Alzheimer Disease ; genetics ; metabolism ; therapy ; Humans ; tau Proteins ; genetics ; metabolism

OBJECTIVETo establish homozygous transgenic mouse strain expressing human tau isoform with P301L mutation.

METHODSFive transgenic mice expressing human tau isoform with P301L mutation were obtained by microinjection into male nuclei. Homozygote and hemizygote were identified by PCR and real-time fluorescent quantitative PCR.

RESULTSNinety five homozygous transgenic mice were selected, and the results indicated that homozygous transgenic mice were superior to hemizygote in simulating the changes of biological characteristics.

CONCLUSIONExogenous gene tau is able to stably transmit to next generation and the combination of SYBR Green real-time fluorescent quantitative PCR with the traditional mating is a fast, reliable and economical way to screen homozygous and hemizygous transgenic mice.

Animals ; Female ; Homozygote ; Humans ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Microinjections ; Mutation ; tau Proteins ; genetics

Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50-59 year group. Gerstmann-Sträussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt-Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.
14-3-3 Proteins/cerebrospinal fluid* ; China ; Creutzfeldt-Jakob Syndrome/genetics* ; Humans ; Mutation/genetics* ; Prion Diseases/genetics* ; Prion Proteins/genetics* ; Prions/genetics* ; tau Proteins/cerebrospinal fluid*

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 (PSEN1^G378E/WT; Tyrobp^+/-) and the homozygous hybrid mice (PSEN1^G378E/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 PSEN1^G378E 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 (PSEN1^G378E/G378E; Tyrobp^-/- mice) compared with PSEN1^G378E/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.
Mice ; Animals ; Alzheimer Disease/genetics* ; Neuroinflammatory Diseases ; Hippocampus/pathology* ; Mutation ; Cytokines/pharmacology* ; Disease Models, Animal ; tau Proteins/pharmacology* ; Amyloid beta-Peptides/metabolism* ; Adaptor Proteins, Signal Transducing/pharmacology*

OBJECTIVETo construct a prokaryotic expression vector of human tau multiepitope peptide for examining the immunogenicity of a TauP1/P2 DNA vaccine in mice using the expressed product.

METHODSThe coding sequence of Tau multiepitope peptide gene was amplified from the plasmid pVAX1-Tau by PCR and inserted into the prokaryotic expression vector pGEX-4T-2 to construct the recombinant plasmid pGEX-4T-2-TauP1/P2. The positive recombinants were transformed into E.coli BL21 cells, and the expression of fusion protein GST-TauP1/P2 was induced by IPTG and identified by SDS-PAGE. Mice was immunized with TauP1/P2 DNA vaccine and the production of the specific antibodies was detected by Dot-blot analysis using the purified fusion protein.

RESULTSA gene fragment 300 bp in length was amplified. Enzyme digestion and DNA sequencing verified correct construction of the prokaryotic expression plasmid pGEX-4T-2-TauP1/P2. The expression of target fusion protein GST-TauP1/P2 was detected by SDS-PAGE. Specific antibodies against TauP1/P2 were detected in the serum of mice immunized with the DNA vaccine using GST-TauP1/P2 fusion protein.

CONCLUSIONThe constructed prokaryotic expression plasmid of human Tau multiepitope peptide is capable of expressing the target fusion protein, which specifically recognizes the specific antibodies against TauP1/P2 in mice immunized with TauP1/P2 DNA vaccine.

Animals ; Epitopes ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Mice ; Mice, Inbred C57BL ; Peptides ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Vaccines, DNA ; biosynthesis ; immunology ; tau Proteins ; biosynthesis ; genetics ; immunology

ObjectiveRapid eye movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during rapid eye movement sleep. RBD is closely related to α-synucleinopathies including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Many studies have investigated the markers of imaging and neurophysiological, genetic, cognitive, autonomic function of RBD and their predictive value for neurodegenerative diseases. This report reviewed the progress of these studies and discussed their limitations and future research directions.

Data SourcesUsing the combined keywords: "RBD", "neurodegenerative disease", "Parkinson disease", and "magnetic resonance imaging", the PubMed/MEDLINE literature search was conducted up to January 1, 2018.

Study SelectionA total of 150 published articles were initially identified citations. Of the 150 articles, 92 articles were selected after further detailed review. This study referred to all the important English literature in full.

ResultsSingle-nucleotide polymorphisms in SCARB2 (rs6812193) and MAPT (rs12185268) were significantly associated with RBD. The olfactory loss, autonomic dysfunction, marked electroencephalogram slowing during both wakefulness and rapid eye movement sleep, and cognitive impairments were potential predictive markers for RBD conversion to neurodegenerative diseases. Traditional structural imaging studies reported relatively inconsistent results, whereas reduced functional connectivity between the left putamen and substantia nigra and dopamine transporter uptake demonstrated by functional imaging techniques were relatively consistent findings.

ConclusionsMore longitudinal studies should be conducted to evaluate the predictive value of biomarkers of RBD. Moreover, because the glucose and dopamine metabolisms are not specific for assessing cognitive cognition, the molecular metabolism directly related to cognition should be investigated. There is a need for more treatment trials to determine the effectiveness of interventions of RBD on preventing the conversion to neurodegenerative diseases.

Biomarkers ; blood ; Humans ; Lysosome-Associated Membrane Glycoproteins ; genetics ; Neurodegenerative Diseases ; blood ; genetics ; physiopathology ; Parkinson Disease ; blood ; genetics ; physiopathology ; Polymorphism, Single Nucleotide ; genetics ; REM Sleep Behavior Disorder ; blood ; genetics ; physiopathology ; Receptors, Scavenger ; genetics ; tau Proteins ; genetics

OBJECTIVETo explore the effect of different culture media on viability and expression of tau protein in organotypic hippocampal slice.

METHODSBrain slices (400 microm) from 1, 2, 4, and 8 week-old Wistar rats were prepared and cultured in minimum essential medium (MEM) or Dulbecco's modified eagle medium: nutrient mixture (DMEM/F12) medium respectively for 21 days. Viability of the slices was measured by lactate dehydrogenase (LDH) assay and expression of tau protein was detected by Western blot.

RESULTSThe viability of the slices was not influenced significantly by the two different culture media, while the expression level of tau protein was significantly higher in DMEM/F12 than in MEM (P < 0.05), especially in the slices from 2 and 4 week-old rats.

CONCLUSIONThe slices from 2 or 4 week-old rat hippocampi and DMEM/F12 medium may be the preferred choice for tau associated researches. An ideal Alzheimer's disease model may be established based on the results of these researches.

Animals ; Culture Media ; Hippocampus ; growth & development ; metabolism ; L-Lactate Dehydrogenase ; biosynthesis ; Organ Culture Techniques ; methods ; Rats ; Rats, Wistar ; tau Proteins ; biosynthesis ; genetics

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.
Male ; Animals ; Rats ; Rats, Sprague-Dawley ; Glycogen Synthase Kinase 3 beta ; Tubulin ; Alzheimer Disease/therapy* ; tau Proteins/genetics* ; Acupuncture Therapy ; Hippocampus

Sleep exerts important functions in the regulation of cognition and emotion. Recent studies have found that sleep disorder is one of the important risk factors for Alzheimer's disease (AD), but the effects of chronic sleep deprivation on the cognitive functions of AD model mice and its possible mechanism are still unclear. In the present study, 8-month-old male APP/PS1/tau triple transgenic AD model (3xTg-AD) mice and wild type (WT) mice (n = 8 for each group) were subjected to chronic sleep deprivation by using the modified multiple platform method, with 20 h of sleep deprivation each day for 21 days. Then, open field test, elevated plus maze test, sugar water preference test, object recognition test, Y maze test and conditioned fear memory test were performed to evaluate anxiety- and depression-like behaviors, and multiple cognitive functions. In addition, the immunohistochemistry technique was used to observe pathological characteristics in the hippocampus of mice. The results showed that: (1) Chronic sleep deprivation did not affect anxiety- (P = 0.539) and depression-like behaviors (P = 0.874) in 3xTg-AD mice; (2) Chronic sleep deprivation exacerbated the impairments of object recognition memory (P < 0.001), working memory (P = 0.002) and the conditioned fear memory (P = 0.039) in 3xTg-AD mice; (3) Chronic sleep deprivation increased amyloid β (Aβ) deposition (P < 0.001) and microglial activation (P < 0.001) in the hippocampus of 3xTg-AD mice, without inducing abnormal tau phosphorylation and neurofibrillary tangles. These results indicate that chronic sleep deprivation exacerbates the impairments of recognition memory, working memory and conditioned fear memory in 3xTg-AD mice by aggravating Aβ deposition and the excessive activation of microglia in the hippocampus.
Alzheimer Disease ; Amyloid beta-Peptides ; Amyloid beta-Protein Precursor/genetics* ; Animals ; Cognition ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Presenilin-1 ; Sleep Deprivation ; tau Proteins

OBJECTIVETo explore the relations among apolipoprotein E4, Tau protein and glycogen synthase kinase 3β (GSK-3β).

METHODSU87 cells were transfected with pIRES-EGFP (control) or the recombinant plasmids ApoE4/pIRES-EGFP or ApoE3/pIRES-EGFP, and the expression levels of p-Tau/Tau and GSK-3β in the cells were examined with Western blotting. To further confirm the effect of ApoE on GSK-3β and p-Tau expressions, a short interfering RNA (siRNA) targeting ApoE (ApoE-siRNA) was transfected into U87 cells via Lipofectamine 2000 and the protein expressions were examined 24 h later.

RESULTSCompared with those in the control group, the expressions levels of both GSK-3β and p-Tau/Tau increased significantly in the cells transfected with ApoE4 and ApoE3 plasmids (P<0.01), and the ApoE4 plasmid produced a more potent effect than the ApoE3 plasmid on the protein expressions (P<0.01). ApoE knockdown resulted in significantly reduced expressions of GSK-3β (P<0.001) and p-Tau (P<0.01) in the cells.

CONCLUSIONApoE4 can enhance Tau phosphorylation though upregulating GSK-3β, which sheds light on a new role of ApoE4 in Alzheimer's disease.

Alzheimer Disease ; genetics ; Apolipoprotein E3 ; genetics ; Apolipoprotein E4 ; genetics ; Cell Line ; Gene Silencing ; Glycogen Synthase Kinase 3 beta ; genetics ; metabolism ; Humans ; Phosphorylation ; RNA, Small Interfering ; genetics ; Transfection ; tau Proteins ; metabolism