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Objective:To investigate the effects of artesunate ( ART ) on neuronal apoptosis, inflammatory response after stroke in rats and microglia polarization.Methods:(1)Animal experiment: twenty-seven male SD rats of SPF grade were divided into sham operation group, model group and ART treatment group according to the random number table method, with 9 rats in each group.Rats in the model group and ART treatment group were used to establish a stroke model by middle cerebral artery occlusion (MCAO). And rats in the ART treatment group were intraperitoneally injected with ART (25 mg/kg) once a day for three days before modeling, while the rats in sham operation group and the model group were injected with the same amount of solvent.And 24 h after the modeling, TTC staining was used to evaluate the volume of cerebral infarction, Western blot was used to detect the expression of Bcl2 in the infarct area, penumbra and hippocampus, TUNEL method was used to detect neuronal apoptosis, and tissue immunofluorescence was used to observe the expression of tumor necrosis factor-α(TNF-α) in the penumbra region of cerebral cortex.(2)Cell experiments: microglia BV2 were cultured and divided into control group, oxygen-glucose deprivation/reoxygenation group, oxygen-glucose deprivation/reoxygenation + 0.05 μmol/L ART group, oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group and oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group.The levels of inflammatory factors interleukin-6(IL-6), interleukin-1β(IL-1β) and TNF-α were detected by qRT-PCR, the expressions of M2 type microglia marker protein CD206 and ARG1 were detected by Western blot, the BV2 cell medium after treatment in each of the above groups was collected as conditioned medium to culture HT22 hippocampal neuron cells and cell activity was measured by CCK8 method.GraphPad Prism 7 software was used for data analysis.One-way ANOVA was used for comparison of differences among multiple groups, and LSD was used for further two-by-two comparisons.Results:(1)Animal experiment results: TTC staining results showed that the percentage of cerebral infarction volume in the ART treatment group was smaller than that in the model group ((23.09±8.51)%, (39.63±5.71)%, t=33.93, P<0.01). The results of TUNEL staining showed that the number of apoptotic cells in the model group and ART treatment group was higher than that in the sham operation group ((638.90±177.82)cells/mm 2, (72.75±13.21) cells/mm 2, (16.16±2.73) cells/mm 2, both P<0.05), and the number of apoptotic cells in the ART treatment group was lower than that in the model group ( P<0.05). Western blot results showed that the levels of Bcl2 protein in penumbra and infarct area of the model group were both lower than those in sham group(both P<0.05). The levels of Bcl2 protein in penumbra, the hippocampus and infarcted area of the ART treatment group were significantly lower than those of the model group(all P<0.05). The results of tissue immunofluorescence showed that the fluorescence intensities of TNF-α in the model group and ART treatment group were higher than those in the sham group (all P<0.05), while the fluorescence intensity of TNF-α in the ART treatment group was lower than that in the model group ( P<0.05). (2)Cell experiment: qRT-PCR results showed that compared with the control group, the mRNA levels of IL-6, IL-1β and TNF-α (all P<0.05) in oxygen-glucose deprivation/reoxygenation group were significantly higher than those of the control group.And the mRNA levels of IL-1β, IL-6 and TNF-α in oxygen-glucose deprivation/reoxygenation + 0.05 μmol/L ART group, oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group and oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group were significantly lower than those of the oxygen-glucose deprivation/reoxygenation group (all P<0.05). Western blot results showed that compared with the control group, the expression of CD206 ((0.85±0.04), (1.07±0.07), P<0.05) was significantly down-regulated in the oxygen-glucose deprivation/reoxygenation group.The CD206 and ARG in oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group((1.22±0.06), (1.35±0.08)) and oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group((1.24±0.14), (1.14±0.07)) were significantly higer than those of oxygen-glucose deprivation/reoxygenation group((0.85±0.04), (0.85±0.05))(all P<0.05). The results of CCK8 showed that compared with the control group, the cell viability in the oxygen-glucose deprivation/reoxygenation group was significantly decreased( P<0.05). The cell viability of the oxygen-glucose deprivation/reoxygenation + 0.05 μmol/L ART group, the oxygen-glucose deprivation/reoxygenation + 0.1 μmol/L ART group, the oxygen-glucose deprivation/reoxygenation + 0.5 μmol/L ART group were all higher than those of oxygen-glucose deprivation/reoxygenation group(all P<0.05). Conclusion:ART reduces neuronal apoptosis after stroke, decreases the neuroinflammatory response after stroke, and promotes oxygen-glucose deprivation/reoxygenation-activated microglia BV2 polarization to the M2 type.
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Objective To investigate MR findings and dynamic changes of the brain after gas explosion,and to evaluate the relationship between MR findings and post-traumatic stress disorder (PTSD).Methods Forty-nine survivors of a gas explosion (group A) were examined with brain MRI within 1 to 3 days,and serial MR follow-up examinations were also performed.Forty miners not under the ground that day were assigned as group B,and 40 staff working on the ground as group C.The signal intensity values of hippocampus and globus pallidus on T2WI were measured in the three groups and F test was performed by using SPSS 13.0.The relationship between signal intensity values of hippocampus/globns pallidus and PTSD was explored,and the relationship between ADC values of hippocampus and PTSD was also investigated.Results In group A,slight low signal on T1WI and high signal on T2WI were detected on initial MRI in hippocampus (33 cases),globus pallidus (12 cases),cortex (10 cases),and midbrain (2 cases),respectively.On follow-up MRI at 2 months,lesions in hippocampus disappeared (25 cases) or remained slight high signal on T2WI (8 cases),lesions in globus pallidus disappeared (3 cases,5 sides) or showed shrinkage and encephalomalacia (9 cases),cortical lesions resulted in encephalomalacia in 2 cases and returned normal in the others,and lesions in the midbrain showed encephalomatacia.For comparison of T2 signal intensity values in hippocampus and globus pallidus,there was significant difference between group A and group B(P <0.01),and also between group A and group C(P <0.01),but no difference was detected between group B and group C (P>0.05).In group A,the T2 signal intensities of PTSD and non-PTSD were 455±37 and 462±53 in the left hippocarnpus,and 458±36 and 460±43 in the right hippoeampus on 1 to 3 days,and the T2 signal intensities of PTSD and non-PTSD were 438±29 and 424±37 in the left hippocampns,and 442±31 and 430±32 in the right hippocampus at 2 months.The T2 signal intensities of PTSD and non-PTSD were 361 ±35 and 366±63 in the left globus pallidus,and 363 ±41 and 375±62 in the right globus pallidus on 1 to 3 days,and the T2 signal intensities of PTSD and non-PTSD were 341±24 and 337±39 in the left globns pallidus,340±26 and 332±35 in the tight glohus pallidns at 2 months.There was no difference of T2 signal intensity values in hippocampus and globus pallidus between PTSD and non-PTSD( t=0.350,0.826,0.503,0.907,P>0.05).In group A,ADC values of PTSD and nun-PTSD were (8.1±1.1)×10-4 and(8.1 ±0.9)×10-4mm2/s in the left hippocampus,and (8.2±1.0)×10-4 and(8.2±0.8)×10-4mm2/s in the tight hippocampus on 1 to 3 days,ADC values were (8.8±0.7)×10-4 and (9.0±1.0)×10-4mm2/s in the left hippocampus,and (8.5±0.9)×10-4 and (9.3±1.1)×10-4mm2/s in the tight hippocampus at 2 months.ADC values in hippocampns showed no difference between PTSD and non-PTSD(t=0.016,0.081,P>0.05)on initial MRI,but showed significant difference between PTSD and non-PTSD in tight hippocampus (t=7.407,P < 0.05) on follow-up MRI at 2 months,while no difference in left hippocampus (t =0.333,P>0.05) was observed at 2 months.Conclusion Hippocampns and globus pallidus are the most vulnerable structures in gas explosion.The occurrence of PTSD may be related to the injury of fight hippocampus,but not related to the injury of globns pallidus.
