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Objective:To evaluate the effect of sirtuin 3 (SIRT3) overexpression on hypoxia-reoxygenation (H/R) injury to hippocampal neurons of mice exposed to high glucose and its relationship with SOD2.Methods:The normally cultured HT22 neurons at the logarithmic phase were selected and divided into 3 groups ( n=12 each) using a random number table method: high-glucose normoxia group (HG group), high glucose+ H/R group (HHR group) and high glucose+ H/R+ SIRT3 overexpression group (HHR+ SIRT3 group). To establish high glucose model, the neurons in 3 groups were cultured in high-glucose culture medium (glucose concentration of 50 mmol/L) for 8 h. In HHR and HHR+ SIRT3 groups, the cells were exposed to glucose-free and hypoxia for 6 h and then cultured in the high-glucose normoxic environment for 24 h to establish the high glucose and HR injury model.In HHR+ SIRT3 group, the neurons were transfected with SIRT3 overexpressed lentivirus.The cell viability was recorded by the cell counting kit-8 assay, reactive oxygen species (ROS) content was detected by flow cytometry, mitochondrial malonaldehyde (MDA) content, superoxide dismutase (SOD) activity, catalase (CAT) activity and adenosine triphosphate (ATP) content were determined by colorimetry, mitochondrial membrane potential (MMP) was detected by JC-1 probe, and the expression of nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), SIRT3, SOD2 and acetylated SOD2 (ac-SOD2) was detected by Western blot. Results:Compared with HG group, cell viability, SOD activity, CAT activity, ATP content, MMP, NRF1 and the expression of TFAM and SIRT3 were significantly decreased, and ROS content, MDA content and ac-SOD2/SOD2 ratio were increased in group HHR and group HHR+ SIRT3 ( P<0.05). Compared with HHR group, cell viability, SOD activity, CAT activity, ATP content, MMP, NRF1 and the expression of TFAM and SIRT3 were significantly increased, and ROS content, MDA content and ac-SOD2 /SOD2 ratio were decreased in HHR+ SIRT3 group ( P<0.05). Conclusion:SIRT3 overexpression can alleviate hypoxia-reoxygenation (H/R) injury to hippocampal neurons of mice incubated in high glucose medium, and the mechanism is related to activation of SOD2 deacetylation.
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Objective@#To investigate the role of clock gene Bmal1, Per2 and Egr1 expression in learning and memory undergoing sevoflurane anesthesia after acute sleep deprivation.@*Methods@#72 male SD rats were equally divided into four groups using a random number table (n=18) : normal control group (group Control), do not do any processing; sleep deprivation group (group SD), acute sleep deprivation for 96 h; sevoflurane group (group Sev), suffering 2.5% sevoflurane for 3 h; sleep deprivation+sevoflurane group (group SD+Sev), 96 h sleep deprivation followed by 3 h 2.5% sevoflurane inhalation. The Morris water maze, for spatial memory acquisition test, was used to measure the time percent of target quadrant and numbers of platform-site crossovers before sleep deprivation (T0) and at 1 d (T1), 3 d (T2), 7 d (T3) after inhalation anesthesia. Rats were sacrificed after spatial memory acquisition test. Brain hippocampus samples were obtained for determination of Bmal1, Per2 and Egr1 expression by Western blot, and neuron morphology was observed by the Nissl staining.@*Results@#Compared with Control group, the percentage of time in target quadrant and the numbers of platform-site crossovers were significantly decreased at T1 and T2 in Sev group (P<0.05); and compared with Control group, the percentage of time in target quadrant and the numbers of platform-site crossovers were also significantly decreased at T1, T2 and T3 in SD group rats (P<0.05). Compared with Sev group rats (the percentages of time in target quadrant: T1: (32.37±1.36)%; T2: (30.91±1.26)%; T3: (33.78±2.20)%; the numbers of platform-site crossovers: T1: (4.55±0.39); T2: (3.11±0.37); T3: (3.95±0.34)), the percentages of time in target quadrant (T1: (27.20±1.42)%; T2: (28.19±1.04)%; T3: (30.06±1.22)%) and the numbers of platform-site crossovers (T1: (3.11±0.46); T2: (3.30±0.38); T3: ( 3.20±0.39)) in SD+Sev group rats were significantly decreased at T1, T2 and T3 (all P<0.05). Compared with control group, the levels of hippocampal proteins Bmal1, Per2 and Egr1 were significantly reduced at T1 in Sev group (P<0.05). Compared with control group, the level of hippocampal protein Per2 was significantly increased, but the levels of hippocampal proteins Bmal1 and Egr1 were significantly decreased at T1 and T2 in SD group (P<0.01). Compared with Sev group, the levels of hippocampal proteins Bmal1 and Egr1 were significantly reduced at T1, T2 and T3 in SD+Sev group (P<0.01), and the protein level of hippocampal Per2 was significantly decreased at T1, but then increased at T2 and T3 in SD+Sev group (P<0.01). The hippocampal Nissl staining in CA1 at T2 revealed that there were irregular distribution of pyramidal neurons existed in Sev group, and vacuolar degeneration with vague outlines of pyramidal neurons in SD group, while pyramidal neuron atrophy and few number of Nissl bodies, compared with control group, were observed in SD+Sev group.@*Conclusion@#Acute sleep deprivation following with sevoflurane anesthesia resulted in hippocampal memory impairment, which was associated with abnormal expression of hippocampal Bmal1, Per2 and Egr1.
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Objective To evaluate the effects of sevoflurane on the expression of early growth response gene 1 (Egr-1) and Egr-2 in the suprachiasmatic nuclei (SCN) of sleep-deprived rats.Methods Forty-eight pathogen-free healthy male Sprague-Dawley rats,were divided into 4 groups (n =12 each) using a random number table:control group (group C),sleep deprivation group (group SD),sevoflurane group (group SEV) and sleep deprivation plus sevoflurane group (group SD+SEV).The rats were subjected to sleep deprivation for 96 h in group SD.The rats inhaled 2.5％ sevoflurane for 3 h in group SEV.The rats inhaled 2.5％ sevoflurane for 3 h after being subjected to sleep deprivation for 96 h in group SD+SEV.The mechanical paw withdrawal threshold (MWT) was measured at 12 h,3 days and 7 days after emergence from anesthesia (T1-3).The animals were sacrificed after blood samples were obtained from the external carotid artery,and the cerebral SCN was removed for determination of Egr-1 and Egr-2 expression by Western blot.Results Compared with group C,the MWT was significantly decreased at T1-3 in SD,SEV and SD+SEV groups,the expression of Egr-1 and Egr-2 in SCN was significantly up-regulated at T1-3 in SD and SD+SEV groups,and the expression of Egr-1 in SCN was significantly up-regulated at T1-3,and the expression of Egr-2 in SCN was up-regulated at T1 in group SEV (P＜0.05).Compared with SD and SEV groups,the MWT was significantly decreased at T1-3 in group SD+SEV,and the expression of Egr-1 and Egr-2 in SCN was significantly up-regulated at T1-3 in group SD+SEV (P＜0.05).Conclusion The mechanism by which sevoflurane aggravates hyperalgesia is related to up-regulation of Egr-1 and Egr-2 expression in SCN of sleepdeprived rats.
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It is reported that type Ⅲ interferon (IFN-λ) has an anti-tumor effect on melanoma,hepatocellular carcinoma,esophageal carcinoma and fibrosarcoma in recent years.IFN-λ could not only inhibit melanoma metastasis,but also induce cell apoptosis;its constitutively expression could activate natural killer cells,affecting hepatocellular carcinoma growth;IFN-λ could induce cells of G1 phase in esophageal carcinoma directly to stagnation or apoptosis;IFN-λ could cause native and adaptive immune response to suppress fibrosarcoma growth.Research on the anti-tumor mechanisms of IFN-λ will provide new ideas for clinical tumor therapy.