RÉSUMÉ
BACKGROUND: Application of neural stem cells (NSCs) is of great current interest in neuroscience, but NSCs origin is very limited. And they always differentiate into a large percentage of glial cells and small percentage of neurons in natural differentiation process, so researchers should take effective measures to promote NSCs differentiation into certain offsprings. Previous studies have shown that ginseng saponin ingredients, such as Rb1 and Rg1, have certain influence on NSCs differentiation, but it is unclear whether Rg3 plays a role on NSCs differentiation. OBJECTIVE:To preliminarily investigate the effect of ginsenoside Rg3 on mouse NSCs differentiation into neurons and astrocytes in vitro. METHODS: The fetal cortices of embryonic 14 days (E14) C57BL/6 mice were isolated for culturing primary NSCs. Then passaged NSCs were identified by their purity with NSCs specific antibodies, Nestin and Sox2, by immunofluorescence staining. NSCs were induced for 3 days in the differentiation medium containing ginsenoside Rg3 of different concentrations (blank control, 50 and 250 nmol/L). After that, immunofluorescence staining was used to identify differentiated neurons with neuronal specific antibody, Tuj1, and differentiated astrocytes with astrocyte specific antibody, GFAP. Then, we calculated and statistically analyzed Tuj1+/DAPI and GFAP+/DAPI percentages in the three different groups. Besides, real-time PCR assay was used to test Tuj1 and GFAP mRNA expression in the three groups after 3 days of differentiation. RESULTS AND CONCLUSION: Primary and passaged NSCs were successfully cultured and almost of cells were positive for both Nestin and Sox2, so these high-purity NSCs could be used in the following experiments. Immunofluorescence staining and statistical analysis results showed that compared with the blank control and 250 nmol/L groups, 50 nmol/L group had an obviously increased neuronal percentage after 3 days differentiation (P < 0.01), while the blank control and 250 nmol/L groups had no significant difference (P > 0.05); compared with the blank control group, 50 and 250 nmol/L groups had significantly increased astrocyte percentages (P < 0.05), whereas there was no obvious difference between 50 and 250 nmol/L groups (P > 0.05). The results of real-time PCR assay were similar with the above immunofluorescence results. In conclusion, 50 nmol/L ginsenoside Rg3 can enhance mouse NSCs differentiation into neurons and astrocytes, while 250 nmol/L ginsenoside Rg3 can only promote mouse NSCs differentiation into astrocytes.
RÉSUMÉ
Objective To investigate the effects of transient axonal glycoprotein-1 (TAG-1) on activity of U251 cells and expressions of AICD, p53 and EGFR genes in the cells. Methods The viability of U251 cells was tested by MTT assay at 48 h following the addition of various concentrations of TAG-1 (0, 5, 10 and 20 μg/mL). The expression ofamyloid precursor protein (ALP) was detected by immunofluorescent staining. The apoptotic cells were examined by TUNEL. Real-time PCR was employed to detect the influence of TAG-1 on the expressions of AICD, p53 and EGFR genes in U251 cells. Results TAG-1 did not play an inhibitory effect on the proliferation of the U251 cells. APP was abundantly expressed on membrane of the U251 cells. U251 cells did not show apoptotic cells but increased expressions of AICD, p53 and EGFR genes were noted when U251 cells were exposed at 10 μg/mL of TAG-1. Conclusion TAG-1 plays an important role in regulating the proliferation of glioma and may not induce the apoptosis of U251 cells through the signal pathway of TAG-1/APP/AICD/p53 or TAG- 1/APP/AICD/EGFR.
RÉSUMÉ
Objective To map the vision cortex of rats by dynamic manganese-enhanced functional magnetic resonance imaging and provide a method for researching the nervous function. Methods Six adult male Wistar rats were chosen and the process was divided into 4 continuous phases. No agent was injected into the rats in the first phase (5 min). Disrupting the BBB with marmitol and injecting manganese chloride were performed in the fight internal carotid artery (ICA) in the second phase (10 min). In the third phase (15 min), manganese chloride was administrated into theright ICA and vision stimulation was performed before the imaging process. The mixed liquor of manganese chloride and glutamate was injected into the rats in the forth phase (5 min). MRI was performed instantly after the handles in each phase. SPM and Matlab software were employed to help analyze the imaging data. Region-of-interest (ROI) was recorded to observe the stimulated regions and compare the signal intensity in the visual cortex. Results No specific enhanced region was found in the rat brain in the first and second phases. The right visual cortex was enhanced specifically on T1WI in the third phase. Many brain regions of the right hemisphere, the sites that agents was injected, were obviously enhanced in the forth 2008A1-E4011)phase. ROI analysis showed that the signal intensity in the third phrase (1.897±0.172) was significantly stronger as compared with that in the second phrase(1.549±0.163)(P<0.05). Conclusion The dynamic manganese-enhanced functional magnetic resonance imaging can analyze the functional activities of the vision cortex in rats and provide a new method for researching the function of the nervous system.