Puerarin alleviates cognitive impairment and tau hyperphosphorylation in APP/PS1 transgenic mice / 中国中药杂志

To observe the effect of puerarin on learning and memory function and tau phosphorylation in APP/PS1 transgenic mice, drugs were administered to 3-month old APP/PS1 transgenic mice. Learning and memory function of mice were assessed by Morris water maze test 3 months after treatment. Animals were decapitated after behavioral test. The levels of Aβ were detected by ELISA, the expression of protein [tau, phosphorylated tau, GSK3β and p-GSK3β(Ser9)] were assessed by Western blot. Morris water maze test showed that the escape latency of APP/PS1 double transgenic mice was significantly longer than that of the normal control group, and the residence time of the original quadrant was significantly shorter. The escape latency of puerarin group was significantly shorter and the residence time of the original quadrant was prolonged compared with the model group. Compared with the normal control group, the levels of Aβ in the cortex of APP/PS1 transgenic mice were increased, the expression of phosphorylated tau was significantly increased, and the expression of phosphorylated GSK3β(Ser9) protein was decreased. Treatment with puerarin, the latency of APP/PS1 transgenic mice was significantly reduced, the level of Aβ was decreased, the expression of phosphorylated tau was significantly decreased, and the expression of phosphorylated GSK3β(Ser9) protein was increased. Puerarin improves the learning and memory impairment by reducing the formation of Aβ, activating the GSK3β signaling pathway, inhibiting the phosphorylation of tau in APP/PS1 double transgenic mice.

[Biomechanical characteristics analysis on discs with coflex fixation on the different segments of lower lumbar spine].

OBJECTIVE: To investigate the biomechanical differences between the surgery and adjacent segments of intervertebral discs in the lower lumbar spine, which were implanted with Coflex into the segments of L4, and L5S1, respectively. METHODS: Three finite-element models (the model of the intact lower lumbar sacrum,the L4.5 and L5S1 segments implanted by Coflex) were developed, respectively. According to the spinal three-column loading theory, three models were forced by the physiological loads of upright standing, flexion and extension. The stress of the different areas of the disc annulus, the changes of intervertebral dorsal height and the degree of nucleus pulposus pressure were compared and analyzed. RESULTS: Coflex implanted into the L4.5 and L5S1 segments in compression and extension could both decrease the stress of the posterior area of intervertebral disc in the surgery segment, resist the changes of the intervertebral disc dorsal height and reduce the perssure of nucleus pulposus. Furthermore, the stress of the L5S1 segment decreased when Coflex fixed the L4.5 segment in extension. However, when Coflex fixed the L5S1 segment, the stress of L4.5 segment had no significant changes. CONCLUSION: Coflex fixing the L4,5 and L5S1 segments can effectively decrease the stress of the surgery segmental discs, respectively. Furthermore, Coflex fixing L4,5 segment may play a biomechanical role in reducing the stress of L5S1 segment.

Influence of breviscapine on memory and antioxidation ability in rats with Alzheimer's disease / 中国药学杂志

OBJECTIVE: To study the effect of breviscapine on memory and antioxidation ability in A(342-induced Alzheimer's disease (AD) rat model. METHODS: AD rat model was established by intracerebroventricular injection of A (342. Besides, sham-operated mice served as control group. The learning and memory ability was determined by Morris water maze test. The activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and the content of Malondialdehyde (MDA) in brain tissue were measured with spectrophotometer. RESULTS: Compared with control group, AD model significantly prolonged the latency of searching the hidden platform in directional swimming test, and decreased time spent in swimming in the target quadrant in probe test. Breviscapine dose-dependently shortened the latency of searching the hidden platform in directional swimming test, and increased the time spent swimming in the target quadrant in probe test. The activities of GSH-Px and SOD were decreased, and the MDA content was increased in AD model rats. In breviscapine treatment groups, the activities of GSH-Px and SOD heightened and MDA content decreased, and there was significant difference compared with AD model group. CONCLUSION: Breviscapine can dose-dependently ameliorate the impaired learning and memory function of AD model rats and improve antioxidation ability. Copyright 2012 by the Chinese Pharmaceutical Association.

Effect of oxidative low-density lipoprotein on the proliferation of bone marrow stem cell- derived smooth muscle cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish the model of bone mesenchymal stem cell-derived smooth muscle cells (BMSC-SMCs) and investigate the role of BMSC-SMCs in the development and progression of artherosclerosis.</p><p><b>METHODS</b>BMSCs were isolated from the femoral bone of SD rats by adherent tissue culture method, and vascular smooth muscle cells (VSMCs) were obtained from the thoracic aorta. The differentiation of BMSCs into BMSC-SMCs was induced in the conditioned medium. The specific markers of BMSCs and BMSC-SMCs were identified by immunofluorescence (IF) staining. After treatment with 80 mg/L oxidative low-density lipoprotein (ox-LDL) for 72 h, the growth characteristics of BMSC-SMCs and VSMCs were observed. Flow cytometry was applied to analyze the cell cycle of BMSC-SMCs and VSMCs.</p><p><b>RESULTS</b>BMCS-SMCs transformed into foam cells after treatment with ox-LDL, which was more obvious in comparison with VSMCs. The growth curve of BMSC-SMCs and VSMCs presented with an S-shape pattern with the cell doubling time of 20 and 32 h, which was reduced to 15 and 28 h after treatment with 80 mg/L ox-LDL, respectively. Flow cytometry showed that exposure to 80 mg/L ox-LDL significantly increased G(0)/G(1) and decreased S and G(2)/M phase cells in both BMSC-SMCs (P<0.01, n=3) and VSMCs (P<0.05, n=3) in comparison with the control cells.</p><p><b>CONCLUSION</b>BMSC-SMC might be involved in the formation of fatty core and accelerate the development of atherosclerosis.</p>

Mechanisms of foam cell formation in smooth muscle cell derived from bone marrow stem cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a model of smooth muscle cells differentiated from bone mesenchymal stem cells (BMSC-SMCs) in vitro and explore the relationship between scavenger receptors A (SR-A) and caveolin-1.</p><p><b>METHODS</b>BMSCs were isolated from the femoral bone of SD rats by adherent culture. After treatment of the BMSC-SMCs with 80 mg/L ox-LDL for 72 h, Western blotting was performed to detect the expression of scavenger receptor SR-A, cell cholesterol transport protein ATP-binding cassette transporter Al (ABCA1) and caveolin-1.</p><p><b>RESULTS</b>BMCS-SMCs became foam cells after treatment with ox-LDL. BMSC-SMC gave rise to more foam cell formation than VSMCs did. Western blotting showed that treatment with 80 mg/L ox-LDL for 72 h resulted in significantly increased expression of SR-A and significantly decreased expressions of ABCA1 and caveolin-1.</p><p><b>CONCLUSIONS</b>Treatment of BMCS-SMCs with ox-LDL results in cholesterol ester accumulation in the cells to result in foam cells, the mechanism of which involves up-regulation of scavenger receptor SR-A expression and down-regulation of the reverse cholesterol transport protein ABCA1 and caveolin-1 expression.</p>