AIM: To investigate the changes of expression of Nogo-A at different time points in brain ischemic infarct rats.METHODS: The model of 80 cases of middle cerebral artery occlusion(MCAO) in rats was established.The expression of Nogo-A mRNA and protein were determined by Western blotting and hybridization,and the relationship between functional scoring and Nogo-A was also evaluated.RESULTS: In the brain of MCAO rats,Nogo-A mRNA expression was decreased on day 3 and increased significantly on day 7.The highest level was observed at the 21th d,keeping the same level at the 28th d.Nogo-A protein expression showed the same results.These results were correlated with the brain function scoring.CONCLUSION: Expression of Nogo-A does not increase in the early stage,but increases significantly in the late stage of MCAO,suggesting that Nogo-A expression may play an important role in the nerve regeneration of brain ischemic injury.

BACKGROUND: The study about the multiple differentiation potentials of the mesenchymal stem cells is still on the stage of the animal experimentation. Can mesenchymal stem cells have the ability to differentiate into certain tissues and develop the corresponding functions after they are transplanted into certain tissues?OBJECTIVE: To observe the differentiation of the bone marrow mesenchymal stem cells into the nerve and its effect on the nerve functional recovery after they are transplanted into the peripheral zone of the ischemic infarction focus of the cerebral cortex.DESIGN: A randomized controlled study.SETTING: The Department of Anatomy of the School of Basic Medical College of Sun Yat-sen University; the Department of Neurology of the First Hospital of Sun Yat-sen University; Department of Pathology of the Medical College of Jinan University.MATERIALS: The experiment was conducted at the Medical College of Sun Yat-sen University from November 2002 to November 2003. Forty-eight male SD rats were chosen and randomly divided into two groups, with 32 rats in cerebral infarction model group and 16 in the non-model control group. In the cerebral infarction group, the rats were randomly divided again into two groups: 16 rats in the transplantation group and 16 in the phosphate buffered fluid group. The anterior fontanel taken as the reference point, 5 μL(5 × 104 L-1) of the bone marrow mesenchymal stem cells or the phosphate buffered fluid was respectively transplanted at the site 3 mm away on the caudal side and 1.5 mm aside at the depth of 2. 0 - 3. 0 mm.METHODS: The bone marrow mesenchymal stem cells were obtained through the separation and purification of the bone marrow of the ribs taken away in the thoracic surgery from the patients without the hematological diseases, and then the cells underwent in vitro culture, the amplification and the identification. At the 2nd and 6t1 weekend after the transplantation,the rats of every group were anesthetized, and the samples were taken from the transplantation site and made into the 25 μm of continuous frozen section. Then, the immunohistochemical method was used for the detection of the expressions of neuron specific enolase, neurofibril protein, glial fibrillary acidic protein, and nidogen to evaluate the ability of the bone marrow mesenchymal stem cells to differentiate into neurons and glial cells. Eight rats of the transplantation group and 8 rats of the phosphate buffered fluid group were randomly taken out, and 2 and 6 weeks before and after the transplantation the bar walking test evaluation method was used to identify the general status and reaction ability of the rats. Sixteen rats of the control group were assessed at the same time.enolase, neurofibril protein, glial fibrillary acidic protein and nidogen in the bar walking test.2nd weekend after the transplantation, there were positive expressions of glial fibrillary acidic protein and nidogen at the transplantation site of the bone marrow mesenchymal stem cells. At the 6th weekend there were positive expressions of neuron specific enolase and neurofibril protein at the transplantation site of the bone marrow mesenchymal stem cells. While in the phosphate buffered fluid group, there were negative expressions of neuron specific enolase, neurofibril protein, glial fibrillary acidic protein and nidosymptoms in the control group and the evaluation scores were all 9. 2 weeks after the transplantation, and the evaluation scores of the motor function in the transplantation group were higher than the ones in the phosphate buffered fluid group, [(6.7±0.9), (5.3-±1.0), (P ＜0.05)]. Six weeks after the transplantation, the evaluation scores of the motor function in the transplantation group were also higher than those in the phosphate buffered fluid group[(8.9±1. 1),(7.2±0.8),(P ＜0.05)].CONCLUSION: After their transplantation into the central nervous system,the bone marrow mesenchymal stem cells showed the ability to differentiate into neurons and glial cells, in which the characteristics of some neurons and glial cells were found. Bar walking test found that the evaluation scores of the motor function in the transplantation group were higher than those in the phosphate buffered fluid group, which suggests that the bone marrow mesenchymal stem cells have a significant effect on restoration of the functions of the nerves.

AIM: To investigate the dynamic changes of Nogo-A expression in ischemic infarct brain in rats. METHODS: The model of middle cerebral artery occlusion (MCAO) in 80 rats was established and expression of Nogo-A mRNA was measured by immunohistochemistry and hybridization. RESULTS: In the brain of MCAO rats, Nogo-A mRNA expression was decreased at the third day and increased significantly at the 7th day, and reached high level at the 21th day, then remained the high level to the 28th day. Nogo-A protein expression showed the same results. CONCLUSION: Expression of Nogo-A did not change in the early stage of MCAO, but increased significantly in the late stage of MCAO, suggesting that Nogo-A expression may play an important role in the nerve regeneration of brain ischemic injury. [

AIM: To study the protective effect of puerarin on the atherosclerosis of RAW264.7-derived foam cells.METHODS: The model of foam cells was established by incubating the RAW264.7 cells with ox-LDL.The choles-terol uptake was evaluated by a DiI-ox-LDL binding assay.The ability of cholesterol efflux of the RAW264.7-derived foam cells was detected by cholesterol efflux assay.The protein levels of LC3II, P62, CD36, ABCA1, LAL and p-AMPK were determined by Western blot.RESULTS: Puerarin treatment reduced the cholesterol uptake capacity and enhanced the cho-lesterol efflux rate.The protein levels of LC3II, ABCA1 and LAL in puerarin group were higher than that in ox-LDL group, while the protein levels of P62 and CD36 were obviously decreased, and those in rapamycin treatment group had the same change as puerarin group.The protein levels of LC3II, ABCA1 and LAL were obviously decreased and the protein level of p-AMPK was increased after co-treated with 3-MA.CONCLUSION: Puerarin promotes LAL and ABCA1-mediated cho-lesterol efflux in ox-LDL-treated RAW264.7 macrophages, which might enhance autophagy through AMPK-dependent path-way for cholesterol efflux regulation, and reduce the uptake of lipids by CD36 negative regulation.

AIM: To explore the differentiation and the functional behavior of marrow mesenchymal stem cells (MSC) transplanted into the cerebral infarction area after cerebral middle artery ischemia in rats. METHODS: MSC were isolated from human rib marrow and cultured in L DMEM medium in vitro. The model of rat cerebral infarction by cerebra middle artery occlusion was established, and the identified MSC were transplanted intracerebrally 10 days later. Immunohistochemistry technique was used to identify the cell survivor and its differentiation to the neurogenesis in the transplantation site, and at 2 weeks and 6 weeks after transplantation, the functional tests were comparatively studied. RESULTS: The results showed that the survivor of transplanted MSC was differentiated to neural phenotype cells, and the functional behavior of the injury rats was recovered significantly after MSC transplantation (P