Repair of glutamate-induced excitotoxic neuronal damage mediated by intracerebroventricular transplantation of neural stem cells in adult mice.

OBJECTIVE: To investigate a possibility of repairing damaged brain by intracerebroventricular transplantation of neural stem cells (NSCs) in the adult mice subjected to glutamate-induced excitotoxic injury. METHODS: Mouse NSCs were isolated from the brains of embryos at 15-day postcoitum (dpc). The expression of nestin, a special antigen for NSC, was detected by immunocytochemistry. Immunofluorescence staining was carried out to observe the survival and location of transplanted NSCs. The animals in the MSG + NSCs group received intracerebroventricular transplantation of NSCs (approximately 1.0 x 10(5) cells) separately on day 1 and day 10 after 10-d MSG exposure (4.0 g/kg per day). The mice in control and MSG groups received intracerebroventricular injection of Dulbecco's minimum essential medium (DMEM) instead of NSCs. On day 11 after the last NSC transplantation, the test of Y-maze discrimination learning was performed, and then the histopathology of the animal brains was studied to analyze the MSG-induced functional and morphological changes of brain and the effects of intracerebroventricular transplantation of NSCs on the brain repair. RESULTS: The isolated cells were Nestin-positive. The grafted NSCs in the host brain were region-specifically survived at 10-d post-transplantation. Intracerebroventricular transplantation of NSCs obviously facilitated the brain recovery from glutamate-induced behavioral disturbances and histopathological impairs in adult mice. CONCLUSION: Intracerebroventricular transplantation of NSCs may be feasible in repairing diseased or damaged brain tissue.

[Tubeimoside I-induced ultrastructural changes of human cervical carcinoma HeLa cell line and the protective effect of cyclosporine A].

OBJECTIVE: To observe the ultrastructural changes of HeLa cells in response to tubeimoside I (TBMS1) treatment and the protective effect of cyclosporine A (CsA), and explore the role of intrinsic apoptosis pathway in TBMS1-induced HeLa cell apoptosis. METHODS: HeLa cells were treated with TBMS1 (10-50 micromo/L) alone or in combination with 2 micromol/L CsA for 12 and 24 h and observed with transmission electron microscope (TEM) for the ultrastructural changes of the cells. RESULTS: TBMS1 induced apoptosis of HeLa cells in a concentration- and time-dependant manner. Under TEM, the treated cells progressively shrunk and the intercellular space widened with loss of microvillus, mitochondrial swelling, rough endoplasmic reticulum enlargement, chromatin condensation, nuclear shrinkage and nuclear pyknosis as TBMS1 concentration increased. At low concentrations, CsA offered partial protection of the mitochondria from TBMS1-induced damage whereas high-concentration CsA did not. CONCLUSION: TBMS1 induces ultrastructural changes typical for apoptosis of the HeLa cells, which provides morphological evidence for the role of intrinsic apoptosis pathway in TBMS1-induced apoptosis.

[Role of mitochondria in Tubeimoside I-mediated apoptosis in human cervical carcinoma HeLa cell line].

OBJECTIVE: To investigate the role of mitochondria in TBMS1-medited apoptosis of human cervical carcinoma HeLa cell line. METHOD: Mitochondrial transmembrane potentia (deltapsim) was assayed by flow cytometry. Apoptotic induction by TBMS1 was determined by gel electrophoresis of fragmented DNA. Cytochrome c (Cyt c) was detected by Western blotting. RESULT: The results showed that TBMS1 induced apoptosis in HeLa cells, that TBMS1 decreased deltapsim and facilitated Cyt c release, and that TBMS1 induced apoptosis of HeLa cells dose-and time-dependently in accordance with increase of cytosolic Cyt c. TBMS1 had direct effect on isolated rat mitochondria which induced a time- and dose-dependent release of Cyt c from mitochondria. The results also showed that CsA protected partly HeLa cells from the effect of TBMS1. CONCLUSION: The mitochondrial apoptosis pathway has effects on TBMS1 induced human cervical carcinoma HeLa cell line apoptosis.

[Apoptosis of human nasopharyngeal carcinoma CNE-2Z cells induced by tubeimoside I].

BACKGROUND & OBJECTIVE: Tubeimu, Bolbostemma pani- culatum(Maxim.) Franquet (Cucurbitaceae), is a kind of traditional Chinese medicinal herb. Our previous studies revealed that tubeimoside I, a triterpenoid saponin isolated from the tubers of Bolbostemma paniculatum, showed potent antitumor effect. This study was designed to investigate the effect of tubeimoside I on the apoptosis of human nasopharyngeal carcinoma cell line CNE-2Z. METHODS: Cell growth inhibition mediated by tubeimoside I was measured by MTT assay after treatment with tubeimoside I. The effect of tubeimoside I on apoptotic induction in CNE-2Z cells was determined using the fluorescent microscopy, electronic microscopy,DNA agarose gel electrophoresis, and flow cytometry,respectively. Western blot analysis was performed to detect the changes of apoptosis-related genes bcl-2 and bax protein expression. RESULTS: Tubeimoside I displayed growth inhibitory activity against CNE-2Z cells with IC(50) values of 32.5, 20.7, and 16.7 micromol/L for 24, 48, and 72 hours, and CNE-2Z cells showed typical apoptotic morphological features observed by fluorescent microscopy and electronic microscopy. In CNE-2Z cells occurred typical "Ladder"bands after being exposed to tubeimoside I (10 micromol/L, 24, 48, 72 hours; 30, 40, 50, 60 micromol/L, 12 hours). Sub-G1 peak was found using flow cytometry. When CNE-2Z cells were exposed to tubeimoside I (50 micromol/L, 12 hours), the apoptosis index was 72.8%. The down regulation and phosphorylation of bcl-2 (an inhibitor of apoptosis) were detected at 1 hour after the addition of tubeimoside I. In contrast, the levels of bax appeared to be significantly upregulated at 1, 3, 5, and 24 hours after the addition of tubeimoside I. CONCLUSION: Tubeimoside I can induce the apoptosis of CNE-2Z cells, and the induction of apoptosis by tubeimoside I is closely associated with downregulation and phosphorylation of bcl-2 and bax activation.

[Cell cycle arrest and apoptosis induced by tubeimoside in HeLa cell].

BACKGROUND & OBJECTIVE: Tubeimoside, which is composed of tubeimoside I (79%) and II (21%), was isolated from the tubers of Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), a traditional Chinese medicine, "Tu-Bei-Mu". This study was designed to investigate the anti-tumor mechanism of tubeimoside. METHODS: Growth inhibition was measured by MTT assay. Induction of cell cycle arrest and apoptosis was determined by flow cytometry, fluorescence and electron microscopy, and gel electrophoresis of fragmented DNA. RESULTS: Tubeimoside display strong growth inhibitory effect in a dose- and time-dependant manner against HeLa cells with estimated IC50 values of 20.0, 18.8, and 8.8 mumol/L after 24, 48, and 72 h of treatment with tubeimoside. The flow cytometry profiles revealed that treatment with tubeimoside (5 h; 15, 30, 35 mumol/L) led to a dose-dependant shift from 9.80% up to 21.90%, and 27.00% in percentage of cells with a G2/M-like DNA content. On the other hand, treatment with tubeimoside (12 h, 15, 30, 35 mumol/L) led to a time-dependant shift from 8.20% up to 21.40%, 31.15%, and 34.55%, respectively. Exposure of HeLa cells to 40 mumol/L of tubeimoside induced nuclear shrinkage, chromation condensation and margination against nuclear envelope, subdiploid peak, and DNA fragmentation, characteristic as seen in apoptotic cells. CONCLUSION: Induction of cell cycle arrest and apoptosis may play an important role in the anti-tumor effect of tubeimoside.