To assess the neurotoxic effects and redox responses of Aroclor 1254 (A1254) on perinatally exposed rat offspring, A1254 was administered by gavage from gestational day (GD) 6 to postnatal day (PND) 21. Neurobehavioral development, antioxidant enzyme activities, lipid peroxidation (LPO), nitric oxide (NO), and NO synthase (NOS) levels were analyzed in the offspring. Neurobehavioral development analysis revealed delayed appearance of the righting reflex, negative geotaxis, and cliff drop test responses in A1254 exposed group. Developmental A1254 exposure also caused oxidative stress in the brain of PND 22 offspring via reductions in the activity of SOD and GSH-Px, and by promoting a rise in the levels of NO and NOS.
Aging ; metabolism ; Animals ; Cerebral Cortex ; drug effects ; enzymology ; metabolism ; Chlorodiphenyl (54% Chlorine) ; toxicity ; Female ; Glutathione Peroxidase ; metabolism ; Kidney ; drug effects ; enzymology ; metabolism ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; enzymology ; metabolism ; Mice ; Nervous System ; drug effects ; growth & development ; metabolism ; physiopathology ; Nervous System Diseases ; chemically induced ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Oxidative Stress ; drug effects ; Pregnancy ; Prenatal Exposure Delayed Effects ; chemically induced ; Random Allocation ; Rats ; Superoxide Dismutase ; metabolism

OBJECTIVETo investigate the protective effects of insulin-like growth factor-1 (IGF-1) on the nerve cells of neonatal rats under oxidative stress.

METHODSPrimary cortical neurons, oligodendrocytes, and astrocytes from newborn rats were cultured. An oxidative stress model was established with different concentrations of H2O2 (0-60 μmol/L); the degree of damage of nerve cells was evaluated by lactate dehydrogenase assay, and the viability of nerve cells was tested by MTT assay. An oxidative stress model was established with different concentration of H2O2 (0-80 μmol/L). Expression of Akt/p-Akt (Ser473) in neurons was measured by Western blot before and after IGF-1 (25 ng/mL) administration.

RESULTSCompared with those not treated with H2O2, the cortical neurons, oligodendrocytes, and astrocytes treated with different concentrations of H2O2 for 24 hours showed increased damage and decreased cell viability; compared with oligodendrocytes and astrocytes, neurons showed significantly more changes (P<0.01). Compared with those not treated with H2O2, the cortical neurons treated with different concentrations of H2O2 for 5 minutes showed a significant decrease in p-Akt (Ser473) level (P<0.01), which was dependent on the concentration of H2O2. For the neurons treated with low-concentration H2O2, the addition of IGF-1 could reverse the inhibition of Akt phosphorylation, eliminating the difference in p-Akt level compared with the neurons not treated with H2O2, (P>0.05); however, it had no significant effect on the inhibition of Akt phosphorylation by high-concentration H2O2, and the treated neurons still had a lower p-Akt level than untreated neurons (P<0.01 for all). For the cortical neurons that had been treated with different concentration of H2O2 for 1 hour, the addition of IGF-1 (25 ng/mL) could eliminate thedifference in p-Akt level between the treated neurons and untreated neurons (P>0.05).

CONCLUSIONSCortical neurons are more sensitive to oxidative stress induced by H2O2 than other nerve cells. IGF-1 has protective effects on cortical nerve cells under oxidative stress.

Animals ; Animals, Newborn ; Cerebral Cortex ; cytology ; drug effects ; Hydrogen Peroxide ; pharmacology ; Insulin-Like Growth Factor I ; pharmacology ; Neurons ; drug effects ; metabolism ; Oxidative Stress ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Reactive Oxygen Species ; metabolism

The present paper is aimedto investigate the effect of basic fibroblast growth factor (bFGF) on proliferation, migration and differentiation of endogenous neural stem cell in rat cerebral cortex with global brain ischemia-reperfusion. A global brain ischemia-reperfusion model was established. Immunohistochemistry was used to observe the pathological changes and the expression of BrdU and Nestin in cerebral cortex. RT-PCR was used to measure the NSE mRNA in brain tissue. The results of measurements indicated that in sham operation group, there was no positive cell in cerebral cortex, and the content of NSE mRNA did not change. In the operation group, the expression of BrdU and Nestin increased significantly at the end of the 3rd day, and peaked on the 7th day. NSE mRNA expression did not significantly increase. In bFGF group, compared with sham operation group and model group, the number of BrdU-positive and Nestin-positive cells increased significantly at each time point (P<0. 05), and peaked at the end of the 11th day, and the content of NSE mRNA increased significantly (P<0. 05). This research demonstrated that the proliferation of endogenous neural stem cells in situ could be induced by global cerebral ischemia and reperfu- sion, and could be promoted and extended by bFGF. In additiion, bFGF might promote endogenous neural stem cells differentiated into neurons.
Animals ; Brain Ischemia ; pathology ; Cell Differentiation ; Cell Movement ; Cell Proliferation ; Cerebral Cortex ; cytology ; metabolism ; pathology ; Fibroblast Growth Factor 2 ; pharmacology ; Nestin ; metabolism ; Neural Stem Cells ; drug effects ; Rats ; Reperfusion Injury

Hypoxia is one of the major causes of neonatal mortality. Hypoxia-induced tissue injuries are resulted from complex mechanisms such as DNA damage and apoptosis. In this study, we aimed to elucidate the changes in the expression of DNA repairing enzymes such as 8-hydroxyguanine glycosylase 1 (OGG1) and apurinic/apyrimidinic endonuclease 1 (APE1) and brain derived neurotrophic factor (BDNF) in the fetal cerebral tissue after intrauterine hypoxic injury. For this study, pregnant Sprague-Dawley rats were exposed to hypoxic gas (10% O2, 5% CO2, 85% N2) for 2 or 4 hours at postconception day 14.5 and 15.5. After 24 hours, the animals were anesthetized with ethyl ether and fetuses were obtained by laparatomy. Hematoxylin-eosin stain, immunohistochemical stain, and western blot were employed for analysis. The caspase-3 immunolabeled cells were significantly increased within the cerebral cortex after hypoxic injury. The expressions of OGG1, APE1, and BDNF were also increased in the cerebral tissue after hypoxic injury at post-conception day 14.5, in a dose-dependent manner. However, the expression of BDNF was significantly decreased in the cortical tissue exposed to hypoxic injury at postconception day 15.5. These results demonstrate that fetal hypoxic injury induces apoptosis of the nerve cells and promotes the expressions of the DNA repairing enzymes and neurotrophic factors. In addition, these results suggest that protection mechanisms against hypoxic injury alter along the progression of the fetal development.
Animals ; Anoxia ; Apoptosis ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; Caspase 3 ; Cerebral Cortex ; DNA ; DNA Damage ; DNA Repair ; Ether, Ethyl ; Fetal Development ; Fetus ; Guanine ; Humans ; Infant ; Infant Mortality ; Nerve Growth Factors ; Neurons ; Rats ; Rats, Sprague-Dawley

It is well known that differentiation and growth of central nervous system are accomplished through relatively early stages of development. The formation of neural synapse indicates beginning of electrical signaling between neurons, so that may be a critical step in the differentiation of neurons as well as the development and growth of central nervous system. The purpose of this study was to investigate the differential expression levels and patterns of synaptic marker (synaptophysin) between superficial and deep layers of cerebral cortex according to the developmental stages. We introduced immunofluorescence staining of synaptophysin combined with densitometric analysis for the morphological quantification. The intensities of synaptophysin immuno-reactivities in deep layers of cerebral cortices were significantly higher compared to superficial layers in cerebral cortices of embryonic and neonatal mice. The significant increase of synaptophysin expression in the deep layer of cerebral cortex was mainly confined to the embryonic stage. As the expression of synaptophysin gradually decrease thereafter, the difference of expression level between superficial and deep layers could not find in the adult mice. From this study, we could confirm indirectly through synaptophysin that synaptogenic activities in the deep layer of cerebral cortex shows unique pattern especially during the early stages of brain development. Results from this study will be helpful for understanding different patterns of synaptogenesis among the various regions of developing brain.
Adult ; Animals ; Brain ; Central Nervous System ; Cerebral Cortex ; Fluorescent Antibody Technique ; Growth and Development ; Humans ; Mice ; Neurons ; Synapses ; Synaptophysin

It is well known that differentiation and growth of central nervous system are accomplished through relatively early stages of development. The formation of neural synapse indicates beginning of electrical signaling between neurons, so that may be a critical step in the differentiation of neurons as well as the development and growth of central nervous system. The purpose of this study was to investigate the differential expression levels and patterns of synaptic marker (synaptophysin) between superficial and deep layers of cerebral cortex according to the developmental stages. We introduced immunofluorescence staining of synaptophysin combined with densitometric analysis for the morphological quantification. The intensities of synaptophysin immuno-reactivities in deep layers of cerebral cortices were significantly higher compared to superficial layers in cerebral cortices of embryonic and neonatal mice. The significant increase of synaptophysin expression in the deep layer of cerebral cortex was mainly confined to the embryonic stage. As the expression of synaptophysin gradually decrease thereafter, the difference of expression level between superficial and deep layers could not find in the adult mice. From this study, we could confirm indirectly through synaptophysin that synaptogenic activities in the deep layer of cerebral cortex shows unique pattern especially during the early stages of brain development. Results from this study will be helpful for understanding different patterns of synaptogenesis among the various regions of developing brain.
Adult ; Animals ; Brain ; Central Nervous System ; Cerebral Cortex ; Fluorescent Antibody Technique ; Growth and Development ; Humans ; Mice ; Neurons ; Synapses ; Synaptophysin

This paper is to report the study of the pharmacokinetics of a fusion protein TAT-haFGF(14-154) for human acidic fibroblast growth factor and transcriptional activator protein in rat plasma, and the investigation of their penetration across blood-brain barrier in mice and rats, in order to provide a basis for clinical development and treatment of Alzheimer's disease. Enzyme-linked immunosorbent assay (ELISA) was used to determine concentration of TAT-haFGF(14-154) in rat plasma and in mouse brain homogenate; and immunohistochemistry was used to analyze the distribution in brain. The concentration-time curve fitted two-compartment open model which was linear kinetics elimination after a single intravenous injection of TAT-haFGF(14-154) in rat at the dose of 300 microg x kg(-1). The half life time was 0.049 +/- 0.03 h for distribution phase and 0.55 +/- 0.05 h for elimination phase, and the weight was 1/C2. The result showed that TAT-haFGF(14-154) could be detected in the brain by ELISA and immunohistochemistry, the elimination of TAT-haFGF(14-154) in rat was swift, and TAT-haFGF(14-154) could penetrate across the blood-brain barrier, distribute in pallium and hippocampus and locate in the nucleus.
Animals ; Blood-Brain Barrier ; metabolism ; Brain ; metabolism ; Cell Nucleus ; metabolism ; Cerebral Cortex ; metabolism ; Female ; Fibroblast Growth Factor 1 ; administration & dosage ; pharmacokinetics ; Gene Products, tat ; administration & dosage ; pharmacokinetics ; Hippocampus ; metabolism ; Injections, Intravenous ; Male ; Mice ; Rats ; Rats, Sprague-Dawley ; Recombinant Fusion Proteins ; administration & dosage ; pharmacokinetics

OBJECTIVETo investigate the protective effects of putative AGEs (advanced glycation endproducts) inhibitor salidroside against aging in an accelerated mouse aging model induced by D-galactose.

METHODSA group of 5-month-old C57BL/6J mice were treated daily with D-galactose, D-galactose combined with salidroside, salidroside alone, and control buffer for 8 weeks. At the end of the treatment, serum AGEs levels, neurological activities, expression of glial fibrillary acidic protein (GFAP) and neurotrophin-3 (NT-3) in the cerebral cortex, as well as lymphocyte proliferation and IL-2 production were determined.

RESULTSD-galactose induced mouse aging model was developed as described before. As expected, salidroside blocked D-galactose induced increase of serum AGEs levels. It also reversed D-galactose induced aging effects in neural and immune system, as evidenced by improving motor activity, increasing memory latency time, and enhancing lymphocyte mitogenesis and interleukin-2 (IL-2) production. Furthermore, elevated expression of GFAP and NT-3 in the aged model mice was also reduced upon salidroside treatment.

CONCLUSIONSalidroside inhibits AGEs formation in vivo, which at least partially contributes to its anti-aging effect in D-galactose induced aging model.

Aging, Premature ; blood ; chemically induced ; prevention & control ; Animals ; Cerebral Cortex ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Galactose ; Glial Fibrillary Acidic Protein ; Glucosides ; pharmacology ; therapeutic use ; Glycation End Products, Advanced ; blood ; Interleukin-2 ; metabolism ; Memory ; drug effects ; Mice ; Mice, Inbred C57BL ; Motor Activity ; drug effects ; Nerve Growth Factors ; metabolism ; Nerve Tissue Proteins ; metabolism ; Phenols ; pharmacology ; therapeutic use ; Spleen ; drug effects ; immunology ; T-Lymphocytes ; drug effects

OBJECTIVE: To study the changes of expression of relevant factors in rat brain after concussion injury and to provide scientific basis for forensic estimation of brain injury interval. METHODS: Brain tissues were sampled from the established SD rat animal model of brain concussion, routinely processed and stained with HE and immunohistochemically stained with antibodies directed against heat shock protein 70 (HSP70), transforming growth factor beta 1 (TGF-beta1) and basic fibroblast growth factor (bFGF). The sections were examined under light microscope with IMAGE analytical system and homologous statistical analysis. RESULTS: The expression of HSP 70 was observed in 30 minutes after brain injury. The amount of neurons expressing HSP 70 increased gradually, reached its peak at 12 hours and then declined at 24 hours after brain injury. The expression of bFGF was observed 3 hours after injury in brain stem, reached its peak at 12 hours, and then declined. The expression of TGF-beta1 was detected 6-24 hours after brain injury, remained at its peak up to 3 days. CONCLUSION Brain injury can induce a chronological expression of HSP70, bFGF and TGF-beta1. The results can be a potential for estimating the age of brain injury using several markers.
Animals ; Brain/pathology* ; Brain Concussion/pathology* ; Cerebral Cortex/pathology* ; Disease Models, Animal ; Fibroblast Growth Factor 2/metabolism* ; HSP70 Heat-Shock Proteins/metabolism* ; Hippocampus/pathology* ; Immunohistochemistry ; Male ; Neurons/metabolism* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Staining and Labeling ; Time Factors ; Transforming Growth Factor beta1/metabolism*

OBJECTIVE: To study the alteration of basic fibroblast growth factor (bFGB) expression in astrocytes in vitro after mechanical injury and to understand the repair mechanism of brain injury. METHODS: Astrocytes were isolated from cerebral cortex of SD rats born in 24 hours, and then cultured and purified. The cultured astrocytes were randomly divided into control group and injury groups that were subjected to mechanical injury at 30 min, 1h, 3h, 6h, 12h, 24h, 3d, and 7d. The levels of bFGF expression in the astrocytes after injury were detected by ABC immunohistochemistry. RESULTS: More than 95% of the cultured cells were astrocytes. The levels of bFGF expression werevery low in the control group. On the other hand, increased levels of bFGF expression could be observed at 1-3h after injury. The expression levels increased significantly at 6-12h, reached peak level at 24h, remained at the high level up to 3 days, and the decreased gradually. CONCLUSION The changes of bFGF expression levels in cultured astrocytes in vitro after mechanical injury are similar to that observed in vivo experimental model, both of which show time-dependant characteristic, with only slightly earlier expression of bFGF observed in vitro. Thus, the expression of bFGF after injury can be one of evidences for estimation of brain injury intervals. the cell injury model in vitro may have superiority in the study of the molecule mechanism of tissue and cell injury.
Animals ; Astrocytes/metabolism* ; Cells, Cultured ; Cerebral Cortex/cytology* ; Fibroblast Growth Factor 2/metabolism* ; Forensic Pathology ; Immunohistochemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Staining and Labeling ; Time Factors ; Wounds and Injuries