Time course changes of estrogen receptor α expression in the adult rat hippocampus after kainic acid-induced status epilepticus

Although estrogens possess neuroprotective and epileptogenic properties, the expression pattern of the estrogen receptor (ER) following status epilepticus (SE) remains unclear. We therefore examined the expression pattern of ER in the adult rat hippocampus after SE. SE was induced in rats by kainic acid (KA; 12 mg/kg, i.p.). ER expression was assessed by immunostaining and Western blotting at various times (24 h, and 7, 14, and 21 days) after SE onset. Immunohistochemistry disclosed ER expression in the CA1 and CA3 pyramidal cells of control rats, whereas, after SE, ER-immunoreactive neurons decreased in number due to neuronal death in the CA1 from days 7 to 21. On the other hand, ER-immunoreactive cells with astrocytic morphology were observed in the CA1 beginning on day 7 after SE. This immunoreactivity increased in proportion to the hypertrophy of astrocytes up to day 21. Western blotting revealed a significant decrease in ER expression on day 7 after SE in comparison with control level. However, ER expression on days 14 and 21 were similar when comparing KA-treated and control rats. These results indicate that reactive astrocytes are important sites of estrogen action in the hippocampal CA1 after SE.     

Ketogenic diet-induced peroxisome proliferator-activated receptor-γ activation decreases neuroinflammation in the mouse hippocampus after kainic acid-induced seizures

Similar to fasting, the ketogenic diet (KD) has anti-inflammatory effects and protects against excitotoxicity-mediated neuronal cell death. Recent studies have shown that peroxisome proliferator-activated receptor (PPAR)γ has anti-inflammatory effects in seizure animal models. However, the exact mechanisms underlying the anti-inflammatory effects of the KD have not been determined for seizures. Here we investigated the effect of the KD and acetoacetate (AA) on neuroinflammation in a seizure animal model and glutamate-treated HT22 cells, respectively. Mice were fed the KD for 4 weeks and sacrificed 2 or 6 h after KA injection. The KD reduced hippocampal tumor necrosis factor alpha (TNF-α) levels and nuclear factor (NF)-κB translocation into the nucleus 2 h after KA treatment. KD-induced PPARγ activation was decreased by KA in neurons as assessed by western blotting and immunofluorescence. Finally, the KD inhibited cyclooxygenase (COX)-2 and microsomal prostaglandin E₂ synthase-1 (mPGES-1) expression in the hippocampus 6 h after KA treatment. AA treatment also protected against glutamate-induced cell death in HT22 cells by reducing TNF-α and PPARγ-mediated COX-2 expression. Thus, the KD may inhibit neuroinflammation by suppressing a COX-2-dependent pathway via activation of PPARγ by the KD or AA.     

Characterization of the expression of macrophage inflammatory protein-1α (MIP-1α) and C-C chemokine receptor 5 (CCR5) after kainic acid-induced status epilepticus (SE) in juvenile rats

X. B. Zhu, Y. B. Wang, O. Chen, D. Q. Zhang, Z. H. Zhang, A. H. Cao, S. Y. Huang and R. P. Sun (2012) Neuropathology and Applied Neurobiology 38, 602–616 Characterization of the expression of macrophage inflammatory protein‐1α (MIP‐1α) and C‐C chemokine receptor 5 (CCR5) after kainic acid‐induced status epilepticus (SE) in juvenile rats Aims: To identify the potential role of macrophage inflammatory protein‐1α (MIP‐1α) with its C‐C chemokine receptor 5 (CCR5) in epileptogenic brain injury, we examined their expression in juvenile rat hippocampus and explored the potential link between MIP‐1α, CCR5 and neuropathological alterations after status epilepticus (SE) induced by intracerebroventricular (i.c.v.) kainic acid (KA) injection. Methods: Based on the determination of the development of spontaneous seizures initiated by SE in developing rat brain, we firstly examined hippocampal neurone damage through Nissl and Fluoro‐Jade B staining, and evaluated microglial reaction during the early phase following KA‐induced SE in 21‐day‐old rats. MIP‐1α and CCR5 protein were quantified by ELISA and Western blot respectively following mRNA by real‐time PCR. We also mapped MIP‐1α and CCR5 expression in the hippocampus by immunohistochemistry and identified their cellular sources using double‐labelling immunofluorescence. Results: In juvenile rats, KA caused characteristic neurone damage in the hippocampal subfields, with accompanying microglial accumulation. In parallel with mRNA expression, MIP‐1α protein in hippocampus was transiently increased after KA treatment, and peaked from 16 to 72 h. Double‐labelling immunofluorescence revealed that MIP‐1α was localized to microglia. Up‐regulated CCR5 remained prominent at 24 and 72 h and was mainly localized to activated microglia. Further immunohistochemistry revealed that MIP‐1α and CCR5 expression were closely consistent with microglial accumulation in corresponding hippocampal subfields undergoing degenerative changes. Conclusions: Our data indicated that MIP‐1α as a regulator, linking with the CCR5 receptor, may be involved within the early stages of the epileptogenic process following SE by i.c.v. KA injection.     

Changes of K+–Cl− cotransporter 2 (KCC2) and circuit activity in propofol-induced impairment of long-term potentiation in rat hippocampal slices

Enhancing inhibition via gamma-aminobutyric acid type A (GABA_A) receptors contributes to anesthetic-induced impairment of long-term potentiation (LTP) of excitatory synaptic transmission, which may account for general anesthesia-associated memory impairment (amnesia). The neuron-specific K⁺–Cl⁻ cotransporter 2 (KCC2) is necessary for fast synaptic inhibition via maintaining the low intracellular chloride concentration required for the hyperpolarizing actions of GABA via GABA_A receptors. To explore a possible role of KCC2-dependent inhibition in anesthetic-induced impairment of LTP, we used field excitatory postsynaptic potentials (fEPSP) recording and immunoblotting to study the effect of propofol on LTP maintenance and KCC2 expression in CA1 region of rat hippocampal slices. We found that propofol (30 μM) not only impaired LTP expression but also prevented LTP-accompanied downregulation of KCC2 without affecting the basal transmission of glutamatergic synapses. Moreover, the recurrent inhibition in hippocampal slices was enhanced by propofol. These propofol-induced effects were completely abolished by picrotoxin, a specific GABA_A receptor-chloride channel blocker. Thus, enhancement of GABAergic inhibition and suppression of neuronal excitability may account for the sustained expression of KCC2 and the impairment of LTP by propofol. Together, this study supports a novel role for KCC2 in LTP expression and gives hints to a molecular mechanism, by which anesthetics might cause impairment of LTP.     

Dynamic expression of Slit1–3 and Robo1–2 in the mouse peripheral nervous system after injury

The Slit family of axon guidance cues act as repulsive molecules for precise axon pathfinding and neuronal migration during nervous system development through interactions with specific Robo receptors.Although we previously reported that Slit1–3 and their receptors Robo1 and Robo2 are highly expressed in the adult mouse peripheral nervous system,how this expression changes after injury has not been well studied.Herein,we constructed a peripheral nerve injury mouse model by transecting the right sciatic nerve.At 14 days after injury,quantitative real-time polymerase chain reaction was used to detect mRNA expression of Slit1–3 and Robo1–2 in L4–5 spinal cord and dorsal root ganglia,as well as the sciatic nerve.Immunohistochemical analysis was performed to examine Slit1–3,Robo1–2,neurofilament heavy chain,F4/80,and vimentin in L4–5 spinal cord,L4 dorsal root ganglia,and the sciatic nerve.Co-expression of Slit1–3 and Robo1–2 in L4 dorsal root ganglia was detected by in situ hybridization.In addition,Slit1–3 and Robo1–2 protein expression in L4–5 spinal cord,L4 dorsal root ganglia,and sciatic nerve were detected by western blot assay.The results showed no significant changes of Slit1–3 or Robo1–2 mRNA expression in the spinal cord within 14 days after injury.In the dorsal root ganglion,Slit1–3 and Robo1–2 mRNA expression were initially downregulated within 4 days after injury;however,Robo1–2 mRNA expression returned to the control level,while Slit1–3 mRNA expression remained upregulated during regeneration from 4–14 days after injury.In the sciatic nerve,Slit1–3 and their receptors Robo1–2 were all expressed in the proximal nerve stump;however,Slit1,Slit2,and Robo2 were barely detectable in the nerve bridge and distal nerve stump within 14 days after injury.Slit3 was highly ex-pressed in macrophages surrounding the nerve bridge and slightly downregulated in the distal nerve stump within 14 days after injury.Robo1 was upregulated in vimentin-positive cells and migrating Schwann cells inside the nerve bridge.Robo1 was also upregulated in Schwann cells of the distal nerve stump within 14 days after injury.Our findings indicate that Slit3 is the major ligand expressed in the nerve bridge and distal nerve stump during peripheral nerve regeneration,and Slit3/Robo signaling could play a key role in peripheral nerve repair after injury.This study was approved by Plymouth University Animal Welfare Ethical Review Board (approval No.30/3203) on April 12,2014.     

Transient magnetic resonance diffusion abnormalities in West syndrome: the radiological expression of non‐convulsive status epilepticus?

The purpose of this study was to report patients with pharmacoresistant West syndrome of unknown cause whose magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI) showed a transient decrease of diffusion in subcortical structures. Of 20 patients investigated over a 2-year period, three males and three females constitute the present series. They had daily clusters of infantile spasms with hypsarrhythmia for 4 to 24 months before the first investigation. Four were severely hypotonic. All aetiological studies involving intermediary metabolism, peroxysomes, mitochondria, and neurotransmitters in cerebrospinal fluid were negative. Patients underwent DWI when first examined at the mean age of 13 months, and on follow-up examination 6 to 18 months later. Diffusion was decreased in the pallidi and posterior brainstem. It was also decreased for five patients in thalami and for three in dentate nuclei. Repeat MRI, performed when spasms were still present but hypsarrhythmia had ceased, did not show the same abnormalities. Because of recruitment bias, this series probably overestimates the true incidence of such DWI abnormalities. The eventuality of toxic lesions, including some inborn error of metabolism or drug toxicity, is considered unlikely although it could not be excluded. The contribution of the epileptic encephalopathy itself appears the most likely course.     

Effect of lidocaine on retinal aquaporin-4 expression after ischemia/reperfusion injury in the rat★

BACKGROUND: Several studies have demonstrated that high doses of lidocaine can reduce edema in rats with brain injury by down-regulating aquaporin-4 (AQP4) expression. The hypothesis for the present study is that lidocaine could retinal edema that is associated with AQP4 expression. OBJECTIVE: This study was designed to investigate the interventional effects of lidocaine on retinal AQP4 expression and retinal edema following ischemia/reperfusion injury in the rat. DESIGN, TIME AND SETTING: This study, a randomized, controlled, animal experiment, was performed at the Basic Research Institute, Chongqing Medical University from September 2006 to May 2007. MATERIALS: Seventy-five, healthy, adult, female, Sprague-Dawley rats were included. A total of 50 rats were used to establish a retinal ischemia/reperfusion injury model using an anterior chamber enhancing perfusion unit. Rabbit anti-rat AQP4 antibody was purchased from Santa Cruz Biotechnology, USA. METHODS: All 75 rats were randomly divided into three groups, with 25 rats in each: control, model, and lidocaine. At each time point (1, 6, 12, 24, and 48 hours after modeling, five rats for each time point), each rat in the lidocaine group was intraperitoneally administered lidocaine with an initial dose of 30 mg/kg, followed by subsequent doses of 15 mg/kg every six hours. The entire treatment process lasted three days for each rat. At each above-mentioned time point, rats in the model group were modeled, but not administered any substances. Rats in the control group received the same treatments as in the lidocaine group except that lidocaine was replaceld by physiological saline. MAIN OUTCOME MEASURES: Following hematoxylin-eosin staining, rat retinal tissue was observed to investigate retinal edema degree through the use of an optical microscope and transmission electron microscope. Retinal AQP4 expression was determined by immunohistochemistry. RESULTS: At each above-mentioned time point, AQP4 expression was significantly increased in the model group compared to the control group (P < 0.05); this change was consistent with the degree of retinal edema. In the lidocaine group, retinal AQP4 expression was significantly decreased (P < 0.05), and retinal edema was reduced, compared with the model group. CONCLUSION: Lidocaine inhibits rat retinal AQP4 expression following ischemia/reperfusion injury, leading to a reduction of retinal edema. Key Words: ischemia/reperfusion; lidocaine; aquaporin-4     

Effect of lidocaine on retinal aquaporin-4 expression after ischemia/reperfusion injury in the rat★

BACKGROUND: Several studies have demonstrated that high doses of lidocaine can reduce edema in rats with brain injury by down-regulating aquaporin-4 (AQP4) expression. The hypothesis for the present study is that lidocaine could retinal edema that is associated with AQP4 expression.OBJECTIVE: This study was designed to investigate the interventional effects of lidocaine on retinal AQP4 expression and retinal edema following ischemia/reperfusion injury in the rat.DESIGN, TIME AND SETTING: This study, a randomized, controlled, animal experiment, was performed at the Basic Research Institute, Chongqing Medical University from September 2006 to May 2007.MATERIALS: Seventy-five, healthy, adult, female, Sprague-Dawley rats were included. A total of 50 rats were used to establish a retinal ischemia/reperfusion injury model using an anterior chamber enhancing perfusion unit. Rabbit anti-rat AQP4 antibody was purchased from Santa Cruz Biotechnology, USA.METHODS: All 75 rats were randomly divided into three groups, with 25 rats in each: control, model, and lidocaine. At each time point (1, 6, 12, 24, and 48 hours after modeling, five rats for each time point), each rat in the lidocaine group was intraperitoneally administered lidocaine with an initial dose of 30 mg/kg, followed by subsequent doses of 15 mg/kg every six hours. The entire treatment process lasted three days for each rat. At each above-mentioned time point, rats in the model group were modeled, but not administered any substances. Rats in the control group received the same treatments as in the lidocaine group except that lidocaine was replaceld by physiological saline.MAIN OUTCOME MEASURES: Following hematoxylin-eosin staining, rat retinal tissue was observed to investigate retinal edema degree through the use of an optical microscope and transmission electron microscope. Retinal AQP4 expression was determined by immunohistochemistry.RESULTS: At each above-mentioned time point, AQP4 expression was significantly increased in the model group compared to the control group (P<0.05); this change was consistent with the degree of retinal edema. In the lidocaine group, retinal AQP4 expression was significantly decreased (P<0.05), and retinal edema was reduced, compared with the model group.CONCLUSION: Lidocaine inhibits rat retinal AQP4 expression following ischemia/reperfusion injury, leading to a reduction of retinal edema.     

Does early life toluene exposure alter the expression of NMDA receptor subunits and signal transduction pathway in infant mouse hippocampus?

We aim to investigate the critical window of susceptibility to toluene exposure during brain development and the effects of fetal and neonatal toluene exposure on the expression of N-methyl-d-aspartate (NMDA) receptor subunits and related transduction pathway in infant mice hippocampus. Pregnant mice (GD 14), male offspring (postnatal day; PND 2) or PND 8 were exposed to either a filtered air control (0 ppm), or 5, or 50 ppm of toluene for 6 h per day for 5 consecutive days. On PND 21, the expression levels of NMDA receptor subunits, cyclic AMP responsive element binding protein (CREB)-1, calcium/calmodulin-dependent protein kinase (CaMK)-IV, and apoptotic related genes (Bax, Bcl) mRNAs in the hippocampus were estimated using quantitative real-time RT-PCR and immunohistochemical analyses. NR2B, CaMKIV and CREB1 mRNAs increased significantly in the hippocampus of mice exposed to 50 ppm toluene on PND 2–6. In contrast, almost all memory function-related gene mRNAs and proapoptotic and anti-apoptotic ratio increased significantly in mice exposed to 5 or 50 ppm toluene on PND 8–12. However, mice exposed to toluene on GD 14–18 showed no significant change. Increased active caspase-3 immunoreactive cells were found in hippocampal CA1 area of PND 21 male mice exposed to 5 ppm toluene during PND 8–12. Our results suggest that late postnatal period may be a vulnerable and critical period to toluene exposure. Then, we have also examined the effect of toluene exposure in brain development on learning ability in young adult mice and found that poor spatial learning performance in PND 49 male mice exposed to 5 ppm toluene during critical period. This is the first study to show that the early toluene exposure induces persistent of the alteration of memory function-related genes in infant mice and memory deficit in later life via modulating the synaptic morphology and function.     

Phase-delay in the light–dark cycle impairs clock gene expression and levels of serotonin,norepinephrine, and their metabolites in the mouse hippocampus and amygdala

ObjectiveA number of animal studies have implicated circadian clock genes in the regulation of mood, anxiety, and reward. However, the effect of misalignment of the environmental light–dark and internal circadian clock on the monoamine system is not fully understood. In the present study, we examined whether an abnormal light–dark schedule would affect behavior-, circadian clock–, and monoamine-related gene expressions, along with monoamine contents in the amygdala and hippocampus of mice.MethodsMice were subjected to an 8-hour phase delay in the light–dark cycle (Shift) every two days for four weeks, and locomotor activity was continuously measured. We examined the circadian expression of clock genes (Per1, Per2, and Bmal1) and genes of the NE/5HT uptake transporters (Net and Sert). In addition, the levels of NE/5HT and their metabolites MHPG/5HIAA were analyzed in the amygdala and hippocampus.ResultsLocomotor activity showed a free-running phenotype with a longer period (>24 hours) and showed misalignment between the light–dark and inactive–active cycles. The amplitude of the day–night fluctuation of Bmal1 expression was reduced in the amygdala and hippocampus of light–dark–shifted mice. Net gene expression in the Shift group showed different profiles compared with the Control group. In addition, NE and 5HT levels in the amygdala of the Shift group increased during the active period.ConclusionsThe present results suggest that misalignment of the internal and external clocks by continuous shifting of the light–dark cycle affects the circadian clocks and monoamine metabolism in the amygdala and hippocampus of mice.     

Na+–K+–2Cl− Cotransport Inhibitor Attenuates Cerebral Edema Following Experimental Stroke via the Perivascular Pool of Aquaporin-4

Introduction  

The Na⁺–K⁺–2Cl⁻ cotransporter localized in the brain vascular endothelium has been shown to be important in the evolution of cerebral edema following experimental stroke. Previous in vivo studies have demonstrated that bumetanide, a selective Na⁺–K⁺–2Cl⁻ cotransport inhibitor, attenuates ischemia-evoked cerebral edema. Recently, bumetanide has been shown to also inhibit water permeability via aquaporin-4 (AQP4) expressed in Xenopus laevis oocytes. We tested the hypothesis that the perivascular pool of AQP4 plays a significant role in the anti-edema effect of bumetanide by utilizing wild-type (WT) mice as well as mice with targeted disruption of α-syntrophin (α-Syn^−/−) that lack the perivascular pool of AQP4.     

Effect of chronic administration of estradiol, progesterone, and tibolone on the expression and phosphorylation of glycogen synthase kinase-3β and the microtubule-associated protein tau in the hippocampus and cerebellum of female rat

Gonadal hormones regulate expression and activation of protein tau. Tibolone is a drug used as first- choice comprehensive treatment for the relief of menopausal symptoms, because it and its various metabolites have estrogenic properties and progestogenic/androgenic effects; however, the effect on the activation of tau protein and its signaling cascade in the brain is unknown. We studied the effect of chronic administration of estradiol (E2), progesterone (P4), and tibolone (TIB) on the expression and phosphorylation of microtubule-associated protein tau and glycogen synthase kinase-3β (GSK3β) in the hippocampus and cerebellum of ovariectomized rats. Ovariectomized adult female rats were implanted with pellets of vehicle, E2, or P4 or were treated with TIB by oral administration for 60 days. The animals were sacrificed, and tissue proteins were analyzed by Western blot. We observed that, in the hippocampus, administration of E2, P4, or TIB significantly decreased the protein content of hyperphosphorylated tau and increased the tau dephosphorylated form, whereas only treatment with TIB increased the content of the phosphorylated form of GSK3β. In the cerebellum, E2 and TIB treatments resulted in a significant decrease in the expression of hyperphosphorylated tau, whereas E2 and TIB increased phosphorylated GSK3β; P4 had no effect. These results indicate that chronic administration of gonadal hormones and tibolone modulates tau and GSK3β phosphorylation in hippocampus and cerebellum of the rat and may exert a neuroprotective effect in these tissues.     

Do common genotypes of FK506 binding protein 5 (FKBP5) moderate the effects of childhood maltreatment on cognition in schizophrenia and healthy controls?

Common variants of the FK506 binding protein 5 (FKBP5) gene are implicated in psychotic and other disorders, via their role in regulating glucocorticoid receptor (GR) receptor sensitivity and effects on the broader function of the HPA system in response to stress. In this study, the effects of four FKBP5 polymorphisms (rs1360780, rs9470080, rs4713902, rs9394309) on IQ and eight other cognitive domains were examined in the context of exposure to childhood maltreatment in 444 cases with schizophrenia and 292 healthy controls (from a total sample of 617 cases and 659 controls obtained from the Australian Schizophrenia Research Bank; ASRB). Participants subjected to any kind of maltreatment (including physical, emotional, or sexual abuse or physical or emotional neglect) in childhood were classified as ‘exposed’; cognitive functioning was measured with Repeatable Battery for the Assessment of Neuropsychological Status, the Controlled Oral Word Association Test, and IQ was estimated with the Weschler Test of Adult Reading. Hierarchical regressions were used to test the main effects of genotype and childhood maltreatment, and their additive interactive effects, on cognitive function. For rs1360870, there were significant main effects of genotype and childhood maltreatment, and a significant interaction of genotype with childhood trauma affecting attention in both schizophrenia and healthy participants (C-homozygotes in both groups showed worse attention in the context of maltreatment); in SZ, this SNP also affected global neuropsychological function regardless of exposure to childhood trauma, with T-homozygotes showing worse cognition than other genotypes. The mechanisms of trauma-dependent effects of FKBP5 following early life trauma deserve further exploration in healthy and psychotic samples, in the context of epigenetic effects and perhaps epistasis with other genes. Study of these processes may be particularly informative in subgroups exposed to various other forms of early life adversity (i.e., birth complications, immigration).     

Interventional effect of flunarizine on the expression of cyclooxygenase-2 and plasminogen activator inhibitor type-1 during experimental cerebral ischemia/reperfusion in gerbils

INTRODUCTIONInduced cyclooxygenase-2 (COX-2) is a key rate-limiting enzyme for catalysis arachidonic acid (AA) to synthesize prostaglandin and thromboxane and can cause brain injury through a series of ways at the phase of cerebral ischemia/hypoxia[1-4]. …     

Effect of IFN-ß therapy on the frequency and function of CD4+CD25+ regulatory T cells and Foxp3 gene expression in relapsing–remitting multiple sclerosis (RRMS): A preliminary study

Interferon-ß (IFN-ß) is an immunomodulatory drug of choice to control relapsing–remitting multiple sclerosis (RR-MS), although its function is still unclear. A reduced suppressive function of CD4⁺CD25⁺ regulatory T cells (T_reg) has been shown in RR-MS patients. In this study, to understand the effect of IFN-ß on CD4⁺CD25⁺ regulatory T cells, we analyzed the frequency and function of these cells and Foxp3 gene expression before and after treatment.We evaluated the frequency and function of CD4⁺CD25⁺Foxp3⁺ regulatory T cells by flow cytometry and co-culture inhibition test respectively and gene expression of Foxp3 by real-time PCR in a longitudinal follow-up study in 18 relapsing–remitting MS patients. Our data revealed that IFN-ß significantly improved frequency and suppressive function of T_reg cells (P < 0.05) without any significant effect on gene expression of Foxp3 after 6 months. The results of the present study indicate that IFN-ß therapy in some of patients with RR-MS may restore function of regulatory T cells and control the unchecked immune cascade activity. Larger longitudinal studies on more MS patients are required to confirm our findings.     

The effects of isoquinoline carboxamide and melatonin on the differentiation of N1Е-115 mouse neuroblastoma cells (clone C-1300) and on the expression of the TSPO translocation protein and 2’,3’-cyclonucleotide-3’-phosphodiesterase in these cells

We studied the effect of isoquinoline carboxamide (PK11195) applied alone or in combination with melatonin on the differentiation of N1E-115 mouse neuroblastoma cells (clone C-1300). PK11195 is a synthetic ligand of the mitochondrial translocator protein (TSPO), which is one of the mitochondrial proteins that are responsible for the opening of the mitochondrial pore (mPTP); expression of this protein is enhanced in different types of cancer cells. PK11195 is considered as a potential anticancer drug. It has been shown that PK11195 at a nontoxic/subtoxic concentration induces the differentiation of the N1Е-115 mouse neuroblastoma cells and suppresses cell proliferation; the magnitude of this effect coincides with the effect induced by melatonin at a nontoxic concentration. The combination of PK11195 with melatonin did not intensify its effect as a differentiation inducer. Based on the results of Western blot analysis, it has been hypothesized that the differentiation of N1Е-115 neuroblastoma cells is associated with the expression of mitochondrial 2’,3’-cyclonucleotide-3’-phosphodiesterase but not with the expression of the mitochondrial translocator protein TSPO.     

Effect of basic fibroblast growth factor and danshen on bcl-2 and p53 mRNA expression in the brain of rats exposed to repeated,high, positive acceleration （＋Gz）

BACKGROUND： Both animal experiments and clinical studies have shown that basic fibroblast growth factor （bFGF） and danshen （Salvia miltiorrhiza） can exhibit protective effects on ischemia-reperfusion cerebral injury.
OBJECTIVE： To test whether bFGF and danshen can protect cerebral injury induced by exposure to repeated, high, positive acceleration （＋Gz） in an animal model and to analyze the possible mechanisms.
DESIGN, TIME AND SETTING： Randomized controlled animal study. The experiment was performed at the Research Center for Molecular Biology, Air-force General Hospital of Chinese PLA from April to August 2000.
MATERIALS： A total of 20 clean grade, healthy, Sprague Dawley rats of both genders, weighing （200 ± 15） g, were provided by our experimental animal center. Rats were randomly divided into 5 groups： the control group, ＋Gz exposure group, bFGF group, danshen group, and saline group, with 4 animals per group. bFGF （Beijing Bailuyuan Biotechnology Co. Ltd.） and danshen solution （Shanghai Zhongxi Pharmaceutical Co. Ltd.） were used.
METHODS： All rats were fixed on a rotary arm of a centrifugal apparatus （2 m in radius） with their heads oriented towards the center of the apparatus. Except for rats in the control group, the value of ＋Gz exposure was ＋14 Gz with an acceleration rate of 1.5 G/s. The peak force lasted for 45 seconds. ＋Gz exposure was performed three times with intervals of 30 minutes. Rats in the control group received the same ＋Gz procedure, but the G value was ＋1 Gz. Rats in bFGF group and danshen group were intraperitoneally injected with 100 μg/kg bFGF or 15 g/kg danshen solution, respectively, at 30 minutes prior to centrifugation and immediately after centrifugation. Rats in saline group were injected with the same volume of saline. Six hours after exposure, rats were decapitated. One hemisphere was preserved in liquid nitrogen for RNA extraction and the other was processed for apoptosis detection.
MAIN OUTCOME MEASURES： mRNA