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

OBJECTIVEThe present study aimed to explore the role of P2Y(1) receptor in glial fibrillary acidic protein (GFAP) production and glial cell line-derived neurotrophic factor (GDNF) secretion of astrocytes under ischemic insult and the related signaling pathways.

METHODSUsing transient right middle cerebral artery occlusion (tMCAO) and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, enzyme linked immunosorbent assay (ELISA) were used to investigate location of P2Y(1) receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules.

RESULTSBlockage of P2Y(1) receptor with the selective antagonist N(6)-methyl-2'-deoxyadenosine 3',5'-bisphosphate diammonium (MRS2179) reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y(1) receptor caused elevation of phosphorylated Akt and cAMP response element binding protein (CREB), and reduction of phosphorylated Janus kinase2 (JAK2) and signal transducer and activator of transcription3 (STAT3, Ser727). After blockage of P2Y(1) receptor and deprivation of oxygen-glucose-serum, AG490 (inhibitor of JAK2) reduced phosphorylation of STAT3 (Ser727) as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3-K), decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase1/2 (MEK1/2) U0126, an important molecule of Ras/extracellular signal-regulated kinase (ERK) signaling pathway, decreased the phosphorylation of JAK2, STAT3 (Ser727), Akt and CREB.

CONCLUSIONThese results suggest that P2Y(1) receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.

Animals ; Astrocytes ; metabolism ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique ; Glial Cell Line-Derived Neurotrophic Factor ; biosynthesis ; Glial Fibrillary Acidic Protein ; biosynthesis ; Infarction, Middle Cerebral Artery ; metabolism ; RNA, Messenger ; analysis ; Rats ; Receptors, Purinergic P2 ; metabolism ; Receptors, Purinergic P2Y1 ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; physiology

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 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

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 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

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

OBJECTIVE: To investigate the changes of anti-apoptotic protein Bcl-2 expression in neurons and activation of brain astroglial cells, and the relationship between astrocytes and neurons in mice after a single intracerebroventricular (ICV) stereotaxic injection of lipopolysaccharide (LPS). METHODS: C57BL/6J mice of different ages were divided into a control group and an experiment group. Immunohistochemistry to Bcl-2 and that to GFAP were conducted to observe the expression of Bcl-2 protein in neurons and GFAP in astrocytes in the brain at different time-points after the LPS injection. The glial cell type expressing Bcl-2 was characterized with immunofluorescence double labeling. RESULTS: GFAP-immunoreactive cells in the control mice were observed mainly within hippocampal formation, piriform, entorhinal cortex, septum, striatum, amygdaloid nucleus, subcortical white matter, as well as in the main fiber tracts. At 24 h after the LPS treatment there was no obvious difference in GFAP immunoreactivity compared with the controls. Astrocytes were markedly activated in periventricular brain regions such as hippocampus, the hypothalamic parenchyma surrounding the third ventricle, with larger cell body and hypertrophic processes 2 days after the endotoxin treatment. After the LPS injection, Bcl-2 positive cells were distributed widely in the brain, such as in the cortex (primary and secondary motor cortex, somatosensory cortex), hypothalamic parenchyma surrounding the third ventricle, diagonal band, hippocampus, septum and the red nucleus of the midbrain. At these sites, Bcl-2 induction increased significantly 2 days after the ICV LPS injection, with some subregional differences, peaking on 4th day. No immunofluorescent double labeling cells for GFAP and Bcl-2 were observed in the brain of the mice after the LPS administration, but merging GFAP positive astrocytes and Bcl-2 positive neurons were seen. Double staining for Bcl-2 and GFAP also showed that the projections of activated astrocytes were found in the sheath of Bcl-2 positive neurons 4 days after the ICV LPS administration. CONCLUSION LPS can activate astroglial cells and upregulate of Bcl-2 expression in the neurons in the mouse brain, which may participate in the administration of central nervous system to central-immunity stimulated regulation and the protective response to the inflammatory stimulus. The projections of activated astrocytes are found in the sheath of Bcl-2 positive neurons, indicating that there is close relationship between astrocytes and neurons.
Animals ; Astrocytes ; cytology ; drug effects ; metabolism ; Brain ; cytology ; drug effects ; metabolism ; Fluorescent Antibody Technique ; Glial Fibrillary Acidic Protein ; biosynthesis ; Immunohistochemistry ; Injections, Intraventricular ; Lipopolysaccharides ; administration & dosage ; pharmacology ; Mice ; Mice, Inbred C57BL ; Neurons ; cytology ; drug effects ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Random Allocation

OBJECTIVETo study the clinicopathologic features of subependymal giant cell astrocytoma.

METHODSThe clinical and pathologic characteristics of 18 cases of subependymal giant cell astrocytoma were retrospectively analyzed.

RESULTSAmongst the 18 cases studied, there was a male predominance (male-to-female ratio = 2:1). The age of patients ranged from 7 to 54 years (mean age = 18.2 years). The tumor often occurred in the lateral ventricles (16/18, 88.9%). Most patients presented with headache and vomiting (11/18, 61.1%), followed by visual disturbance (3/18, 16.7%). Eleven patients (61.1%) had clinical features of tuberous sclerosis, usually in the form of facial angiofibroma (8/18, 44.4%). Computerized tomography was performed in 10 cases, in which 7 cases were of high density and 5 cases showed contrast enhancement. MRI revealed isointense mass lesion on T1WI (7/11, 63.6%), highly intense lesion on T2WI (10/11, 90.9%) and contrast enhancement in some cases (9/11, 81.8%). Four patients had follow-up information available and all of them were alive from 1 to 5 years (mean = 3.5 years). Histologically, there were bundles of spindle cells mixed with clusters of gemistocytes and ganglion-like cells. The spindle cells showed immunoreactivity for glial fibrillary acidic protein (18/18, 100%), while the gemistocytes and ganglion-like cells expressed synaptophysin (14/18, 77.8%). Most of the cases (16/18, 88.9%) had MIB-1 index

CONCLUSIONSSubependymal giant cell astrocytoma is a benign brain tumor with distinctive histopathologic features. The tumor typically affects children and young adults. It is associated with a favorable clinical outcome, especially if completely excised.

Adolescent ; Adult ; Astrocytoma ; complications ; metabolism ; pathology ; Cerebral Ventricle Neoplasms ; complications ; metabolism ; pathology ; Child ; Female ; Follow-Up Studies ; Glial Fibrillary Acidic Protein ; biosynthesis ; Humans ; Immunohistochemistry ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Retrospective Studies ; Synaptophysin ; biosynthesis ; Tomography, X-Ray Computed ; Tuberous Sclerosis ; complications ; metabolism ; pathology ; Young Adult

OBJECTIVETo study the alterations of alpha-7 nicotinic receptor (nAChR) status in human brain tissues with Alzheimer's disease (AD) and mouse brain tissues with Swedish APP670/671 gene mutation, and to study the effect of beta-amyloid peptides (A-beta) on alpha-7 nAChR status in cultured astrocytes and neurons.

METHODSPostmortem brain tissues from patients with AD and mouse brain tissues with Swedish APP mutation were collected. The expression of alpha-7 nAChR on astrocytes and neurons was detected by immunohistochemistry (ABC method). The alpha-7 nAChR protein level was measured by Western blotting. On the other hand, cultured astrocytes and neurons were treated with different concentrations of A-beta 25 - 35. The alpha-7 nAChR protein level was then measured.

RESULTSIncreased number of astrocytes surrounding senile plaques was observed in AD brain tissues. In AD brain tissues, as compared to age-matched controls, alpha-7 nAChR protein level was increased in astrocytes, but decreased in neurons. High level of alpha-7 nAChR protein was also observed in mouse brain tissues with APP mutation. Exposure to A-beta 25 - 35 induced an increase (up to 38%) in alpha-7 nAChR protein level in astrocytes but a decrease (up to 32%) in neurons.

CONCLUSIONSDecrease in alpha-7 nAChR level in neurons may be related to the pathogenesis of AD, whereas an increased level of alpha-7 nAChR in astrocytes, as induced by excessive A-beta, may represent a compensatory neuroprotective response.

Aged ; Aged, 80 and over ; Alzheimer Disease ; genetics ; metabolism ; pathology ; Amyloid beta-Peptides ; chemistry ; genetics ; metabolism ; Animals ; Astrocytes ; cytology ; drug effects ; metabolism ; Brain ; metabolism ; pathology ; Cell Line, Tumor ; Cells, Cultured ; Glial Fibrillary Acidic Protein ; analysis ; Humans ; Immunoblotting ; Immunohistochemistry ; Male ; Mice ; Mutation ; Neurons ; cytology ; drug effects ; metabolism ; Peptide Fragments ; pharmacology ; Receptors, Nicotinic ; biosynthesis