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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Effects of on behavior and blood-brain barrier in Alzheimer's disease mice / 浙江大学学报·医学版

To investigate the effects of on behavior and blood brain barrier (BBB) in Alzheimer's disease mice. Thirty-eight 4-month-old APP/PS1 double transgenic mice were randomly divided into three groups: model group, low-dose group and high-dose group. Saline, and 12 g·kg·d were given to each group by continuous gavage once a day for respectively. The changes in activities of daily live and fear conditioning memory behavior of mice were examined by nesting behavior test and fear conditioning test, respectively. The β-amyloid protein (Aβ) depositions in cortex and hippocampal CA1 area of mice were detected by thioflavin T staining. The CD34 and activities fibrinogen (Fib) immunofluorescence double staining were used to determine the vascular endothelial integrity and BBB exudation. Compared with model mice, activities of daily live were significantly improved in low-dose and high-dose groups (both <0.01), the fear memory ability was significantly increased in high-dose group (<0.01). The amount of Aβ deposition in cortex and hippocampal CA1 decreased significantly in high-dose group, the area ratio decreased significantly; the area ratio of Aβ deposition in hippocampal CA1 region in low-dose group also decreased (all <0.05). The proportions of CD34 positive area of cortex in low and high dose groups increased, the percentage of fibrinogen positive area decreased (all <0.05). The proportion of CD34 positive area in hippocampal CA1 region in high-dose group was significantly increased, the percentage of fibrinogen positive area decreased significantly (both <0.05). especially high-dose can improve the activities of daily live and fear conditioning memory function of APP/PS1 mice, reduce the deposition of Aβ in brain. The mechanism may be related to the reduction of BBB permeability and the protection of the integrity of BBB.

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.

Danggui Shaoyaosan Inhibits Neuroinflammation in AD Rats by Regulating NLRP3/Caspase-1 Pathway / 中国实验方剂学杂志

Objective:To investigate the neuroprotective effect of Danggui Shaoyaosan （DSS） in a rat model of amyloid-<italic>β</italic>-peptide_1-42 （A<italic>β</italic>_1-42）-induced Alzheimer's disease （AD） as well as its regulatory effect on NOD-like receptor protein 3 （NLRP3）/cysteinyl aspartate-specific protease-1 （Caspase-1） signaling pathway. Method:The AD animal model was established via intracerebral injection of A<italic>β</italic>_1-42 and treated with different concentrations of DSS after the division of rats into the sham operation group， model group， as well as the high-， medium-， and low-dose DSS groups. Morris water maze test was conducted to determine the learning and memory abilities of rats. The morphology and function of neurons were detected by hematoxylin-eosin （HE） staining and Golgi staining， followed by immunofluorescence co-localization of NLRP3 inflammasome activation. The mRNA expression levels of interleukin （IL）-1<italic>β</italic> and IL-18 were measured by Real-time polymerase chain reaction （Real-time PCR）， and the protein expression levels of NLRP3， Caspase-1， and IL-1<italic>β </italic>were assayed by Western blot. Result:Compared with the sham operation group， the model group exhibited significantly decreased learning and memory abilities （<italic>P</italic><0.01）， impaired neuronal morphology and function， up-regulated IL-1<italic>β</italic> and IL-18 mRNA expression， enhanced NLRP3 inflammasome activation， and elevated NLRP3， Caspase-1， and IL-1<italic>β</italic> protein expression （<italic>P</italic><0.01）. Compared with the model group， DSS at both medium and high doses remarkably improved the learning and memory abilities of AD rats （<italic>P</italic><0.05， <italic>P</italic><0.01）， restored neuronal morphology and function， down-regulated the mRNA expression levels of inflammatory factors IL-1<italic>β</italic> and IL-18， reduced the activation of NLRP3 inflammasomes， and lowered the protein expression levels of NLRP3， Caspase-1， and IL-1<italic>β</italic> （<italic>P</italic><0.01）. Conclusion:DSS inhibits inflammasome activation and neuroinflammatory response possibly by regulating the NLRP3/Caspase-1 signaling pathway， thus exerting the neuroprotective effect.

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.

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.

Nucleotide-binding Oligomerization Domain-like Receptor Family Pyrin Domain Containing 3 Inflammasome in Alzheimer's Disease / 中国医学科学院学报

Alzheimer's disease(AD)is a chronic neurodegenerative disease whose cause remains unclear.The β-amyloid plaques in the brain are one of the major pathological features of AD.However,the drugs targeting extracellular β-amyloid plaques have failed to cure the disease.Innate immunity and neuroinflammation play a role in the pathogenesis and progression of AD.As the macrophages existing in the central nervous system,microglia are related with extracellular β-amyloid deposition,intracellular neurofibrillary tangle formation,and neuron injury.Accumulating evidence demonstrates that the activation of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3(NLRP3)inflammasome in microglia plays a role in AD,suggesting new therapeutic target for AD in this signaling pathway.This article reviewed the studies about the activation and regulation of NLRP3 inflammasome in the pathogenesis and progression of AD as well as the development of AD therapies targeting this pathway,aiming to provide reference for further studies in this field.

Progress on loss-of-function hypothesis of presenilin-1 mutations in Alzheimer diseases / 浙江大学学报·医学版

Alzheimer's disease (AD) is an aging-related neurodegenerative disease and is associated with the accumulation of amyloid-β (Aβ) peptides in patient brains. AD can be classified into the familial type and sporadic type. () is the major risk gene for familial AD (fAD) because its mutations comprised over 80%of the total mutations causing fAD. PS1 is the catalytic subunit of the enzyme γ-secretase, which is responsible for the proteolytic cleavage of amyloid precursor protein (APP) to produce Aβ. Although novel fAD-causing mutations in PS1 are being reported increasingly, the molecular mechanisms underlying how these mutations induce fAD remain elusive. Since over 90%of the fAD-causing mutations in PS1 leads to a reduction of γ-secretase activity, the loss-of-function mutation hypothesis has been emerged, which suggests that the loss of PS1 functions may be the root cause of AD. Recently, increasing number of evidence supports this hypothesis. First, loss-of-function mutations increase the production of long-length Aβ by disturbing the cleavage sites of γ-secretase APP, thereby increasing the ratio of Aβ/Aβ; Second, loss-of-function mutations dysregulate endoplasmic reticulum calcium homeostasis in neurons; Third, loss-of-function mutations inhibit the autophagy activity of neurons, resulting in the abnormal accumulation of cleaved products from APP; Fourth, loss-of-function mutations alter the endocytosis and transcytosis processes in neurons, leading to neuratrophy; Fifth, loss-of-function mutations activate brain immune cells (astrocytes and microglia), which mount a strong neuroinflammation response; Last, loss-of-function mutations reduce the rates of glycolysis and the production of lactic acid, disrupting the balance of neuronal energy supply. In this article we summary the research progress on the loss-of-function hypothesis and pose several topics which would guide studies of this field in future.

Effects of Effective Part of Tinospora sinensis on Hippocampus Proteomics of AD Rats Induced by Beta-amyloid Protein and D-galactose / 中国药学杂志

OBJECTIVE: To investigate the effect of the 80% ethanol elution part of Tinospora sinensis macroporous resin extract on the expression of hippocampus proteome in Alzheimer′s disease (AD) model rats induced by D-galactose combined with Aβ2535. METHODS: The AD rats model replicated by D-galactose combined with Aβ2535, The AD rat model was replicated by D-galactose combined with Aβ2535, and randomly divided into sham operation group, model group, Donepezil group (donepezil, 6.0 mg•kg-1), and 80% extraction of Tinospora sinensi group (crude drug 6 g•kg-1). Donepezil group: donepezil 0.1 mL•10 g-1 ig. 80% extraction of Tinospora sinensi group: Tinospora sinensis effective part extraction 0.1 mL•10 g-1 ig. Model group and sham-operation group: physiological saline 0.1 mL•10 g-1 ig. Once a day, continuous administration for 15 d. Separating the hippocampus and extracting the protein, take the system test with nanol-ESI liquid-mass spectrometry, protein discovery software was used for identification, and qualitative analysis different groups of hippocampal proteins by SIEVE software. Take the GO analysis on differential protein with the ANTHER classification system and use IPAD to enrich the pathway. RESULTS: Compared with the model group, the drug-administered group had 66 differential proteins, including tubulin, heat shock proteins, energy metabolism-related proteins, vesicle production/transport related proteins, and brain protection-related proteins, which are closely related to AD. The above differential proteins involve a total of 21 signaling pathways. CONCLUSION: Tinospora sinensis may promote the synthesis and release of neurotransmitters by up-regulating clathrin and vesicle-forming transport and neurotransmitter release, and improve the function of cholinergic function in the brain to achieve the pathological process of AD.