small ; 15(49): e1904715, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31642190

RESUMO

A new hole transporting material (HTM) named DMZ is synthesized and employed as a dopant-free HTM in inverted planar perovskite solar cells (PSCs). Systematic studies demonstrate that the thickness of the hole transporting layer can effectively enhance the morphology and crystallinity of the perovskite layer, leading to low series resistance and less defects in the crystal. As a result, the champion power conversion efficiency (PCE) of 18.61% with JSC = 22.62 mA cm-2 , VOC = 1.02 V, and FF = 81.05% (an average one is 17.62%) is achieved with a thickness of ≈13 nm of DMZ (2 mg mL-1 ) under standard global AM 1.5 illumination, which is ≈1.5 times higher than that of devices based on poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT:PSS). More importantly, the devices based on DMZ exhibit a much better stability (90% of maximum PCE retained after more than 556 h in air (relative humidity ≈ 45%-50%) without any encapsulation) than that of devices based on PEDOT:PSS (only 36% of initial PCE retained after 77 h in same conditions). Therefore, the cost-effective and facile material named DMZ offers an appealing alternative to PEDOT:PSS or polytriarylamine for highly efficient and stable inverted planar PSCs.

7.
Arch Microbiol ; 200(10): 1465-1470, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30151776

RESUMO

A Gram-staining-positive, aerobic, rod-shaped (201802YP6T) bacteria was isolated from soil, Northeast of China. Growth occurred at 10-40 °C (optimum 25-30 °C), at pH 6.0-8.0 (optimum 7.0) and at 0-2% NaCl. Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbors of strain 201802YP6T were identified as Bhargavaea cecembensis DSE10T (99.52%), Bhargavaea beijingensis ge10T (99.45%), Bhargavaea indica KJW98T (99.45%), Bhargavaea ullalensis ZMA19T (98.81%), and Bhargavaea ginsengi ge14T (98.76%). Levels of similarity among strain 201802YP6T and other Bhargavaea species were lower than 98.76%. GyrB amino acid sequence-based analysis supported the phylogenetic position and also distinguished strain 201802YP6T from the other species of the genus Bhargavaea. DNA-DNA hybridization values between strain 201802YP6T and B. cecembensis, B. beijingensis, B. indica, B. ullalensis, B. ginsengi were 43.5%, 43%, 32.5%, 30.5% and 20.4%, respectively. The DNA G + C content of strain 201802YP6T was 51.23 mol%. The average nucleotide identity (ANI) of the draft genome was 87.04% to B. cecembensis DSE10T. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, glycolipids, phosphatidylethanolamine, and phosphatidyllipid. The predominant menaquinone was MK-8. The major fatty acids were iso-C15:0 (39.91%), anteiso-C15:0 (28.86%), anteiso-C17:0 (6.30%) and C16:0 (6.13%). On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain 201802YP6T represents a novel species of the genus Bhargavaea, for which the name Bhargavaea changchunensis sp. nov. is proposed. The type strain is 201802YP6T (= CGMCC 1.13508T = KCTC 33975T).


Assuntos
Planococáceas/classificação , Microbiologia do Solo , Composição de Bases , China , DNA Bacteriano/química , Ácidos Graxos/análise , Hibridização de Ácido Nucleico , Filogenia , Planococáceas/genética , Planococáceas/isolamento & purificação , RNA Ribossômico 16S/genética
8.
J Nanosci Nanotechnol ; 17(4): 2601-605, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29659223

RESUMO

Bismuth oxychloride (BiOCl) is well known for its photocatalytic activity and many methods are reported to prepare this layered-structure material. In this study, bismuth hexafluoroacetylacetonate Bi(C5HF6O2)3 was chosen as Bi source in the synthesis of BiOCl. Uniform BiOCl nanoplates were fabricated without any organic additive to control the morphology. In the formation process, Bi(C5HF6O2)3 acted as both reagent and soft-template agent. Moreover BiOCl nanoplates exhibited quite high photocatalytic activity. Both P25 and BiOCl nanoplates can decompose the whole RhB dye within 30 minutes, which indicates that BiOCl nanoplates are of the comparative photocatalytic performance as P25.

9.
Micromachines (Basel) ; 14(1)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36677291

RESUMO

The bit density is generally increased by stacking more layers in 3D NAND Flash. Lowering dopant activation of select transistors results from complex integrated processes. To improve channel dopant activation, the test structure of vertical channel transistors was used to investigate the influence of laser thermal annealing on dopant activation. The activation of channel doping by different thermal annealing methods was compared. The laser thermal annealing enhanced the channel activation rate by at least 23% more than limited temperature rapid thermal annealing. We then comprehensively explore the laser thermal annealing energy density on the influence of Poly-Si grain size and device performance. A clear correlation between grain size mean and grain size sigma, large grain size mean and sigma with large laser thermal annealing energy density. Large laser thermal annealing energy density leads to tightening threshold voltage and subthreshold swing distribution since Poly-Si grain size regrows for better grain size distribution with local grains optimization. As an enabler for next-generation technologies, laser thermal annealing will be highly applied in 3D NAND Flash for better device performance with stacking more layers, and opening new opportunities of novel 3D architectures in the semiconductor industry.

10.
J Alzheimers Dis ; 94(2): 537-546, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37334604

RESUMO

BACKGROUND: The profile of naturally occurring antibodies to amyloid-ß (NAbs-Aß) is altered in patients with Alzheimer's disease (AD). However, the diagnostic potential of NAbs-Aß for AD is not clear yet. OBJECTIVE: This study aims to investigate the diagnostic capacities of NAbs-Aß for AD. METHODS: A total of 40 AD patients and 40 cognitively normal (CN) controls were enrolled in this study. Levels of NAbs-Aß were detected by ELISA. The correlations of NAbs-Aß levels with cognitive function and AD-associated biomarkers were examined by Spearman correlation analysis. Diagnostic abilities of NAbs-Aß were evaluated by the receiver operating characteristic (ROC) curve analyses. The integrative diagnostic models were established by logistic regression models. RESULTS: We found that NAbs-Aß7-18 had the highest diagnostic capability (AUC = 0.72) among all single NAbs-Aß. The combined model (NAbs-Aß7-18, NAbs-Aß19-30, and NAbs-Aß25-36) had a noticeable improvement (AUC = 0.84) in the diagnostic capacity compared with each single NAbs-Aß. CONCLUSION: NAbs-Aßs are promising in the diagnosis of AD. Further investigations are needed to confirm the translational potential of this diagnostic strategy.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico , Autoanticorpos , Peptídeos beta-Amiloides , Cognição , Ensaio de Imunoadsorção Enzimática , Biomarcadores
11.
J Alzheimers Dis ; 92(2): 477-485, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36776069

RESUMO

BACKGROUND: The kidney-brain crosstalk has been involved in Alzheimer's disease (AD) with the mechanism remaining unclear. The anti-aging factor Klotho was reported to attenuate both kidney injury and AD pathologies. OBJECTIVE: To investigate whether plasma Klotho participated in kidney-brain crosstalk in AD. METHODS: We enrolled 33 PiB-PET-positive AD patients and 33 amyloid-ß (Aß)-negative age- and sex-matched cognitively normal (CN) controls from the Chongqing Ageing & Dementia Study (CADS). The levels of plasma Klotho, Aß, and tau in the cerebrospinal fluid (CSF) were measured by enzyme-linked immunosorbent assay. RESULTS: We found higher plasma Klotho and lower estimated glomerular filtration rate (eGFR) levels in AD patients compared with CN. The eGFR was positively associated with Aß42, Aß40 levels in CSF and negatively associated with CSF T-tau levels. Plasma Klotho levels were both negatively correlated with CSF Aß42 and eGFR. Mediation analysis showed that plasma Klotho mediated 24.96% of the association between eGFR and CSF Aß42. CONCLUSION: Renal function impacts brain Aß metabolism via the kidney-brain crosstalk, in which the plasma Klotho may be involved as a mediator. Targeting Klotho to regulate the kidney-brain crosstalk provides potential therapeutic approaches for AD.


Assuntos
Doença de Alzheimer , Humanos , Envelhecimento , Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/metabolismo , Biomarcadores/líquido cefalorraquidiano , Encéfalo/metabolismo , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/metabolismo
12.
Neurosci Bull ; 39(2): 261-272, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35974288

RESUMO

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aß neurotoxicity and promotes Aß 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.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/patologia , Receptor de Fator de Crescimento Neural , Peptídeos beta-Amiloides , Autoanticorpos , Camundongos Transgênicos
13.
Mol Neurodegener ; 17(1): 9, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-35033164

RESUMO

BACKGROUND: Loss of brain capillary pericyte is involved in the pathologies and cognitive deficits in Alzheimer's disease (AD). The role of pericyte in early stage of AD pathogenesis remains unclear. METHODS: We investigated the dynamic changes of soluble platelet-derived growth factor receptor ß (sPDGFRß) in cerebrospinal fluid (CSF), a marker of brain pericyte injury, in transition from normal ageing to early AD in a cognitively unimpaired population aged 20 to 90 years. Association between sPDGFRß and ATN biomarkers were analyzed. RESULTS: In lifetime, CSF sPDGFRß continually increased since age of 20 years, followed by the increases of phosphorylated tau-181 (P-tau181) and total tau (T-tau) at the age of 22.2 years and 31.7 years, respectively; CSF Aß42 began to decline since the age of 39.6 years, indicating Aß deposition. The natural trajectories of biomarkers suggest that pericyte injury is an early event during transition from normal status to AD, even earlier than Aß deposition. In AD spectrum, CSF sPDGFRß was elevated in preclinical stage 2 and participants with suspected non-AD pathophysiologies. Additionally, CSF sPDGFRß was positively associated with P-tau181 and T-tau independently of Aß42, and significantly strengthened the effects of Aß42 on P-tau181, suggesting that pericyte injury accelerates Aß-mediated tau hyperphosphorylation. CONCLUSIONS: Our results suggest that pericyte injury contributes to AD progression in the early stage in an Aß-independent pathway. Recovery of pericyte function would be a target for prevention and early intervention of AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Humanos , Pessoa de Meia-Idade , Fragmentos de Peptídeos/líquido cefalorraquidiano , Adulto Jovem , Proteínas tau/líquido cefalorraquidiano
14.
J Alzheimers Dis ; 87(2): 711-719, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35342089

RESUMO

BACKGROUND: The G protein-coupled receptor P2RY2 protein of the purinergic receptor family is involved in the pathogenesis of Alzheimer's disease (AD). Naturally occurring antibodies against P2RY2 (NAbs-P2RY2) are present in human plasma, with their clinical relevance in AD unknown. OBJECTIVE: To explore the alteration of NAbs-P2RY2 in AD patients and its associations with biomarkers and cognition of AD patients. METHODS: The levels of naturally occurring antibodies against the four extracellular domains of P2RY2 (NAbs-P2RY2-1, NAbs-P2RY2-2, NAbs-P2RY2-3, and NAbs-P2RY2-4) were measured in the plasma of 55 AD patients, 28 non-AD dementia patients, and 70 cognitively normal participants. The correlations of autoantibody levels with cognitive scale scores, AD plasma biomarkers, and brain amyloid burden were examined. RESULTS: NAbs-P2RY2-1, NAbs-P2RY2-3, and NAbs-P2RY2-4 were reduced in AD patients. Plasma levels of NAbs-P2RY2-2 and NAbs-P2RY2-3 levels were positively associated with cognitive and functional performances. Among these antibodies, plasma NAbs-P2RY2-2 levels were positively associated with plasma amyloid-ß 42 levels. While plasma NAbs-P2RY2-3 levels were negatively associated with brain amyloid burden in AD patients. CONCLUSION: These findings indicate an alteration of humoral immunity against P2RY2 in AD patients. Further mechanistical investigations are needed to reveal the role of NAbs-P2RY2 in the pathogenesis of AD.


Assuntos
Doença de Alzheimer , Amiloidose , Disfunção Cognitiva , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Amiloidose/metabolismo , Autoanticorpos , Biomarcadores , Encéfalo/patologia , Disfunção Cognitiva/metabolismo , Humanos , Receptores Purinérgicos P2Y2/metabolismo , Proteínas tau/metabolismo
15.
Neurosci Bull ; 38(3): 290-302, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34611829

RESUMO

Deficits in the clearance of amyloid ß protein (Aß) by the peripheral system play a critical role in the pathogenesis of sporadic Alzheimer's disease (AD). Impaired uptake of Aß by dysfunctional monocytes is deemed to be one of the major mechanisms underlying deficient peripheral Aß 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 Aß 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 Aß deposition, neuroinflammation, neuronal loss, and tau hyperphosphorylation. These results suggest that PSK holds promise as a preventive agent for AD by strengthening the Aß clearance by blood monocytes and alleviating AD-like pathology.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Cognição , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Monócitos/metabolismo , Monócitos/patologia , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Proteoglicanas
16.
Chin Med J (Engl) ; 135(5): 591-597, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34985014

RESUMO

BACKGROUND: Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans. METHODS: We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient. RESULTS: The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion. CONCLUSION: Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral ß-amyloid deposition and neurodegeneration in humans.


Assuntos
Doença de Alzheimer , Circulação Cerebrovascular , Idoso , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Artérias , Atrofia , Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Constrição Patológica/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos
17.
Front Aging Neurosci ; 14: 943380, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35923549

RESUMO

Background: Cognitive impairment (CI) has become a worldwide health problem. The relationship between CI and uric acid (UA) is contradictory. Objective: We included participants with a full spectrum of CI, from cognitively unimpaired (CU) to dementia, from the Chongqing Ageing & Dementia Study (CADS). Methods: First, we identified the relationships between serum UA (sUA) and cognitive function in different stages of CI. Second, we analyzed these relationships among different stages and types of CI. Finally, we explored the association between sUA and amyloid/tangle/neurodegeneration (ATN) biomarkers. Results: We recruited 427 participants from the CADS, including 382 participants with mini-mental state examination (MMSE) evaluation. The levels of sUA were positively correlated with MMSE scores (p < 0.001), and the correlation was prominent in the course of dementia and in the type of Alzheimer's disease (AD). The levels of UA had a positive correlation with plasma amyloid-ß 42 (Aß42) (p = 0.004). Higher levels of sUA weakened the correlation of MMSE scores with CSF ATN biomarkers and the correlation of CSF Aß42 with tau. Conclusion: UA is positively correlated with cognitive function, especially in the advanced stage of AD. The probable neuroprotective effects of sUA mainly act on Aß42 and the downstream pathological cascade.

18.
Neurosci Bull ; 38(9): 1025-1040, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35570231

RESUMO

Increased neuronal apoptosis is an important pathological feature of Alzheimer's disease (AD). The Bcl-2-interacting mediator of cell death (Bim) mediates amyloid-beta (Aß)-induced neuronal apoptosis. Naturally-occurring antibodies against Bim (NAbs-Bim) exist in human blood, with their levels and functions unknown in AD. In this study, we found that circulating NAbs-Bim were decreased in AD patients. Plasma levels of NAbs-Bim were negatively associated with brain amyloid burden and positively associated with cognitive functions. Furthermore, NAbs-Bim purified from intravenous immunoglobulin rescued the behavioral deficits and ameliorated Aß deposition, tau hyperphosphorylation, microgliosis, and neuronal apoptosis in APP/PS1 mice. In vitro investigations demonstrated that NAbs-Bim were neuroprotective against AD through neutralizing Bim-directed neuronal apoptosis and the amyloidogenic processing of amyloid precursor protein. These findings indicate that the decrease of NAbs-Bim might contribute to the pathogenesis of AD and immunotherapies targeting Bim hold promise for the treatment of AD.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos
19.
Sci Adv ; 8(13): eabm5667, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35363517

RESUMO

CD22 has been suggested to contribute to Alzheimer's disease (AD) pathogenesis by inhibiting microglial amyloid ß (Aß) phagocytosis. Soluble CD22 (sCD22) generated by cleavage from cell membranes may be a marker of inflammation and microglial dysfunction; but alterations of sCD22 levels in AD and their correlation with AD biomarkers remain unclear. Plasma sCD22 levels were measured in cognitively normal non-AD participants and patients with preclinical AD and AD dementia from a Chinese cohort and the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing. Plasma sCD22 levels were elevated in patients with preclinical and dementia AD. Plasma sCD22 levels were negatively correlated with cerebrospinal fluid (CSF) Aß42 levels and Aß42/Aß40, and positively correlated with CSF phosphorylated tau levels and brain Aß burden, but negatively correlated with cognitive function. Moreover, higher plasma sCD22 levels were associated with faster cognitive decline during follow-up. These findings suggest that CD22 plays important roles in AD development, and that sCD22 is a potential biomarker for AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Peptídeos beta-Amiloides , Austrália , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Humanos , Fragmentos de Peptídeos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico
20.
Transl Psychiatry ; 12(1): 252, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35710549

RESUMO

Cerebrospinal fluid (CSF) biomarkers are essential for the accurate diagnosis of Alzheimer's disease (AD), yet their measurement levels vary widely across centers and regions, leaving no uniform cutoff values to date. Diagnostic cutoff values of CSF biomarkers for AD are lacking for the Chinese population. As a member of the Alzheimer's Association Quality Control program for CSF biomarkers, we aimed to establish diagnostic models based on CSF biomarkers and risk factors for AD in a Chinese cohort. A total of 64 AD dementia patients and 105 age- and sex-matched cognitively normal (CN) controls from the Chongqing Ageing & Dementia Study cohort were included. CSF Aß42, P-tau181, and T-tau levels were measured by ELISA. Combined biomarker models and integrative models with demographic characteristics were established by logistic regression. The cutoff values to distinguish AD from CN were 933 pg/mL for Aß42, 48.7 pg/mL for P-tau181 and 313 pg/mL for T-tau. The AN model, including Aß42 and T-tau, had a higher diagnostic accuracy of 89.9%. Integrating age and APOE ε4 status to AN model (the ANA'E model) increased the diagnostic accuracy to 90.5% and improved the model performance. This study established cutoff values of CSF biomarkers and optimal combined models for AD diagnosis in a Chinese cohort.


Assuntos
Doença de Alzheimer , Envelhecimento , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , China , Humanos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano
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