OBJECTIVETo study the effect of progesterone on matrix metalloproteinase-3 (MMP-3) expression in neonatal rat brain after hypoxic-ischemia.

METHODSFollowed the hypoxic-ischemia of neonatal rat brain, Evans blue (EB) staining and transmission electron microscopy were used to detect the blood-brain barrier pathological changes on permeability. MMP-3 protein expression in cerebral cortex was measured with Western blot.

RESULTSTransmission electron microscopy results showed that the blood brain barrier in hypoxic-ischemic group changed significantly compare to progesterone group. EB staining results suggested that the blood-brain barrier permeability of hypoxic-ischemic group was significantly increased compared to sham-operated group (P < 0.01). The blood-brain barrier permeability in progesterone group was also decreased in comparison to that of hypoxic-ischemic group (P < 0.05). Western blot image analysis results indicated that MMP-3 protein expression in the hypoxic-ischemic group increased significantly than that in sham-operated group (P < 0.01), and the progesterone group was decreased significantly than that in hypoxic-ischemic group (P < 0.05).

CONCLUSIONProgesterone may reduce the blood-brain barrier damage by reducing MMP-3 expression. This might be one of the protective mechanisms in the hypoxic-ischemic brain injury.

Animals ; Animals, Newborn ; Blood-Brain Barrier ; physiopathology ; Hypoxia-Ischemia, Brain ; metabolism ; pathology ; physiopathology ; Matrix Metalloproteinase 3 ; metabolism ; Progesterone ; pharmacology ; Rats ; Rats, Sprague-Dawley

Hypoxic-ischemic brain damage (HIBD) is referred to a common type of cerebral damage, which is caused by injury, leading to shallow bleeding in the cortex with intact cerebral pia mater. In recent years, studies show that a various kinds of immune cells and immune cellular factors are involved in the occurrence of HIBD. CC chemokine receptor 2 (CCR2) is a representative of CC chemokine receptor, and is widely distributed in cerebral neuron, astrocyte, and microglial cells, and is the main chemo-tactic factor receptor in brain tissue. CC chemokine ligand 2 (CCL2) is a kind of basophilic protein and the ligand of CCR2, and plays an important role in inflammation. In order to provide evidence for correlational studies in HIBD, this review will introduce the biological characteristics of CCR2 and CCL2, and illustrate the relationship between the immunoreactivity and HIBD.
Animals ; Brain Injuries/pathology* ; Cerebral Cortex/physiopathology* ; Chemokine CCL2/metabolism* ; Chemokines, CC/metabolism* ; Hypoxia-Ischemia, Brain/metabolism* ; Macrophage Inflammatory Proteins/metabolism* ; RNA, Messenger/metabolism* ; Rats ; Rats, Sprague-Dawley ; Receptors, CCR2/metabolism*

OBJECTIVETo study correlation of brain hypoxia of different degrees with brain function and damage.

METHODSThe brain regional oxygen saturation (rSO2) was determined by using a non-invasive near infrared spectroscopy (NIRS) technique in 15 piglets; the piglets were subjected to inhale 3% - 11% oxygen-nitrogen mixed gas through mechanical ventilation for 30 min. The piglets were divided into groups according to the level of brain rSO2 (i.e. < 30%, 30% - 35%, 35% - 40%, and 40% - 50%), and the data were compared with those of the control group (rSO2 > 60%). Changes of brain function were detected through amplitude and frequency of EEG waves and signal complexity. The piglets were sacrificed via decapitation 72 h after brain damage, and then histopathological and ultrastructural examinations were performed on cerebral cortex and hippocampal CA1 area.

RESULTSIn the group with rSO2 > 40%, the mean arterial pressure (MAP) after hypoxia was (56 +/- 0.00) mm Hg (1 mm Hg = 0.133 kPa), the blood lactic acid (LA) was (2.3 +/- 1.2) mmol/L, the EEG findings were within normal range, and there was no change in brain tissue ultrastructure. In the group with brain rSO2 = 30% approximately 40%, the MAP was (73 +/- 8) mm Hg, the LA was (8.2 +/- 3.9) mmol/L, the EEG waves showed decreased amplitude, frequency and complexity, but restored to some extent after hypoxia. The brain tissue ultrastructure showed damages to the cerebral cortex and neuron mitochondria at hippocampal CA1 area. In the group with brain rSO2 < 30%, the MAP was (35 +/- 0) mm Hg, the LA was (12 +/- 2) mmol/L, the EEG showed decreased amplitude, frequency, and complexity of signals compared with those of the normal control group, and was difficult to restore after hypoxia in some of the piglets; the brain tissue ultrastructure appeared to be similar to the changes seen with high-degree swollen cerebral cortex and neuron mitochondria at hippocampal CA1 area.

CONCLUSIONDifferent degrees of hypoxia had different influence on brain function and brain damage. The lower the brain rSO2, the more severe the damages to the brain and its function. The rSO2 of brain tissues detected with noninvasive NIRS can reflect brain injury and its severity during cerebral anoxia.

Animals ; Blood Gas Analysis ; Brain Injuries ; complications ; Cerebral Cortex ; physiopathology ; Cerebrovascular Circulation ; physiology ; Electroencephalography ; Female ; Hypoxia ; metabolism ; pathology ; Hypoxia, Brain ; complications ; Hypoxia-Ischemia, Brain ; physiopathology ; Male ; Neurons ; pathology ; Oximetry ; instrumentation ; Oxygen ; metabolism ; Oxygen Consumption ; Spectroscopy, Near-Infrared ; methods ; Statistics as Topic ; Swine

Brief episodes of cerebral hypoxia-ischemia cause transient ischemic tolerance to subsequent ischemic events that are otherwise lethal. This study was conducted to evaluate the protective effect of hypoxic preconditioning on hypoxic-ischemic injury in the neonatal rat and the persistence of a protective window after hypoxic preconditioning. The rats were preconditioned with hypoxia (8% oxygen, 92% nitrogen) for three hours, subjected to ischemia using ligation of the right common carotid artery, and then exposed to another three hours of hypoxia. Using proton magnetic resonance spectroscopy, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining, and morphologic scores, this study shows that hypoxic preconditioning 6-hr to 1-day before hypoxic-ischemic injury increases survival rates and has neuroprotective effects against subsequent hypoxic-ischemic injury. The mechanism of the protective effects of hypoxic preconditioning in the newborn rat brain may involve downregulation of apoptotic cell death.
Animals ; Animals, Newborn ; Apoptosis ; Aspartic Acid/analogs & derivatives/analysis ; Brain/metabolism/pathology ; Carotid Arteries/surgery ; Creatine/analysis ; Hypoxia-Ischemia, Brain/metabolism/pathology/*physiopathology ; In Situ Nick-End Labeling ; Ischemic Preconditioning/*methods ; Magnetic Resonance Spectroscopy ; Rats ; Rats, Sprague-Dawley ; Survival Rate

A 68-year-old man presented with a three-week history of rapidly progressive dementia, gait ataxia and myoclonus. Subsequent electroencephalography showed periodic sharp wave complexes, and cerebrospinal fluid assay revealed the presence of a 14-3-3 protein. A probable diagnosis of sporadic Creutzfeldt-Jakob disease was made, which was further supported by magnetic resonance (MR) imaging of the brain showing asymmetric signal abnormality in the cerebral cortices and basal ganglia. The aetiology, clinical features, diagnostic criteria, various MR imaging patterns and radiologic differential diagnosis of sporadic Creutzfeldt-Jakob disease are discussed in this article.
Aged ; Brain ; pathology ; Cerebral Cortex ; Cerebrospinal Fluid ; metabolism ; Creutzfeldt-Jakob Syndrome ; diagnostic imaging ; Dementia ; physiopathology ; Diagnosis, Differential ; Diffusion Magnetic Resonance Imaging ; Electroencephalography ; Humans ; Hypoxia-Ischemia, Brain ; diagnostic imaging ; Male ; Prion Diseases ; physiopathology

OBJECTIVETo investigate the effect of physical training on cerebral structure and spatial learning and memory in neonatal rats submitted to hypoxic-ischemic brain damage (HIBD).

METHODSForty-eight 7-day-old Sprague-Dawley rats were randomly divided into three groups: a group that was subjected to left carotid ligation followed by 2 hrs hypoxic stress (HIBD); a group that received physical training 2 weeks after the HIBD event; a control group that was subjected to a sham-operation without ligation and hypoxic stress. Following four weeks physical training, motor function test and water maze tasks were performed. Bilateral brain weight, cerebral morphology and left hippocampal ultrastructrue of the animals were examined. The expression levels of phosphor calmodulin-dependent protein kinase II (CaMKII) and brain derived neurotrophic factor (BDNF) were determined by immunohistochemistry.

RESULTSCompared with the control group, the motor function and the spatial learning and memory ability in the non-trained HIBD group were significantly decreased, whereas there was no significant difference between the trained-HIBD and the control groups. The left hemisphere weight and neurons in the left hippocampal CA1 zone of both HIBD groups decreased and the reduction was more significant in non-trained HIBD group. The ultrastructure of the left hippocampus was remarkably abnormal in the non-trained HIBD group, while no obvious abnormality was observed in the trained HIBD and the control groups. Phosphor-CaMKII and BDNF expression in the left hippocampus in the trained HIBD group increased significantly compared with that in the non-trained HIBD group.

CONCLUSIONSPhysical training can restrain brain damage and ameliorate spatial learning and memory impairments in rats with HIBD.

Animals ; Animals, Newborn ; Brain-Derived Neurotrophic Factor ; metabolism ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; metabolism ; Hypothalamus ; metabolism ; ultrastructure ; Hypoxia-Ischemia, Brain ; pathology ; physiopathology ; psychology ; therapy ; Maze Learning ; Memory ; Phosphorylation ; Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley

OBJECTIVENeonatal hypoxic-ischemic encephalopathy (HIE) harms the lives and health of newborn infants and children severely. Given the absence of effective therapies for HIE, it is important to derive new strategies. Neural stem cells (NSCs) have great potential as a therapeutic tool for the repair of a number of central nervous system disorders that involve cell loss. This study was designed to transplant the neural stem cells derived from human fetal brain (hNSCs) into cerebral ventricle of neonatal rat following hypoxic-ischemic injury and to investigate their survival, migration and differentiation in rat brain.

METHODSCells obtained from the forebrain of a 12-week old fetus were cultured in the presence of epidermal growth factor, basic fibroblast growth factor and leukemia inhibitory factor for 11 days. Animal models were built in 7-day-postnatal Wistar rats, 3-days after hypoxia-ischemia (HI), 5 microl suspension containing 5.0 x 10(5) hNSCs was injected into the left cerebral ventricle of each HIE rat by using stereotactic instrument. No immunosuppression therapy was given to the animals. At 1, 2, 4 weeks and 3 months after transplantation, the rats were sacrificed and brain tissues were harvested and were then examined by H-E staining and immunohistochemical analysis.

RESULTSImplanted cells expressing human nuclear protein (hNP) migrated form the subventricular zone (SVZ) along corpus callosum to the damaged areas, especially to the injured side of cortex and hippocampus. In different areas, the implanted hNSCs differentiated into different cell types which were similar to the host cells. The 85% implanted cells in cortex consisted of hNuc-NF or hNuc-Tublin double positive cells, while in the migratory way, 60% implanted cells differentiated into hNuc-GFAP double positive cells. Compared with the 1-week time point, an increased number of hNP-positive cells were observed at 2-weeks, but the number of these cells greatly decreased at 4-weeks and 3 months.

CONCLUSIONThe implanted hNSCs could extensively survive, migrate in the brain of neonatal rat with HIE and could differentiate into neurons and astrocytes in a regionally specific manner.

Animals ; Animals, Newborn ; Brain ; pathology ; Carotid Artery, Common ; surgery ; Cell Differentiation ; Cell Movement ; Disease Models, Animal ; Fetal Stem Cells ; transplantation ; Humans ; Hypoxia ; complications ; physiopathology ; Hypoxia-Ischemia, Brain ; pathology ; physiopathology ; therapy ; Immunohistochemistry ; Injections, Intraventricular ; methods ; Ligation ; methods ; Neurons ; Nuclear Proteins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Stem Cell Transplantation ; methods ; Survival Analysis ; Time Factors

OBJECTIVETo investigate whether desferoxamine (DFO) preconditioning can induce tolerance against cerebral ischemia and its effect on the expression of hypoxia inducible factor 1alpha (HIF-1alpha) and erythropoietin (EPO) in vivo and in vitro.

METHODSRat model of cerebral ischemia was established by middle cerebral artery occlusion with or without DFO administration. Infarct size was examined by TTC staining, and the neurological severity score was evaluated according to published method. Cortical neurons were cultured under ischemia stress which was mimicked by oxygen-glucose deprivation (OGD), and the neuron damage was assessed by MTT assay. Immunofluorescent staining was employed to detect the expressions of HIF-1alpha and EPO.

RESULTSThe protective effect induced by DFO (decreasing the infarction volume and ameliorating the neurological function) appeared at 2 d after administration of DFO (post-DFO), lasted until 7 d and disappeared at 14 d (P < 0.05); the most effective action was observed at 3 d post-DFO. DFO induced tolerance of cultured neurons against OGD: neuronal viability was increased 23%, 34%, 40%, 48% and 56% at 8 h, 12 h, 24 h, 36 h, and 48 h, respectively, post-DFO (P < 0.05). Immunofluorescent staining found that HIF-1alpha and EPO were upregulated in the neurons of rat brain at 3 d and 7 d post-DFO; increase of HIF-1alpha and EPO appeared in cultured cortex neurons at 36 h and 48 h post-DFO.

CONCLUSIONDFO induced tolerance against focal cerebral ischemia in rats, and exerted protective effect on OGD cultured cortical neurons. DFO significant induced the expression of HIF-1alpha and EPO both in vivo and in vitro. DFO preconditioning can protect against cerebral ischemia, which may be associated with the synthesis of HIF-1alpha and EPO.

Animals ; Brain Ischemia ; drug therapy ; metabolism ; physiopathology ; Cells, Cultured ; Cerebral Infarction ; drug therapy ; metabolism ; physiopathology ; Deferoxamine ; pharmacology ; therapeutic use ; Disease Models, Animal ; Erythropoietin ; metabolism ; Fluorescent Antibody Technique ; Hypoxia-Inducible Factor 1, alpha Subunit ; drug effects ; metabolism ; Hypoxia-Ischemia, Brain ; drug therapy ; metabolism ; physiopathology ; Infarction, Middle Cerebral Artery ; drug therapy ; metabolism ; physiopathology ; Iron ; metabolism ; Ischemic Preconditioning ; methods ; Nerve Degeneration ; drug therapy ; metabolism ; physiopathology ; Neurons ; drug effects ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Siderophores ; pharmacology ; therapeutic use ; Time Factors ; Treatment Outcome ; Up-Regulation ; drug effects ; physiology

OBJECTIVETo investigate the protective effects of Huperzine A, a potent acetylcholinesterase inhibitor, against the hypoxic ischemic brain damage (HIBD) of the cognitive and morphology in the neonatal rats.

METHODSPostnatal 7 days old rats were given vehicle or Huperzine A (0.05 mg/kg or 0.1 mg/kg, i.p.) following HIBD (unilateral carotid artery ligation followed by hypoxia) or sham operation, and then tested the learning ability and memory in the Morris water maze (MWM) from 36 to 40 postnatal days. The performance in MWM (escape latency, probe time) were recorded to evaluate the learning and memory dysfunction. At the end of MWM trials, the rats were decapitated and their brains were histologically analyzed. The tissue loss in different brain regions including striatum, cortex, and hippocampus were analyzed by image analysis system. The CA(1) subfield neurons numbers were counted to evaluate the brain damage. The acetylcholinesterase histochemistry staining was used to determine the activity of acetylcholinesterase in different brain regions.

RESULTSCompared with sham-operated group, HIBD rats with the vehicle treatment displayed significant tissue losses in the hippocampus (including CA(1) neurons), cortex, and striatum, as well as severe spatial memory deficits (escape latency: 44 s vs 30 s, P < 0.05, probe time: 14 s vs 40 s, P < 0.01). Huperzine A treatment (0.1 mg/kg) resulted in significant protection against both HI-induced brain tissue losses and spatial memory impairments (mean escape latency: 34 s vs 44 s, P < 0.05, probe time: 35 s vs 14 s,P < 0.01). However, Huperzine A treatment (0.05 mg/kg) did not show any significant improvement of spatial memory impairments (mean escape latency: 45 s vs 44 s, P > 0.05, probe time: 17 s vs 14 s, P > 0.05), but moderate to severe brain tissue losses. There was a pronounced reduction of CA(1) neuron density in ipsilateral hemisphere of vehicle-treated group and 0.05 mg/kg Huperzine A group compared with contralateral hemisphere or ipsilateral hemisphere of sham-operated group and 0.1 mg/kg Huperzine A group (72 vs 232, P < 0.01, 72 vs 229, P < 0.01, respectively). There was a close linear correlation between the CA(1) neurons cell number and the mean escape latency for 5 d acquisition trials (r = 0.777, P < 0.01).

CONCLUSIONThe unilateral HI brain injury in a neonatal rat model was associated with cognitive deficits, and that Huperzine A treatment may be protective against both brain injury and spatial memory impairment. Huperzine A showed a therapeutic potential for the treatment of hypoxic-ischemic encephalopathy (HIE) caused by the perinatal asphyxia.

Acetylcholinesterase ; metabolism ; Alkaloids ; Animals ; Animals, Newborn ; Cerebral Cortex ; drug effects ; enzymology ; pathology ; Cognition Disorders ; drug therapy ; physiopathology ; Corpus Striatum ; drug effects ; enzymology ; pathology ; Female ; Hippocampus ; drug effects ; enzymology ; pathology ; Hypoxia-Ischemia, Brain ; drug therapy ; Male ; Maze Learning ; drug effects ; Neuroprotective Agents ; administration & dosage ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sesquiterpenes ; administration & dosage ; therapeutic use ; Treatment Outcome