Effect of aluminum exposure on abnormal phosphorylationof tau protein in PC12 cells of rats / 预防医学

Objective @#To investigate the effect of aluminum exposure on expression of miR-497-5p, wingless murine breast cancer virus integration site family member 3a (Wnt3a), β-catenin protein, glycogen synthase kinase-3β (GSK-3β) protein and tau protein in rat adrenal pheochromocytoma PC12 cells, so as to provide insight into unraveling the mechanisms underlying aluminum exposure-induced abnormal phosphorylation of tau protein.@* Methods@# PC12 cells were exposed to Al(mal)3 at concentrations of 0, 100, 200, 400 μmol/L for 24 h. The viability of PC12 cells was measured using cell counting kit-8 (CCK-8) assay. The relative expression of miR-497-5p and Wnt3a was detected using a real-time fluorescent quantitative PCR (RT-qPCR) assay, and the expression of Wnt3a, β-catenin, GSK-3β, P-GSK-3β (Ser9), tau and p-tau (Ser396) proteins were determined using Western blotting. @*Results @#The viability of PC12 cells appeared a tendency towards a decline with the increase of aluminum dose (Ftrend=323.473, P=0.001). RT-qPCR assay detected that the relative miR-497-5p expression appeared a tendency towards a rise with the increase of aluminum dose (Ftrend=14.888, P=0.031), and the relative Wnt3a expression appeared a tendency towards a decline with the increase of aluminum dose (Ftrend=165.934, P<0.001). The miR-497-5p expression negatively correlated with the relative Wnt3a expression (r=-0.693, P=0.012). The expression of Wnt3a (Ftrend=357.656, P=0.001), β-catenin (Ftrend=208.750, P=0.001) and p-GSK-3β (Ser9) proteins (Ftrend=512.583, P<0.001) appeared a tendency towards a decline with the increase of aluminum dose, and the expression of GSK-3β (Ftrend=39.965, P<0.001), tau (Ftrend=277.929, P=0.006) and p-tau (Ser396) proteins (Ftrend=96.247, P=0.002) appeared a tendency towards a rise with the increase of aluminum dose. @*Conclusion@# Up-regulation of miR-497-5p and GSK-3β expression and down-regulation of Wnt3a and β-catenin expression may be a mechanism underlying aluminum exposure-induced abnormal phosphorylation of tau protein.

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.

Theoretical Exploration of Luobing Theory Guides Study on Alzheimer's Disease Based on Neurovascular Protection / 中国实验方剂学杂志

Based on the correlation between Qi and blood in traditional Chinese medicine， the collateral disease theory puts forward that the Qi-collateral go hand in hand with the vessel-collateral of the brain， and to be as close as lips to teeth in structure and function， which is an important basis for the function of brain governing mind. And this theory proposes that deficiency/stagnancy of collateral-Qi， stagnation of collaterals and loss of consciousness are the main pathogenesis of Alzheimer's disease（AD）， which is different from the research strategy of modern medicine focusing on neurons. It is suggested that it is necessary to treat AD from two aspects， including neuronal protection（elimination of pathological products such as β-amyloid and phosphorylated tau protein） and cerebral microvascular protection（protection of cerebral microvascular structure and function， promotion of therapeutic angiogenesis and increase of cerebral blood flow. Tongxinluo capsules is a representative drug for dredging collaterals developed under the guidance of the therapeutic principle of collaterals need circulation， it can protect microvessels and play a neuroprotective role mediated by vascular protection. Clinical studies have confirmed that Tongxinluo capsules can effectively treat AD， vascular dementia and cognitive impairment related diseases， which can provide new ideas and effective treatment ways to prevent and treat AD from neurovascular protection in a comprehensive manner.

Effect of Danzhi Xiaoyaosan on Phosphorylation of Tau Protein in Rats with Alzheimer's Disease Based on PP2A and GSK-3β / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Danzhi Xiaoyaosan on the phosphorylation of tau protein and different sites of glycogen synthase kinase-3β （GSK-3β） and phosphoseryl/suanyl phosphate protein phosphatase 2A （PP2A） in the hippocampus of rats with Alzheimer's disease （AD） and its mechanism. MethodThe rat model of AD was established by injecting okadaic acid into the bilateral hippocampus of 90 male Wistar rats in SPF grades. The rats with successful modeling were selected and randomly divided into model group， aricept group （0.5 mg·kg-1）， and Danzhi Xiaoyaosan high， medium， and low groups （17.55， 8.77， and 4.38 g·kg-1）， and then gavaged for 42 d， once a day. Morris water maze was used to detect the learning and memory ability of rats， Nissl's staining was used to observe the morphological structure of neurons in the hippocampus， and Real-time polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression levels of tau protein， GSK-3β， and PP2A. Western blot was used to determine the protein expression levels of tau protein， GSK-3β， and PP2A. ResultAs compared with the control group， the learning and memory abilities of the rats in the model group were significantly decreased （P<0.01）， and the hippocampal CA3 region cells had abnormal structure， disorderly arrangement， and decreased number. The expression levels of GSK-3β mRNA， GSK-3β， p-GSK-3β-Tyr216， p-PP2A， and p-tau were increased in the model group as compared with the control group （P<0.01）， and those of p-GSK-3β-Ser9 and PP2A decreased significantly （P<0.01）. As compared with the model group， the learning and memory ability of the Aricept group and the Danzhi Xiaoyaosan groups were improved （P<0.05， P<0.01）， and the cell morphology and the number of hippocampal CA3 regions were better. The mRNA expression levels of PP2A and tau in the Aricept group were significantly up-regulated （P<0.05）， the mRNA expression level of GSK-3β was significantly down-regulated （P<0.01）， and the protein expression levels of GSK-3β， p-GSK-3β-Tyr216， and p-PP2A were down-regulated （P<0.05， P<0.01）， and the protein expression level of PP2A was significantly up-regulated （P<0.01）. As compared with the model group， the mRNA expression level of PP2A in the high-dose Danzhi Xiaoyaosan group was significantly up-regulated （P<0.01）， and that of GSK-3β was significantly down-regulated （P<0.01）， whereas the protein expression levels of p-PP2A， p-GSK-3β-Tyr216， and p-tau were down-regulated （P<0.05， P<0.01）， and the protein expression level of PP2A was significantly up-regulated （P<0.01）. As compared with the model group， the mRNA expression level of GSK-3β was significantly down-regulated in the medium-dose Danzhi Xiaoyaosan group （P<0.01）， the protein expression levels of GSK-3β， p-GSK-3β-Tyr216， and p-tau were down-regulated （P<0.05， P<0.01）， and the protein expression level of PP2A was significantly up-regulated （P<0.01）. As compared with the model group， the mRNA expression level of PP2A was significantly up-regulated in the low-dose Danzhi Xiaoyaosan group （P<0.01）， and that of GSK-3β was significantly down-regulated （P<0.01）， whereas the protein expression levels of GSK-3β and p-GSK-3β-Tyr216 were down-regulated （P<0.05， P<0.01）， and those of p-GSK-3β-Ser9 and PP2A were significantly up-regulated （P<0.01）. ConclusionDanzhi Xiaoyaosan can improve the learning and memory ability of rats with AD， and its mechanism may be related to the regulation of the activities of GSK-3β and PP2A protein-related sites and the phosphorylation of tau protein.

Development of a tau-V337M mouse model using CRISPR/Cas9 system and enhanced ssODN-mediated recombination / 生物工程学报

The generation of a tau-V337M point mutation mouse model using gene editing technology can provide an animal model with fast disease progression and more severe symptoms, which facilitate the study of pathogenesis and treatment of Alzheimer's disease (AD). In this study, single guide RNAs (sgRNA) and single-stranded oligonucleotides (ssODN) were designed and synthesized in vitro. The mixture of sgRNA, Cas9 protein and ssODN was microinjected into the zygotes of C57BL/6J mice. After DNA cutting and recombination, the site homologous to human 337 valine (GTG) in exon 11 was mutated into methionine (ATG). In order to improve the efficiency of recombination, a Rad51 protein was added. The female mice mated with the nonvasectomy male mice were used as the surrogates. Subsequently, the 2-cell stage gene edited embryos were transferred into the unilateral oviduct, and the F0 tau-V337M mutation mice were obtained. Higher mutation efficiency could be obtained by adding Rad51 protein. The F0 tau-V337M point mutation mice can pass the mutation on to the F1 generation mice. In conclusion, this study successfully established the first tau-V337M mutation mouse by using Cas9, ssODN and Rad51. These results provide a new method for developing AD mice model which can be used in further research on the pathogenesis and treatment of AD.

Therapeutic Mechanism of Kai Xin San on Alzheimer's Disease Based on Network Pharmacology and Experimental Validation / 中国结合医学杂志

OBJECTIVE@#To explore the specific pharmacological molecular mechanisms of Kai Xin San (KXS) on treating Alzheimer's disease (AD) based on network pharmacology and experimental validation.@*METHODS@#The chemical compounds of KXS and their corresponding targets were screened using the Encyclopedia of Traditional Chinese Medicine (ETCM) database. AD-related target proteins were obtained from MalaCards database and DisGeNET databases. Key compounds and targets were identified from the compound-target-disease network and protein-protein interaction (PPI) network analysis. Functional enrichment analysis predicted the potential key signaling pathways involved in the treatment of AD with KXS. The binding affinities between key ingredients and targets were further verified using molecular docking. Finally, the predicted key signaling pathway was validated experimentally. Positioning navigation and space search experiments were conducted to evaluate the cognitive improvement effect of KXS on AD rats. Western blot was used to further examine and investigate the expression of the key target proteins related to the predicted pathway.@*RESULTS@#In total, 38 active compounds and 469 corresponding targets of KXS were screened, and 264 target proteins associated with AD were identified. The compound-target-disease and PPI networks identified key active ingredients and protein targets. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis suggested a potential effect of KXS in the treatment of AD via the amyloid beta (A β)-glycogen synthase kinase-3 beta (GSK3 β)-Tau pathway. Molecular docking revealed a high binding affinity between the key ingredients and targets. In vivo, KXS treatment significantly improved cognitive deficits in AD rats induced by Aβ1-42, decreased the levels of Aβ, p-GSK3β, p-Tau and cyclin-dependent kinase 5, and increased the expressions of protein phosphatase 1 alpha (PP1A) and PP2A (P<0.05 or P<0.01).@*CONCLUSION@#KXS exerted neuroprotective effects by regulating the Aβ -GSK3β-Tau signaling pathway, which provides novel insights into the therapeutic mechanism of KXS and a feasible pharmacological strategy for the treatment of AD.

Effect of exogenous trivalent iron ions on tau phosphorylation and aggregation in SH-SY5Y cells / 环境与职业医学

Background A large amount of iron deposition in the brain can cause neuronal damage by inducing oxidative stress, neuroinflammation, and abnormal mitochondrial function. In addition, iron deposition is also reported to be closely related to the pathogenesis of Alzheimer's disease (AD). The neurofibrillary tangles aggregated by tau hyperphosphorylation are one of the important pathological features of AD. Objective To investigate potential effect of exogenous trivalent iron ions on neuronal activity in human neuroblastoma (SH-SY5Y) cells and tau hyperphosphorylation and aggregation. Methods SH-SY5Y cells were treated with ferric chloride (FeCl3) at four concentrations (10, 100, 200, and 400 mg·L−1). Cell survival rate was then detected by CCK8 assay. Intracellular iron content was determined prussian blue (Perl's) by iron staining after 24 h exposure to FeCl3 at 10 or 200 mg·L−1. Transfection of tau-P301L plasmid was conducted to construct an AD-like cell model for tau overexpression. The differences in the expression of the phosphorylated tau (p-tau) protein in SH-SY5Y cells and SH-SY5Y cells with tau overexpression were detected by Western blotting after 24 h exposure to FeCl3 at 10 and 200 mg·L−1. After dilution with phosphate buffered saline (PBS), FeCl3, human tauR3, and FeCl3 + tauR3 were incubated at 37℃, and the fluorescence intensity reflecting tau aggregation level was measured by thioflavin T(ThT) method at 12, 24, 36, 48, 60, 72, 84, and 96 h, respectively. Meanwhile, after 96 h coincubation of FeCl3 and tauR3, the fibers formed by tau aggregation were observed under a transmission electron microscope (TEM). Results After 24 h of FeCl3 exposure, the cell survival rate of SH-SY5Y cells among all groups was statistically different (F=8.63, P<0.01). The cell survival rates in the 200 and 400 mg·L−1 groups were 80.1% and 68.7% of the control group, respectively (P<0.05). Compared with the control group, the nuclei of the 200 mg·L−1 FeCl3 group were mainly yellowish-brown after iron staining and the positive cell rate was up-regulated by 12.9% (P<0.01). After 24 h of FeCl3 exposure , the p-tau (Ser396) protein expression was statistically different among all groups (F=11.6, P<0.01). Compared with the control group, the p-tau protein expression level of SH-SY5Y cells in the 200 mg·L−1 group was up-regulated by 72.7% (P<0.01). After FeCl3-treated SH-SY5Y cells with tau overexpression for 24 h, the p-tau (Ser396) protein expression was statistically different among all groups (F=27.8, P<0.01). Compared with the tau group, the p-tau (Ser396) protein expression level of SH-SY5Y cells in the tau + 200 mg·L−1 group was up-regulated by 44.6% (P<0.05). Compared with the tauR3 group, the fluorescence intensities in the 84 and 96 h tauR3 + FeCl3 groups were up-regulated by 49.9% and 53.7% (P<0.01) respectively. After 96 h of coincubation, compared with the tauR3 group, FeCl3 + tauR3 aggravated tau aggregation and formed fiber deposition under TEM. Conclusion Exogenous trivalent iron ions may inhibit SH-SY5Y cell viability, promote the phosphorylation of tau in SH-SY5Y cells transfected with tau-P301L plasmid, and aggravate tauR3 aggregation and fiber production.

Effects of Yizhi Tiaoshen acupuncture on learning and memory function and the expression of phosphorylated tau protein in the hippocampus of Alzheimer's disease model rats / 中国针灸

OBJECTIVE@#To observe the effects of Yizhi Tiaoshen (benefiting mental health and regulating the spirit) acupuncture on learning and memory function, and the expression of phosphorylated tubulin-associated unit (tau) protein in the hippocampus of Alzheimer's disease (AD) model rats, and explore the effect mechanism of this therapy on AD.@*METHODS@#A blank group and a sham-operation group were randomly selected from 60 male SD rats, 10 rats in each one. AD models were established in the rest 40 rats by the intraperitoneal injection of D-galactose and okadaic acid in the CA1 region of the bilateral hippocampus. Thirty successfully-replicated model rats were randomly divided into a model group, a western medication group and an acupuncture group, 10 rats in each one. In the acupuncture group, acupuncture was applied to "Baihui" (GV 20), "Sishencong" (EX-HN 1), "Neiguan" (PC 6), "Shenmen" (HT 7), "Xuanzhong" (GB 39) and "Sanyinjiao" (SP 6); and the needles were retained for 10 min. Acupuncture was given once daily. One course of treatment was composed of 6 days, with the interval of 1 day; the completion of treatment included 4 courses. In the western medication group, donepezil hydrochloride solution (0.45 mg/kg) was administrated intragastrically, once daily; it took 7 days to accomplish one course of treatment and a completion of intervention was composed of 4 courses. Morris water maze (MWM) and novel object recognition test (NORT) were used to assess the learning and memory function of the rats. Using HE staining and Nissl staining, the morphological structure of the hippocampus was observed. With Western blot adopted, the protein expression of the tau, phosphorylated tau protein at Ser198 (p-tau Ser198), protein phosphatase 2A (PP2A) and glycogen synthase kinase-3β (GSK-3β) in the hippocampus was detected.@*RESULTS@#There were no statistical differences in all of the indexes between the sham-operation group and the blank group. Compared with the sham-operation group, in the model group, the MWM escape latency was prolonged (P<0.05), the crossing frequency and the quadrant stay time in original platform were shortened (P<0.05), and the NORT discrimination index (DI) was reduced (P<0.05); the hippocampal cell numbers were declined and the cells arranged irregularly, the hippocampal neuronal structure was abnormal and the numbers of Nissl bodies decreased; the protein expression of p-tau Ser198 and GSK-3βwas increased (P<0.05) and that of PP2A decreased (P<0.05). When compared with the model group, in the western medication group and the acupuncture group, the MWM escape latency was shortened (P<0.05), the crossing frequency and the quadrant stay time in original platform were increased (P<0.05), and DI got higher (P<0.05); the hippocampal cell numbers were elevated and the cells arranged regularly, the damage of hippocampal neuronal structure was attenuated and the numbers of Nissl bodies were increased; the protein expression of p-tau Ser198 and GSK-3β was reduced (P<0.05) and that of PP2A was increased (P<0.05). There were no statistically significant differences in the above indexes between the acupuncture group and the western medication group (P>0.05).@*CONCLUSION@#Acupuncture therapy of "benefiting mental health and regulating the spirit" could improve the learning and memory function and alleviate neuronal injure of AD model rats. The effect mechanism of this therapy may be related to the down-regulation of GSK-3β and the up-regulation of PP2A in the hippocampus, and then to inducing the inhibition of tau protein phosphorylation.

Effects of Dianxianqing granules on tau protein in P301S mice by regulating mitophagy / 中国药房

OBJECTIVE To study the effects of Dianxianqing granules on the tau protein in P301S mice by regulating mitophagy. METHODS Totally 36 P301S mice were randomly divided into model group， Dianxianqing granule group （12.48 g/kg）， donepezil hydrochloride group （positive control， 1.3 mg/kg）， with 12 mice in each group； another 10 C57BL6 mice were selected as control group. Administration groups were given relevant drug solutions intragastrically， and control group and model group were given constant volume of water intragastrically. The gavage volume was 20 mL/kg， once a day， for consecutive 5 months. During the experiment， the general condition of mice was observed in each group. After the last medication， the learning and memory ability was determined by Y maze test and Morris water maze test； HE staining was used to observe the morphological changes in brain tissue， and Nissl staining was used to observe the structure of neural cells and the number of Nissl bodies in cerebral tissue. Immunohistochemistry was used to detect the expressions of phospho-tau serine 202/threonine 205 （abbreviated as AT8） in brain tissue. Western blot assay was used to determine the expressions of mitophagy-associated proteins [PTEN-induced putative kinase-1 （PINK1）， Parkin， microtubule-associated protein 1 light chain 3B （LC3B）， p62]， synaptic-associated proteins [postsynaptic density protein-95 （PSD-95）， synaptophysin （SYP）， and growth-associated protein-43 （GAP-43）] and the phosphorylation of tau protein [expressed by the phosphorylation levels of serine 199 （Ser199） and Ser202] in brain tissue. RESULTS The mice in E-mail：lnzyxyqy2003@163.com model group showed symptoms such as white hair， decreased body mass， and lower limb paralysis， with incomplete hippocampal structures in their brain tissue， as well as incomplete cell membrane edges and cell structures； the spontaneous alternating response rate， the times of crossing platform， the number of Nissl bodies， the protein expressions of PINK1， Parkin， LC3B， SYP， GAP-43， and PSD-95 were decreased significantly， compared with control group； swimming latency （fourth and fifth day）， the protein expressions of AT8 and p62，the phosphorylation levels of Ser199 and Ser202 were increased or lengthened significantly， compared with control group （P＜0.05 or P＜0.01）. Compared with model group， the above symptoms and indexes of mice were improved significantly in administration groups （P＜0.05 or P＜0.01）. CONCLUSIONS Dianxianqing granules can effectively improve cognitive impairment in P301S mice，the mechanism of which may be associated with inducing mitochondrial autophagy， reducing the hyperphosphorylation of tau protein， up-regulating the expression of synaptic-associated proteins in brain tissue，and repairing damaged neural cells.

Neuroprotective and mechanistic study of GJ-4 on okadaic acid-induced memory impairment in mice / 药学学报

GJ-4 is crocin enrichments extracted from Gardenia jasminoides J. Ellis, and our previous studies have shown that GJ-4 significantly improved learning and memory impairment induced by Aβ in mice. Herein, a memory deficit model was developed by injecting okadaic acid (OA) into the lateral ventricle of mice, and the neuroprotection and underlying mechanism of GJ-4 on neuronal injury caused by Tau hyperphosphorylation were investigated. The Animal Care & Welfare Committee, Institute of Materia Medica, CAMS & PUMC has approved all procedures (No.00000318). GJ-4 at different doses was intragastric administration to mice for 16 days. Step-down test and Morris water maze test showed that GJ-4 could significantly improve OA-induced memory impairment in mice, and reduced the loss of Nissl bodies in the hippocampus of mice. GJ-4 could also decrease the phosphorylation level of Tau protein at Ser396, Thr231 and Ser404 via increasing protein phosphatase 2A (PP2A) activity and inhibiting glycogen synthase kinase-3β (GSK-3β) activity. Besides, further researches indicated that GJ-4 could inhibit the level of oxidative stress in the brain of OA mice, reduce neuronal apoptosis and inhibit the neuroinflammation mediated by activation of astrocytes in the hippocampus of mice, and eventually achieve its effects in improving learning and memory impairment in mice. According to these findings, we anticipated that GJ-4 might be a potential therapeutic drug for Alzheimer's disease.

The Discovery of Putative Small Molecules via Ligand-based Pharmacophore Modelling Targeting Human Tau Protein for an Effective Treatment of Parkinson’s Disease

@#Introduction: The human tau protein is a key protein involved in various neurodegenerative disease (NDs) including Parkinson’s disease (PD). The protein has high tendency to aggregate into oligomers, subsequently generating insoluble mass in the brain. Symptoms of PD include tremor, bradykinesia, rigidity, and postural instability. Currently drugs for PD treatment are only symptom-targeted while effective therapeutic treatment remains a challenge. The objective of this study is to identify novel promising anti-PD drugs using computational techniques. Method: ligand-based (LB) receptor modelling was conducted using LigandScout, validated and subjected to Glide XP docking, virtual screening, ADMET, and molecular dynamics predictions. Results: The adopted LB modelling generated pharmacophoric features of 5 hydrogen bond donors, 1 aromatic rings, and 7 hydrogen bond acceptors. The validation result indicated GH score of 0.73 and EF of 36.30 as validation protocols, probing it to be an ideal model. Using 3D query of the modelling a total of 192 compounds were retrieved from interbioscreen database containing 70,436 natural compounds. Interestingly, ligands 1, 2, 3, 4 and 5 orderly indicated higher binding affinities to the receptor with Glide XP docking of -7.451, -7.368, -7.101, -6.878, and -6.789 compared to a clinical drug Anle138b with -4.552 kcal/mol respectively. Furthermore, molecular dynamics and pkCSM pharmacokinetics demonstrated ligands 1, 2, & 4 having better stability and low toxicity profiles compared to the reference. Conclusion: In summary, the study pave way for discovery of small molecules that could be recommended as adjuvant /single candidate as ant-PD candidates upon further translational study.

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.

Drofenine as a Kv2.1 inhibitor alleviated AD-like pathology in mice through A β/Kv2.1/microglial NLRP3/neuronal tau axis / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer disease(AD)is a neurodegenerative disease with clinical hallmarks of pro-gressive cognitive impairment.Synergistic effects of Aβ-tau cascade reaction are tightly implicated in AD patholo-gy,and microglial NLRP3 inflammasome activation drives neuronal tauopathy through microglia and neurons cross-talk.However,the underlying mechanism of how Aβ medi-ates NLRP3 inflammasome remains unclear.Shab related potassium channel member 1(Kv2.1)as a voltage gated po-tassium channel widely distributed in the central nervous system and plays an important role in regulating the out-ward potassium flow in neurons and glial cells.In current work,we aimed to explore the underlying mechanism of Kv2.1 in regulating Aβ/NLRP3 inflammasome/tau axis by using a determined Kv2.1 inhibitor drofenine(Dfe).METHODS Cell-based assays including Western blot-ting and immunofluorescence staining against primary microglia or neurons were carried out to expound the role of Kv2.1 channel in NLRP3 inflammasome activa-tion and subsequent neuronal tau hyperphosphorylation.For animal studies,new object recognition,Y-maze and Morris water maze were performed to evaluate the ame-lioration of Kv2.1 inhibition through either Kv2.1 inhibitor Dfe treatment or adeno-associated virus AAV-ePHP-si-Kv2.1injectionon5×FADADmodel mice.Assays of histol-ogy and immunostaining of tissue sections and Western blotting of brain tissues were performed to verify the con-clusion of cellular assays.RESULTS We reported that oligomeric Aβ(o-Aβ)bound to microglial Kv2.1 and pro-moted Kv2.1-dependent potassium leakage to activate NLRP3 inflammasome through JNK/NF-κB pathway sub-sequently resulting in neuronal tauopathy.Treatment of either Kv2.1 inhibitor Dfe or AAV-ePHP-si-Kv2.1 for brain-specific Kv2.1 knockdown deprived o-A β of its capability in inducing microglial NLRP3 inflammasome activation and neuronal tau hyperphosphorylation,while improved the cognitive impairment of 5×FAD AD model mice.CONCLUSION Our results have highly addressed that Kv2.1 channel is required for o-Aβ driving NLRP3 inflammasome activation and neuronal tauopathy in AD model mice and highlighted that Kv2.1 inhibition is a prom-ising therapeutical strategy for AD and Dfe as a Kv2.1 inhibitor shows potential in the treatment of this disease.

Proteína tau como biomarcador en Alzheimer preclínico / Tau protein as a biomarker in preclinical Alzheimer's disease

El desarrollo de biomarcadores de la proteína tau para el diagnóstico temprano de la enfermedad de Alzheimer (EA) emerge como un desafío fundamental, pudiendo mejorar la efectividad de un tratamiento preventivo o que enlentezca la progresión de la enfermedad. Esta revisión analiza las evidencias que justificarían el uso de la proteína tau como biomarcador en Alzheimer preclínico. Para esto se seleccionaron artículos científicos (2011-2021) que incluyeran a la proteína tau en plasma y plaquetas como biomarcador. La presencia de la proteína tau fosforilada en el líquido cefalorraquídeo presenta limitaciones por su carácter invasivo mientras que las técnicas de imagen son costosas. La medición de tau en plaquetas se correlaciona con la severidad de la demencia, y sería útil en el seguimiento de la EA. Sin embargo, la pertinencia de su uso en la detección temprana de EA se mantiene en discusión. La presencia de proteína tau fosforilada en plasma correspondería al biomarcador con mayor nivel de desarrollo, respecto de beta amiloide. La proteína tau plasmática detecta la EA con gran precisión en casos de demencia y ha sido validada por estudios neuropatológicos. p-tau217 plasmática medida por primera vez junto a técnicas de imagen, fue importante en la etapa preclínica de EA pudiendo predecir la formación de ovillos neurofibrilares. La correlación entre especies fosforiladas de tau en plasma y EA preclínica ha sido bien establecida, por lo que su uso como biomarcador podría ser de utilidad para la comprensión del proceso fisiopatológico de la neurodegeneración y la detección temprana de EA

The development of tau protein biomarkers for the early diagnosis of Alzheimer's disease (AD) emerges as a fundamental challenge, which may improve the effectiveness of preventive treatment or slow the progression of the disease. This review analyzes the evidence that would justify the use of tau protein as a biomarker in preclinical Alzheimer's disease. For this purpose, we selected scientific articles (2011-2021) that included tau protein in plasma and platelets as a biomarker. Phosphorylated tau protein in cerebrospinal fluid has limitations due to its invasiveness, while imaging techniques are expensive. The tau measurement in platelets correlates with the severity of dementia and would be helpful in the follow-up of AD. However, the relevance of its use in the early detection of AD remains under discussion. Plasma phosphorylated tau protein would correspond to the biomarker with the highest level of development for beta-amyloid. Plasma tau protein detects AD with high accuracy in cases of dementia, and neuropathological studies validate its use. Plasma p-tau217 measured for the first time with imaging techniques was important in preclinical AD and could predict the formation of neurofibrillary tangles. The correlation between plasma phosphorylated tau species and preclinical AD is well-established, so its use as a biomarker would help understand the pathophysiological process of neurodegeneration and early AD detection.

From clinical phenotype to proteinopathy: molecular neuroimaging in neurodegenerative dementias / Do fenótipo clínico à proteinopatia: a neuroimagem molecular nas demências neurodegenerativas

ABSTRACT Neurodegenerative dementias are characterized by the abnormal accumulation of misfolded proteins. However, its diagnostic criteria are still based on the clinical phenotype. The development of biomarkers allowed in vivo detection of pathophysiological processes. This article aims to make a non-systematic review of the use of molecular neuroimaging as a biomarker. Molecular neuroimaging is based on the use of radiotracers for image acquisition. The radiotracer most used in PET is 18F-fluorodeoxyglucose (FDG), with which it is possible to study the regional brain glucose metabolism. The pattern of regional hypometabolism provides neuroanatomical information on the neurodegenerative process, which, in turn, has a good specificity for each type of proteinopathy. FDG is very useful in the differential diagnosis of neurodegenerative dementias through the regional pattern of involvement, including dementia with Lewy bodies and the spectrum of frontotemporal dementia. More recently, radiotracers with specific ligands to some of the pathological proteins have been developed. Pittsburgh compound B (PIB) labeled with 11C and the ligands that use 18F (florbetapir, florbetaben and flutemetamol) are the most used radiotracers for the detection of insoluble β-amyloid peptide in Alzheimer's disease (AD). A first generation of ligands for tau protein has been developed, but it has some affinity for other non-tau protein aggregates. A second generation has the advantage of having a higher affinity for hyperphosphorylated tau protein, including in primary tauopathies.

RESUMO As demências neurodegenerativas caracterizam-se pelo acúmulo anormal de proteínas mal dobradas. Entretanto, os seus critérios diagnósticos ainda se baseiam no fenótipo clínico. O desenvolvimento de biomarcadores permitiu a detecção in vivo do processo fisiopatológico. O objetivo deste artigo é fazer uma revisão não-sistemática sobre o papel da neuroimagem molecular como biomarcador. A neuroimagem molecular baseia-se no uso de radiotraçadores para aquisição da imagem. O mais usado no PET é o 18F-fluorodeoxiglicose (FDG), com o qual é possível estudar o metabolismo regional de glicose cerebral. O padrão de hipometabolismo regional fornece uma informação neuroanatômica do processo neurodegenerativo que, por sua vez, tem uma boa especificidade para cada tipo de proteinopatia. O PET-FDG é muito útil no diagnóstico diferencial das demências neurodegenerativas através do padrão de acometimento regional, incluindo a demência com corpos de Lewy e o espectro das demências frontotemporais. Mais recentemente, radiotraçadores com ligantes específicos a algumas das proteínas patológicas têm sido desenvolvidos. O composto B de Pittsburgh (PIB) com 11C e os ligantes dos que usam 18F (florbetapir, florbetaben e flutemetamol) são os radiotraçadores mais usados para a detecção de peptídeo β-amiloide insolúvel na doença de Alzheimer (DA). Uma primeira geração de ligantes para proteína tau foi desenvolvida, mas apresenta alguma afinidade a outros agregados proteicos não-tau. Uma segunda geração tem a vantagem de apresentar uma maior afinidade à proteína tau hiperfosforilada, incluindo nas taupatias primárias.

Effects of TYROBP Deficiency on Neuroinflammation of a Alzheimer's Disease Mouse Model Carrying a PSEN1 p.G378E Mutation / 中国医学科学杂志(英文版)

Objective To study the effects of TYRO protein kinase-binding protein (TYROBP) deficiency on learning behavior, glia activation and pro-inflammatory cycokines, and Tau phosphorylation of a new Alzheimer's disease (AD) mouse model carrying a PSEN1 p.G378E mutation.Methods A new AD mouse model carrying PSEN1 p.G378E mutation was built based on our previously found AD family which might be ascribed to the PSEN1 mutation, and then crossed with TYROBP deficient mice to produce the heterozygous hybrid mice (PSEN1G378E/WT; Tyrobp+/-) and the homozygous hybrid mice (PSEN1G378E/G378E; Tyrobp-/-). Water maze test was used to detect spatial learning and memory ability of mice. After the mice were sacrificed, the hippocampus was excised for further analysis. Immunofluorescence was used to identify the cell that expresses TYROBP and the number of microglia and astrocyte. Western blot was used to detect the expression levels of Tau and phosphorylated Tau (p-Tau), and ELISA to measure the levels of pro-inflammatory cytokines. Results Our results showed that TYROBP specifically expressed in the microglia of mouse hippocampus. Absence of TYROBP in PSEN1G378E mutation mouse model prevented the deterioration of learning behavior, decreased the numbers of microglia and astrocytes, and the levels of interleukin-6, interleukin-1β and tumor necrosis factor-α in the hippocampus (all P < 0.05). The ratios of AT8/Tau5, PHF1/Tau5, pT181/Tau5, pT231/Tau5 and p-ERK/ERK were all higher in homozygous hybrid mice (PSEN1G378E/G378E; Tyrobp-/- mice) compared with PSEN1G378E/G378E mice (all P < 0.05). Conclusions TYROBP deficiency might play a protective role in the modulation of neuroinflammation of AD. However, the relationship between neuroinflammation processes involving microglia and astrocyte activation, and release of pro-inflammatory cytokines, and p-Tau pathology needs further study.

Hypothesis on ontogenesis and pathophysiology of Alzheimer's disease

Abstract Alzheimer's disease is a neurodegenerative condition that causes changes in memory and cognition, in addition to behavioral disorders, and most commonly affects the elderly. Several studies in the literature have presented therapeutic measures in an attempt to interfere with the pathogenic mechanisms of the disease and to mitigate its clinical manifestations. Some factors, such as excitotoxicity, cholinergic dysfunctions, oxidative stress, tau protein hyperphosphorylation, changes in amyloid-beta peptide metabolism, herpes viruses, apolipoprotein E, glycogen synthase kinase 3, insulin resistance, and the endocannabinoid system seem to be related to pathophysiology of Alzheimer's disease. Given this, a literature review was carried out to address the molecular mechanisms associated with the pathophysiological hypotheses previously mentioned, aiming to better understanding their underlying causes and contributing to possible pharmacological strategies about treatment of the disease.

Spinocerebellar ataxia type 11: a case report / 中华神经科杂志

Spinocerebellar ataxia (SCA) is a group of highly heterogeneous autosomal dominant genetic disease, including many subtypes. SCA11 is a rare subtype of SCA, and is caused by mutant TTBK2 gene. A case of SCA11 was reported in this article. Whole exome sequencing showed that there was a c.1284dupA frameshift mutation in TTBK2 gene. Literature review found that only 6 pedigrees of SCA11 have been reported, but the mutation site of this case is a novel identified mutation that has not been reported in the Human Gene Mutation Database.

Mechanism of dexmedetomidine preventing sevoflurane-indued neurotoxicity to neonatal mice: the relationship with Tau phosphorylation / 中华麻醉学杂志

Objective:To investigate the mechanism of dexmedetomidine preventing sevoflurane-indued neurotoxicity to neonatal mice and the relationship with Tau phosphorylation.Methods:Seventy-two SPF healthy newly born C57BL/6 wild-type mice of both sexes, aged 6 days, were divided into 4 groups ( n=18 each) using a random number table method: normal control group (C group), dexmedetomidine control group (D group), sevoflurane-induced neurotoxicity group (S group), and dexmedetomidine prevention group (SD group). Mice inhaled 2.1%-3.3% sevoflurane 2 h daily on postnatal days 6, 9 and 12, and dexmedetomidine 10 μg/kg was intraperitoneally injected at 30 min before anesthesia in group SD.Six mice were randomly selected after the end of injection, and the hippocampus tissues were removed for determination of the expression of phosphorylated Tau protein (AT8) and Tau46 protein at Tau-PS202 and Tau-PT205 sites by Western blot.The new object recognition test was performed on postnatal days 29-30 (the discrimination ratio of new objects was observed), and the Morris water maze test was performed from postnatal day 31 to 37 (the escape latency and the times of crossing the platform were observed). The hippocampi were harvested under anesthesia to detect the expression of postsynapatic density-95 by Western blot. Results:Compared with group C, the expression of AT8 was significantly up-regulated, the expression of PSD-95 was down-regulated, the number of crossing the platform and new object discrimination ratio were decreased ( P<0.05), and no significant change was found in Tau46 protein expression or escape latency in group S ( P>0.05). There was no significant difference in the indexes mentioned above between group D and group SD ( P>0.05). Compared with group S, the expression of AT8 was significantly down-regulated, the expression of postsynapatic density-95 was up-regulated, the number of crossing the platform and new object discrimination ratio were increased ( P<0.05), and no significant change was found in Tau46 protein expression and escape latency in group SD ( P>0.05). Conclusions:The mechanism of dexmedetomidine preventing sevoflurane-induced neurotoxicity to neonatal mice is related to the inhibition of Tau phosphorylation.

Research progress on the bidirectional relationship between sleep disorders and Parkinson's disease / 中华老年医学杂志

Parkinson's disease(PD)is a progressive neurodegenerative disorder that tends to occur in the elderly.Its clinical manifestations mainly include motor symptoms and non-motor symptoms, with sleep disorders among common non-motor symptoms of PD.The latest lines of evidence show that sleep disorders are not only clinical manifestations of neurodegenerative diseases, but also an important risk factor for the development and progression of neurodegenerative diseases.There is a bidirectional relationship between sleep disorders and neurodegenerative diseases, including PD.The possible mechanisms include accelerated α-synuclein pathology, deposition of Tau protein, inhibition of the glymphatic system, neuroinflammation and changes in the circadian rhythm system.In this article, we review research progress on the bidirectional relationship between sleep disorders and PD, related mechanisms, and the outlook on the treatment of PD through the management of sleep disorders.