AIM: To study the contribution of tonicity response element binding protein(Ton EBP) in retinal ganglion cell(RGC) death of diabetic retinopathy(DR).METHODS: Diabetes was induced in C57BL/6 mice by five consecutive in...AIM: To study the contribution of tonicity response element binding protein(Ton EBP) in retinal ganglion cell(RGC) death of diabetic retinopathy(DR).METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin(STZ). Control mice received vehicle(phosphate-buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of Ton EBP and aldose reductase(AR) were examined.RESULTS: The Ton EBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase(Td T)-mediated d UTP nick end labeling(TUNEL)-positive signals co-localized with Ton EBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls.CONCLUSION: The present data show that AR and Ton EBP are upregulated in the DR and Ton EBP may contribute to apoptosis of RGC in the DR.展开更多
At 8 weeks after intragastric administration of icariin to senescence-accelerated mice （P8 strain）, Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increa...At 8 weeks after intragastric administration of icariin to senescence-accelerated mice （P8 strain）, Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse.展开更多
BACKGROUND： cAMP-response element binding protein （CREB） is a key modulator of various signaling pathways. CREB activation initiates a series of intracellular signaling pathways that promote neuronal survival. OBJE...BACKGROUND： cAMP-response element binding protein （CREB） is a key modulator of various signaling pathways. CREB activation initiates a series of intracellular signaling pathways that promote neuronal survival. OBJECTIVE： To investigate the regulatory effects of basic fibroblast growth factor （bFGF） on cerebral neuronal CREB expression following ischemia/reperfusion injury. DESIGN, TIME AND SETTING： An immunohistochemical detection experiment was performed at the Department of Anatomy, Shenyang Medical College, between October 2006 and April 2008. MATERIALS： A total of 60 healthy, adult, Wistar rats were randomly divided into three groups： sham-operated （n =12）, ischemia/reperfusion （n = 24）, and bFGF-treated （n = 24）. Rabbit anti-rat CREB （1： 100） and biotin labeled goat anti-rabbit IgG were purchased from the Wuhan Boster Company, China. MetaMorph-evolution MP5.0-BX51 microscopy imaging system was provided by China Medical University, China. METHODS： Rat models of cerebral ischemia/reperfusion injury were developed using the suture method for right middle cerebral artery occlusion. Two-hour ischemia was followed by reperfusion. Rats from the bFGF-treated and ischemia/reperfusion groups were intraperitoneally administered endogenous bFGF （500 IU/mL, 2 000 IU/kg） or an equal amount of physiological saline. Rats from the sham-operated group underwent a similar surgical procedure, without induction of ischemia/reperfusion injury and drug administration. MAIN OUTCOME MEASURES： After 48-hour reperfusion, hippocampal and parietal cortical neuronal CREB expression was detected by immunohistochemistry, and the absorbance of hippocampal CREB-positive products was determined using MetaMorph-evolutionMP5.0-BX51 microscopy imaging system. RESULTS： The sham-operated group exhibited noticeable CREB expression in hippocampal and parietal cortical neurons. In the ischemia/reperfusion group, the CREB expression was discrete and neurons were poorly arranged. The bFGF-treated group exhibited increased CREB expression and better neuronal arrangement compared with the ischemia/reperfusion group. The mean absorbance of CREB-immunoreactive products in the hippocampus and parietal cortex was significantly higher in the ischemia/reperfusion group than in the sham-operated group （P 〈 0.05）, and significantly higher in the bFGF-treated group than in the ischemia/reperfusion group （P 〈 0.05）. CONCLUSION： bFGF significantly upregulates CREB expression in hippocampal and parietal cortical neurons following ischemia/reperfusion injury.展开更多
The present study established a rat model of vascular dementia induced by chronic cerebral hypoperfusion through permanent ligation of bilateral common carotid arteries.At 60 days after modeling,escape latency and swi...The present study established a rat model of vascular dementia induced by chronic cerebral hypoperfusion through permanent ligation of bilateral common carotid arteries.At 60 days after modeling,escape latency and swimming path length during hidden-platform acquisition training in Morris water maze significantly increased in the model group.In addition,the number of accurate crossings over the original platform significantly decreased,hippocampal CA1 synaptophysin and growth-associated protein 43 expression significantly decreased,cAMP response element-binding protein expression remained unchanged,and phosphorylated cAMP response element-binding protein expression significantly decreased.Results suggested that abnormal expression of hippocampal synaptic structural protein and cAMP response element-binding protein phosphorylation played a role in cognitive impairment following chronic cerebral hypoperfusion.展开更多
The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signal transduction pathway plays an important role in the mechanism of action of antidepressant drugs ...The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signal transduction pathway plays an important role in the mechanism of action of antidepressant drugs and has dominated recent studies on the pathogenesis of depression. In the present review we summarize the known roles of extracellular signal-regulated kinase, cAMP response element-binding protein and brain-derived neurotrophic factor in the pathogenesis of depression and in the mechanism of action of antidepressant medicines. The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor pathway has potential to be used as a biological index to help diagnose depression, and as such it is considered as an important new target in the treatment of depression.展开更多
BACKGROUND： Neuronal necrosis and apoptosis play important roles in the pathophysiology of cerebral ischemia and resulting cognitive impairment. However, inhibition of neuronal necrosis and apoptosis has been shown t...BACKGROUND： Neuronal necrosis and apoptosis play important roles in the pathophysiology of cerebral ischemia and resulting cognitive impairment. However, inhibition of neuronal necrosis and apoptosis has been shown to attenuate cognitive impairment following cerebral ischemia. OBJECTIVE： To investigate the effects of sevoflurane on cyclic adenosine monophosphate response element binding protein （CREB）, phosphorylated CREB （pCREB）, and Livin expression in the cortex and hippocampus of a rat model of vascular cognitive impairment.DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed in the Chongqing Key Laboratory of Neurology between June 2007 and July 2008.MATERIALS： Sevoflurane was provided by Abbott Laboratory, UK; Morris water maze was provided by Chinese Academy of Medical Sciences, China; goat anti-rat CREB, goat anti-rat pCREB and goat anti-rat Livin antibodies were provided by Biosource International, USA. METHODS： A total of 42 female, Wistar rats were randomly assigned to the following groups： sham operation, vascular cognitive impairment, and sevoflurane treatment. The vascular cognitive impairment rat model was established by permanent bilateral occlusion of both common carotid arteries, and 1.0 MAC sevoflurane was immediately administered by inhalation for 2 hours. MAIN OUTCOME MEASURES： CREB, pCREB, and Livin expression was measured in the cortex and hippocampus by Western blot and reverse transcription-polymerase chain reaction. Behavior was evaluated with Morris water maze. RESULTS： CREB, pCREB, and Livin expression in the sevoflurane treatment group was significantly greater than the vascular cognitive impairment group （P 〈 0.01）. However, expression of CREB and pCREB was significantly less in the sevoflurane treatment and vascular cognitive impairment groups, compared with the sham operation group （P 〈 0.01）. Livin expression in the sevoflurane treatment and vascular cognitive impairment groups was significantly greater than the sham operation group （P 〈 0.01）. Learning, memory, and behavior disorders were observed in the vascular cognitive impairment group. Sevoflurane treatment significantly improved these observed disorders. CONCLUSION： Sevoflurane improved cognitive impairment due to permanent bilateral occlusion of both common carotid arteries. Improved function was associated with increased CREB, pCREB, and Livin expression in the cortex and hippocampus.展开更多
Objective To investigate whether chronic constriction injury(CCI)of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB)protein in dorsal root ganglia...Objective To investigate whether chronic constriction injury(CCI)of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB)protein in dorsal root ganglia(DRG)and superficial dorsal horn neurons of the spinal cord.Methods Chronic constriction injury(CCI)of the sciatic nerve was employed as a model of neuropathic pain.Thirty-two Sprague-Dawley rats were randomly divided into Na⒍ve,Sham,CCI2w(received CCI for2weeks)and CCI4w(received CCI for4weeks)groups.Hind pawwithdrawal threshold to mechanical stimuli and withdrawal latency to thermal stimuli were used to determine the mechanical and thermal hyperalgesia.Then all the rats were deeply anesthetized and perfused intracardially with paraformaldehyde.The fixed L 4-5 spinal cord and the L 5 DRG ipsilateral to CCI were harvested for fixation.The pCREB-immunoreactive(pCREB-IR)cells in both DRG and superficial dorsal horn neurons were quantified for analysis using immunohistochemistry methods.Results On the14th day after sciatic nerve injury,all the rats exhibited significant mechanical and thermal hyperalgesia.The mechanical withdrawal thresholds to von Frey filament from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01);Thermal withdwal latencies from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01).Some rats from Sham group also showed mechanical hyperalgesia compared to both baseline values and those of Na⒍ve group(P<0.01).28days after CCI,both mechanical and thermal hypersensitivity were significantly alleviated,with no statistical significance compared to those of Sham group.On the14th day after CCI,the number of pCREB-IR cells significantly increased in ipsilateral L 5 DRGs and superficial dorsal horns(P<0.01)compared to Sham group.The number of phosphorylated CREB-IR cells in the ipsilateral DRGs from Sham group also increased compared to that of Naive rats(P<0.05).There were no significant statistical differences of numbers of CREB-IR neuron between Sham group and CCI4wgroup.Conclusion CCI increases CREB phosphorylation both in DRG and superficial dorsal horn neurons of the lumbar spinal cord,and may be one of the key molecular mechanisms of central and peripheral sensitization following peripheral nerve injury.展开更多
Metal ions play critical roles in the interaction between deoxyribonucleic acid(DNA) and protein.The experimental research has demonstrated that the Mg^2+ ion can affect the binding between transcription factor and DN...Metal ions play critical roles in the interaction between deoxyribonucleic acid(DNA) and protein.The experimental research has demonstrated that the Mg^2+ ion can affect the binding between transcription factor and DNA.In our work,by full-atom molecular dynamic simulation, the effects of the Mg^2+ ion on the cyclic adenosine monophosphate(cAMP)response element binding protein(CREB)/cAMP response elements(CRE) complex are investigated.It is illustrated that the number of hydrogen bonds formed at the interface between protein and DNA is significantly increased when the Mg^2+ ion is added.Hence, an obvious change in the structure of the DNA is observed.Then the DNA base groove and base pair parameters are analyzed.We find that, due to the introduction of the Mg2+ ion, the DNA base major groove becomes narrower.A potential mechanism for this observation is proposed.It is confirmed that the Mg^2+ ion can enhance the stability of the DNA–protein complex.展开更多
Objective:Gastric cancer(GC)is a globally common cancer characterized by high incidence and mortality worldwide.Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy.Long...Objective:Gastric cancer(GC)is a globally common cancer characterized by high incidence and mortality worldwide.Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy.Long non-coding RNAs(lncRNAs)and their downstream regulators are regarded to be implicated in the progression of multiple types of malignancies.Studies have shown that the lncRNA small nucleolar RNA host gene 4(SNHG4)serves as a tumor promoter in various malignancies,while its function in GC has yet to be characterized.Therefore,our study aimed to explore the role and underlying mechanism of SNHG4 in GC.Methods:We used qRT-PCR to analyze SNHG4 expression in GC tissues and cells.Kaplan-Meier analysis was used to assess the correlation between SNHG4 expression and the survival rate of GC patients.Cellular function experiments such as CCK-8,BrdU,colony formation,flow cytometry analysis,and transwell were performed to explore the effects of SNHG4 on GC cell proliferation,apoptosis,cell cycle,migration,and invasion.We also established xenograft mouse models to explore the effect of SNHG4 on GC tumor growth.Mechanically,dual luciferase reporter assay was used to verify the interaction between SNHG4 and miR-409-3p and between miR-409-3p and cAMP responsive element binding protein 1(CREB1).Results:The results indicated that SNHG4 was overexpressed in GC tissues and cell lines,and was linked with poor survival rate of GC patients.SNHG4 promoted GC cell proliferation,migration,and invasion while inhibiting cell apoptosis and cell cycle arrest in vitro.The in vivo experiment indicated that SNHG4 facilitated GC tumor growth.Furthermore,SNHG4 was demonstrated to bind to miR-409-3p.Moreover,CREB1 was directly targeted by miR-409-3p.Rescue assays demonstrated that miR-409-3p deficiency reversed the suppressive impact of SNHG4 knockdown on GC cell malignancy.Additionally,miR-409-3p was also revealed to inhibit GC cell proliferation,migration,and invasion by targeting CREB1.Conclusion:In conclusion,we verified that the SNHG4 promoted GC growth and metastasis by binding to miR-409-3p to upregulate CREB1,which may deepen the understanding of the underlying mechanism in GC development.展开更多
The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding pla...The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.展开更多
AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cell...AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.展开更多
Transthyretin (TTR), a carrier protein present in the liver and choroid plexus of the brain, has been shown to be responsible for binding thyroid hormone thyroxin (T4) and retinol in plasma and cerebrospinal fluid (CS...Transthyretin (TTR), a carrier protein present in the liver and choroid plexus of the brain, has been shown to be responsible for binding thyroid hormone thyroxin (T4) and retinol in plasma and cerebrospinal fluid (CSF). TTR aids in sequestering of beta-amyloid peptides Aβ deposition, and protects the brain from trauma, ischemic stroke and Alzheimer disease (AD). Accordingly, hippocampal gene expression of TTR plays a significant role in learning and memory as well as in simulation of spatial memory tasks. TTR via interacting with transcription factor CREB regulates this process and decreased expression leads to memory deficits. By different signaling pathways, like MAPK, AKT, and ERK via Src, TTR provides tropical support through megalin receptor by promoting neurite outgrowth and protecting the neurons from traumatic brain injury. TTR is also responsible for the transient rise in intracellular Ca2+ via NMDA receptor, playing a dominant role under excitotoxic conditions. In this review, we tried to shed light on how TTR is involved in maintaining normal cognitive processes, its role in learning and memory, under memory deficit conditions;by which mechanisms it promotes neurite outgrowth;and how it protects the brain from Alzheimer disease (AD).展开更多
Objective： To investigate the effect and molecular mechanism of Tiantai No.1 （天泰1号）, a compound Chinese herbal preparation, for the prevention and reduction of neurotoxicity induced by betaamyloid peptides （Ab...Objective： To investigate the effect and molecular mechanism of Tiantai No.1 （天泰1号）, a compound Chinese herbal preparation, for the prevention and reduction of neurotoxicity induced by betaamyloid peptides （Abeta） in vitro and its effects on nuclear factor-κB （NF-κB） and cAMP responsive element-binding protein （CREB） pathways using the gene transfection technique. Methods： B104 neuronal cells were used to examine the effects of Tiantai No.1 on lowering the neurotoxicity induced by Abeta. The cells were pre-treated with Tiantai No.1 at doses of 50, 100,150, or 200μg/mL respectively for 3 days and co-treated with Tiantai No.1 and beta-amyloid peptidel-40 （Aβ 1-40, 10 μmol/L） for 48 h or post-treated with Tiantai No.1 for 48 h after the cells were exposed to beta-amyloid peptides25-35 （Aβ 25-35） for 8 h. In gene transfection assays, cells were treated with Tiantai No.1 at 50 μg/mL and 150μg/mL for 5 days or co-treated with Tiantai No.1 and A 13 1-40 （5 μmo/L） for 3 days after electroporation for the evaluation of NF- κB and CREB expression. Results： Pre-treating and co-treating B104 neuronal cells with Tiantai No.1 lowered the neurotoxicity induced by Abeta, and post-treating with Tiantai No.1 reduced or blocked B104 neuronal apoptotic death induced by Abeta （P〈0.05, P〈0.01）. With a dose-dependent relationship, the same treatments increased the expression of NF-κB or CREB in B104 neuronal cells （P〈0.05, P〈0.01）. Meanwhile, Tiantai No.1 reduced Aβ-40 induced inhibition on NF-κB expression （P〈0.01）. Conclusions： Tiantai No.1 can protect neurons against the neurotoxicity induced by Abeta. The neuroprotective mechanisms may be associated with the activation of NF-κB and cAMP cellular signal pathways.展开更多
基金Supported by the Basic Research Program of the Korea Science & Engineering Foundation (No. 2009-0068732)the Basic Research Program of the National Research Foundation of Korea (No.2011-0020163)+1 种基金the Bio-Industry Technology Development Program funded by the Korea Institute of Planning & Evaluation for Technology in Food, Agriculture Forestry & Fisheries (No.112005-3)the BK21 Program and by the MRC program of KRF (R13-2005-012-01001-1)
文摘AIM: To study the contribution of tonicity response element binding protein(Ton EBP) in retinal ganglion cell(RGC) death of diabetic retinopathy(DR).METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin(STZ). Control mice received vehicle(phosphate-buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of Ton EBP and aldose reductase(AR) were examined.RESULTS: The Ton EBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase(Td T)-mediated d UTP nick end labeling(TUNEL)-positive signals co-localized with Ton EBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls.CONCLUSION: The present data show that AR and Ton EBP are upregulated in the DR and Ton EBP may contribute to apoptosis of RGC in the DR.
文摘At 8 weeks after intragastric administration of icariin to senescence-accelerated mice （P8 strain）, Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse.
基金Scientific Research Foundation of Liaoning Provincial Education Department for Higher Education Institutions, No.05L442
文摘BACKGROUND： cAMP-response element binding protein （CREB） is a key modulator of various signaling pathways. CREB activation initiates a series of intracellular signaling pathways that promote neuronal survival. OBJECTIVE： To investigate the regulatory effects of basic fibroblast growth factor （bFGF） on cerebral neuronal CREB expression following ischemia/reperfusion injury. DESIGN, TIME AND SETTING： An immunohistochemical detection experiment was performed at the Department of Anatomy, Shenyang Medical College, between October 2006 and April 2008. MATERIALS： A total of 60 healthy, adult, Wistar rats were randomly divided into three groups： sham-operated （n =12）, ischemia/reperfusion （n = 24）, and bFGF-treated （n = 24）. Rabbit anti-rat CREB （1： 100） and biotin labeled goat anti-rabbit IgG were purchased from the Wuhan Boster Company, China. MetaMorph-evolution MP5.0-BX51 microscopy imaging system was provided by China Medical University, China. METHODS： Rat models of cerebral ischemia/reperfusion injury were developed using the suture method for right middle cerebral artery occlusion. Two-hour ischemia was followed by reperfusion. Rats from the bFGF-treated and ischemia/reperfusion groups were intraperitoneally administered endogenous bFGF （500 IU/mL, 2 000 IU/kg） or an equal amount of physiological saline. Rats from the sham-operated group underwent a similar surgical procedure, without induction of ischemia/reperfusion injury and drug administration. MAIN OUTCOME MEASURES： After 48-hour reperfusion, hippocampal and parietal cortical neuronal CREB expression was detected by immunohistochemistry, and the absorbance of hippocampal CREB-positive products was determined using MetaMorph-evolutionMP5.0-BX51 microscopy imaging system. RESULTS： The sham-operated group exhibited noticeable CREB expression in hippocampal and parietal cortical neurons. In the ischemia/reperfusion group, the CREB expression was discrete and neurons were poorly arranged. The bFGF-treated group exhibited increased CREB expression and better neuronal arrangement compared with the ischemia/reperfusion group. The mean absorbance of CREB-immunoreactive products in the hippocampus and parietal cortex was significantly higher in the ischemia/reperfusion group than in the sham-operated group （P 〈 0.05）, and significantly higher in the bFGF-treated group than in the ischemia/reperfusion group （P 〈 0.05）. CONCLUSION： bFGF significantly upregulates CREB expression in hippocampal and parietal cortical neurons following ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China,No.30973782the National Natural Science Foundation for the Youth,No.81001693+1 种基金the Natural Science Foundation of Beijing,No.7102014,7122018the Science and Technology Foundation for Chinese Medicine in Beijing,No.JJ2008-042
文摘The present study established a rat model of vascular dementia induced by chronic cerebral hypoperfusion through permanent ligation of bilateral common carotid arteries.At 60 days after modeling,escape latency and swimming path length during hidden-platform acquisition training in Morris water maze significantly increased in the model group.In addition,the number of accurate crossings over the original platform significantly decreased,hippocampal CA1 synaptophysin and growth-associated protein 43 expression significantly decreased,cAMP response element-binding protein expression remained unchanged,and phosphorylated cAMP response element-binding protein expression significantly decreased.Results suggested that abnormal expression of hippocampal synaptic structural protein and cAMP response element-binding protein phosphorylation played a role in cognitive impairment following chronic cerebral hypoperfusion.
基金supported by the National Natural Science Foundation of China,No.81202620the Domestic Visiting Scholar Program for Young Talent Teachers in University of Shandong Province
文摘The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signal transduction pathway plays an important role in the mechanism of action of antidepressant drugs and has dominated recent studies on the pathogenesis of depression. In the present review we summarize the known roles of extracellular signal-regulated kinase, cAMP response element-binding protein and brain-derived neurotrophic factor in the pathogenesis of depression and in the mechanism of action of antidepressant medicines. The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor pathway has potential to be used as a biological index to help diagnose depression, and as such it is considered as an important new target in the treatment of depression.
文摘BACKGROUND： Neuronal necrosis and apoptosis play important roles in the pathophysiology of cerebral ischemia and resulting cognitive impairment. However, inhibition of neuronal necrosis and apoptosis has been shown to attenuate cognitive impairment following cerebral ischemia. OBJECTIVE： To investigate the effects of sevoflurane on cyclic adenosine monophosphate response element binding protein （CREB）, phosphorylated CREB （pCREB）, and Livin expression in the cortex and hippocampus of a rat model of vascular cognitive impairment.DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed in the Chongqing Key Laboratory of Neurology between June 2007 and July 2008.MATERIALS： Sevoflurane was provided by Abbott Laboratory, UK; Morris water maze was provided by Chinese Academy of Medical Sciences, China; goat anti-rat CREB, goat anti-rat pCREB and goat anti-rat Livin antibodies were provided by Biosource International, USA. METHODS： A total of 42 female, Wistar rats were randomly assigned to the following groups： sham operation, vascular cognitive impairment, and sevoflurane treatment. The vascular cognitive impairment rat model was established by permanent bilateral occlusion of both common carotid arteries, and 1.0 MAC sevoflurane was immediately administered by inhalation for 2 hours. MAIN OUTCOME MEASURES： CREB, pCREB, and Livin expression was measured in the cortex and hippocampus by Western blot and reverse transcription-polymerase chain reaction. Behavior was evaluated with Morris water maze. RESULTS： CREB, pCREB, and Livin expression in the sevoflurane treatment group was significantly greater than the vascular cognitive impairment group （P 〈 0.01）. However, expression of CREB and pCREB was significantly less in the sevoflurane treatment and vascular cognitive impairment groups, compared with the sham operation group （P 〈 0.01）. Livin expression in the sevoflurane treatment and vascular cognitive impairment groups was significantly greater than the sham operation group （P 〈 0.01）. Learning, memory, and behavior disorders were observed in the vascular cognitive impairment group. Sevoflurane treatment significantly improved these observed disorders. CONCLUSION： Sevoflurane improved cognitive impairment due to permanent bilateral occlusion of both common carotid arteries. Improved function was associated with increased CREB, pCREB, and Livin expression in the cortex and hippocampus.
文摘Objective To investigate whether chronic constriction injury(CCI)of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB)protein in dorsal root ganglia(DRG)and superficial dorsal horn neurons of the spinal cord.Methods Chronic constriction injury(CCI)of the sciatic nerve was employed as a model of neuropathic pain.Thirty-two Sprague-Dawley rats were randomly divided into Na⒍ve,Sham,CCI2w(received CCI for2weeks)and CCI4w(received CCI for4weeks)groups.Hind pawwithdrawal threshold to mechanical stimuli and withdrawal latency to thermal stimuli were used to determine the mechanical and thermal hyperalgesia.Then all the rats were deeply anesthetized and perfused intracardially with paraformaldehyde.The fixed L 4-5 spinal cord and the L 5 DRG ipsilateral to CCI were harvested for fixation.The pCREB-immunoreactive(pCREB-IR)cells in both DRG and superficial dorsal horn neurons were quantified for analysis using immunohistochemistry methods.Results On the14th day after sciatic nerve injury,all the rats exhibited significant mechanical and thermal hyperalgesia.The mechanical withdrawal thresholds to von Frey filament from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01);Thermal withdwal latencies from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01).Some rats from Sham group also showed mechanical hyperalgesia compared to both baseline values and those of Na⒍ve group(P<0.01).28days after CCI,both mechanical and thermal hypersensitivity were significantly alleviated,with no statistical significance compared to those of Sham group.On the14th day after CCI,the number of pCREB-IR cells significantly increased in ipsilateral L 5 DRGs and superficial dorsal horns(P<0.01)compared to Sham group.The number of phosphorylated CREB-IR cells in the ipsilateral DRGs from Sham group also increased compared to that of Naive rats(P<0.05).There were no significant statistical differences of numbers of CREB-IR neuron between Sham group and CCI4wgroup.Conclusion CCI increases CREB phosphorylation both in DRG and superficial dorsal horn neurons of the lumbar spinal cord,and may be one of the key molecular mechanisms of central and peripheral sensitization following peripheral nerve injury.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11705064,11675060,and 91730301)the Fundamental Research Funds for the Central Universities,China(Grant Nos.2662016QD005 and 26622018JC017)the Huazhong Agricultural University Scientific and Technological Self-Innovation Foundation Program,China(Grant No.2015RC021)
文摘Metal ions play critical roles in the interaction between deoxyribonucleic acid(DNA) and protein.The experimental research has demonstrated that the Mg^2+ ion can affect the binding between transcription factor and DNA.In our work,by full-atom molecular dynamic simulation, the effects of the Mg^2+ ion on the cyclic adenosine monophosphate(cAMP)response element binding protein(CREB)/cAMP response elements(CRE) complex are investigated.It is illustrated that the number of hydrogen bonds formed at the interface between protein and DNA is significantly increased when the Mg^2+ ion is added.Hence, an obvious change in the structure of the DNA is observed.Then the DNA base groove and base pair parameters are analyzed.We find that, due to the introduction of the Mg2+ ion, the DNA base major groove becomes narrower.A potential mechanism for this observation is proposed.It is confirmed that the Mg^2+ ion can enhance the stability of the DNA–protein complex.
文摘Objective:Gastric cancer(GC)is a globally common cancer characterized by high incidence and mortality worldwide.Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy.Long non-coding RNAs(lncRNAs)and their downstream regulators are regarded to be implicated in the progression of multiple types of malignancies.Studies have shown that the lncRNA small nucleolar RNA host gene 4(SNHG4)serves as a tumor promoter in various malignancies,while its function in GC has yet to be characterized.Therefore,our study aimed to explore the role and underlying mechanism of SNHG4 in GC.Methods:We used qRT-PCR to analyze SNHG4 expression in GC tissues and cells.Kaplan-Meier analysis was used to assess the correlation between SNHG4 expression and the survival rate of GC patients.Cellular function experiments such as CCK-8,BrdU,colony formation,flow cytometry analysis,and transwell were performed to explore the effects of SNHG4 on GC cell proliferation,apoptosis,cell cycle,migration,and invasion.We also established xenograft mouse models to explore the effect of SNHG4 on GC tumor growth.Mechanically,dual luciferase reporter assay was used to verify the interaction between SNHG4 and miR-409-3p and between miR-409-3p and cAMP responsive element binding protein 1(CREB1).Results:The results indicated that SNHG4 was overexpressed in GC tissues and cell lines,and was linked with poor survival rate of GC patients.SNHG4 promoted GC cell proliferation,migration,and invasion while inhibiting cell apoptosis and cell cycle arrest in vitro.The in vivo experiment indicated that SNHG4 facilitated GC tumor growth.Furthermore,SNHG4 was demonstrated to bind to miR-409-3p.Moreover,CREB1 was directly targeted by miR-409-3p.Rescue assays demonstrated that miR-409-3p deficiency reversed the suppressive impact of SNHG4 knockdown on GC cell malignancy.Additionally,miR-409-3p was also revealed to inhibit GC cell proliferation,migration,and invasion by targeting CREB1.Conclusion:In conclusion,we verified that the SNHG4 promoted GC growth and metastasis by binding to miR-409-3p to upregulate CREB1,which may deepen the understanding of the underlying mechanism in GC development.
文摘The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.
基金Supported by Medical Specialty Development Projects of Beijing Municipal Administration of Hospitals,No.ZYLX201402Ministry of Education of The People’s Republic of China,No.20121107110012+1 种基金Beijing Municipal Commission of Education,No.11320016Collaborative Innovation Center of Infectious Diseases and Beijing Key Laboratory of Emerging Infectious Diseases,Beijing,China
文摘AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.
文摘Transthyretin (TTR), a carrier protein present in the liver and choroid plexus of the brain, has been shown to be responsible for binding thyroid hormone thyroxin (T4) and retinol in plasma and cerebrospinal fluid (CSF). TTR aids in sequestering of beta-amyloid peptides Aβ deposition, and protects the brain from trauma, ischemic stroke and Alzheimer disease (AD). Accordingly, hippocampal gene expression of TTR plays a significant role in learning and memory as well as in simulation of spatial memory tasks. TTR via interacting with transcription factor CREB regulates this process and decreased expression leads to memory deficits. By different signaling pathways, like MAPK, AKT, and ERK via Src, TTR provides tropical support through megalin receptor by promoting neurite outgrowth and protecting the neurons from traumatic brain injury. TTR is also responsible for the transient rise in intracellular Ca2+ via NMDA receptor, playing a dominant role under excitotoxic conditions. In this review, we tried to shed light on how TTR is involved in maintaining normal cognitive processes, its role in learning and memory, under memory deficit conditions;by which mechanisms it promotes neurite outgrowth;and how it protects the brain from Alzheimer disease (AD).
文摘Objective： To investigate the effect and molecular mechanism of Tiantai No.1 （天泰1号）, a compound Chinese herbal preparation, for the prevention and reduction of neurotoxicity induced by betaamyloid peptides （Abeta） in vitro and its effects on nuclear factor-κB （NF-κB） and cAMP responsive element-binding protein （CREB） pathways using the gene transfection technique. Methods： B104 neuronal cells were used to examine the effects of Tiantai No.1 on lowering the neurotoxicity induced by Abeta. The cells were pre-treated with Tiantai No.1 at doses of 50, 100,150, or 200μg/mL respectively for 3 days and co-treated with Tiantai No.1 and beta-amyloid peptidel-40 （Aβ 1-40, 10 μmol/L） for 48 h or post-treated with Tiantai No.1 for 48 h after the cells were exposed to beta-amyloid peptides25-35 （Aβ 25-35） for 8 h. In gene transfection assays, cells were treated with Tiantai No.1 at 50 μg/mL and 150μg/mL for 5 days or co-treated with Tiantai No.1 and A 13 1-40 （5 μmo/L） for 3 days after electroporation for the evaluation of NF- κB and CREB expression. Results： Pre-treating and co-treating B104 neuronal cells with Tiantai No.1 lowered the neurotoxicity induced by Abeta, and post-treating with Tiantai No.1 reduced or blocked B104 neuronal apoptotic death induced by Abeta （P〈0.05, P〈0.01）. With a dose-dependent relationship, the same treatments increased the expression of NF-κB or CREB in B104 neuronal cells （P〈0.05, P〈0.01）. Meanwhile, Tiantai No.1 reduced Aβ-40 induced inhibition on NF-κB expression （P〈0.01）. Conclusions： Tiantai No.1 can protect neurons against the neurotoxicity induced by Abeta. The neuroprotective mechanisms may be associated with the activation of NF-κB and cAMP cellular signal pathways.
