ABSTRACT
Objective To investigate the effects of phosphcreatine preconditioning on lung injury induced by renal ischemia-reperfusion (IR) in rats.Methods Forty-five SPF male Sprague-Dawley rats, aged 8-10 weeks, weighing 180-220 g, were randomly divided into 3 groups using a random number table:sham operation group (group S), renal IR group (group IR), and phosphcreatine preconditioning group (group PCr), 15 cases in each group.The rats in group S recieved dissoci ation of renal pedicles and right nephrectomy, on top of which renal IR model was prepared in group IR and group PCr.phosphcreatine 150 mg/kg was injected in group PCr for 30 minutes before ischemia, where as rats in group S and group I/R recieved the normal saline at the same time.The blood samples were obtained from left ventricle at 6 hours after reperfusion, the arterial blood gas analysis was performed in order to determined the oxygen partial pressure (PaO2).Serum levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were also determined.Fluo 3-AM staining and flow cytometry were used to measure the concentration of alveolar macrophage calcium ions.The lung tissue was obtained with HE staining for determination of microscope examination of pathologic changes, and weight/dry (W/D) ratio were also determined.The lung tissue cell apoptotic rate was measured by Annexin V/PI apoptosis detection reagent staining and flow cytometry.Fluo 3-AM staining and flow cytometry were used to measure the concentration of alveolar macrophage calcium ions.Results Compared with group S, the histopathological demages, W/D ratio, lung tissue cell apoptotic rate, the serum levels of MDA and the concentration of alveolar macrophage calcium ions were signifcant increased (P<0.05), whereas the PaO2 and the activity of SOD were signifcantly decreased in group IR and group PCr (P<0.05).Compared with group IR, the histopathological demages, W/D ratio, lung tissue cell apoptotic rate, the serum levels of MDA and the concentration of alveolar macrophage calcium ions were signifcant decreased (P<0.05), whereas the PaO2 and the activity of SOD were signifcantly increased in group PCr (P<0.05).Conclusion Phosphcreatine preconditioning can attenuate lung injury induced by renal I/R, the mechanism is related to inhabit oxidative stress, and reduce cell apopotosis and calcium overload.
ABSTRACT
Objective:To study the effect and underlying mechanism of rosmarinic acid in the apoptosis of HepG2 cells. Meth-ods:An MTT method was used to determine the inhibitory effect on the growth of HepG2 cells treated with rosmarinic acid for 48 hours. Flow cytometry was used to detect the cell apoptosis after treated with rosmarinic acid at different concentrations for 24 h and 48 h. Western Blotting was used to detect the expression of P53 and c-Myc protein after treated with rosmarinic acid for 48 h. Results:When HepG2 cells were treated with rosmarinic acid at the concentrations of 12. 50, 25. 00, 50. 00 and 100. 00 μg·ml-1 for 48 h, the cell growth was inhibited and the half-inhibitory concentration (IC50) was 43. 48μg·ml-1. By comparing HepG2 cells treated with rosma-rinic acid at different concentrations for 24 h and 48 h, rosmarinic acid had the effect on the early apoptosis of HepG2 cells after the 48-hour treatment. When treated with rosmarinic acid at the different concentrations for 48 h, the expression of c-Myc decreased with the concentration increase of rosmarinic acid, and the expression of P53 increased with the concentration increase of rosmarinic acid. Con-clusion:The inhibitory effect of rosmarinic acid on the proliferation of HepG2 cells is in a dose-dependent manner, and it can promote the apoptosis of HepG2 cells through the activation of P53 and the cleavage of proto-oncogene c-Myc protein.
ABSTRACT
Objective To evaluate the effect of aminoguanidine on cell apoptosis induced by acute myocardial ischemia in rats.Methods Thirty adult male Sprague-Dawley rats,weighing 250-290 g,were randomly divided into 3 groups (n =10 each):sham operation group (group S),myocardial ischemia group (group Ⅰ),and aminoguanidine group (group AG).The model of acute myocardial ischemia was established by ligating the left anterior descending branch of the coronary artery of rats anesthetized with chloral hydrate.Aminoguanidine 100 mg/kg was intraperitoneally administrated at 6 h of ischemia in AG group,while the equal volume of normal saline was given instead of aminoguanidine in group Ⅰ.The chest was opened at 3 h after aminoguanidine administration and hearts were quickly removed for detection of apoptosis in cardiomyocytes (by TUNEL) and expression of Bcl-2 and Bax in cardiomyocytes (by immuno-histochemistry),and for microscopic examination with light microscope.Apoptotic rate was calculated.Results Compared with group S,the apoptotic rate was significantly increased,the expression of Bax was up-regulated,and the expression of Bcl-2 was downregulated and the ratio of Bcl-2/Bax was decreased in group Ⅰ.Compared with group Ⅰ,the apoptotic rate was significantly decreased,the expression of Bax was down-regulated,and the expression of Bcl-2 was up-regulated,and the ratio of Bcl-2/Bax was increased in group AG.The pathological changes of myocardial cells were significantly attenuated in AG group as compared with group Ⅰ.Conclusion Amionguanidine can inhibit apoptosis in cardiomyocytes and is helpful in mitigating injury induced by acute myocardial ischemia in rats.
ABSTRACT
Objective To explore the relationship between nuclear factor ?B (NF ?B) and the occurrence, metastasis, and treatment of colon cancer. Methods The literature on the structure and the property of molecular biology of NF ?B, the relationship between NF ?B and apopotosis, malignant tumor and colon cancer were reviewed.Results NF ?B had action of antiapopotosis. The occurrence of malignant tumor had close relation with the oncogene by NF ?B, the metastasis of malignant tumor was that cell of cancer escaped the killing and supervising of immunity by NF ?B. NF ?B affected the occurrence and metastasis of colon cancer by regulating c myc, Cox2, ICAM 1.Conclusion NF ?B has important action in the occurrence and metastasis of colon cancer. It will become a new target of treatment.
ABSTRACT
Objectives:To study the apoptosis-inducing effects of vitamin K3(VitK3) on human breast carcinoma cell line MCF-7,and approach its possible mechanism.Methods:MCF-7 is cultured in the presence of different concentration of VitK3 or in combination with catalase.The inhibitory effects of VitK3 and the influence of catalase were detected by MTT colorimetry.Apoptosis was observed using flow cytometry.The mRNA expression of RelA,Bcl-2,Bax and cyclin-dependent kinase inhibitor p21CIP1/WAF1,p27KIP1 were assessed by RT-PCR.Results:VitK3 can inhibit MCF-7 cell proliferation,and catalase significantly decreases the growth inhibition due to VitK3.Apoptosis is the reason of growth-inhibitory effect of VitK3.The mRNA expressions of RelA,Bax,p21CIP1/WAF1 were up-regulated after the treatment of VitK3.Conclusion:VitK3 can induce apoptosis of MCF-7 cell,at least in part by promoting the expression of Bax and inducing G1 arrest of cell cycle through up-regulation of p21CIP1/WAF1.
ABSTRACT
Objective To evaluate the effect of aminoguanidine (AG) on neuronal apoptosis induced by focal cerebral ischemia in rats and the possible mechanism of protective effect of AG against cerebral ischemic injury.Methods Fifty-four male SD rats weighing 250-290 g were randomly divided into 3 groups: (1) sham operated group (SH group, n = 18); (2) ischemic group (IS group, n = 18) and (3) AG group(n = 18). SH, IS and AG groups were further divided into 3 subgroups according to the administration time:2, 6 or 12 h following cerebral ischemia. In AG group AG 100 mg? kg-1 was given intraperitoneally twice a day for 3 consecutive days. In IS group normal saline was given instead of AG. Focal cerebral ischemia was produced by middle cerebral artery occlusion (MCAO). A nylon thread with rounded tip which was inserted into left internal carotid artery cranially until resistance was felt. The distance from bifurcation of common carotid artery to the tip of the thread was about 18-19 mm. Focal cerebral ischemia was confirmed by left Homer's syndrome and right side hemiplegia. In SH group the carotid artery was exposed but no thread was inserted. The nylon thread was with drawn to allow reperfusion after 2, 6 or 12 h MCAO. The animals were detected by flow cytometry. Results Significantly increased DNA fragmentation indicative of apoptosis was detected after MCAO. The percentage of apoptotic cells and expression of Bax protein were significantly lower after 2, 6 and 12 h ischemia in AG group than in IS group but still significantly higher than in SH group. The expression of Bcl-2 protein was significantly higher after 2,6 and 12 h in AG group than in IS group. There was no significant difference in the expression of Bcl-2 protein between IS and SH group. Conclusion AG can protect neurons from apoptosis through increasing the Bcl-2 protein expression and inhibiting the Bax protein expression.
ABSTRACT
The crucial role of cell death in many diseases is obvious and has intense researches to understand the regulation of apoptotic pathways. Caspase activation is central to many of the apoptotic pathways. In recent years, the research on the regulation and activation of caspase has made a great progress. Caspase inhibitors prevent active caspases from committing the cell to irreversible destruction. This review will mainly focus on the characteristics of natural anticaspase inhibitor-IAP, regulation of IAP expression, mechanisms of action of IAP.
ABSTRACT
Aim To investigate the effect of L-NA on cerebral ischemic injury and the possible mechanism by evaluating the effect of N~G-nitro-L-arginine(L-NA) on neuronal apopotosis induced by transient focal cerebral ischemia in rats.Methods Male SD rats weighing 250～300 g were randomly divided into 3 groups: sham operation group(SH),ischemic group(IS) and LNA group(L-NA).IS and L-NA group were further divided into 3 subgroups according to the duration of ischemia 2 h,6 or 12 h(n=6).In L-NA group,L-NA(20 mg?kg~(-1),ip) was administrated,2 times per day,for 3 consecutive days.Saline was administrated in IS group.The focal cerebral ischemic model(MCAO) was made by thread embolism of left middle cerebral artery.In sham operation group,the external carotid artery was surgically prepared for insertion of the filament,but the filament was not inserted.Rats were killed at the scheduled time.Apoposis was detected with FCM.The expression of caspase-3 protein was observed using Western blot analysis and immunohistochemistry.The expression of bcl-2 and Bax protein was measured using immunohistochemistry and FCM.Results After MCAO significant DNA fragmentation was detected.The percentage of apoptotic cells and the expression of caspase-3 and Bax protein were increased.The ratio of bcl-2/Bax was decreased.The difference of bcl-2 protein between IS group and L-NA group was not statistically significant.In L-NA 12 h group,the percentage of apoptotic cells and the expression of caspase-3 and Bax protein were decreased.The expression of bcl-2 and the ratio of bcl-2/Bax were increased.There was no significant difference in the percentage of apoptotic cells and the expression of caspase-3,Bax,bcl-2 protein and bcl-2 /Bax between L-NA 2,6 h group and IS group.Conclusion L-NA has beneficial effect on late stage ischemic brain of rats.The protective mechanism is that administration of L-NA could reduce the expression of caspase-3,increase the expression of bcl-2 protein,and regulate the balance between bcl-2 and Bax protein.