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Objective: To study the effects of prescriptions including Ginseng Decoction, Xixin Decoction, and Dabuyuan Decoction for tonifying spleen and stomach on learning and memory ability and PKA/ERK/p-CREB pathway in hippocampus of SAMP8 mice, and explore the mechanism in the prevention and treatment of Alzheimer's disease (AD). Methods: Three-month-old SAMP8 mice were randomly divided into model group, Donepezil Hydrochloride group, prescription group of Tonifying Spleen and Stomach Yuanqi Prescription (Ginseng, Xixin Decoction, and Dabuyuan Decoction). Moreover, three-month-old SAMR1 mice were recruited as a normal control group, six groups in total. Related indices were detected after 10 weeks continuous gastrogavage. The spatial learning-memory deficit of mice was detected by Morris water maze test. The expression levels of PKA protein in hippocampal region of mice were detected by immunohistochemistry, and the expression levels of ERK and p-CREB protein in hippocampal region of mice were detected by immunofluorescence. The protein expression levels of PKA, ERK, and p-CREB in hippocampus were detected by Western blotting. Results: Compared with the model group, the escape latency of the prescription group of tonifying spleen and stomach was decreased (P < 0.05, P < 0.01), while the swimming time and the times of crossing the platform in the target quadrant were increased (P < 0.01). Results of immunohistochemistry showed that the protein expression of PKA was significantly increased and the expression of ERK and p-CREB in hippocampal region was significantly increased (P < 0.05, P < 0.01). The results of Western blotting were consistent with those of immunohistochemistry and immunofluorescence (P < 0.05, P < 0.01). Conclusion: The Tonifying Spleen and Stomach Yuanqi Prescription showed obvious improvement on the spatial learning-memory deficit in SAMP8 mice, which might be associated with affecting the PKA/ERK/p-CREB pathway in hippocampal region.
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Objective To investigate the antidepressant effect of Bupleuri Radix and Paeoniae Alba Radix drug pair based on the cAMP-CREB-BDNF pathway. Methods The rat depression model was established by CUMS. The contents of cAMP, p-CREB, BDNF, and PDE4 in rat hippocampal and cAMP levels in rat plasma were determined by ELISA. The expression of BDNF mRNA in hippocampus, hypothalamus, and cortex were measured by RT-PCR. Results Compared with the model group, the positive drug group and Bupleuri Radix and Paeoniae Alba Radix drug pair can reverse the cAMP content in the hippocampus and plasma and the decreased contents of CREB and BDNF in the rat hippocampus. At the same time, the positive drug group, Bupleuri Radix, and Paeoniae Alba Radix can increase the expression of BDNF mRNA in hippocampus, cortex, and hypothalamus of rats. Conclusion The Bupleuri Radix and Paeoniae Alba Radix drug pair has obviously antidepressant effect on CUMS rat model, which can achieve antidepressant effect by regulating cAMP-CREB-BDNF pathway.
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Objective To investigate the effects of DNMT1 on neuropathic pain behavior and neuropathic pain modulation.Methods Thirty-two male SD rats, weighing 200-250 g, were randomly assigned into 4 groups (n =8 each):sham operation group (group S),chronic constrictive injury group (group CCI),CCI+ DNMT1-siRNA group (group CDS),CCI+ control-siRNA group (group CCS).Group CDS were intrathcally injected of DNMT1-siRNA (2 μg/10 μl),and group CCS were intrathcally injected of control-siRNA 7,8,9 days after operation.Mechanical withdrawal threshold (MWT)and thermal withdrawal latency (TWL)were measured before operation and on day 3,5,7,9,12,14 after operation.The rats were then sacrificed and L4-L6 segments of the spinal cord were removed for determination of SOCS1,p-ERK,p-CREB expression using Western blot on day 14.Results Compared with group S,MWT and TWL in group CCI and CCS were significantly decreased on day 3,5,7,9,12,14 after operation (P <0.05).Compared with group CCS,MWT and TWL in group CDS were significantly increased on day 9,12,14 after operation (P < 0.05 ). Compared with group S and CDS,SOCS1 was significantly downregulated,p-ERK and p-CREB were significantly upregulated in group CCI and CCS (P <0.05 ).Conclusion Intrathcal injection of DN-MT1-siRNA significantly relieves neuropathic pain by upregulating SOCS1,downregulating p-ERK and p-CREB in rats spinal cords.
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OBJECTIVE@#To To investigate the changes of MicroRNA-134, CREB and p-CREB expression in epileptic rat brains in order to elucidate the molecular mechanisms of epilepsy, providing new ideas for clinical treatment.@*METHODS@#Sixty-four Spraque-Dawley (SD) rats were divided into groups randomly, including control group, six hours after seizure group, 24-hour group, three-day group, one-week group, two-week group, four-week group, and eight-week group. All groups were placed under a pilocarpine-induced epilepsy model except the control group, and all rats were decapitated in different points of time. Brain specimens were taken for quantitative PCR experiments, immunohistochemistry and Western blot experiments. The results of the epilepsy model groups and the control group were compared.@*RESULTS@#There were no significant differences between the six hours after seizure group, the 24-hour group and the control group about the MicroRNA-134 levels. MicroRNA-134 in the hippocampus tissue of the three-day group significantly reduced compared with the control group; same result was observed with the one-week, two-week, four-week and eight-week groups. The CREB and p-CREB levels in the three-day group's rat hippocampus significantly increased compared with the control group; and the high levels of CREB and p-CREB were constantly maintained in the one-week, two-week, four-week and eight-week groups.@*CONCLUSIONS@#The MicroRNA-134 level of the epileptic rat hippocampus is significantly lower than normal after three days, and continues to maintain a low level; while CREB and p-CREB levels are rsignificantly increased after three days, and continue to remain at a high level. MicroRNA-134 plays a role in inhibiting synaptic plasticity by inhibiting CREB and p-CREB expressions.
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Objective: To To investigate the changes of MicroRNA-134, CREB and p-CREB expression in epileptic rat brains in order to elucidate the molecular mechanisms of epilepsy, providing new ideas for clinical treatment. Methods: Sixty-four Spraque-Dawley (SD) rats were divided into groups randomly, including control group, six hours after seizure group, 24-hour group, three-day group, one-week group, two-week group, four-week group, and eight-week group. All groups were placed under a pilocarpine-induced epilepsy model except the control group, and all rats were decapitated in different points of time. Brain specimens were taken for quantitative PCR experiments, immunohistochemistry and Western blot experiments. The results of the epilepsy model groups and the control group were compared. Results: There were no significant differences between the six hours after seizure group, the 24-hour group and the control group about the MicroRNA-134 levels. MicroRNA-134 in the hippocampus tissue of the three-day group significantly reduced compared with the control group; same result was observed with the one-week, two-week, four-week and eight-week groups. The CREB and p-CREB levels in the three-day group’s rat hippocampus significantly increased compared with the control group; and the high levels of CREB and p-CREB were constantly maintained in the one-week, two-week, four-week and eight-week groups. Conclusions: The MicroRNA-134 level of the epileptic rat hippocampus is significantly lower than normal after three days, and continues to maintain a low level; while CREB and p-CREB levels are rsignificantly increased after three days, and continue to remain at a high level. MicroRNA-134 plays a role in inhibiting synaptic plasticity by inhibiting CREB and p-CREB expressions.
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Objective: To To investigate the changes of MicroRNA-134, CREB and p-CREB expression in epileptic rat brains in order to elucidate the molecular mechanisms of epilepsy, providing new ideas for clinical treatment. Methods: Sixty-four Spraque-Dawley (SD) rats were divided into groups randomly, including control group, six hours after seizure group, 24-hour group, three-day group, one-week group, two-week group, four-week group, and eight-week group. All groups were placed under a pilocarpine-induced epilepsy model except the control group, and all rats were decapitated in different points of time. Brain specimens were taken for quantitative PCR experiments, immunohistochemistry and Western blot experiments. The results of the epilepsy model groups and the control group were compared. Results: There were no significant differences between the six hours after seizure group, the 24-hour group and the control group about the MicroRNA-134 levels. MicroRNA-134 in the hippocampus tissue of the three-day group significantly reduced compared with the control group; same result was observed with the one-week, two-week, four-week and eight-week groups. The CREB and p-CREB levels in the three-day group's rat hippocampus significantly increased compared with the control group; and the high levels of CREB and p-CREB were constantly maintained in the one-week, two-week, four-week and eight-week groups. Conclusions: The MicroRNA-134 level of the epileptic rat hippocampus is significantly lower than normal after three days, and continues to maintain a low level; while CREB and p-CREB levels are rsignificantly increased after three days, and continue to remain at a high level. MicroRNA-134 plays a role in inhibiting synaptic plasticity by inhibiting CREB and p-CREB expressions.
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Fetal alcohol syndrome (FAS) is a developmental neuropathology resulting from in utero exposure to ethanol; many of ethanol's effects are likely to be mediated by the neurotransmitter gamma-aminobutyric acid (GABA). We studied modulation of the neurotransmitter receptor GABABR and its capacity for intracellular signal transduction under conditions of ethanol treatment (ET) and RNA interference to investigate a potential role for GABA signaling in FAS. ET increased GABAB1R protein levels, but decreased protein kinase A-alpha (PKA-alpha), calcium/calmodulin-dependent protein kinase II (CaMKII) and phosphorylation of cAMP-response element binding protein (p-CREB), in cultured hippocampal neurons harvested at gestation day 17.5. To elucidate GABAB1R response to ethanol, we observed the effects of a GABABR agonist and antagonist in pharmacotherapy for ethanol abuse. Baclofen increased GABABR, CaMKII and p-CREB levels, whereas phaclofen decreased GABABR, CaMKII and p-CREB levels except PKA-alpha. Furthermore, when GABAB1R was knocked down by siRNA treatment, CaMKII and p-CREB levels were reduced upon ET. We speculate that stimulation of GABAB1R activity by ET can modulate CaMKII and p-CREB signaling to detrimental effect on fetal brain development.
Subject(s)
Animals , Pregnancy , Rats , Baclofen , Brain , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Carrier Proteins , Ethanol , Fetal Alcohol Spectrum Disorders , gamma-Aminobutyric Acid , Hippocampus , Neurons , Neurotransmitter Agents , Phosphorylation , Protein Kinases , Receptors, Neurotransmitter , RNA Interference , RNA, Small Interfering , Signal TransductionABSTRACT
Objective:To investigate the effects of valproate sodium on P-CREB1 after hippocampal neuronal epileptiform discharge in rat.Methods:The neonate wistar rats were decapitated quickly to obtain the hippocampal neuron,Which were cultured in vitro,After the epileptiform discharge model of neuron was established,neurons were divided into control group,model group,low valproate dose group(50mg/L) and high dose group(100mg/L).Expression positions of P-CREB1 after epileptiform discharge were examined by immunofluorescence technique,and Western blot was used to examine the expression intensity of P-CREB1 in different group.Results:Through immunofluorescence,P-CREB1 was observed in the nucleus of each group,and the most intensive expression was found in model group.Through western blot,the expression tendency was found to be the same as the former Results,Moreover,after added valproate sodium,the expression of P-CREB1 decreased,and there was statistical significance of the difference between low valproate dose and high dose(P
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Aim To investigate the effect and mechanism of action of chronic morphine treatment on the neurosteroidogensis of primary cultured rat cerebral cortical neurons(CCNs).Methods The effect of morphine on the production of pregnenolone(PREG),dehydroepiandrosterone(DHEA),allopregnanolone(AP),pregnenlolone sulfate(PS)and dehydroepiandrosterone sulfate(DS)in cell culture media was measured by solid-phase extraction and LC-MS,with methyltestosterone(MT)or estrogen sulfate(ES)as internal standards.The dependence-like changes of CCNs were determined by testing the p-CREB level in the nuclear lysates using western blot.Results Compared with the control group,morphine treatment significantly reduced levels of PREG and DS respectively;opioid agonist DAMGO significantly reduced levels of PREG,DS and PS respectively,and increased the level of AP significantly.Compared with the morphine group,?-opioid-antagonist CTAP concomitant with morphine increased the level of PREG significantly.Compared with the control group,chronic morphine treatment or DAMGO treatment significantly increased the level of p-CREB in the CCNs.Compared with the morphine treatment group,?-antagonsit CTAP significantly reduced the level of p-CREB.Conclusion ?-opioid receptor mediated the inhibitory effect of morphine on levels of neurosteroids,and changes of neurosteroid levels might be related to morphine dependence.
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BACKGROUND AND OBJECTIVES: The p-CREB (phospholyated form of cAMP/calcium response element binding protein) was known to be one of transcription factors for immediate early genes in the brain stem nuclei. The purpose of this present study was to evaluate time-dependent expression of p-CREB and investigate the effect of MK801, non-competitive NMDA channel blocker, on p-CREB expression following unilateral labyrinthectomy (ULX). MATERIALS AND METHODS: Adult Sprague-Dalwey rats weighing 250-300 g were divided into a control group and an unilateral labyrinthetomy (ULX) group. The intraperitoneal injection of MK801 was administered either 30 min before or 24 hrs after ULX. The ABC immunohistochemical staining and digital image analysis system were used to measure the p-CREB expression in neuronal cells. RESULTS: The peak level of p-CREB expressions in 4 major vestibular nuclei was observed bilaterally with the other brain stem nuclei including reticular formation and olivary complex at 30 min following ULX. Thereafter, the p-CREB immunoreactivity in these nuclei was reduced rapidly to the control level for 6 hrs after ULX. Treatment of MK801 for 30 min preceding ULX decreased p-CREB immunoreactivity significantly in both the injured and intact sides of the 4 major vestibular nuclei with dose-dependent relationship. However, MK801 did not affect the change of p-CREB immunoreactivity in bilateral vestibular complex 24 hrs after ULX. CONCLUSION: These results suggest that cAMP/calcium response element binding protein plays an important role in the initial events of vestibular compensation in which its activity is in part regulated by NMDA receptor.