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Objective:To explore the effects and possible mechanisms of melatonin combined with enriched environment on the learning and memory ability of senescence-accelerated mouse prone 8(SAMP8).Methods:Forty-eight SAMP8 male mice aged 4 months were randomly divided into model group, enriched environment group, melatonin group and melatonin combined with enriched environment group (combined intervention group) by random number table method, with 12 mice in each group. Mice in the melatonin group and combined intervention group were subcutaneously injected with melatonin at a dose of 8 mg·kg -1·d -1, and the mice in the model group and the enriched environment group were given the same amount of normal saline instead.The mice in model group and melatonin group were raised in a standard environment, and the mice in enriched environment group and combined intervention group were raised in an enriched environment.The intervention lasted 28 days. The aging degree of mice was scored before and 28 days after the intervention. Morris water maze test was used to detect the learning and memory ability of mice. Nissl staining and TUNEL staining were used to observe the Nissl staining positive cells and apoptotic cells in the CA1 area of hippocampus.ELISA was used to detect the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the hippocampus of mice. Western blot was used to detect the levels of amyloid β-protein (Aβ) 1-42, microtubule-associated protein tau (tau) phosphorylated at threonine (Thr) 205 (Tau pT205), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) p65 protein in the hippocampus of mice. qRT-PCR was used to detect the levels of TLR4, NF-κB p65 mRNA in the hippocampus of mice. SPSS 22. 0 statistical software was used for repeated measure ANOVA, one-way ANOVA and LSD test. Results:(1) Aging score: after intervention, the aging scores of mice in the four groups were significantly different ( F=120.601, P<0.01). The aging scores of mice in the enriched environment group, melatonin group, and combined intervention group were lower than those in the model group (all P<0.05), while the aging score of mice in the combined intervention group was significantly lower than those in the enriched environment group and melatonin group (both P<0.05). (2) The results of the location navigation experiment showed that the time × group interaction effect of the escape latencies of mice in the four groups were significant ( F=30.524, P<0.001). From the 2nd to 4th day, the escape latencies of mice in the enriched environment group, melatonin group and combined intervention group were all lower than that in the model group (all P<0.05). The results of the space exploration experiment showed that the residence time in the target quadrant and the number of platform crossings of mice in the four groups were significantly different ( F=291.328, 113.482, both P<0.01). The residence time in the target quadrant ((29.45±1.70)s, (32.44±1.55)s, (37.48±0.84) s) and the number of platform crossings ((6.44±0.61) times, (7.16±0.70) times, (12.60±1.23) times) of mice in the enriched environment group, melatonin group and combined intervention group were higher than those in the model group ((15.07±1.28) s, (4.10±0.61) times), while the residence time in the target quadrant and the number of platform crossings of mice in the enriched environment group and the melatonin group were significantly lower than those in the combined intervention group (all P<0.05). (3) Nissl and TUNEL staining showed that the number of Nissl positive neurons in the hippocampal CA1 region of mice in the four groups were significantly different ( F=809.264, P<0.01), and the number of apoptotic cells in the hippocampal CA1 region were also significantly different ( F=1 060.583, P<0.01). The number of Nissl stained positive neurons in the hippocampal CA1 region of mice in the combined intervention group was more than those in the model group, enriched environment group, and melatonin group (all P<0.05), and the number of apoptotic cells were less than those in the model group, enriched environment group, and melatonin group (all P<0.05). (4) The results of ELISA assay showed that there were significantly different in the levels of IL-1β, IL-6 and TNF-α in the hippocampus of mice in the four groups ( F=152.887, 63.506, 432.026, all P<0.01). The contents of IL-1β, IL-6 and TNF-α in the hippocampus of mice in the enriched environment group, melatonin group, and combined intervention group were lower than those in the model group(all P<0.05). Among them, the contents of IL-1β, IL-6 and TNF-α in the hippocampus of mice in the enriched environment group and melatonin group were significantly higher than those in the combined intervention group (all P<0.05). (5) Western blot analysis showed that there were significantly different in the protein expression levels of Aβ1~42, tau pT205, TLR4, NF-κB p65 in the hippocampus of mice in the four groups ( F=122.349, 98.934, 201.635, 116.553, all P<0.01). The protein expression levels of Aβ1-42, tau pT205, TLR4, and NF-κB p65 in the hippocampus of mice in the enriched environment group, melatonin group, and combined intervention group were lower than those in the model group.Among them, the protein expression levels of Aβ1-42, tau pT205, TLR4, NF-κB p65 in the hippocampus of mice in the enriched environment group and melatonin group were significantly higher than those in the combined intervention group (all P<0.05). (6) qRT-PCR showed that the mRNA expression levels of TLR4 and NF-κB p65 in the hippocampus of mice in the four groups were significantly different ( F=42.913, 102.446, both P<0.01). The mRNA expression levels of TLR4 ((0.63±0.05), (0.55±0.04), (0.42±0.03)) and NF-κB p65 ((0.98±0.06), (0.82±0.04), (0.72±0.04)) in the hippocampus of mice in the enriched environment group, melatonin group and combined intervention group were lower than those in the model group ((0.74±0.07), (1.20±0.05)) (all P<0.05). Among them, the mRNA expression levels of TLR4 and NF-κB p65 in the hippocampus of mice in the enriched environment group and melatonin group were significantly higher than those in the combined intervention group (all P<0.05). Conclusion:Melatonin combined with enriched environment can improve the learning and memory ability and neuroinflammatory response of SAMP8 mice, and its mechanism may be related with the down-regulation of TLR4/NF-κB p65 signaling pathway.
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Aiming at the problem of timeliness of CBCT reconstruction, a CBCT fast short scan reconstruction method is proposed. At the same time, the image reconstruction process in which a new attenuation compensation algorithm is applied to improve image quality. When performing FDK three-dimensional reconstruction of a single-frame acquisition image, the Parker-weighted image is calculated in real time, and a new attenuation compensation algorithm is applied in the back projection process to complete the short scan Parker-weighted reconstruction. This method simulates the CBCT synchronous acquisition and reconstruction process by establishing collection and reconstruction threads. Under the premise of satisfying the reconstruction quality, the reconstruction can be completed within 1 to 2 seconds after the patient collection is completed, which achieves the purpose of real-time.
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Humanos , Algoritmos , Tomografia Computadorizada de Feixe Cônico , Processamento de Imagem Assistida por Computador , Tomografia Computadorizada de Feixe Cônico EspiralRESUMO
Objective To explore the regulation of PI3K-mTOR signaling pathways on autophagy of hippocampus nerve cells after subarachnoid hemorrhage (SAH)in rats.Methods We randomly divided 72 male Sprague-Dawley rats into sham group,SAH model group and LY294002 group with 24 rats in each group.We established SAH model with the secondary injection of blood method while the sham group was not injected with blood.PI3K signaling pathways specific inhibitor LY294002 was injected with 500μmol per rat 30 minutes before modeling.After 6,24,72 and 144 h morphologic changes of hippocampus CA1 neural cells were observed by microscopy;the expression levels of PI3K,mTOR,Beclin-1 and LC3-Ⅱ were detected by immunohistochemical method.Results The density of survival neurons in the SAH group was significantly lower than that in the control group (P<0.05),PI3K-mTOR signaling pathways were activated obviously,and the expressions of Beclin 1 and LC3-Ⅱ were significantly higher than those in the control group (P<0.05 ).The number of survival neurons significantly decreased in the LY294002 group compared with the SAH group at each time point (P<0.05),PI3K-mTOR signaling pathways were suppressed.The expressions of Beclin-1 and LC3-Ⅱ were significantly lower than those in the SAH group (P<0.05).Conclusion PI3K-mTOR signaling pathways protect neurons by activating the autophagy of neurons after SAH.
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Objective Moderate autophagy helps improve the viability of neurocytes.This study aims to investigate the effect of SP600125 on the autophagy and loss of nerve cells in the hippocampus in rats with subarachnoid hemorrhage (SHA).Methods Forty healthy male SD rats were equally randomized into a sham operation, an DMSO group, an SAH model, and an SP600125 group.The SAH model was established by vascular puncture and the rats of the SP600125 group were injected with 10 μL of SP600125 (3 μg/μL) into the lateral cerebral ventricle at 30 minutes before modeling.Sham group and SAH group were injected with equal volume of normal saline, DMSO group was injected with the same amount of DMSO.The animals were sacrificed at 24 hours after modeling for observation of the changes in the morphology and the number of neurons in the hippocampus by HE staining and qualitative and quantitative determination of the expressions of the p-JNK protein and the autophagy markers beclin-1 and LC3-II by immunohistochemistry and Western blot.Results Compared with the sham operation group, the neurons exhibited a disordered arrangement and the cells were polygonal and decreased in number in the hippocampus of the SAH models, while milder neuronal injury and more cells were observed in the rats of the SP600125 group than in the SAH models.The mean optical density values of Beclin-1, LC3-II and p-JNK in the hippocampus were significantly higher in the SAH models (14.66±4.40, 12.62±3.46, and 12.82±3.68) and DMSO (13.85±3.85、11.59±4.52、13.03±3.53), and the SP600125 group (9.86±3.14, 6.78±2.56, and 5.60±2.42) than in the sham operation group (1.56±0.28, 1.60±0.30, and 1.58±0.32) (P<0.05), but markedly lower in the SP600125 than in the SAH model group (P<0.05).The expressions of Beclin-1, LC3-II and p-JNK were remarkably increased in the SAH models (0.474±0.122, 0.668±0.130, and 0.496±0.124) and DMSO (0.432±0.102、0.628±0.113、0.416±0.094) and the SP600125 group (0.264±0.106, 0.332±0.113, and 0.219±0.104) than in the sham operation group (1.56±0.28, 1.60±0.30, and 1.58±0.32) (P<0.05), but significantly decreased in the SP600125 group as compared with the SAH models (P<0.05).Conclusion SP600125 has a protective effect on the neurocytes in the hippocampus of SAH rats, which may be associated with SP600125 moderately activating neuronal autophagy by inhibiting the activity of the JNK signaling pathway.
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ABSTRACT:Objective To explore role of U0126,the specific inhibitor of ERK signaling pathway,in early brain injury (EBI)and the autophagy of nerve cells in hippocampus area in subarachnoid hemorrhage (SAH). Methods A total of 48 male adult SD rats were randomly divided into control group,SAH group,DMSO+SAH group,and U0126+SAH group,with 12 in each.We established SAH rat model by the puncture of internal carotid artery.The same amount of saline water,DMSO and U0126 solution of 0.5 mL per rat was injected respectively into the rats of different groups 30 min before modeling.The rats were killed at 24 h.To measure brain water content by Wet and dry method after 24 h,the morphological changes of hippocampus CA1 neural cells were observed by microscopy;the expression levels of ERK,Beclin-1 and LC3 were detected by using immunohistochemical method. Results Compared with that in sham group,brain water content increased obviously in SAH model group.The density of surviving neurons in SAH group was significantly lower than that in control group (P<0 .0 5 ).ERK signaling pathway was activated obviously,the expressions of Beclin 1 and LC3-Ⅱ were significantly higher than those in control group (P<0.05).Compared with SAH model group,in U0126 group brain water content increased obviously.Compared with those in SAH group,the density of surviving neurons was significantly lower (P<0.05), ERK signaling pathway was suppressed,the expressions of Beclin-1 and LC3-Ⅱ were significantly lower (P<0.05). Conclusion The U0126,the ERK signaling pathway inhibitor,can inhibit neuron autophagy and increase EBR of SAH.
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Objective To explore the effect of extracellular regulated protein kinases (ERK) signaling pathway on early brain injury and autophagy of nerve cell in hippocampus area in rats with subarachnoid hemorrhage (SAH). Methods Forty-eight adult male Sprague-Daw-ley rats were randomly divided into sham group, SAH group, SAH+dimethyl sulfoxide (DMSO) group and SAH+U0126 group, with 12 rats in each group. The SAH model was established with puncture of internal carotid artery. The SAH+U0126 group was injected with U0126 0.05 mg/kg;the sham group and SAH group were injected with normal saline, and the SAH+DMSO group was injected with DMSO 30 min-utes before modeling. They were sacrificed 24 hours after modeling. The brain water content was measured with wet and dry method. The morphology changes of neural cells in hippocampus CA1 were observed by HE staining. The expression of phosphorylation ERK (p-ERK), Beclin-1 and LC3-Ⅱwere detected with immunohistochemical method and Western blotting. Results Compared with the sham group, the brain water content increased (P0.05). Conclusion The activation of ERK signaling pathway may alleviate early brain injury after SAH by regulation of autophagy.
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Objective To investigate the effect of BQ-123 on the ability of learning and memory and nerve cell autophagy in hippocam-pus in rats with subarachnoid hemorrhage (SAH). Methods 72 male Sprague-Dawley rats were randomly divided into sham group, SAH model group (SAH group) and BQ-123 group with 24 rats in each group. SAH model was established by injecting the autologous blood into cisterna magna twice. The sham group was not injected blood. BQ-123 group received intracerebroventricular injection with BQ-123 18μg 30 minutes before modeling. 6, 24, 72 and 144 hours after modeling, the passive avoidance latency (PAL) and active avoidance reaction rate (AARR) were tested with Shutter Box Test, the nerve cell morphological changes of hippocampus were observed with HE staining, and the expressions of Beclin-1 and LC3-II were detected with immunohistochemical staining. Results Compared with the sham group, the PAL pro-longed, the AARR decreased (P<0.05), the nerve cells in the hippocampus reduced (P<0.05), and the expressions of Beclin-1 and LC3-II in-creased (P<0.05) in SAH group. Compared with SAH group, PAL shortened (P<0.05), AARR increased (P<0.05), the nerve cells in the hip-pocampus increased (P<0.05), and the expressions of Beclin-1 and LC3-II increased (P<0.05) in BQ-123 group. Conclusion BQ-123 can promote the recovery of learning and memory ability, which may relate to the activation of nerve cell autophagy in the hippocampus.
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MCP-1-induced protein-1 (MCPIP1) is a newly identified protein that is crucial to immune regulation. Mice lacking MCPIP1 gene suffer from severe immune disorders, and most of them cannot survive longer than 12 weeks. Considerable progress has been made in revealing the mechanism underlying the immune regulatory function of MCPIP1. MCPIP1 can act as an RNase to promote the mRNA degradation of some inflammatory cytokines, such as IL-6 and IL-1. Pre-microRNAs are also confirmed to be the substrate of MCPIP1 RNase. The structure of MCPIP1 N-terminal conserved domain shows a PilT N-terminus-like RNase structure, further supporting the notion that MCPIP1 has RNase activity. MCPIP1 can also deubiquitinate TNF receptor-associated factor family proteins, which are known to mediate immune and inflammatory responses. In this review, we summarize recent progress on the immune regulatory role of MCPIP1 and discuss the mechanisms underlying its function.
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Animais , Humanos , Sequência de Aminoácidos , Imunidade , Dados de Sequência Molecular , Ribonucleases , Metabolismo , Fatores de Transcrição , Química , Metabolismo , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral , Metabolismo , UbiquitinaçãoRESUMO
The guanine-nucleotide exchange factor (GEF) RalGPS1a activates small GTPase Ral proteins such as RalA and RalB by stimulating the exchange of Ral bound GDP to GTP, thus regulating various downstream cellular processes. RalGPS1a is composed of an Nterminal Cdc25-like catalytic domain, followed by a PXXP motif and a C-terminal pleckstrin homology (PH) domain. The Cdc25 domain of RalGPS1a, which shares about 30% sequence identity with other Cdc25-domain proteins, is thought to be directly engaged in binding and activating the substrate Ral protein. Here we report the crystal structure of the Cdc25 domain of RalGPS1a. The bowl shaped structure is homologous to the Cdc25 domains of SOS and RasGRF1. The most remarkable difference between these three Cdc25 domains lies in their active sites, referred to as the helical hairpin region. Consistent with previous enzymological studies, the helical hairpin of RalGPS1a adopts a conformation favorable for substrate binding. A modeled RalGPS1a-RalA complex structure reveals an extensive binding surface similar to that of the SOS-Ras complex. However, analysis of the electrostatic surface potential suggests an interaction mode between the RalGPS1a active site helical hairpin and the switch 1 region of substrate RalA distinct from that of the SOS-Ras complex.
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Humanos , Sequência de Aminoácidos , Sítios de Ligação , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli , Guanosina Difosfato , Metabolismo , Guanosina Trifosfato , Metabolismo , Modelos Moleculares , Conformação Molecular , Dados de Sequência Molecular , Plasmídeos , Metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Genética , Proteínas Recombinantes , Química , Genética , Metabolismo , Proteínas ral de Ligação ao GTP , Química , Genética , Metabolismo , Fator ral de Troca do Nucleotídeo Guanina , Química , Genética , MetabolismoRESUMO
Objective To explore the nursing strategies for preoperative ventilator-dependent patients undergoing discontinuing mechanical ventilation after lung transplantation.Methods The clinical data and nursing experiences of 10 preoperative ventilator-dependent patients undergoing discontinuing mechanical ventilation after lung transplantation from September 2002 to December 2008 were retrospectively analyzed.Results The time of discontinuing mechanical ventilation ranged from 7 to 30 days and the average time was 16.5 days.Conclusion The key points to ensure the success of discontinuing mechanical ventilation were careful observation of ventilation modes,preparations before discontinuing,airway management,nutritional support and psychological nursing.
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Objective To investigate the expression of regeneration gene protein-2(Reg-2) after the transection injury in rat spinal cord. Methods Forty five SD rats were randomly divided into two groups: in the injury group,the SCI was produced by complete transection of the cord at the 9(th) thoracic level,and the sham operation rats were taken as the normal control.The animals were perfused at 1h,1d,3d,7d,14d after the operation,and the spinal cord was taken out at different time points.The expressions of Reg-2 were tested by immunohistochemical analysis and Western blotting,the double staining of Reg-2 and different neural cells special markers(GFAP,Olig2,NPY,CGRP,GAP-43,et al)was done with immunofluorescence method. Results The expression of Reg-2 was found at 1h after the spinal cord injury,reached the peak on day 3 after the injury in the neurons of dorsal horn and day 7 in the neurons of ventral horn.The high expression persisted for 1 week,then decreased gradually.Conclusion Reg-2 may work as an important growth factor and participate in the regeneration and rehabilitation process after the spinal cord injury.