ABSTRACT
Objective To investigate the neuroprotective effect and its mechanism of p38 mitogenactivated protein kinase inhibitor after subarachnoid hemorrhage (SAH).Methods Twenty-seven SPF-grade adult male SD rats were selected to induce a SAH model using the prechiasmal pool blood injection.Three dead rats were excluded.Twenty-four rats were randomly divided into four groups:sham operation group,SAH group,dimethyl sulfoxide (DMSO) group,and DMSO +p38 inhibitor group (n =6 in each group).Western blot was used to detect the expression levels of p38,phosphorylation p38,Parkinson's disease protein 7 (DJ-1),autophagy associated gene 5 (Atg5),autophagy adaptor protein p62,microtubule-associated protein Ⅰ Light Chain 3 (LC3-Ⅰ),microtubule-associated protein Ⅱ light chain 3 Ⅱ (LC3-Ⅱ),and the Garcia neurological function score was used to judge the nerve injury.PC12 cell oxygenated hemoglobin was used to induce an in vitro SAH model.They were completely randomly divided into four groups:sham operative group,SAH group,DMSO group,and DMSO + p38 inhibitor group.Fluorescent probe JC-1 was used to observe the changes of mitochondrial membrane potential.Results (1) There were significant differences in the expression of p38,phosphorylation-p38 and DJ-1 in rat brain tissue among the 4 groups (F values were 94.959,150.293 and 698.476,respectively,all P ＜ 0.01).There were significant differences in mitochondrial membrane potential in PC12 cells among the 4 groups (F value was 24.989,P ＜ 0.01).There were significant differences in the expression levels of autophagy related protein LC3-Ⅱ/LC3-Ⅰ ratio,Atg5 and p62 in rat brain tissue among the 4 groups (F values were 235.319,110.490 and 36.311,respectively,all P ＜ 0.01).There was significant difference in nerve function score among the 4 groups (F value was 25.550,P ＜ 0.01).(2) Compared with the sham operative group,the expression levels of p38,phosphorylation-p38 and DJ-1 were upregulated significantly after SAH (from 0.43 ±0.06,0.41 ±0.02 and 0.07 ±0.01 to 0.61 ± 0.08,0.79 ± 0.07 and 0.17 ± 0.03,respectively,all P ＜ 0.01),mitochondria membrane potential depolarization (from 8.29 ±0.28 to 9.23 ±0.42,P ＜0.01);upregulation of Atg5 expression and increase of LC3-Ⅱ/LC3-Ⅰratio (from 0.23 ± 0.04 and 0.25 ± 0.04 to 0.47 ± 0.04 and 0.46 ± 0.04,respectively,all P ＜ 0.01),down regulation of p62 expression (from 1.09 ± 0.14 to 0.54 ± 0.10,P ＜ 0.01);neurological score was decreased (from 17.5 ± 0.6 to 11.3 ± 2.7,P ＜ 0.01);p38 inhibitor was significantly down regulated the expression of phosphorylation-p38 after SAH (from 0.79 ± 0.07 to 0.47 ± 0.04,P ＜ 0.01),the expression of DJ-1 was up-regulated (from 0.17 ± 0.03 to 1.02 ± 0.06,P ＜ 0.01),mitochondrial membrane potential recovery (from 9.23 ±0.42 to 8.47 ±0.36,P ＜0.01),cell autophagy related protein LC3-Ⅱ/LC3-Ⅰ ratio and Atg5 were upregulated(from 0.46 ±0.04 and 0.47 ±0.04 to 0.77 ± 0.06 and 0.95 ± 0.12,all P ＜ 0.01),p62 expression returned to the levels of SAH group (from 0.57 ± 0.09,to 0.54 ± 0.10,P =0.650),and the neurological score was significantly improved (from 11.3 ± 2.7 to 15.5 ± 1.0,P ＜0.01).Conclusions After SAH,the p38 inhibitor downregulates the activity of2 phosphorylation p38.It may inhibit abnormal autophagy and maintain mitochondrial function by up-regulating the expression of DJ-1 protein,and then play a neuroprotective function.
ABSTRACT
Objective To observe the effect of suramin combinated with PG-Rg3 on xenograft growth of lung adeno-carcinoma in mice, and the related mechanism thereof. Methods Forty C57BL/6J mice bearing Lewis cells were random-ized into five groups:control group, cisplatin (DDP) group, suramin group, PG-Rg3 group and combination group. Appropri-ate interventions were given in five groups of mice. Mice were sacrificed at day 24 after tumor inoculation. The subcutaneous tumors were stripped for histological examination. The tumor inhibitory rate was measured. The expressions of erythropoietin-producing hepatoma amplified sequences (Eph) B4 protein, Bcl-2 and tumors microvessel density (MVD) were determined by immunohistochemistry method with image analyze system. The apoptosis of tumor cells was measured by biotinyated dUTP nick and labeling (TUNEL) method. Results There were significantly lower values in subcutaneous tumor volume and weight in drug-treated groups than those in control group (P<0.05). The inhibitory rates were 39.20%, 49.11%, 54.86%and 62.49%in cisplatin group, suramin group, PG-Rg3 group and combined group (P<0.05). The values of EphB4, MVD and Bcl-2 grey values were significantly decreased, the apoptotic index was significantly increased, in suramin group, PG-Rg3 group and combined group than those of control group and DDP group (P<0.05). The values of EphB4, MVD and Bcl-2 grey values were significantly increased, the apoptotic index was significantly decreased, in suramin group and PG-Rg 3 group than those of combined group (P<0.05). Conclusion Suramin combinated with PG-Rg3 can produce a synergetic inhibitory activity against tumor growth of lung adenocarcinoma, which may be associated with the effect of suppressing the expression of EphB4 and angiogenesis, and the promotion of tumor cell apoptosis.