Prospects for the application of blood-based biomarkers in Alzheimer′s disease / 中华检验医学杂志

The early diagnosis of Alzheimer′s disease (AD) has long been a challenge in the field of medicine. In recent years, research on blood biomarkers of AD has flourished, which holds significant promise for advancing the early diagnosis, monitoring, and early intervention of AD. With the new generation of ultra-sensitive detection techniques, a series of studies have successfully validated core biomarkers, non-specific biomarkers, and other relevant biomarkers of AD in blood. However, the use of blood-based biomarkers for the diagnosis and prediction of AD still faces some challenges related to accuracy and robustness. This article compiles and analyzes the advances, strengths, and limitations of each type of biomarkers, and provides several potential strategies to address these challenges.

Mechanism of Linggui Zhugantang in Promoting Astrocyte Endocytosis and Degradation of Amyloid β / 中国实验方剂学杂志

ObjectiveTo investigate the effects of Linggui Zhugantang （LGZGT）-containing serum on primary astrocytes （AS） induced by β amyloid 1-42 （Aβ1-42） in a rat model of Alzheimer's disease （AD） and explore the phagocytic and degradative effects of LGZGT on Aβ. MethodAn AD model was established by inducing AS with Aβ1-42. The cells were divided into normal group， model group， LGZGT low-， medium-， and high-dose （LGZGT-L， LGZGT-M， and LGZGT-H） groups， and donepezil hydrochloride group. The model group was treated with Aβ1-42 at a final concentration of 10 μmol∙L-1. The LGZGT-L， LGZGT-M， and LGZGT-H groups were treated with 10% serum containing LGZGT on the basis of the model group. Cell viability was assessed using a cell counting kit-8 （CCK-8）， lactate dehydrogenase （LDH） activity was measured using an LDH assay kit， and cell morphology was observed using an inverted microscope. The expression of Aβ-related degradation enzymes insulin-degrading enzyme （IDE） and cathepsin D （CTSD） was detected using Western blot， and the fluorescence intensity of cathepsin B （CTSB） was measured using immunofluorescence. The content of Aβ1-42 in cells was determined using an enzyme-linked immunosorbent assay （ELISA）. ResultCompared with the normal group， the viability of AS in all groups decreased， and Aβ1-42 at different concentrations had inhibitory effects on AS proliferation. After administration， compared with the normal group， the cell survival rate of the model group decreased significantly （P<0.05）. Compared with the model group， the cell survival rates of the LGZGT-H group and donepezil hydrochloride group increased significantly （P<0.05）. The LDH activity of cells in the model group was significantly increased compared with that in the normal group （P<0.05）， and cell bodies were swollen and enlarged with increased protrusions and elongation， suggesting more obvious cell damage. Compared with the model group， the LDH activity of cells in the donepezil hydrochloride， LGZGT-L， LGZGT-M， and LGZGT-H groups decreased significantly （P<0.05）. After administration， the cell swelling in the LGZGT-M， LGZGT-H， and donepezil hydrochloride groups improved， cell protrusions shortened， and cell clustering decreased. Compared with the normal group， the expression of IDE and CTSD in the model group decreased significantly （P<0.05）. Compared with the model group， the expression of IDE increased significantly in the LGZGT-M and LGZGT-H groups （P<0.05）. Compared with the model group， the expression of CTSD increased significantly in the LGZGT-L， LGZGT-M， LGZGT-H， and donepezil hydrochloride groups （P<0.05）. The average fluorescence intensity of CTSB in the model group was significantly lower than that in the normal group （P<0.05）. Compared with the model group， the average fluorescence intensity of CTSD in the LGZGT-L， LGZGT-M， LGZGT-H， and donepezil hydrochloride groups increased significantly （P<0.05）. The intracellular content of Aβ1-42 in cells in the model group was significantly higher than that in the normal group （P<0.05）. After administration， compared with the model group， the intracellular content of Aβ1-42 in cells in the LGZGT-L， LGZGT-M， LGZGT-H， and donepezil hydrochloride groups decreased significantly （P<0.05）， and LGZGT-containing serum reduced Aβ1-42 in a dose-dependent manner （P<0.05）. ConclusionLGZGT has a protective effect on Aβ1-42-induced AS and can promote the degradation of Aβ. Its mechanism may be related to reducing Aβ toxicity， enhancing cell viability， promoting the expression of IDE， CTSD， and CTSB， and restoring lysosomal function.

Expression relationship and significance of NEAT1 and miR-27a-3p in serum and cerebrospinal fluid of patients with Alzheimer disease / 北京大学学报(医学版)

Objective:To explore the expression relationship and significance of long chain non-coding RNA nuclear-enriched abundant transcript 1(LncRNA NEAT1)and miR-27a-3p in serum and cerebro-spinal fluid of patients with Alzheimer disease(AD).Methods:Sixty-six AD patients received by the department of neurology of our hospital from October 2019 to September 2021 were gathered,according to the clinical dementia rating scale score,they were grouped into mild group(≤ 1 point,n=41)and moderate-to-severe group(＞1 point,n=25).Another 66 cases of serum and cerebrospinal fluid sam-ples from outpatient physical examination personnel were regarded as the control group.The general infor-mation on all subjects was recorded and cognition was assessed;real-time quantitative PCR was performed to measure the expression levels of miR-27a-3p and NEAT1 in serum and cerebrospinal fluid;enzyme-linked immunosorbent assay was performed to measure the protein levels of β-amyloid precursor protein cleaving enzyme 1(BACE1),β-amyloid(Aβ)40 and Aβ42 in cerebrospinal fluid;Spearman's method was performed to analyze the correlation of serum miR-27a-3p and NEAT1 levels with mini-mental state examination(MMSE)and montreal cognitive assessment(MoCA)scores;Pearson method was per-formed to analyze the correlation between serum miR-27a-3p and NEAT1 levels and Aβ deposition standard uptake value ratio(SUVR)and cerebrospinal fluid miR-27a-3p,NEAT1,BACE1,Aβ42 and Aβ40 levels.Results:The MMSE score[21(17,25),9(7,11)vs.27(21,34)],MoCA score[17(12,21),10(7,13)vs.27(21,31)],serum miR-27a-3p level(0.55±0.13,0.46±0.06 vs.0.97± 0.22),cerebrospinal fluid miR-27a-3p(0.48±0.10,0.35±0.10 vs.1.03±0.31),Aβ42 levels[(303.55±36.77)ng/L,(231.45±34.14)ng/L vs.(499.99±53.63)ng/L]and Aβ42/Aβ40 ra-tio(0.030±0.008,0.022±0.007 vs.0.048±0.010)of AD patients in mild group and moderate-to-severe group were all lower than those in the control group,and the moderate-to-severe group were lower than the mild group(all P＜0.05);the serum NEAT1 level(2.31±0.64,3.13±0.76 vs.1.05± 0.20),SUVR(1.50±0.29,1.76±0.52 vs.0.74±0.15),and cerebrospinal fluid NEAT1(3.51± 1.24,4.30±1.65 vs.1.01±0.23)and B ACE 1 levels[(55.78±5.98)μg/L,(72.32±16.08)μg/L vs.(21.39±3.73)μg/L]were higher than those in the control group,and the moderate-to-se-vere group were higher than the mild group(all P＜0.05).Serum NEAT1 level in AD patients was posi-tively correlated with SUVR,cerebrospinal fluid NEAT1 and BACE1(r=0.350,0.606,0.341,P＜0.05),and negatively correlated with MMSE score and MoCA score(r=-0.473,-0.482,all P＜0.05);serum miR-27a-3p level was positively correlated with cerebrospinal fluid miR-27a-3p level,MMSE score and MoCA score(r=0.695,0.424,0.412,all P＜0.05),and negatively correlated with SUVR and cerebrospinal fluid BACE1 level(r=-0.521,-0.447,all P＜0.05).Conclusion:The expression trends of NEAT1 and miR-27a-3p in the serum and cerebrospinal fluid of AD patients are con-sistent,the level of NEAT1 is increased,and the level of miR-27a-3p is decreased.The levels of the two are negatively correlated,which is related to the degree of Aβ deposition in the brain of AD patients and is involved in the progression of AD.

Analysis of inflammatory factors and BDNF expression in the brain hippocampus of Alzheimer's disease-like mice caused by Aβ25-35 / 重庆医学

Objective To investigate the expression of inflammatory factors and brain-derived neurotro-phic factor(BDNF)in the brain hippocampus of Alzheimer's disease(AD)-like mice caused by amyloid β-protein 25-35(Aβ25-35).Methods A total of 40 six-week-old male Kunming mice were taken to construct an AD-like mouse model using bilateral ventricular injection of Aβ25-35,and were divided into the 0 d,7 d,14 d,and 28 d groups for observation,with 10 mice in each group.The Y-maze and new object recognition assay were used to test the learning and memory functions of the mice.The hematoxylin-eosin(HE)staining was used to observe the neuronal damage in the hippocampal region.Immunohistochemical staining was used to detect the expression levels of phosphorylated-tau(p-tau),CD11b and BDNF in hippocampus.ELISA was used to detect the expression levels of inflammatory factors in hippocampus,including interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF)-α,and real-time quantitative reverse transcription PCR(RT-qPCR)and Western blot were used to detect the mRNA and protein expression levels of BDNF.Results Aβ25-35 could impair memory and cognitive function in the mice.Compared with the 0 d group,the neuron number in the hippocampal tissue of mice in the 14 d and 28 d groups was significantly reduced(P<0.05),and the optical density values of p-Tau and CD11b,and expression levels of IL-1β and TNF-α in the hippocampal region of mice in the 14 d and 28 d groups were significantly increased(P<0.05).In addition,compared with the 0 d group,the relative expression levels of BDNF mRNA and protein in the hippocampal tissue of mice were sig-nificantly increased in the 7 d group(P<0.05),while the relative expression levels of BDNF mRNA and pro-tein were significantly decreased in the 14 d and 28 d groups(P<0.05).Conclusion Aβ25-35 may increase the expression of TNF-α,IL-1β and p-tau in hippocampal tissue by activating microglia,which in turn impaired the memory and cognitive functions of mice,and the expression level of BDNF in hippocampal tissue showed a first increase and then a decrease in the injury period.

Amelioration of Cognitive Dysfunction in Diabetic Rats by Jianpi Qinghua Prescription / 中国实验方剂学杂志

ObjectiveTo explore the amelioration of cognitive dysfunction in diabetes mellitus （DM） by Jianpi Qinghua prescription （JPQH） based on type 2 diabetes （T2DM） model rats. MethodFifty healthy male Wistar rats of SPF grade were randomly divided into control group （n=10） and experimental group （n=40）. The rats in the control group were fed conventionally， while those in the experimental group were fed on a high-sugar， high-fat diet for six weeks and administered with streptozotocin （STZ） for the induction of the DM model. The model rats were randomly divided into model group， sitagliptin group （1.2 g·L-1）， pioglitazone group （0.8 g·L-1）， and JPQH group （1.3 g·mL-1）， with 10 rats in each group. After six weeks of drug intervention， the changes in body weight， blood glucose， and other related indexes of each group were recorded. Enzyme-linked immunosorbent assay （ELISA） was performed to detect the levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-6 （IL-6） in the peripheral blood and brain. The Morris water maze test was used to evaluate the cognitive function in rats. Hematoxylin-eosin （HE） staining was used to observe the pathological morphology of the hippocampal CA region. The amyloid β-protein 40 （Aβ40） level was detected by immunohistochemistry. The protein expression of t-tau and p-tau in hippocampal neurons of rats was detected by Western blot. ResultCompared with blank group， the body weight of model group was significantly decreased （P<0.05）， blood glucose level was significantly increased （P<0.01）， inflammatory cytokines TNF-α and IL-1β were increased （P<0.05）， learning and spatial ability were significantly decreased （P<0.01）， the arrangement of hippocampal cells was loose and disordered， and the intercellular space was significantly increased. The number of cells decreased significantly， and the expression of Aβ40 increased significantly. and increased t-tau and p-tau protein content in the hippocampus （P<0.01）. Compared with model group， the JPQH group showed reduced blood glucose （P<0.01）， decreased TNF-α and IL-1β levels in the peripheral blood and cerebrospinal fluid （P<0.05）， a downward trend of IL-6 without a statistical difference， improved learning and spatial memory ability （P<0.01）， densely arranged cells in the hippocampal CA1 area， increased cell number， reduced Aβ40 expression， and decreased p-tau protein expression （P<0.05）. ConclusionJPQH can prevent cognitive dysfunction in DM by reducing inflammatory factor levels， decreasing neurotoxicity caused by Aβ40 deposition， and inhibiting hyperphosphorylation of tau protein in DM rats.

Changes in Plasma Amyloid-β Level and Their Relationship With White Matter Microstructure in Patients With Mild Cognitive Impairment / 中国医学科学院学报

Objective To investigate the changes in plasma amyloid-β (Aβ) level and their relationship with white matter microstructure in the patients with amnesic mild cognitive impairment(aMCI) and vascular mild cognitive impairment (vMCI).Methods A total of 36 aMCI patients,20 vMCI patients,and 34 sex and age matched healthy controls (HC) in the outpatient and inpatient departments of the First Affiliated Hospital of Anhui Medical University were enrolled in this study.Neuropsychological scales,including the Mini-Mental State Examination,the Montreal Cognitive Assessment,and the Activity of Daily Living Scale,were employed to assess the participants.Plasma samples of all the participants were collected for the measurement of Aβ42 and Aβ40 levels.All the participants underwent magnetic resonance scanning to obtain diffusion tensor imaging (DTI) data.The DTI indexes of 48 white matter regions of each individual were measured (based on the ICBM-DTI-81 white-matter labels atlas developed by Johns Hopkins University),including fractional anisotropy (FA) and mean diffusivity (MD).The cognitive function,plasma Aβ42,Aβ40,and Aβ42/40 levels,and DTI index were compared among the three groups.The correlations between the plasma Aβ42/40 levels and DTI index of aMCI and vMCI patients were analyzed.Results The Mini-Mental State Examination and the Montreal Cognitive Assessment scores of aMCI and vMCI groups were lower than those of the HC group (all P<0.001).There was no significant difference in the Activity of Daily Living Scale score among the three groups (P=0.654).The plasma Aβ42 level showed no significant difference among the three groups (P=0.227).The plasma Aβ40 level in the vMCI group was higher than that in the HC group (P=0.014),while it showed no significant difference between aMCI and HC groups (P=1.000).The plasma Aβ42/40 levels in aMCI and vMCI groups showed no significant differences from that in the HC group (P=1.000,P=0.105),while the plasma Aβ42/40 level was lower in the vMCI group than in the aMCI group (P=0.016).The FA value of the left anterior limb of internal capsule in the vMCI group was lower than those in HC and aMCI groups (all P=0.001).The MD values of the left superior corona radiata,left external capsule,left cingulum (cingulate gyrus),and left superior fronto-occipital fasciculus in the vMCI group were higher than those in HC (P=0.024,P=0.001,P=0.003,P<0.001) and aMCI (P=0.015,P=0.004,P=0.019,P=0.001) groups,while the MD values of the right posterior limb of internal capsule (P=0.005,P=0.001) and left cingulum (hippocampus) (P=0.017,P=0.031) in the aMCI and vMCI groups were higher than those in the HC group.In the aMCI group,plasma Aβ42/40 level was positively correlated with FA of left posterior limb of internal capsule (r=0.403,P=0.015) and negatively correlated with MD of the right fonix (r=-0.395,P=0.017).In the vMCI group,plasma Aβ42/40 level was positively correlated with FA of the right superior cerebellar peduncle and the right anterior limb of internal capsule (r=0.575,P=0.008;r=0.639,P=0.002),while it was negatively correlated with MD of the right superior cerebellar peduncle and the right anterior limb of internal capsule (r=-0.558,P=0.011;r=-0.626,P=0.003).Conclusions Plasma Aβ levels vary differently in the patients with aMCI and vMCI.The white matter regions of impaired microstructural integrity differ in the patients with different dementia types in the early stage.The plasma Aβ levels in the patients with aMCI and vMCI are associated with the structural integrity of white matter,and there is regional specificity between them.

A state-of-the-art review on miRNA in prevention and treatment of Alzheimer 's disease / 浙江大学学报·医学版

Alzheimer's disease (AD) is a multifactorial and heterogenic disorder. MiRNA is a class of non-coding RNAs with 19-22 nucleotides in length that can regulate the expression of target genes in the post-transcriptional level. It has been found that the miRNAome in AD patients is significantly altered in brain tissues, cerebrospinal fluid and blood circulation, as compared to healthy subjects. Experimental studies have suggested that expression changes in miRNA could drive AD onset and development via different mechanisms. Therefore, targeting miRNA expression to regulate the key genes involved in AD progression is anticipated to be a promising approach for AD prevention and treatment. Rodent AD models have demonstrated that targeting miRNAs could block biogenesis and toxicity of amyloid β, inhibit the production and hyper-phosphorylation of τ protein, prevent neuronal apoptosis and promote neurogenesis, maintain neural synaptic and calcium homeostasis, as well as mitigate neuroinflammation mediated by microglia. In addition, animal and human studies support the view that miRNAs are critical players contributing to the beneficial effects of cell therapy and lifestyle intervention to AD. This article reviews the most recent advances in the roles, mechanisms and applications of targeting miRNA in AD prevention and treatment based on rodent AD models and human intervention studies. The potential opportunities and challenges in clinical application of targeting miRNA for AD patients are also discussed.

Electroacupuncture Improves Blood-Brain Barrier and Hippocampal Neuroinflammation in SAMP8 Mice by Inhibiting HMGB1/TLR4 and RAGE/NADPH Signaling Pathways / 中国结合医学杂志

OBJECTIVE@#To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo.@*METHODS@#Senescence-accelerated mouse prone 8 (SAMP8) mice were used as AD models and received EA at Yingxiang (LI 20, bilateral) and Yintang (GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin (2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier (BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid- β (Aβ), and ionized calcium-binding adapter molecule 1 (IBa-1) in mouse hippocampus (CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining. Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining.@*RESULTS@#Fibrin was time-dependently deposited in the hippocampus of SAMP8 mice and this was inhibited by EA treatment (P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aβ in the hippocampus of SAMP8 mice (P<0.01), which was reversed by fibrin injection (P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability (P<0.05 or P<0.01). Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8 mice, which was reversed by fibrin injection (P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1 (HMGB1)/toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) signaling pathways (P<0.01).@*CONCLUSION@#EA may potentially improve cognitive impairment in AD via inhibition of fibrin/A β deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.

Research Progress on Neuroprotective Effects and Mechanisms of Glucagon-like Peptide 1 Analogues in Alzheimer's Disease / 实验动物与比较医学

Glucagon-like peptide 1 (GLP-1) is a kind of incretin produced in the intestinal with multiple pharmacological effects, which can stimulate insulin secretion effectively. Various GLP-1 analogues have been widely used in the treatment of type 2 diabetes mellitus. Alzheimer's disease (AD) is closely related to type 2 diabetes mellitus, with some common pathological features, such as insulin resistance, and epidemiological studies also showed that patients with type 2 diabetes mellitus have an increased risk of developing AD. GLP-1 analogues have shown beneficial effects in both preclinical animal research and clinical trials of AD. Therefore, the authors summarized the main characteristics of GLP-1 and AD, and analyzed the mechanisms of GLP-1 in preclinical AD studies of animal models. GLP-1 readily crosses the blood-brain barrier and exerts its neuroprotective effects by binding to and activating the widely distributed GLP-1 receptors (GLP-1Rs) in the brain, affecting multiple physiological and pathological processes including glucose metabolism, neuroinflammation, mitochondrial function, and cell proliferation. Insulin resistance and inflammation are key common pathways in AD and type 2 diabetes. GLP-1 may exert its neuroprotective effects by improving mitochondrial function and glycolysis, reducing oxidative stress levels, exerting anti-inflammatory and anti-apoptotic effects, inducing neurogenesis, and inhibiting glial cell proliferation. This paper maybe provide the reference for further study of GLP-1 analogues in AD, hoping to open new therapy venues for AD patients.

Alterations of gut microbiota composition and cogni-tive behavior in APP/PS1/tau triple-transgenic mouse model of Alzheimer's disease / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer's disease(AD)is a progressive neurological disease.Given the important role of gut microbiota composition in AD pathology,the observed perturbation in the microbiota composition and diversity may serve as the mechanisms underlying age-dependent APP/PS1/tau triple-transgenic mouse(3×Tg-AD)mice amyloid deposition and memory deficits.Here-in,we intended to investigate the gut microbiota and as-sessed its relationship with the triggering and develop-ment of cognitive impairment of AD.METHODS This study involves the comparative assessment of spatial learning,amyloid β-protein(Aβ)accumulation,and fecal microbiota alterations in 3×Tg-AD mice from three age groups:AD asymptomatic stage(3 m),presymptomatic stage(6 m),and the symptomatic stage of AD(9 m).RE-SULTS We demonstrate that spatial memory deficits,brain Aβ accumulation,and weight gain in 3×Tg-AD mice gradually appear after 6 months of age.However,the total gut bacterial counts underwent changes from 3 to 6 months of age and were further altered at 9 months of age.Importantly,changes in gut bacteria abundance of Desulfobacterota and Actinobacteriota phylain 6-month-old mice preceded apparent spatial memory deficits.CONCLUSION Changes in the gut microbial community are one of the mechanisms of early AD pathology.

Research progress on the use of Rhizoma coptidis extract against Alzheimer's disease / 中华老年医学杂志

Rhizoma coptidis extract has a variety of pharmacological activities, including alleviating cognitive impairment in Alzheimer's disease(AD). The main mechanisms of its anti-AD activity include reducing the production of amyloid β(Aβ), inhibiting the phosphorylation of Tau protein, inhibiting cholinesterase, anti-inflammation, anti-oxidation, improving apoptosis, etc.This paper reviewed the anti-AD effect of Rhizoma coptidis extract and the specific mechanisms, aiming to provide a theoretical basis for relevant research and clinical practice.

Advances in molecular imaging of cerebral amyloid angiopathy / 中华神经科杂志

Cerebral amyloid angiopathy (CAA) is a common age-related small vessel disease characterized by amyloid-β (Aβ) deposition in the wall of small arterioles and capillaries of the leptomeninges and cerebral cortex. Several molecular imaging technologies such as amyloid-β positron-emission tomography (PET) and 18F-fluorodeoxyglucose-PET have been successfully applied in the patients with CAA. Amyloid-PET may indicate the distribution and burden of Aβ deposition by the tracer′s specific binding to the pathological markers, providing qualitative and quantitative information for the diagnosis of CAA. However, amyloid-β PET is inadequate to differentiate CAA from other Aβ-related diseases like Alzheimer′s disease. Other novel techniques of molecular imaging including tau-PET, single photon emission computed tomography and other highly selective PET radioligands have been investigated widely at present. This article mainly reviewed the advances in molecular imaging of CAA.

Mechanism of Linggui Zhugantang in Repairing Blood-brain Barrier Injury of Alzheimer's Disease / 中国实验方剂学杂志

ObjectiveTo observe the effect of Linggui Zhugantang （LG） on the blood-brain barrier （BBB） model of Alzheimer's disease （AD） in vitro and to explore the mechanism of LG in repairing the BBB injury in AD. MethodA total of 50 male SPF rats were randomized into five groups： high-dose （4.8 g·kg-1）， medium-dose （2.4 g·kg-1）， and low-dose （1.2 g·kg-1） LG groups， western medicine （0.5 g·kg-1 donepezil hydrochloride） group， and normal group （normal saline of equivalent volume）. They received （ig） corresponding drugs twice a day for 7 d. Drug-containing serum was respectively collected from the abdominal aorta 1 h after the last administration. The BBB injury of AD in vitro was induced with the cell co-culture method， and 6 groups were designed： normal group， model group， high-， medium-， and low-dose LG groups， and western medicine group. The model group was added with 100 μL amyloid β1-42 （Aβ1-42， final concentration： 5 μmol·L-1）， and high-dose， medium-dose， and low-dose LG groups and the western medicine group were added with corresponding 10% drug-containing serum in addition to the 100 μL Aβ1-42 （final concentration： 5 μmol·L-1）. Cell survival rate was detected by methyl thiazolyl tetrazolium （MTT） assay， expression of BBB-related skeleton proteins （claudin-5， ZO-1， occludin）， matrix metalloproteinase-2 （MMP-2）， and matrix metalloproteinase-9 （MMP-9） by Western blot， and content of inflammatory factors interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） by enzyme-linked immunosorbent assay （ELISA）. BBB Aβ transporter low-density lipoprotein receptor-related protein 1 （LRP-1） and advanced glycation end product receptor （RAGE） at different time points in high-dose， medium-dose， and low-dose LG groups were determined by Real-time PCR and Western blot. ResultCell survival rate of the model group was lower than that of the normal group （P<0.05） and the survival rates of the western medicine group and high-dose LG group was higher than that in the model group （P<0.05）. The skeleton proteins were down-regulated and MMP-2 and MMP-9 were up-regulated in the model group compared with those in the normal group （P<0.05）. The expression of skeleton proteins was higher （P<0.05） and that of MMP-2 and MMP-9 was lower （P<0.05） in the western medicine group and high-dose LG group than in the model group. Compared with the model group， only the medium-dose LG group showed the up-regulation （P<0.05） of claudin-5 （P<0.05） and the decrease （P<0.05） of MMP-2. IL-1β， IL-6， and TNF-α in the model group were up-regulated （P<0.05） compared with those in the normal group， and those inflammatory factors in the western medicine group and high-dose and medium-dose LG groups were lower （P<0.05） than those in the model group. LRP-1 expression was up-regulated and RAGE expression was down-regulated at 3 h compared with those at 0 h （P<0.05）， while the expression of the two became stable at 6， 12， 24， 36 h. At 3 h， LRP-1 expression was down-regulated and RAGE expression was up-regulated in model group compared with those in the normal group at 3 h （P<0.05）. Moreover， the LRP-1 content was higher and RAGE content was lower in the western medicine group and high-dose LG group than in the model group. ConclusionLG can repair the BBB injury in vitro by inhibiting the expression of inflammatory factors and MMP-2， MMP-9， promoting the expression of skeletal proteins， and regulating the balance of transporters.

Ginsenoside Rg_1 protects PC12 cells against Aβ-induced injury through promotion of mitophagy by PINK1/parkin activation / 中国中药杂志

Amyloid β-protein(Aβ) deposition in the brain is directly responsible for neuronal mitochondrial damage of Alzheimer's disease(AD) patients. Mitophagy, which removes damaged mitochondria, is a vital mode of neuron protection. Ginsenoside Rg_1(Rg_1), with neuroprotective effect, has displayed promising potential for AD treatment. However, the mechanism underlying the neuroprotective effect of Rg_1 has not been fully elucidated. The present study investigated the effects of ginsenoside Rg_(1 )on the autophagy of PC12 cells injured by Aβ_(25-35) to gain insight into the neuroprotective mechanism of Rg_1. The autophagy inducer rapamycin and the autophagy inhi-bitor chloroquine were used to verify the correlation between the neuroprotective effect of Rg_1 and autophagy. The results showed that Rg_1 enhanced the viability and increased the mitochondrial membrane potential of Aβ-injured PC12 cells, while these changes were blocked by chloroquine. Furthermore, Rg_(1 )treatment increased the LC3Ⅱ/Ⅰ protein ratio, promoted the depletion of p62 protein, up-regulated the protein levels of PINK1 and parkin, and reduced the amount of autophagy adaptor OPTN, which indicated the enhancement of autophagy. After the silencing of PINK1, a key regulatory site of mitophagy, Rg_1 could not increase the expression of PINK1 and parkin or the amount of NDP52, whereas it can still increase the LC3Ⅱ/Ⅰ protein ratio and promote the depletion of OPTN protein which indicated the enhancement of autophagy. Collectively, the results of this study imply that Rg_1 can promote autophagy of PC12 cells injured by Aβ, and may reduce Aβ-induced mitochondrial damage by promoting PINK1-dependent mitophagy, which may be one of the key mechanisms of its neuroprotective effect.

Targeting whole body metabolism and mitochondrial bioenergetics in the drug development for Alzheimer's disease

Aging is by far the most prominent risk factor for Alzheimer's disease (AD), and both aging and AD are associated with apparent metabolic alterations. As developing effective therapeutic interventions to treat AD is clearly in urgent need, the impact of modulating whole-body and intracellular metabolism in preclinical models and in human patients, on disease pathogenesis, have been explored. There is also an increasing awareness of differential risk and potential targeting strategies related to biological sex, microbiome, and circadian regulation. As a major part of intracellular metabolism, mitochondrial bioenergetics, mitochondrial quality-control mechanisms, and mitochondria-linked inflammatory responses have been considered for AD therapeutic interventions. This review summarizes and highlights these efforts.

Research progress in clinical treatment of Alzheimer's disease and potential drugs from natural products / 药学学报

With the acceleration of the aging process of our country's population, the impact of aging-related diseases - Alzheimer's disease (AD) on society and families has become increasingly prominent. AD is caused by multiple mechanisms, and the pathogenesis has not been fully elucidated. Most of the clinical treatments are single therapy, which mainly focuses on improving symptoms and are difficult to reverse the disease process. Therefore, the development of drugs that can both improve symptoms and reverse the disease process is extremely urgent in clinical. Increasing number of studies has shown that traditional Chinese medicine plays an important role in the prevention and treatment of AD. The natural products have many advantages, such as novel structures, multiple targets and diverse activities, which can be used as an important source of leading compounds for the treatment of AD. The review summarizes the main clinical treatment methods and the research progress of natural ingredients in traditional Chinese medicine, and provides a reference for the follow-up clinical treatment of AD combined with the advantages of traditional Chinese medicine treatment.

Grain-sized moxibustion inhibits the progression of Alzheimer disease in 5XFAD transgenic mice / 针灸推拿医学（英文版）

Objective: To investigate whether grain-sized moxibustion at Xinshu (BL15) and Shenshu (BL23) can alleviate cognitive decline and other pathologic features in early-stage Alzheimer disease (AD) using transgenic mice with 5 familial AD mutations (5XFAD). Methods: The genotype of transgenic mice was detected by polymerase chain reaction. A total of 40 transgenic mice (1.5 months old) were randomly and equally allocated to an AD model group (5XFAD group) or a grain-sized moxibustion group (5XFAD + GM group), with 20 wild-type (WT) mice (C57BL/6J) serving as the normal control group (WT group). Mice in the 5XFAD + GM group were treated by grain-sized moxibustion at bilateral Xinshu (BL15) and Shenshu (BL23). Mice in the WT group and 5XFAD group received no treatment but were restrained to ensure exposure to a similar experimental condition. Cognitive function and memory were assessed with the Morris water maze and Y-maze tests. The amyloid β 40 (Aβ40) and amyloid β 42 (Aβ42) levels in the brain were evaluated by enzyme-linked immunosorbent assay; amyloid plaque deposition in brain tissue sections was detected by thioflavin-S staining; the expression of glial fibrillary acidic protein (GFAP), cluster of differentiation 11b (CD11b), brain-derived neurotrophic factor (BDNF), and choline acetyltransferase (ChAT) in the hippocampus and prefrontal cortex was analyzed by immunohistochemistry. Results: In the Morris water maze test, compared with the 5XFAD group, mice in the 5XFAD + GM group had a shorter escape latency and more target area crossings and spent more time in the target quadrant (P<0.05). In the Y-maze test, compared with the 5XFAD group, the number of training times of the 5XFAD + GM group was significantly decreased (P<0.05), together with more correct responses (P<0.05). Compared with the 5XFAD group, the levels of Aβ40 and Aβ42 in the brain tissue of the 5XFAD + GM group were significantly lower (P<0.05); in the hippocampus and prefrontal cortex, the total number of amyloid β plaque deposition were significantly lower (P<0.05); the expression levels of GFAP and CD11b were significantly reduced (P<0.05); and the expression levels of ChAT and BDNF were significantly increased (P<0.05).Conclusion: Grain-sized moxibustion at Xinshu (BL15) and Shenshu (BL23) greatly improves learning and memory functions, decreases the levels of Aβ40 and Aβ42, inhibits amyloid β plaque deposition, decreases the expression of GFAP and CD11b, and increases the expression of ChAT and BDNF in AD mice to inhibit the progression of AD.

Protective effect of baicalein on injured PC12 cell induced by Aβ and its mechanism / 国际中医中药杂志

Objective:To investigate the protective effect of baicalein on injured PC12 cell induced by Aβ and explore its mechanism.Methods:The method of MTT was used to detect the cell activity of each group and screened the concentration of baicalein. The PC12 cells were randomly divided into the blank group, the Aβ group, the baicalin group and the estradiol group. 24 hours after inoculation, baicalein group was intervened with 1×10 -6 mol/L baicalein solution, and estradiol group was intervened with 1×10 -5 mol/L estradiol solution. Two hours later, except the blank group, the other groups were added with 1.5×10 -4 mol/L Aβ to make the model. MTT assay was used to detect the cell viability of each group after 24 hours of cultivation. Then used oxidation kit to detect the contents of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and lactate dehydrogenase (LDH) in each group. And the level of caspase-3 mRNA was detected by Real-time Quantitative PCR (RT-PCR). Then the Western blot method was used to detect the expressions of p-PI3K, p-AKT and caspase-3. Results:Compared with the Aβ group, the PC12 cell viability [(96.348 ± 0.571)%, (97.183 ± 0.714)% vs. (86.922 ± 0.429)%] in the baicalin group and the estradiol group significantly increased( P<0.01). The activities of SOD [(54.31 ± 1.34) U/mgprot, (57.38 ± 2.25) U/mgprot vs. (36.18 ± 2.24) U/mgprot] and GSH-PX [(4.46 ± 0.23) U/mgprot, (4.72 ± 0.31) U/mgprot vs. (2.05 ± 0.37) U/mgprot] significantly increased, and the level of LDH [(85.43 ± 0.92) nmol/ml, (82.46 ± 0.27) nmol/ml vs. (99.17 ± 0.52) nmol/ml] significantly decreased ( P<0.01). The expression of caspase-3 mRNA (2.24 ± 0.64, 2.33 ± 0.75 vs. 3.46 ± 0.46) and p-PI3K (0.46 ± 0.03, 0.44 ± 0.06 vs. 0.66 ± 0.09), p-AKT (0.43 ± 0.05, 0.41 ± 0.02 vs. 0.58 ± 0.03), caspase-3 (0.61 ± 0.03, 0.56 ± 0.53 vs. 0.92 ± 0.07) protein significantly decreased ( P<0.01). Conclusion:Baicalein could slow down cell apoptosis and oxidative reaction, reduce the damage of Aβ to PC12 cells by inhibiting the expression of PI3K/AKT pathway.

Tolcapone derivative PCDNA inhibits Aβ42 fibrillogenesis and reduces its cytotoxicity / 药学学报

Abnormal aggregation of amyloid-β protein (Aβ) in brain plays a vital role in the occurrence of Alzheimer's disease (AD). Hence, inhibiting Aβ aggregation is one major tactic for therapy of AD. Previous studies have found that tolcapone can inhibit Aβ42 aggregation and reduce the cytotoxicity induced by Aβ42 aggregates, but clinical studies have found that tolcapone has strong liver toxicity. To reduce the liver toxicity of tolcapone, its side chain structure was modified to obtain its derivative phenethyl (E)-2-cyano-3-(3,4 dihydroxy-5-nitrobenzene)-acrylate (PCDNA). Thioflavin T (ThT) and atomic force microscopy (AFM) assays were used to explore the inhibitory effect of PCDNA on Aβ42 fibrillogenesis. The cytotoxicity assays were used to explore the inhibitory effect of PCDNA against the cytotoxicity induced by Aβ42 aggregates. In addition, the depolymerization effect of PCDNA on mature Aβ42 fibrils was also explored. Finally, molecular docking was used to explore the interaction between PCDNA and Aβ42 pentamer. These results lay the foundation for the study of the structural analogues of tolcapone as Aβ inhibitors.

Mechanism of puerarin reversing SH-SY5Y cell injury induced by Aβ_(1-42) based on proteomics / 中国中药杂志

Puerarin has the anti-Alzheimer's disease (AD) activity,which can reverse nerve injury induced by Aβand inhibit neuronal apoptosis.However,its potential pharmacodynamic mechanism still needs to be further researched.The occurrence and development of AD is due to the change of multiple metabolic links in the body,which leads to the destruction of balance.Puerarin may act on multiple targets and multiple metabolic processes to achieve therapeutic purposes.Quantitative proteomic analysis provides a new choice to understand the mechanism as completely as possible.This research adopted SH-SY5Y cells induced by Aβ_(1-42)to establish AD cell model,and Aβimmunofluorescence detection showed that Aβdecreased significantly after puerarin intervention.The mechanism of puerarin reversing SH-SY5Y cell injured by Aβ_(1-42)was further explored by using label-free non-labeled quantitative technology and Western blot detection based on bioinformatics analysis result.The results showed that most of the differential proteins were related to biological processes such as cellular component organization or biogenesis,cellular component organization and cellular component biogenesis,and they mainly participated in the top ten pathways of P value such as pathogenic Escherichia coli infection,m TOR signaling pathway,regulation of autophagy,regulation of actin cytoskeleton,spliceosome,hepatocellular carcinoma,tight junction,non-small cell lung cancer,apoptosis and gap junction.Annexin V/PI flow cytometry and TUNEL were used to detect apoptosis,and the results showed that Aβdecreased significantly and the rate of apoptosis decreased significantly after puerarin intervention.Western blot analysis found that the protein expression level of autophagy related protein LC3Ⅱwas up-regulated after Aβinduction,and the degree of this up-regulation was further enhanced in puerarin intervention group.The trend of the ratio of LC3Ⅱ/LC3Ⅰamong groups was the same as the protein expression level of LC3Ⅱ，the protein expression level of p62 in the control group,AD model group and puerarin intervention group decreased successively.Protein interaction network analysis showed that CAP1 was correlated with TUBA1B,HSP90AB2P,DNM1L,TUBA1A and ERK1/2,and the correlation between CAP1 and ERK1/2 was the highest among them.Western blot showed that the expressions of p-ERK1/2,Bax and CAP1 were significantly down-regulated and the protein expression level of Bcl-2 was significantly up-regulated after puerarin intervention.Therefore,puerarin might improve the SH-SY5Y cells injured by Aβ_(1-42)through the interaction of multiple biological processes and pathways in cells multiple locations,and CAP1 might play an important role among them.