Résumé
Provirus integration site Moloney murine leukemia virus (Pim-1) is a proto-oncogene reported to be associated with cell proliferation, differentiation and survival. This study was to explore the neuroprotective role of Pim-1 in a rat model subjected to optic nerve crush (ONC), and discuss its related molecules in improving the intrinsic regeneration ability of retinal ganglion cells (RGCs). Immunofluorescence staining showed that AAV2- Pim-1 infected 71% RGCs and some amacrine cells in the retina. Real-time PCR and Western blotting showed that retina infection with AAV2- Pim-1 up-regulated the Pim-1 mRNA and protein expressions compared with AAV2-GFP group. Hematoxylin-Eosin (HE) staining, γ-synuclein immunohistochemistry, Cholera toxin B (CTB) tracing and TUNEL showed that RGCs transduction with AAV2-Pim-1 prior to ONC promoted the survival of damaged RGCs and decreased cell apoptosis. RITC anterograde labeling showed that Pim-1 overexpression increased axon regeneration and promoted the recovery of visual function by pupillary light reflex and flash visual evoked potential. Western blotting showed that Pim- 1 overexpression up-regulated the expression of Stat3, p-Stat3, Akt1, p-Akt1, Akt2 and p-Akt2, as well as βIII-tubulin, GAP-43 and 4E-BP1, and downregulated the expression of SOCS1 and SOCS3, Cleaved caspase 3, Bad and Bax. These results demonstrate that Pim-1 exerted a neuroprotective effect by promoting nerve regeneration and functional recovery of RGCs. In addition, it enhanced the intrinsic regeneration capacity of RGCs after ONC by activating Stat3, Akt1 and Akt2 pathways, and inhibiting the mitochondrial apoptosis pathways. These findings suggest that Pim-1 may prove to be a potential therapeutic target for the clinical treatment of optic nerve injury.
Résumé
Objective To analyse the relationship between cytochrome C release and the opening degree of the permeability transition pore (PTP) during in post cardiopulmonary resuscitation(CPR) rats. Method Adult male Sprague Dawley (SD)rats were randomly (random number ) divided into a surgical sham group (no CA/CPR) ( n = 8) and CA/CPR group ( n = 48). Animals in CA/CPR group was induced by asphyxiation and icecold 0.5 mmol/L KCI and killed by decapitation and processed for isolation of brain cortex mitochondria at 3 h,6 h,12 h,24 h,48 h,72 h after restoration of spontaneous circulation (ROSC). MPTP opening degree was based on the absorbance changes of the mitochondrial suspension at 540 nm. Western blot analysed the release of CytC from mitochondrial to cytoplast. Results Neural cells MPTP always remained opening post ROSC. The opening degree of MPTP was not reaching the peak instantly. While its' change depended on time: remaining low level within 6 h post ROSC,then rapidly opening, till 12 h reaching the largest degree,and at 24 h post ROSC slightly shrunken. All these suggested that mitochondria started to shink. While at 48 h the opening degree largen again, shrunken once more at 72 h,but not reaching the normal level ( P ＜ 0.05 or P ＜ 0.01). Cytochrome C could not be detected in the cytosol in the earlier phases of the sham-operated brain samples but appeared in the mitochondria.The amount of cytochrome C released was proportional after restoration of spontaneous circulation 3 h and 24 h,failed to detect the enzyme in the mitochondria fraction. Conclusions We draw the conclusion MPTP plays a key role in neurocyte apoptosis after CA/CPR, which leads to mitochondria release CytC.
Résumé
Objective:To study the protective effects of trimetazidine (TMZ) on mitochondrial in myocardial ischemia reperfusion rats and its mechanism. Methods: Fifty SD rats were randomly divided into four groups; the pseudooperation group, the saline group and two TMZ treated groups(5 mg/kg and 10 mg/kg). In the pseudooperation group, the coronary artery was not ligated, but the chest was opened. Other groups were subjected to myocardial ischemia reperfusion injury. The serum level of mal onaldehyole ( MDA ) , superoxide dismutase ( SOD ) , glutathione ( GSH ) , glutathione peroxidase (GSH-PX) and the accumulation of Ca2+ in myocardial mitochondrial were detected at the time of 30 min ischemia and 40 min reperfusion. The myocyte ultrastnicture was also observed by electron microscope in the four groups. Results: Compared with the pseudooperation group, the MDA and total Ca2+ were significantly higher and the SOD, GSH, and GSH-PX were significantly lower in saline group and treatment groups. Compared with the saline group, the MDA and total Ca2+ was significantly lower and the SOD, GSH, and GSH-PX were significantly higher in the treatment groups. Conclusion: TMZ could significantly reduce lipid peroxidation in myocardial mitochondrial induced by ischemia and ische-mia-reperfusion. The mechanism may be that TMZ could increase the content of GSH and the acvitity of SOD and GSH-PX, and enhance its antioxidant production. TMZ could protect the cardiac cells by reducing calcium overload in myocardial mitochondrial.
Résumé
Objective To investigate the relationship between a mutation in the platelet-activating factor (PAF) acetylhydrolase gene (Arg92→His) and psoriasis. Methods Genomic DNA was analyzed in 47 patients with psoriasis and 52 healthy controls via polymerase chain reaction and restriction fragment length polymorphism. Results The frequency of the mutation in the PAF acetylhydrolase gene (Arg92→His) was significantly higher in patients with psoriasis than that in the controls (P
Résumé
Rat liver mitochondria were exposed to various conentrations of halothane,enflurane, isoflurane and sevoflurane. Electron transfer rates from NADH and succinate to cytochrome C were measured by scanning dual wavelength spectrophotometer. Statistical analysis of the data suggested that halothane at clinical or higher than clinical concentrations markedly inhibited activities of NADH-Cyt,C reductase.in contrast,no decrease occurred in the activities of NADH dehydrogenase,NADH-coenzyme Q reductase and enzymatical system of succinate chain. Enflurane,isoflurane and sevoflurane had little effect on enzymatical system of mitochondrial electron transfer chain. These data indicate that halothane interfere with utilization of NADH-linked substrate by blocking electon transport from NADH to cytochrome C and it is probable that the locus of action is at Q binding protein(Qpn) or complex of Qpn and ubiquinone.
Résumé
0.1). Plasma PAF-AH activity in the patients with psoriasis was significantly lower than that in the healthy controls(P
Résumé
AIM: To investigate the expression profile of peripheral-type benzodiazepine receptor(PBR) involved in mitochondrial permeability transition(PT) regulation,and to observe the binding dynamic of the mitochondrial PBR with specificity ligand during rat live regeneration.METHODS: Liver regeneration model was produced by 70% partial hepatectomy(PH) performed in male SD rats.The animals of sham groups underwent the same surgical operations as PH groups did,but the liver lobes were not resected.The animals in the PH groups and corresponding sham groups were sacrificed at 3,6,12,24,48,72,120 and 168 hours after the operation.The livers were removed,weighted and processed for isolation of mitochondria.Semi-quantitative RT-PCR was performed to examine the expression level of PBR in 70% hepatectomized rat livers during the whole regeneration process and compared to that in the sham and normal groups.Compared with healthy rats,the kinetic parameters of PBR was evaluated by using a specific radioligand -PK11195.RESULTS: Compared with healthy rats,the expression of PBR was unchanged.Meanwhile,the results obtained in the present experiments by scatchard analysis,Bmax of PK11195 for PBR significantly decreased,returned to normal level in 168 h after PH.Kd of PK11195 for PBR significantly decreased at 72 h and 168 h after PH of rat liver regeneration(P
Résumé
Objective:To study the protective effect of trimetazidine(TMZ) on myocardial ischemia and reperfusion injury and its mechanism.Methods:Totally 50 SD rats were randomly divided into 4 groups:the pseudooperation group,the saline group and the TMZ treated groups(5 mg?kg -1 and 10 mg?kg -1 ).In the pseudooperation group the coronary artery was not ligated but the chest was opened,the other groups were the model of myocardial ischemia reperfusion injury.The level of serum creatine phosphokinase(CK) was detected at ischemia 30 min and reperfusion 40 min; The reperfusion injury myocardial malonaldehyole(MDA),superoxide dismutase(SOD),glutathione(GSH),glutathione peroxidase(GSH Px) were detected at reperfusion 40 min.Results:The level of CK was significantly lower in treated groups than in saline group both at ischemia 30 min and reperfusion 40 min;Compared with the pseudooperation group,the MDA was higher and the SOD,GSH and GSH Px were significantly lower in saline group and treated groups;Compared with the saline group,the MDA was higher and the SOD,GSH and GSH Px were significantly lower in treated groups.Conclusion:TMZ can inhibit enzyme leaking from the ischemia reperfusion myocardial cells,and protect the cardiac cells against ischemia reperfusion injury to some extent.The mechanism may be that TMZ can reduce the injury of lipid peroxidation and harmful metabolites to cardiac cell membrane by increasing the content of GSH,the free radical cleaner,and enhancing the activity of SOD and GSH Px.
Résumé
The alterations in electron transport were studied in the myocardial mitochondria of rats with hemorrhagjc shock. Hemorrhagic shock model was induced by a modified Wigger procedure. Mitochondria were obtained by differential centrifugation. Succinate-, and NADH-respiratory chains were assayed by polarographically and spectrophotometrically in isolated myocardial mitochondria. The results showed that hemorrhagic shock led to progressive decrease in the enzymatic activities of two respiratory chains. The activities of Succinate-Co. Q reductase, Succinate-Cyt. C reductase, NADH-Co. Q reductase, NADH-Cty. C reductase and cytochrome oxidase were remarkably lower in shock 3 h group than those in the shamoperated. This implies that there is not only low-flow hypoxia, but inability to utilizer oxygen in the myocardial mitochondria