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Objective: To 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., Methods: The 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., Results: A 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., Conclusion: The 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.

Objective: To explore the effect of different culture media on viability and expression of tau protein in organotypic hippocampal slice., Methods: Brain 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., Results: The 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., Conclusion: The 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.

Objective: To investigate the effects of intracerebroventricular (ICV) administration of streptozotocin (STZ) on the expressions of Abeta and hyperphosphorylation of tau protein in rat brain., Methods: Twenty-four adult SD rats were randomized into 2 groups to receive ICV of STZ bilaterally at the dose of 3 mg/kg (with the injection repeated on day 3) or normal saline injection in an identical manner. Twenty-one days later, the expressions of Abeta(1-40), Abeta(1-42), tau(202), tau(396) and tau(404) were investigated immunohistochemically., Results: After STZ administration, the expressions of Abeta(1-40), Abeta(1-42), tau(202), tau(396) and tau(404) increased in both the cortex and hippocampus in the rat brain., Conclusion: ICV injection of STZ increases the expression of Abeta and promotes hyerphosphorylation of tau protein.

Objective: To study the effect of Tiaoxin Recipe (TXR) on learning and memory related gene expression in hippocampus of senescence accelerated mice (SAM)., Methods: Changes of learning and memory related gene expression, including mineralocorticoid receptor (MR), presenile protein 1 and 2 (PS-1, PS-2), tau, APP, apoE and bcl-2 in hippocampus of SAM were determined by reverse transcription polymerase chain reaction (RT-PCR). The effect of TXR were tested. E2020 was used as the drug for control., Results: Compared with those in the same aged mice, in the 5-month old SAM, levels of gene expression of MR, tau, PS-2 and APP were significantly higher, that of apo-E lower, levels of gene expression PS-1 and bcl-2 were unobviously changed; while in the 12-month old SAM, gene expression of MR and tau were higher, bcl-2 was lower and PS-1, PS-2, apoE and APP were also unobviously changed. Continuously orally taken TXR could correct the abnormality of MR, tau and apoE gene expression in hippocampus of 5-month SAM and that of MR and bcl-2 in 12-month SAM., Conclusion: Continuously orally taken of TXR has the effect of regulating and correcting learning and memory related gene expression in hippocampus of 5-month and 12-month SAM.