Suppressing poly(ADP-ribose)polymerase-1 inhibits tau phosphorylation in HEK293/tau441 cells / 生理学报

The study aimed to investigate the effect of inhibition of poly(ADP-ribose) polymerase-1 (PARP-1) activity on tau phosphorylation in HEK293/tau441 cells and its mechanism. HEK293/tau441 cells were treated with 3-aminobenzamide (3-AB), a PARP-1 inhibitor, at different doses (0.5, 1, 2, 4 mmol/L). After 24 h, the cell morphology was observed under phase contrast microscope, tau phosphorylation level in different sites (tau-1, tau-5, Thr231) and the activity of glycogen synthase kinase 3 (GSK-3) were detected by Western blotting. The results showed: (1) 3-AB at different doses failed to change the morphology of cells; (2) The 3-AB-induced decrease in activity of PARP-1 resulted in increase of unphosphorylation level in tau-1(Ser195/198/199/202) sites; (3) The phosphorylation of tau was decreased in Thr231 site, while the total tau was slightly changed after 3-AB treatment; (4) With the increased phosphorylation of GSK-3 at Ser9 site, the activity of GSK-3 was decreased after 3-AB treatment. The results suggest that the inhibition of PARP-1 by 3-AB could decrease tau phosphorylation in HEK293/tau441 cells probably through decreasing GSK-3 activity.

The effects of chronic stress on spatial cognitive ability of different sex mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of chronic stress on spatial cognitive ability in different sex mice.</p><p><b>METHODS</b>Thirty-two adult KM mice were divided into four groups (n=8): male control and chronic stress group, female control and chronic stress group. We used the modified Kaz's methods to build on the chronic stress model of mice, and then used the place navigational testing and the probe trial testing by the Morris water maze to measure the spatial cognitive ability of mice.</p><p><b>RESULTS</b>Following two weeks stress treatment, in the place navigational testing, to male group, the average latency to find the platform in water maze of chronic stress group was longer than that of the control; to female group, the average latency of chronic stress group was shorter than the control. Moreover, the male stress group showed faster swimming speed but longer latency to find the platform. In the probe trial testing the female chronic stress group spent more time in the target quadrant compared to the male chronic stress group.</p><p><b>CONCLUSION</b>Two weeks' chronic stress could impair male mice's spatial cognitive ability, but improve the female's.</p>

Effects of cold stress on blood cell parameters of partial sleep deprivation mice / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effect of cold, partial sleep deprivation, partial sleep deprivation plus cold on blood routine parameters and erythrocyte sedimentation rate of mice.</p><p><b>METHODS</b>Twenty-four Mus musculus mice were divided into four groups (n=6) randomly: (1) control, (2) cold group: mice were treated with (10 +/- 2) degrees C cold stimulation for four hours per day, (3) partial sleep deprivation group: mice were deprived sleep from 18:00 to 9:00 next day, (4) partial sleep deprivation plus cold group: mice were treated with cold stimulation based on partial sleep deprivation. After four days treatment, the mice were sacrificed and the blood was collected to detect the blood routine parameters and erythrocyte sedimentation rate.</p><p><b>RESULTS</b>Compared with the control, cold stimulation would increase the contents and proportion of lymphocyte significantly. Partial sleep deprivation would decrease the white blood cell contents, lymphocyte contents and lymphocyte proportion significantly. After treated with cold stimulation plus partial sleep deprivation, the white blood cell and lymphocyte contents decreased and the erythrocyte sedimentation rate increased evidently compared with other three groups.</p><p><b>CONCLUSION</b>Partial sleep deprivation could inhibit immune function of the mice. When the mice were treated with cold stimulation plus partial sleep deprivation, the immune function of the mice would be inhibited further more and at the same time the erythrocyte sedimentation rate increased significantly.</p>

Effect of different culture media on viability and tau protein expression in rat hippocampal slices / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the effect of different culture media on viability and expression of tau protein in organotypic hippocampal slice.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>