ABSTRACT
Objective To explore the effect of autophagy regulator on the injury of rat hippocampal neurons induced by oxygen-glucose deprivation (OGD).Methods Rat hippocampal neurons were cultivated in primary and subjected to OGD to simulate neuronal hypoxic ischemia injury for 2 hours or 6 hours followed by reperfusion for 12 hours with or without 3-methyladenine (3-MA, 20μmol/L) or rapamycin (0.2μmol/L). The morphology of neurons was observed with optical microscope. The expression of autophagy-related protein (LC3, P62) and apoptosis-related protein (cleaved caspase-3) were assessed by Western Blot analysis. The apoptosis of neurons was detected by flow cytometry, the release rate of lactate dehydrogenase (LDH) was calculated by automatic biochemical analyzer, and the cell activity was determined by methyl thiazolyl tetrazolium (MTT) colorimetric assay.Results Compared with the control group, the expression of LC3 Ⅱ/Ⅰ (gray value: 3.091±0.160, 3.422±0.186 vs. 0.256±0.021), cleaved caspase-3 (gray value: 0.230±0.025, 0.440±0.051 vs. 0.050±0.007), neuronal apoptotic rate, LDH release rate [(38.50±4.15)%, (59.60±5.65)% vs. (12.40±1.32)%] were increased, while the expression of P62 (gray value: 0.290±0.025,0.120±0.026 vs. 0.450±0.040), neuronal activity [(71.40±7.23)%, (42.80±4.12)% vs. (100.30±2.30)%] were decreased at 2 hours or 6 hours after OGD (allP < 0.05). When the time of OGD was 2 hours and it was combined with 3-MA, the expression of LC3 Ⅱ/Ⅰ (gray value: 2.281±0.121), the neuronal activity [(51.10±5.73)%] were decreased, while the expression of P62 and cleaved caspase-3 (gray scale: 0.410±0.037, 0.330±0.027, respectively), neuronal apoptotic rate, the injury of neurons [LDH release rate: (47.30±4.43)%] were increased (allP < 0.05). When the time of OGD was 2 hours and it was combined with rapamycin, the expression of LC3 Ⅱ/Ⅰ (gray value: 3.689±0.214), the neuronal activity [(85.30±8.56)%] were increased, while the expression of P62 and cleaved caspase-3 (gray value: 0.170±0.040, 0.090±0.096, respectively), neuronal apoptotic rate, the injury of neurons [LDH release rate: (24.30±2.14)%] were decreased (allP < 0.05). On the contrary, when the time of OGD was 6 hours and it was combined with 3-MA, the expression of LC3 Ⅱ/Ⅰ and cleaved caspase-3 (gray value: 3.021±0.178, 0.240±0.017), neuronal apoptotic rate, the injury of neurons [LDH release rate: (36.60±3.45)%] were decreased, while the expression of P62 (gray value: 0.350±0.060), the neuronal activity [(59.70±6.13)%] were increased (allP < 0.05). When the time of OGD was 6 hours and it was combined with rapamycin, the expression of LC3 Ⅱ/Ⅰ and cleaved caspase-3 (gray value: 3.923±0.201, 0.590±0.062), neuronal apoptotic rate, the injury of neurons [LDH release rate:(71.20±7.81)%] were increased, while the expression of P62 (gray value: 0.070±0.008), the neuronal activity [(27.30±2.12)%] were decreased (allP < 0.05).Conclusion The enhancement of autophagy has protective effect on neurons under the condition of mild OGD, while it can aggravate the injury of neurons induced by a long-time OGD.
ABSTRACT
Objective To explore the effect of Ulinastatin on blood brain barrier (BBB) and apoptosis of neural cells in septic rats.Methods Fifty-two clean level male Sprague-Dawley rats were randomly (random number table) divided into six groups:Sham groups at 6 h and 24 h,each group with six rats.Sepsis groups (CLP) and Ulinastatin treated groups (UTI) at 6 h and 24 h,each group with ten rats.In CLP and UTI groups,cecal ligation and puncture (CLP) were performed to induce sepsis.Sham group was only opened and closed abdomen.Ulinastatin (50 000 U/kg) was administered via femoral vein 1 h after CLP.The same volume of saline instead of Ulinastatin was administered in Sham and CLP groups.The neurological status was assessed by Neurological Deficit Scale Scores (NDSS) at 6 h and 24 h after CLP.Then the brain was harvested for HE staining and weighing water content.The BBB permeability was assayed by Evans Blue dye extravasations.Apoptosis of neural cells were detected by TUNEL immune fluorescence.Statistical analysis was performed with SPSS version 13.0,ANOVA was used for multiple groups comparison and t-test for paired comparison.Results The Neurological Deficit Scale Scores of UTI group was lower than Sham group (P ＜ 0.05) but higher than that of CLP group (P ＜ 0.05).Swelling,degeneration and edema were observed in cerebral cortex and hippocampal neurons in CLP group through light microscope,and were more serious than those in UTI group.Compared with UTI 24 h group,BBB permeability of CLP 24 h group significantly rose (P ＜ 0.05).The number of apoptosis of neural cells increased more in CLP group than it did in UTI group (P ＜ 0.05).Conclusions Ulinastatin could protect the cerebral tissue in septic rats by alleviating the damage of BBB and reducing the apoptosis of neural cells.