Poly (ADP-ribose) polymerase-1 (PARP-1) plays as a double edged sword in cerebral ischemia-reperfusion, hinging on its effect on the intracellular energy storage and injury severity, and the prognosis has relationship with intervention timing. During ischemia injury, apoptosis and oncosis are the two main cell death pathway sin the ischemic core. The participation of astrocytes in ischemia-reperfusion induced cell death has triggered more and more attention. Here, we examined the protective effects and intervention timing of the PARP-1 inhibitor PJ34, by using a mixed oxygen-glucose deprivation/reperfusion (OGDR) model of primary rat astrocytes in vitro, which could mimic the ischemia-reperfusion damage in the "ischemic core". Meanwhile, cell death pathways of various PJ34 treated astrocytes were also investigated. Our results showed that PJ34 incubation (10 μmol/L) did not affect release of lactate dehydrogenase (LDH) from astrocytes and cell viability or survival 1 h after OGDR. Interestingly, after 3 or 5 h OGDR, PJ34 significantly reduced LDH release and percentage of PI-positive cells and increased cell viability, and simultaneously increased the caspase-dependent apoptotic rate. The intervention timing study demonstrated that an earlier and longer PJ34 intervention during reperfusion was associated with more apparent protective effects. In conclusion, earlier and longer PJ34 intervention provides remarkable protective effects for astrocytes in the "ischaemic core" mainly by reducing oncosis of the astrocytes, especially following serious OGDR damage.
Animals ; Apoptosis ; Astrocytes ; cytology ; drug effects ; Cell Survival ; Cells, Cultured ; Glucose ; deficiency ; Humans ; Lactate Dehydrogenases ; metabolism ; Male ; Models, Biological ; Oxygen ; metabolism ; Phenanthrenes ; pharmacology ; Poly(ADP-ribose) Polymerase Inhibitors ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

MicroRNAs (miRNAs) are a class of noncoding RNAs that regulates target gene expression at posttranscriptional level, leading to further biological functions. We have demonstrated that microvesicles (MVs) can deliver miRNAs into target cells as a novel way of intercellular communication. It is reported that in central nervous system, glial cells release MVs, which modulate neuronal function in normal condition. To elucidate the potential role of glial MVs in disease, we evaluated the effects of secreted astrocytic MVs on stress condition. Our results demonstrated that after Lipopolysaccharide (LPS) stimulation, astrocytes released shedding vesicles (SVs) that enhanced vulnerability of dopaminergic neurons to neurotoxin. Further investigation showed that increased astrocytic miR-34a in SVs was involved in this progress via targeting anti-apoptotic protein Bcl-2 in dopaminergic neurons. We also found that inhibition of astrocytic miR-34a after LPS stimulation can postpone dopaminergic neuron loss under neurotoxin stress. These data revealed a novel mechanism underlying astrocyte-neuron interaction in disease.
Animals ; Astrocytes ; cytology ; drug effects ; metabolism ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cell-Derived Microparticles ; metabolism ; Disease Models, Animal ; Dopaminergic Neurons ; drug effects ; pathology ; Down-Regulation ; drug effects ; Humans ; Lipopolysaccharides ; pharmacology ; MicroRNAs ; metabolism ; Neurotoxins ; toxicity ; Oxidopamine ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Stress, Physiological ; drug effects

OBJECTIVETo investigate the effect of propofol on the expression of thrombospondin-1 (THBS-1) mRNA and protein in purified newborn rat cortical astrocytes in vitro.

METHODSAstrocytes were isolated from newborn rat cortex and grown in culture before exposure to propofol at 3, 10, 30, 100 or 300 µmol/L for 6 h, 12, or 24 h. The mRNA level of THBS-1 was detected by RT-PCR, and the protein level of THBS-1 was detected by immunofluorescence cytochemistry and Western blotting.

RESULTSPropofol exposure caused significantly upregulated THBS-1 level in cultured astrocytes (P<0.05) to a level about 1.3 times higher than that in control cells. The mRNA and protein levels of THBS-1 in cultured rat cortical astrocytes were upregulated by exposures to 10, 30 and 100 µmol/L propofol (P<0.01). High expression of THBS-1 mRNA and protein was detected in the cells with exposures for different durations (P<0.05), especially in the 12 h group (P<0.01).

CONCLUSIONPropofol at clinically relevant concentrations can modulate the level of THBS-1 secreted by astrocytes of rat cerebral cortex in vitro.

Animals ; Astrocytes ; drug effects ; metabolism ; Cells, Cultured ; Cerebral Cortex ; cytology ; Propofol ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Thrombospondin 1 ; metabolism

Recent studies have shown that astrocytes play important roles in ATP degradation and adenosine (a well known analgesic molecule) generation, which are closely related to pain signaling pathway. The aim of this study was to investigate whether morphine, a well known analgesic drug, could affect the speeds of ATP enzymolysis and adenosine generation in rat astrocytes. Intracellular calcium concentration ([Ca(2+)](i)) of astrocyte was measured by flow cytometry, and the time points that morphine exerted notable effects were determined for subsequent experiments. Cultured astrocytes were pre-incubated with morphine (1 μmol/L) and then were incubated with substrates, ATP and AMP, for 30 min. The speeds of ATP enzymolysis and adenosine generation were measured by high performance liquid chromatography (HPLC). The results showed that both 1.5 and 48 h of morphine pre-incubation induced maximal ATP enzymolysis speed in astrocytes among all the time points, and there was no statistical difference of ATP enzymolysis speed between morphine treatments for 1.5 and 48 h. As to adenosine, morphine pre-incubation for 1.5 h statistically increased adenosine generation, which was degraded from AMP, in cultured astrocytes compared with control group. However, no difference of adenosine generation was observed after 48 h of morphine pre-incubation. These results indicate that treatment of morphine in vitro dynamically changes the concentrations of ATP and adenosine in extracellular milieu of astrocytic cells. In addition, astrocyte can be regarded as at least one of the target cells of morphine to induce changes of ATP and adenosine levels in central nervous system.
Adenosine ; biosynthesis ; Adenosine Triphosphate ; metabolism ; Analgesics, Opioid ; pharmacology ; Animals ; Animals, Newborn ; Astrocytes ; cytology ; drug effects ; metabolism ; Calcium ; analysis ; metabolism ; Cells, Cultured ; Cerebral Cortex ; cytology ; Morphine ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the analgesic effect of shentong zhuyu decoction (SZD) and its effect on the expression of the spinal cord glial fibrillary acidic protein (GFAP).

METHODSOne hundred C3H/HeNCrlVr male mice were randomly divided into the normal group (n=8), the sham operation group (n=30), the model group (n=30), the Chinese medicine (CM) group 1 (n=8), the CM group 2 (n=8), the CM group 3 (n=8), and the vehicle group (n=8). 0.1 g crude drug of SZD/0.4 mL, 0.3 g crude drug of SZD/0.4 mL, 0.9 g crude drug of SZD/0.4 mL, and 0.4 mL normal saline were respectively given by gastrogavage to mice in CM 1, 2, 3 groups and the vehicle group, once daily for seven days starting from Day 14. The paw withdrawal thermal latency (PWTL), as the behavior indicator, was assessed in mice using radiant thermal stimulator. The lumbar enlargement of the spinal cord was taken after the behavioral test on Day 21. GFAP mRNA and protein expressions were detected using real-time quantitative RT-PCR and Western blot.

RESULTSCompared with the normal group (Day 0) (PWTL: 15.91 +/- 1.65 s) and the sham operation group (PWTL: Day 4: 13.33 +/- 1.44 s; Day 7: 11.28 +/- 0.61 s; Day 10: 15.47 +/- 2.46 s; Day 14: 15.69 +/- 1.98 s; Day 21: 15.69 +/- 1.68 s), the PWTL value in the model group (Day 4: 13.24 +/- 1.02 s; Day 7: 11.30 +/- 1.09 s; Day 10: 9.12 +/- 0.54 s; Day 14: 7.79 +/- 0.77 s; Day 21: 6.36 +/- 0.59 s) progressively decreased (P < 0.05) as time went by, while the spinal cord GFAP mRNA and protein expressions gradually increased. Compared with the normal group (Day 0) and the sham operation group (Day 14), the PWTL value in the CM groups and the vehicle group obviously decreased on Day 14 (P < 0.05). The PWTL value was not significantly different among the model group, CM groups, and the vehicle group on Day 14 (P > 0.05). On Day 21 the PWTL value of CM group 2 and 3 increased and the spinal cord GFAP mRNA and protein expression levels decreased when compared with the model group and the vehicle group (P < 0.05). But no significant difference in the PWTL value or GFAP expression levels was shown among the CM 1 group, the vehicle group, and the model group (P > 0.05).

CONCLUSIONSZD had analgesic effect. Inhibition of the proliferation and activation of the spinal cord astrocytes might be one of its mechanisms.

Animals ; Astrocytes ; cytology ; drug effects ; metabolism ; Bone Neoplasms ; complications ; psychology ; Drugs, Chinese Herbal ; pharmacology ; Glial Fibrillary Acidic Protein ; metabolism ; Male ; Mice ; Mice, Inbred C3H ; Osteosarcoma ; complications ; psychology ; Pain ; etiology ; metabolism ; Spinal Cord ; cytology ; metabolism

BACKGROUNDAdipose-derived stromal cell (ADSC) differentiation into neural cells in vitro is becoming widely studied. However, there are few reports on astrocytes following differentiation, and particularly on maturation and electrophysiology. In this study, we used various methods to determine ADSC-derived astrocyte maturity.

METHODSChemical induction with isobutylmethylxanthine (IBMX) was used to differentiate adult ADSCs into astrocytes followed by hematoxylin-eosin (HE) staining to observe morphology and transmission electron microscopy for cellular ultrastructure assessment. Immunofluorescence was used to detect expression of neural stem cell marker nestin as well as glial markers glial fibrillary acidic protein (GFAP) and S-100. In addition, we measured membrane potentials in bis-(1,3-dibarbituric acid) trimethine oxanol-labeled ADSCs and astrocytes by stimulation with a high potassium solution under an inverted fluorescence microscope. Finally, cell cycle distribution was detected by flow cytometry.

RESULTSTypical astrocyte morphology was shown by HE staining after 48-hour differentiation. Glial fibril was observed with transmission electron microscopy. GFAP and S-100 were not expressed in the control group, but were expressed within 24-hour differentiation and reached a maximum at day 14 with no change up to day 28. Nestin was weakly expressed in control cells and also reached a maximum at day 14 with the percentage of positive cells constant until day 21 followed by a decrease. Differentiated cell membrane potentials after stimulation with potassium were slightly increased, and then gradually declined over time. There was no significant membrane potential change in the control group. Flow cytometry showed that the percentage of cells in G0/G1 phase was 93% and only 5% in S phase.

CONCLUSIONADSCs were differentiated into mature astrocytes with typical characteristics including morphology, ultrastructure, marker protein expression, mature potassium channels and mitotic capacity.

1-Methyl-3-isobutylxanthine ; pharmacology ; Adipose Tissue ; cytology ; Adult ; Astrocytes ; cytology ; Barbiturates ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Electrophysiology ; methods ; Female ; Flow Cytometry ; Glial Fibrillary Acidic Protein ; metabolism ; Humans ; Male ; Membrane Potentials ; drug effects ; Microscopy, Fluorescence ; S100 Proteins ; metabolism ; Stromal Cells ; cytology ; Young Adult

OBJECTIVETo investigate the protective effects of musk extract (ME) and its possible mechanism on rat's cerebral cortical neurons with inflammatory injury induced by lipopolysaccharide (LPS).

METHODSNeurons and astrocytes from newborn rat cerebral cortex were cultured in vitro respectively, and the astrocyte conditioned medium (ACM), obtained by treating astrocytes with 10 mg/L LPS and different concentrations of ME for 24 h, was added in the culture fluid of neurons. The survival rate and apoptotic rate of neurons were measured by MTT method and AO/EB stain; and the changes of inflammatory factors in the ACM were determined by ELISA.

RESULTSThe survival rate (%) of neurons treated by ACM with ME in concentrations of 18 mg/L, 36 mg/L, 72 mg/L and 144 mg/L was 52.55 +/- 3.52, 55.77 +/- 2.36, 64.89 +/- 3.45 and 73.67 +/- 1.80, respectively, significantly higher than that in the model neurons (43.62 +/- 4. 51, P < 0.05), while the apoptotic rate (%) in them, 68.11 +/- 2.16, 44.27 +/- 3.68, 32.56 +/- 2.14 and 21.89 +/- 2.46, respectively, was significantly lower than that in model neurons (71.33 +/- 3.25, P < 0.05 or P < 0.01). Level of IL-6 was decreasing along with the raising of ME concentration in the ACM, showing a concentration-dependent state.

CONCLUSIONME shows apparent protective effect on neurons against inflammatory injury, especially in a high concentration (144 mg/L), which may be associated with the reduction of IL-6 secreted by astrocytes.

Animals ; Animals, Newborn ; Astrocytes ; cytology ; metabolism ; Cell Survival ; drug effects ; Cells, Cultured ; Cerebral Cortex ; cytology ; Fatty Acids, Monounsaturated ; chemistry ; Inflammation ; chemically induced ; prevention & control ; Interleukin-6 ; secretion ; Lipopolysaccharides ; Male ; Materia Medica ; pharmacology ; Neurons ; cytology ; Protective Agents ; pharmacology ; Rats ; Rats, Wistar

The objective of present study is to investigate the effect of human cytomegalovirus (HCMV) infection on human hippocampus neural stem cells NSCs differentiation in vitro, Fetal hippocampus tissue was dissociated mechanically and then cultured in proliferation medium with EGF and bFGF. Immunofluorescence method was used to detect the expression of NSCs marker-Nestin within these cells. Cultured in 10% FBS, NSCs began to differentiate. On the onset of the differentiation, HCMV AD169 (MOI=5) was added into the differentiation medium. After 7 days differentiation, the effect of HCMV infection on NSCs differentiation was observed by detecting the rate of nestin, GFAP and HCMV immediate-early (IE) positive cells with confocal microscopy and immunofluorescence method. The resucts showed most of the cells (passage 4-6 ) were Nestin positive and could differentiate into NSE-positive neurons and GFAP-positive astrocytes. On day 7 postinfection, 86% +/- 12% of infected cells were IE positive. The percentage of Nestin-positive cells was 50% +/- 19% and 93% +/- 10% (t= 6.03, P<0.01)and those of GFAP-positive cells was 81% +/- 11% and 55 +/- 17% (t=3.77, P<0.01) in uninfected and infected cells respectively. These findings indicated that NSCs were HCMV permissive cell and HCMV AD 169 infection suppressed the differentiation of Hippocampus-genetic human neural stem cells into astrocytes.
Astrocytes ; cytology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Cytomegalovirus ; growth & development ; physiology ; Epidermal Growth Factor ; pharmacology ; Fibroblast Growth Factor 2 ; pharmacology ; Hippocampus ; cytology ; Humans ; Intermediate Filament Proteins ; metabolism ; Microscopy, Fluorescence ; Multipotent Stem Cells ; cytology ; drug effects ; metabolism ; virology ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurons ; cytology

OBJECTIVETo investigate whether hypertonic saline (HS) can induce the synthesis and release of glutamate in cultured hypothalamic astrocytes or C6 cell line.

METHODSAstrocytes were isolated, cultured, purified and identified from the hypothalamus of newborn rat (1 day). The astrocytes were randomly divided into five groups: isotonic (IS) and HS groups, astrocytes were incubated by IS and HS (320 mosM NaCl) medium, respectively, for 1, 3, 5, 10 or 15 min; carbenoxolone (CBX)+IS and CBX+HS groups, astrocytes were pre-treated with CBX (100 mmol/L) for 1 h at 37 degrees C in a 5% CO(2) / 95% atmosphere, then removed to IS and HS medium, respectively, for 1, 3, 5, 10 or 15 min; Ca(2+)+HS group, astrocytes were pre-incubated with Ca Ca(2+) (1,000 micromol/L) for 1 h at 37 degrees C in a 5% CO(2) / 95% atmosphere, followed by a wash with isotonic FBS/DMEM, and then removed to hypertonic saline for 1, 3, 5, 10 or 15 min. The media of five groups were collected to analyze the medium glutamate concentration with high performance liquid chromatography. The astrocytes were fixed and double immunofluorescent stained with anti-glial fibrillary acidic protein (GFAP) and anti-glutamate. The C6 cells were divided into four groups: IS, HS, CBX+IS and CBX+HS groups, and used for quantitative measurement of glutamate in cells by flow cytometry (FCM).

RESULTS(1) Anti-GFAP immunofluorescent signal revealed no significant difference among various time points in each group, or among the five groups. (2) The anti-glutamate immunofluorescent signal was increased in HS group and peaked at 5 min, and decreased and returned to the level of IS group at 15 min (P < 0.01 vs the 5 min of HS group). In CBX+HS group, the glutamate intensity was higher than that in CBX+IS and HS groups. (3) The medium glutamate concentration had no change after treatment with HS for 1 and 3 min, while increased markedly after treatment for 5 min to 15 min (P< 0.01 vs 1 min and 3 min). On the contrary, the medium glutamate concentrations in the CBX+HS or Ca(2+)+HS group were significant lower than that in the HS group (P < 0.01). (4) FCM showed HS and CBX+HS induced glutamate increase in C6 cells.

CONCLUSIONHS induced cultured rat hypothalamic astrocytes or C6 cells to synthesize and release glutamate; CBX could block glutamate release, but could not disrupt glutamate synthesis.

Analysis of Variance ; Animals ; Animals, Newborn ; Astrocytes ; drug effects ; metabolism ; Calcium ; pharmacology ; Carbenoxolone ; pharmacology ; Cells, Cultured ; Chromatography, High Pressure Liquid ; methods ; Flow Cytometry ; Gene Expression Regulation ; drug effects ; Glial Fibrillary Acidic Protein ; metabolism ; Glutamic Acid ; metabolism ; Hypothalamus ; cytology ; Rats ; Saline Solution, Hypertonic ; pharmacology ; Time Factors

HIV-1 Tat is considered to be one of key players to facilitate monocyte entry into the CNS, which is characteristic feature of AIDS-related encephalitis and dementia. This study was performed to determine the regulatory function of superoxide dismutase (SOD) on the HIV-1 Tat-induced signaling pathways leading to NF-kappaB activation, expression of adhesion molecules, and monocyte adhesion in CRT-MG human astroglioma cells by using cell-permeable SOD. When cell-permeable SOD was added to the culture medium of CRT-MG cells, it rapidly entered the cells in dose- and time-dependent manners. Treatment of astrocytes with cell-permeable SOD led to decrease in Tat-induced ROS generation as well as NF-kappaB activation. Cell-permeable SOD inhibited the activation of MAP kinases including ERK, JNK and p38 by HIV-1 Tat. Treatment of CRT-MG cells with cell-permeable SOD significantly inhibited protein and mRNA levels of ICAM-1 and VCAM-1 up-regulated by HIV-1 Tat, as measured by Western blot analysis and RT-PCR. Furthermore, enhanced adhesiveness of monocyte to astrocyte by HIV-1 Tat was significantly abrogated by pretreatment with cell-permeable SOD fusion proteins. These data indicate that SOD has a regulatory function for HIV-1 Tat-induced NF-kappaB activation in astrocytes and suggest that cell-permeable SOD can be used as a feasible therapeutic agent for regulation of ROS-related neurological diseases.
Astrocytes/*enzymology ; Cell Adhesion/*physiology ; Cell Membrane Permeability ; Gene Products, tat/*pharmacology ; HIV Infections/metabolism ; HIV-1/*chemistry ; Humans ; Monocytes/cytology/*drug effects ; Signal Transduction ; Superoxide Dismutase/genetics/*physiology