OBJECTIVEAdipose tissue distributes widely in human body. The irradiation response of the adipose cells in vivo remains to be investigated. In this study we investigated irradiation response of adipose-derived stem cells (ASCs) under three-dimensional culture condition.

METHODSASCs were isolated and cultured in low attachment dishes to form three-dimensional (3D) spheres in vitro. The neuronal differentiation potential and stem-liked characteristics was monitored by using immunofluoresence staining and flow cytometry in monolayer and 3D culture. To investigate the irradiation sensitivity of 3D sphere culture, the fraction of colony survival and micronucleus were detected in monolayer and 3D culture. Soft agar assays were performed for measuring malignant transformation for the irradiated monolayer and 3D culture.

RESULTSThe 3D cultured ASCs had higher differentiation potential and an higher stem-like cell percentage. The 3D cultures were more radioresistant after either high linear energy transfer (LET) carbon ion beam or low LET X-ray irradiation compared with the monolayer cell. The ASCs' potential of cellular transformation was lower after irradiation by soft agar assay.

CONCLUSIONThese findings suggest that adipose tissue cell are relatively genomic stable and resistant to genotoxic stress.

Adipose Tissue ; cytology ; radiation effects ; Cell Culture Techniques ; Cell Differentiation ; Flow Cytometry ; Humans ; Neurons ; cytology ; Stem Cells ; cytology ; radiation effects ; X-Rays

OBJECTIVEThe aim of this study is to investigate whether microwave exposure would affect the N-methyl-D-aspartate receptor (NMDAR) signaling pathway to establish whether this plays a role in synaptic plasticity impairment.

METHODS48 male Wistar rats were exposed to 30 mW/cm2 microwave for 10 min every other day for three times. Hippocampal structure was observed through H&E staining and transmission electron microscope. PC12 cells were exposed to 30 mW/cm2 microwave for 5 min and the synapse morphology was visualized with scanning electron microscope and atomic force microscope. The release of amino acid neurotransmitters and calcium influx were detected. The expressions of several key NMDAR signaling molecules were evaluated.

RESULTSMicrowave exposure caused injury in rat hippocampal structure and PC12 cells, especially the structure and quantity of synapses. The ratio of glutamic acid and gamma-aminobutyric acid neurotransmitters was increased and the intracellular calcium level was elevated in PC12 cells. A significant change in NMDAR subunits (NR1, NR2A, and NR2B) and related signaling molecules (Ca2+/calmodulin-dependent kinase II gamma and phosphorylated cAMP-response element binding protein) were examined.

CONCLUSION30 mW/cm2 microwave exposure resulted in alterations of synaptic structure, amino acid neurotransmitter release and calcium influx. NMDAR signaling molecules were closely associated with impaired synaptic plasticity.

Animals ; Gene Expression Regulation ; radiation effects ; Hippocampus ; cytology ; Microwaves ; Neuronal Plasticity ; radiation effects ; Neurons ; radiation effects ; Neurotransmitter Agents ; metabolism ; PC12 Cells ; Rats ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism ; Signal Transduction ; physiology ; radiation effects ; Time Factors

OBJECTIVEIn order to explore effect of electromagnetic radiation on learning and memory ability of hippocampus neuron in rats, the changes in discharge patterns and overall electrical activity of hippocampus neuron after electromagnetic radiation were observed.

METHODSRat neurons discharge was recorded with glass electrode extracellular recording technology and a polygraph respectively. Radiation frequency of electromagnetic wave was 900 MHZ and the power was 10 W/m2. In glass electrode extracellular recording, the rats were separately irradiated for 10, 20, 30, 40, 50 and 60 min, every points repeated 10 times and updated interval of 1h, observing the changes in neuron discharge and spontaneous discharge patterns after electromagnetic radiation. In polygraph recording experiments, irradiation group rats for five days a week, 6 hours per day, repeatedly for 10 weeks, memory electrical changes in control group and irradiation group rats when they were feeding were repeatedly monitored by the implanted electrodes, observing the changes in peak electric digits and the largest amplitude in hippocampal CA1 area, and taking some electromagnetic radiation sampling sequence for correlation analysis.

RESULTS(1) Electromagnetic radiation had an inhibitory role on discharge frequency of the hippocampus CA1 region neurons. After electromagnetic radiation, discharge frequency of the hippocampus CA1 region neurons was reduced, but the changes in scale was not obvious. (2) Electromagnetic radiation might change the spontaneous discharge patterns of hippocampus CA1 region neurons, which made the explosive discharge pattern increased obviously. (3) Peak potential total number within 5 min in irradiation group was significantly reduced, the largest amplitude was less than that of control group. (4) Using mathematical method to make the correlation analysis of the electromagnetic radiation sampling sequence, that of irradiation group was less than that of control group, indicating that there was a tending to be inhibitory connection between neurons in irradiation group after electromagnetic radiation.

CONCLUSIONElectromagnetic radiation may cause structure and function changes of transfer synaptic in global, make hippocampal CA1 area neurons change in the overall discharge characteristic and discharge patterns, thus lead to decrease in the ability of learning and memory.

Animals ; CA1 Region, Hippocampal ; cytology ; radiation effects ; Electromagnetic Radiation ; Male ; Neurons ; physiology ; radiation effects ; Rats ; Rats, Wistar

This in vitro study evaluated the detrimental effect of acute gamma (gamma)-irradiation on rat immature hippocampal neurons. Rat immature hippocampal neurons (0.5 day in vitro) were irradiated with 0~4 Gy gamma-rays. Cytotoxicity was analyzed using a lactate dehydrogenase release assay at 24 h after gamma-irradiation. Radiation-induced cytotoxicity in immature hippocampal neurons increased in a dose-dependent manner. Pre-treatments of pro-apoptotic caspase inhibitors and anti-oxidative substances significantly blocked gamma-irradiation-induced cytotoxicity in immature hippocampal neurons. The results suggest that the caspase-dependent cytotoxicity of gamma-rays in immature hippocampal cultured neurons may be caused by oxidative stress.
Amifostine/pharmacology ; Animals ; Antioxidants/pharmacology ; Caspase 3/metabolism/radiation effects ; Catechin/analogs & derivatives/pharmacology ; Cell Survival/radiation effects ; Cells, Cultured/cytology/enzymology/*radiation effects ; Dose-Response Relationship, Radiation ; Female ; *Gamma Rays ; Hippocampus/cytology/enzymology/*radiation effects ; L-Lactate Dehydrogenase/radiation effects ; Neurons/cytology/enzymology/*radiation effects ; Poly(ADP-ribose) Polymerases/drug effects ; Pregnancy ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo analyze the effects of high-frequency electromagnetic field (HF-EMF, 30 MHz, 0-1600 V/m) on the apoptosis and ultramicrostructure of the hippocamp and demonstrate the cytotoxicity of hippocamp.

METHODS120 Wistar female adult rats were randomly divided into ten groups based on body weight with different levels of 30 MHz electromagnetic field (0, 25, 100, 400, 1600 V/m) for eight hours daily. Five group rats were irradiated for three days. The other five group rats were irradiated for fifty-six days. Weekly the rats were continuously exposed five days. The apoptotic rate of the hippocamp was detected with TUNEL System. Meanwhile, the ultramicrostructure was observed with the transmission electron microscope.

RESULTS(1) There was no significant difference on the apoptotic rate and pathological change of the hippocamp cell between the exposure and the control groups through short term experiment (P > 0.05). (2) The apoptotic rate of the granulocyte on the DG campus of the hippocamp in the 400 V/m group and the 1600 V/m group (0.165% +/- 0.049%, 0.189% +/- 0.049% respectively) were increased significantly (P < 0.01) through inferior chronic experiment compared with the control group (0.052% +/- 0.016%). Along with the increase of radiation dose, the ultramicrostructure of the neuron cell appeared more abnormal cells. Especially there were marked change on the neuron in the 1600 V/m group.

CONCLUSIONSThere is no association between cell apoptotic rate of the hippocamp and short period exposure to HF-EMF (30 MHz, 25-1600 V/m). However inferior chronic exposures to HF-EMF might induce the cytotoxicity, especially in the high dose exposure (1600 V/m) under our experiment.

Animals ; Apoptosis ; radiation effects ; Electromagnetic Fields ; Endocytosis ; radiation effects ; Female ; Hippocampus ; cytology ; pathology ; radiation effects ; Neurons ; pathology ; radiation effects ; Rats ; Rats, Wistar

OBJECTIVETo explore the effect of low doses X-ray on proliferation of hippocampal pyramidal cell in the area of CA1 in prenatal rat and its relevant mechanism.

METHODSA total of 25 pregnant rats were randomly divided into four experimental groups and one control group. The experimental groups, in a duration of consistent 18 days, respectively received different doses as follows: 0.015 mGy/d, 0.03 mGy/d, 0.06 mGy/d and 0.09 mGy/d. The control group received sham radiation. To observe the density and width of hippocampal pyramidal cell in the area of CA1 by HE stained and observe the expression of the ERK1/2 by IHM.

RESULTS(1) Except C group, all other groups presented increment in width of the level of hippocampal pyramidal cell, compared with C group; H group, M group, L1 group and L2 group were higher than that (F value respectively were 8.475, 33.42, 14.395, 44.955; P value respectively were 0.002, 0.048, 0.030, 0.012). But the phenomenon of inhomogeneity in width in H group was observed, at the same time, the density of cell in H group became looser (F = 4.466, P = 0.017). (2) The expression of ERK1/2 in the hippocampus CA1 was seen in cytoplasm of every group, the average optical density of positive ERK1/2 protein significantly increased in L1 group and L2 group, compared with control group respectively (F value respectively were 4.561, 4.103, P value respectively were 0.044, 0.035).

CONCLUSIONLow doses X-ray could promote proliferation of hippocampus CA1 cell in prenatal. The reason could be the increment of the ERK1/2 protein induced by X-ray. When the doses reached 0.09 mGy/d, the excesses proliferation phenomenon was observed.

Animals ; Cell Proliferation ; radiation effects ; Female ; Hippocampus ; cytology ; radiation effects ; Male ; Maternal Exposure ; Neurons ; cytology ; radiation effects ; Pregnancy ; Pyramidal Cells ; cytology ; radiation effects ; Radiation, Ionizing ; Rats ; X-Rays

OBJECTIVETo study the protective effect of ginsenoside Rg1 on cultured rat hippocampal neurons against radiation injury and explore new therapies for preventing radiation encephalopathy.

METHODSRat hippocampal neurons cultured for 12 days were subjected to a single-dose X-ray exposure of 30 Gy. 4',6-diamidino-2-phenylindole (DAPI) staining was used to detect the neuronal apoptosis and NOS activity kit utilized to evaluate NOS activity in the cells after the exposure.

RESULTSNuclear condensation was detected in (25.3-/+3.57)% of the neurons 24 h after 30 Gy X-ray exposure, a rate significantly higher than that in the control cells [(1.95-/+0.78)%, P<0.01]. In the neurons pretreated with ginsenoside Rg1, only (7.43-/+1.51)% of the cells presented with nuclear condensation after the exposure, significantly different from the rates in the control cultures and the exposed cultures (P<0.01). The NOS activity of exposed cultures was 6.46-/+0.95 U/ml, significantly higher than that in the control cultures (3.20-/+0.70 U/ml, P<0.01). The NOS activity of the neurons pretreated with ginsenoside Rg1 was 3.85-/+0.69 U/ml, significantly different from that in the control cultures (P<0.05) and the exposed cultures (P<0.01).

CONCLUSIONGinsenoside Rg1 offers significant protective effect on rat hippocampal neurons from radiation-induced apoptosis by reducing the activity of NOS.

Animals ; Cells, Cultured ; Ginsenosides ; pharmacology ; Hippocampus ; cytology ; drug effects ; radiation effects ; Neurons ; drug effects ; radiation effects ; Neuroprotective Agents ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Radiation Injuries ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the expressions of p35 and p25 and Cdk5 kinase activity in cultured rats hippocampal neurons following X-ray exposure to provide experimental evidence for prevention and treatment of radiation encephalopathy.

METHODSThe hippocampal neurons cultured for 12 days were subjected to a single-dose X-ray exposure of 30 Gy. Western blotting was used to detect the p35 and p25 protein levels, and the effect of pretreatment with roscovitine, a Cdk5 inhibitor, on the apoptosis of the hippocampal neurons following the exposure was examined with 4',6-diamidino-2-phenylindole (DAPI) staining.

RESULTSThe protein level of p35 increased significantly 3.5 and 4 h after the irradiation by 1.51-/+0.13 and 1.45-/+0.14 folds in comparison with the control level, respectively (P<0.01), and the p25 level increased significantly 6 h after irradiation by 1.62-/+0.28 folds (P<0.05). Nuclear condensation occurred in (24.8-/+3.97)% of the neurons 24 h after 30 Gy X-ray exposure, a rate significantly higher than that in the nonexposed cells [(1.82-/+1.08)%, P<0.01) and that in roscovitine-pretreated neurons [(7.74-/+2.27)%, P<0.01).

CONCLUSIONX-ray exposure activates Cdk5 by increasing the p35 and p25 expressions in rat hippocampal neurons, and inhibition of Cdk5 activity with roscovitine can significantly protect the neurons from apoptosis.

Animals ; Animals, Newborn ; Cells, Cultured ; Cyclin-Dependent Kinase 5 ; genetics ; metabolism ; Female ; Hippocampus ; cytology ; metabolism ; radiation effects ; Male ; Neurons ; cytology ; metabolism ; radiation effects ; Phosphotransferases ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo evaluate the effect of neuronal differentiation induced by nerve growth factor (NGF) on the tolerance-dosage of ultraviolet radiation of PC12 Cells.

METHODSNeuron-differentiated PC12 cells and untreated PC12 cells were exposed to different ultraviolet radiation dosage of 10, 30, 60, 80, 100, and 200 mJ/cm2. Cell survival rates were determined by MTT assay.

RESULTSNeuron-differentiated PC12 cells had increased tolerance dose to ultraviolet radiation with noticeable apoptosis at the radiation dose of 100 mJ/cm2 in contrast to 30 mJ/cm2 for normal PC12 cells.

CONCLUSIONNeuronal differentiation exerts the effect of increasing the tolerance dose of PC12 cells to ultraviolet radiation.

Animals ; Cell Differentiation ; Cell Transformation, Neoplastic ; drug effects ; radiation effects ; Dose-Response Relationship, Radiation ; Nerve Growth Factor ; pharmacology ; Neurons ; cytology ; PC12 Cells ; Rats ; Ultraviolet Rays

We investigated the effect of low dose radiation on diabetes induced suppression of neurogenesis in the hippocampal dentate gyrus of rat. After 0.01 Gy, 0.1 Gy, 1 Gy and 10 Gy radiation was delivered, the dentate gyrus of hippocampus of streptozotocin (STZ)-induced diabetic rats were evaluated using immunohistochemistry for 5-bromo-2-deoxyuridine (BrdU), caspase-3, and terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) staining. The number of BrdU positive cells in the non-diabetic rats, diabetic rats without radiation, diabetic rats with 0.01 Gy radiation, diabetic rats with 0.1 Gy radiation, diabetic rats with 1 Gy radiation and diabetic rats with 10 Gy radiation were 55.4+/-8.5/mm2, 33.3+/-6.4/mm2, 67.7+/-10.5/mm2, 66.6+/-10.0/mm2, 23.5+/-6.3/mm2 and 14.3+/-7.2/mm2, respectively. The number of caspase-3 positive cells was 132.6+/-37.4/mm2, 378.6+/-99.1/mm2, 15.0+/-2.8/mm2, 57.1+/-16.9/mm2, 191.8+/-44.8/mm2 and 450.4+/-58.3/mm2, respectively. The number of TUNEL-positive cells was 24.5+/-2.0/mm2, 21.7+/-4.0/mm2, 20.4+/-2.0/mm2, 18.96+/-2.1/mm2, 58.3+/-7.9/mm2, and 106.0+/-9.8/mm2, respectively. These results suggest low doses of radiation paradoxically improved diabetes induced neuronal cell suppression in the hippocampal dentate gyrus of rat.
Rats, Sprague-Dawley ; Rats ; Radiotherapy/methods ; Neurons/*metabolism ; Male ; In Situ Nick-End Labeling ; Hippocampus/*cytology/metabolism/radiation effects ; Diabetes Mellitus, Experimental/radiotherapy ; Dentate Gyrus/drug effects/*radiation effects ; Cell Proliferation ; Caspase 3/metabolism ; Bromodeoxyuridine/pharmacology ; Apoptosis ; Animals