To examine the effects of ischemia and anoxia on cell activation and cell cycle of astrocytes in vitro, the cell cycles and the proliferation of astrocytes in different time points after ischemia and anoxia were studied by flow cytometry and BrdU labeling and the expression of GFAP and cyclin D1 was detected by the fluorescence immunochemistry. After ischemia and anoxia in vitro, the astrocytes in S phase were significantly increased as compared with those in the normal group and the proliferating ability of the astrocytes was highest 6 h after the treatment as revealed by BrdU pulse labeling, but the astrocytes in S phase and proliferating ability were decreased after 6 h. At the early stages of ischemia and anoxia, the positive staining intensity of GFAP was increased, peaked at 6th h, while 12 h after the ischemia and anoxia, the positive staining intensity of GFAP became weak, and the expression of cyclin D1 was gradually increased after the ischemic and anoxic damage. It is concluded that astrocytes are activated to proliferate and enter new cycle events by ischemia and anoxia, and cyclin D1 is implicated in the proliferation and repair of astrocytes. The cell cycle events are closely associated with the proliferation and activation of astrocytes.
Animals, Newborn ; Astrocytes/*cytology ; Cell Cycle ; Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Cyclin D1/biosynthesis ; Cyclin D1/genetics ; Glial Fibrillary Acidic Protein/*biosynthesis ; Glial Fibrillary Acidic Protein/genetics ; Rats, Wistar

Gliofibroma is a rare astrocytic tumor, composed of a glial component ranging from benign to high grade of malignancy and a consistently benign mesenchymal component. Its exact biological behavior is not fully known. In addition, histogenesis and prognostic factors are also still debatable. We herein present a rare case of gliofibroma in a 25-yr-old male with seizure. A computed tomographic scan of the brain showed a 1.5 cm-sized, enhancing mass with calcification. Histologically, the tumor consisted of glial fibrillary acidic protein (GFAP)-positive glial cells admixed with a mesenchymal component and extensive collagen lay down. The glial cells displayed variable cellularity, but without mitosis or necrosis. Since the MIB-1 labeling index was up to 35.8% in the cellular areas of the glial component, it could be considered to be a predictor of worse prognosis.
Adult ; Astrocytoma/*diagnosis/pathology ; Brain Neoplasms/*diagnosis/pathology ; Glial Fibrillary Acidic Protein/biosynthesis ; Human ; Immunohistochemistry ; Male ; Mitosis ; Necrosis ; Prognosis ; Seizures/complications ; Tomography, X-Ray Computed

OBJECTIVE: To demonstrate the spatial organization of neurons, astrocytes and vessels in rat brain. METHODS: Cerebral vascular was shown by vivi-perfusion with ink. Glial fibrillary acidic protein (GFAP) immunohistochemistry and nissl's staining were performed on the serial sections of frozen brain tissues. RESULTS: Astracytes distributed along the branches of blood vessels, and neurons in the region of the relatively rich blood vessels. Neurons and astrocytes presented regional distribution. CONCLUSION This method can well indicate the spatial organization of neurovascular unit, the regional differences in the distribution may be related to physical activities and the corresponding adjustment function.
Animals ; Astrocytes ; cytology ; physiology ; Brain ; cytology ; physiology ; Cerebrovascular Circulation ; physiology ; Female ; Glial Fibrillary Acidic Protein ; biosynthesis ; Male ; Neurons ; cytology ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the expressions of nestin and glial fibrillary acidic protein (GFAP) and their association with reactive astrocytes following spinal cord injury in adult rats.

METHODSAdult rats with compression injury of the spinal cord were divided into 7 groups (n=6) and examined at 1, 3, and 5 days and at 1, 2, 4 and 8 weeks after the injury. The recovery of the locomotor function after the injury was evaluated with Basso, Beattie and Bresnahan (BBB) scale, and the degree and scope of the spinal injury were assessed using toluidine blue staining. Immunohistochemistry, double immunofluorescent labeling and an image analysis system were employed to observe nestin and GFAP expression and cell proliferation in different regions of the spinal cord.

RESULTSThe bilateral hind limb locomotor function of the rats declined severely 24 h after the spinal cord injury and underwent substantial recovery in 1 or 2 weeks after the injury, but followed by rather slow recovery afterwards. Toluidine blue staining of the spinal cord 24 h after the injury showed significant pathological changes in the neurons. The extension of the tissue injury increased with time till 1 week after the spinal cord injury. The site of injury and the adjacent tissues presented with markedly increased nestin and GFAP expressions 24 h after the injury, and nestin+/GFAP(-) cells dominated in the ependymal region around the central canal, whereas nestin+/GFAP+ dominated in the in other regions, showing significant difference from the control group. Nestin and GFAP expression reached the peak level 3 to 7 days after the injury and declined gradually till reaching nearly the control level at 2 weeks.

CONCLUSIONCompression injury of the spinal cord induces up-regulated expressions of nestin and GFAP, and nestin expression is positively correlated to the reactive astrocytes, which, along with the neural stem cells, respond to spinal nerve injury and possibly play a role in repair of the central nervous system injury.

Animals ; Astrocytes ; pathology ; Glial Fibrillary Acidic Protein ; biosynthesis ; genetics ; Intermediate Filament Proteins ; biosynthesis ; genetics ; Male ; Nerve Tissue Proteins ; biosynthesis ; genetics ; Nestin ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; metabolism ; pathology ; Stem Cells ; cytology ; metabolism ; Up-Regulation

OBJECTIVETo investigate the biological effects of ectopic overexpression of glial fibrillary acidic protein (GFAP) in human malignant glioma cell line, and to explore new method of differentiation induction gene therapy for gliomas.

METHODSA eukaryotic expression vector containing 1.1 kb GFAP cDNA fused with green fluorescent protein (GFP) gene, pIRGFP-GFAP, was transfected into human SHG-44 glioma cell line by lipofectamine. The expression of GFAP/GFP gene and their proteins were detected by fluorescent real-time monitoring, in situ hybridization, Western blot and immunocytochemistry. Flow cytometry, soft agar colony formation and other methods were used to measure the effects of exogenous GFAP expression on cell cycle progression, morphology and growth features of the transfected glioma cells.

RESULTSThe expressions of GFAP mRNA and its protein were markedly increased in SHG-44 cells upon stable transfection with pIRGFP/GFAP vector. Profound morphological changes in these cells were also observed, including the formation of abundant, stellate and thin cytoplasmic processes and a reduction of atypia. Cell proliferation rate and its tumorigenecity on soft agar were markedly reduced. In addition, cell cycle analysis revealed a percentage decrease of cell populations at G0/G1 and G2/M phases.

CONCLUSIONSEctopic overexpression of GFAP gene could significantly suppress the growth of SHG-44 malignant glioma cells along with an induction of differentiation. These results imply that forced over-expression of GFAP gene may provide a new strategy for glioma therapy.

Brain Neoplasms ; metabolism ; pathology ; Cell Differentiation ; Cell Line, Tumor ; Cell Proliferation ; DNA, Complementary ; genetics ; Genetic Vectors ; Glial Fibrillary Acidic Protein ; biosynthesis ; genetics ; physiology ; Glioma ; metabolism ; pathology ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; RNA, Messenger ; biosynthesis ; genetics ; Transfection

OBJECTIVETo investigate the expression and significance of peroxisome proliferators-activated receptor gamma (PPAR gamma) in human glioma.

METHODSImmunohistochemical staining for PPAR gamma was performed using biopsy specimens of human glioma of various histological types. Expression of PPAR gamma and GFAP in glioma cell lines SWO-38, U251 and SHG-44 were analyzed using Western blotting and reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSImmunohistochemical study showed that PPAR gamma was expressed in glioma tissues with positive rate of 37.5%. Western blotting and RT-PCR showed that PPAR gamma was expressed in both glioma cell lines SWO-38 and U251, but not in SHG-44 cells. However, high expression of GFAP was detected in SHG-44 cells.

CONCLUSIONPPAR gamma is associated with carcinogens of glioma. Actived PPAR gamma by agonist may be a novel approach to the treatment of glioma.

Blotting, Western ; Brain Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Glial Fibrillary Acidic Protein ; biosynthesis ; genetics ; Glioma ; genetics ; metabolism ; pathology ; Humans ; Immunohistochemistry ; PPAR gamma ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

We studied the expression of caveolin-1 in the spinal cords of rats using 60Co gamma-ray irradiation (single dose of 8 Gray (Gy)) in order to determine the possible involvement of caveolin-1 in the tissues of the central nervous system after irradiation. Spinal cords sampled at days 1, 4, and 9 post-irradiation (PI) (n = 5 per each time point) were analyzed by Western blot and immunohistochemistry. Western blot analysis showed that the expression of caveolin-1 was significantly increased at day 1 PI (p < 0.05), and returned to the level of normal control rats on days 4 and 9 PI. Immunohistochemistry showed that caveolin-1 immunoreactivity was enhanced in some glial cells, vascular endothelial cells, and neurons in the spinal cords. The increased expression of glial fibrillary acidic protein (GFAP), a marker for an astroglial reaction, was consistent with that of caveolin-1. In addition, caveolin-1 was co-localized in hypertrophied GFAP-positive astrocytes. Taking all these facts into consideration, we postulate that irradiation induces the increased expression of caveolin-1 in cells of the central nervous system, and that its increased expression in astrocytes may contribute to hypertrophy of astrocytes in the spinal cord after irradiation. The precise role of caveolin-1 in the spinal cords should be studied further.
Animals ; Astrocytes/metabolism/radiation effects ; Blotting, Western ; Caveolin 1/*biosynthesis ; Gamma Rays ; Glial Fibrillary Acidic Protein/*biosynthesis ; Immunohistochemistry ; Male ; Rats ; Rats, Sprague-Dawley ; Spinal Cord/cytology/*metabolism/*radiation effects ; Whole-Body Irradiation

OBJECTIVE: To investigate the effects of intravenous anesthetics on LPS-induced inflammatory responses of primary cultures of rat glial cells in vitro. METHODS: The primary cultures of rat glial cells were stimulated with lipopolysaccharide( LPS) to produce inflammatory responses. Glial cells were divided into 8 groups (n=4): blank control (Group C), LPS(Group L), 100micromol/L ketamine with LPS(Group K1), 1000micromol/L ketamine with LPS (Group K2), 30micromol/L propofol with LPS (Group P1), 300micromol/L propofol with LPS (Group P2), 3micromol/L midazolane with LPS (Group M1), and 30micromol/L midazolane with LPS (Group M2). TNF-alpha released into the culture media was measured by radioimmunity assay. RESULTS: Compared with the blank control Group C, LPS-induced TNF-alpha productions in Group L, K1, K2, P1, P2, M1 and M2 increased significantly. The levels of TNF-alpha in Group K1 and K2 were significantly lower than those in Group L (P<0.05), but TNF-alpha productions in Group P1, P2, M1 and M2 were not significantly different as compared with that in Group L. CONCLUSION Ketamine can reduce LPS-induced TNF-alpha production of glial cells, thereby inhabiting some of the inflammatory responses. Propofol and midazolam have no effect on the production of TNF-alpha from LPS-stimulated glial cells.
Anesthetics, Intravenous ; pharmacology ; Animals ; Cells, Cultured ; Female ; Glial Fibrillary Acidic Protein ; biosynthesis ; Immunohistochemistry ; Ketamine ; pharmacology ; Lipopolysaccharides ; pharmacology ; Neuroglia ; cytology ; drug effects ; metabolism ; Propofol ; pharmacology ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; biosynthesis

OBJECTIVETo investigate the effects of saikosaponin a (SSa) on Glu-activated hippocampal astrocytes of rats.

METHODSNeonatal rat (1-3 days) hippocampal astrocytes were obtained and divided into control group, L-Glu activation group and SSa groups with SSa treatment at 5, 2.5, and 1.25 mg/L. The cell proliferation, cell cycle changes, and expression of glial fibrillary acidic protein (GFAP) after the treatments were assessed with MTT assay, flow cytometry and Western blotting, respectively.

RESULTSIn comparison with Glu-activation group, SSa treatment resulted in significant inhibition of the cell proliferation, cell division and GFAP expression in the Glu-activated astrocytes (P < 0.05). SSa at 2.5 mg/L showed the strongest inhibitory effects against astrocyte activation and maintained nearly normal level of astrocyte activation in comparison with the control group (P > 0.05).

CONCLUSIONSGlu-induced activation of rat hippocampal astrocytes can be inhibited by SSa, whose antiepileptic effects is probably mediated by inhibition of hippocampal astrocyte activation.

Animals ; Animals, Newborn ; Astrocytes ; cytology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Female ; Glial Fibrillary Acidic Protein ; biosynthesis ; Glutamic Acid ; pharmacology ; Hippocampus ; cytology ; Male ; Oleanolic Acid ; analogs & derivatives ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Saponins ; pharmacology

OBJECTIVETo investigate the expression of alpha7-nAChR on rat hippocampal astrocytes in vivo and in vitro.

METHODSRat hippocampus was isolated and cut into 30-microm cryosections with anti-GFAP antibody staining followed by staining for alpha7-nAChR. The cultured astrocytes obtained from newborn rat (1-2 days old) hippocampus were identified with GFAP, and the expression of alpha7-nAChR was measured by fluorescein isothcyanate-tagged alpha-bungarotoxin staining analysis and double immunolabeling.

RESULTSThe localization of alpha7-nAChR was visualized in green with fluorescein isothiocyanate labeled IgG, whereas that of GFAP in red with Texas red-labeled IgG in the hippocampal slices, and the yellow spots indicating colocalization of the two fluorescent probes was shown in a merging image. alpha-bungarotoxin-binding nicotinic receptors were clustered, and the colocalization of alpha7-nAChR and GFAP on the cultured hippocampal astrocytes was visualized with the two fluorescent probes.

CONCLUSIONThe expression of alpha7-nAChR is identified on hippocampal astrocytes in vivo and in vitro.

Animals ; Animals, Newborn ; Astrocytes ; cytology ; metabolism ; Cells, Cultured ; Glial Fibrillary Acidic Protein ; analysis ; Hippocampus ; cytology ; metabolism ; Immunohistochemistry ; Microscopy, Fluorescence ; Rats ; Rats, Sprague-Dawley ; Receptors, Nicotinic ; biosynthesis ; alpha7 Nicotinic Acetylcholine Receptor