【Abstract】 Objective To investigate the effect of verapamil on apoptosis, calcium and expressions of bcl-2 and c-myc of pancreatic cells in ischemia-reperfusion rat model. Methods Wistar rats were randomly divided into three groups: control group （n=10）; ischemia-reperfusion group （n=10）; verapamil treatment group （n=10）. The anterior mesenteric artery and the celiac artery of rats in both ischemia-reperfusion group and verapamil treatment group were occluded for 15 min followed by 12-hour reperfusion. Verapamil （1 mg／kg） was injected via caudal vein to the rats in verapamil treatment group 15 min before occlusion and 1 hour after the initiation of reperfusion, respectively; and ischemia-reperfusion group was given the same volume of salient twice intravenously. Pancreatic tissues were collected from the dead rats after twelve hours since the reperfusion. The pathologic characters of pancreatic tissue were observed under light microscope; The level of calcium in the tissue was measured by atomic absorption spectrometer; TUNEL was used to detect apoptosis of pancreatic cells; and the expressions of c-myc and bcl-2 in the cells were also analyzed by immunohistochemistry technique and flow cytometry. Results The pathologic change in verapamil treatment group was less conspicuous than that of ischemia-reperfusion group. Both the calcium level and the number of apoptotic cells in verapamil treatment group were less than those of ischemia-reperfusion group 〔（411.1±55.8） μg/g dry weight vs （470.9±31.9） μg/g dry weight, P＜0.05 and （9.5±2.9）% vs （18.4±3.1）% 〕, P＜0.05. After taking verapamil, the number of apoptotic cells decreased, whereas the expressions of bcl-2 and c-myc increased. The fluorescent indexes of bcl-2 and c-myc in verapamil treatment group were significantly higher than those of ischemia-reperfusion group (1.72±0.11 vs 1.41±0.07, P＜0.05; 1.76±0.19 vs 1.55±0.13, P＜0.05. Conclusion Ischemia-reperfusion injury can induce apoptosis of pancreatic cells. Verapamil could protect the injured pancreatic tissue by reducing the level of calcium, stimulating the expressions of bcl-2 and c-myc and inhibiting apoptosis of pancreatic cells.
ObjectiveTo study the effects of astaxanthin on the apoptosis after spinal cord injury in rats.MethodsOne hundred and forty-four healthy adult Sprague Dawley rats were divided into experimental group, control group, and sham group according to the random number table (n=48). In the control group and the experimental group, the modified Allen’s method was used to make the spinal cord injury model; in the sham group, only the lamina was cut without damaging the spinal cord. At immediate after operation, the rats in the experimental group were given intragastric administration of astaxanthin (75 mg/kg) twice a day; and the rats in the control group and the sham group were given equal amount of olive oil by gavage twice a day. BBB score was used to assess the motor function at 1 day and 1, 2, 3, and 4 weeks after operation. The malondialdehyde (MDA) content was determined by the thiobarbituric acid method at 24 hours after operation; and the activity of superoxide dismutase (SOD) was determined by the xanthine oxidase method. Apoptosis index (AI) was determined by TUNEL method at 6, 24, and 48 hours after operation. At 48 hours after operation, the water content of spinal cord was measured by dry-wet weight method, the lesion ratio of spinal cord was calculated, the ultrastructure of the spinal cord was observed by transmission electron microscopy, and ultrastructure scoring was performed using the Kaptanoglu score method.ResultsThe BBB score in the control group and the experimental group was significantly lower than that in the sham group at each postoperative time point (P<0.05); and the BBB score in the experimental group were significantly higher than that in the control group at 1-4 weeks postoperatively (P<0.05). The MDA content in the control group and the experimental group was significantly higher than that in the sham group at 24 hours after operation, and in the experimental group was significantly lower than in the control group (P<0.05). The SOD activity in the control group and the experimental group was significantly lower than that in the sham group, and in the experimental group was significantly higher than in the control group (P<0.05). At each time point postoperatively, the AI in the control group and the experimental group was significantly higher than that in the sham group, and in the experimental group was significantly lower than in the control group (P<0.05). At 48 hours after operation, the water content of spinal cord, the lesion ratio of spinal cord, and the ultrastructure score in the control group and the experimental group were significantly higher than those in the sham group, and in the experimental group were significantly lower than in the control group (P<0.05).ConclusionAstaxanthin can inhibit the lipid peroxidation, reduce the apoptosis, reduce the spinal cord edema, reduce the spinal cord lesion, reduce the histopathological damage after spinal cord injury, and improve the motor function of rats with spinal cord injury, and protect the spinal cord tissue, showing an obvious neuroprotective effect.
Objective To investigate the effect of S-adenosyl-l-methionine (SAM) on oxidative stress and alveolar septal cell apoptosis in mice with emphysema after smoking cessation. Methods Twenty-two male SPF C57BL/6J mice aged 6 - 8 weeks were randomly divided into 4 groups, ie. a healthy control group, an emphysema group, a smoking cessation group, and a SAM intervention for 8 weeks after smoking cessation group, with 8 mice in each group. The mice model of emphysema was established by intraperitoneal injection of cigarette smoke extract (CSE) combined with cigarette smoke exposure. Smoking cessation started after the emphysema model was successfully constructed and lasted for 8 weeks. After smoking cessation, the mice in SAM intervention groups were intraperitoneally injected with SAM mg·kg–1·d–1 for 8 weeks. The right lung sections of the mice were taken for hematoxylin-eosin staining to observe pathological changes, and the mean linea rintercept (MLI) and mean alveola rnumber (MAN) of lungs were measured. The concentrations of malondialdehyde (MDA), superoxide-dismutase (SOD) and glutathione (GSH) in alveolar lavage fluid of left lung were detected by spectrophotometry. Terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) technique was carried out to detect the alveolar septal cells apoptosis. Results MLI, apoptosis index of alveolar septal cell and MDA concentration in bronchoalveolar lavage fluid (BALF) increased significantly in the emphysema group compared with healthy controls, increased significantly in the smoking cessation group compared with the emphysema group, and decreased in the SAM intervention group compared with the smoking cessation group (all P<0.05). GSH concentration and SOD activity in BALF and MAN was significantly lower in the emphysema group compared with the healthy control group, significantly lower in the smoking cessation group compared with the emphysema group, and significantly higher in the SAM intervention group compared with the smoking cessation group (all P<0.05). Conclusions Lung histopathology and apoptosis of alveolar septal cells in emphysema mice progress continuously after smoking cessation. SAM may reduce oxidative stress and improve apoptosis of alveolar septal cells, so as to protect emphysema mice after smoking cessation.
【Abstract】ObjectiveTo explore the effects of p38 mitogenactivated protein kinase (MAPK) on apoptosis of small intestinal epithelial cells after transplantation in rats. MethodsSmall intestinal transplantation was performed in SD and Wistar rats. The recipients were divided into three groups: isograft group (Wistar→Wistar group), allograft group (SD→Wistar group) and allograft+cyclosporine A group (SD→Wistar+CsA group). The grafts were harvested on day 1, 3, 5 and 7 after operation. All graft samples were subjected to histological examination. The apoptosis of graft epithelial cells was detected by TUNEL method. p38 MAPK was measured by Westernblotting method and serum TNFα was determined by ELISA. ResultsMild, moderate and severe rejection reaction occurred in the SD→Wistar group, it was showed that the number of apoptotic cells increased with the severity of the rejection reaction by TUNEL. In SD→Wistar group, the numbers of apoptotic cells were significantly higher than those of the other two groups （P＜0.01）. The severity of rejection reaction in SD→Wistar+CsA group was less than that of SD→Wistar group and the number of apoptotic cells increased with the severity of the rejection reaction (P＜0.01). The level of serum TNFα varied with the apoptotic degree of small intestinal epithelial cells in SD→Wistar group and SD→Wistar+CsA group （P＜0.01）. The expression of p38 MAPK increased with the number of the apoptotic cells in SD→Wistar group and SD→Wistar+CsA group （P＜0.01）, but there was no evident change in Wistar→Wistar group （Pgt;0.05）. The expression of p38 MAPK and the level of serum TNFα were positively correlated with apoptosis in small intestinal rejection after transplantation （r=0.875， P＜0.01； r=0.837， P＜0.01）. p38 MAPK and TNFα were also positively correlated （r=0.826，P＜0.01）. ConclusionApoptosis plays an important role in small intestinal rejection. p38 MAPK is involved in apoptosis and is an important regulator in signal pathway of cell apoptosis.
ObjectiveThis study is aimed to determine the expression of ubiquitin-specific peptidase 39 (USP39) protein in the colorectal cancer (CRC) tissues, and the effect of silencing USP39 gene on the cell growth and cell cycle distribution of CRC cells.Methods① The expressions of USP39 protein in CRC tissues and its paracancerous tissues were determined by immunohistochemical staining method. ② By lentiviral infection, Lv-shUSP39 (KD-1 and KD-2 group) and Lv-shCon (shCon group) were transferred into SW1116 and HCT116 cells, and cells of blank control group did not received any treatment (Con group). To determine the role of USP39 gene in cell growth, MTT assay was performed to draw growth curve, and cell cycle distribution of CRC cells in the 4 groups were determined by flow cytometer.Results① The expression of USP39 protein was higher in CRC tissues compared to adjacent tissues (P=0.007). ② For SW1116 and HCT116 cells, the cell proliferation ability of KD-1 and KD-2 groups were remarkably decreased than those in corresponding shCon and Con groups on 3, 4, and 5-day (P<0.05). ③ Flow cytometry assay showed that, the percentage of G0/G1 phase cells were decreased obviously (P<0.05), while increased significantly in percentage of G2/M phase and number of sub-G1 phase cells in KD-1 group compared with that in the Con group and shCon group of SW1116 and HCT116 cells (P<0.05).ConclusionsThe expression of USP39 protein is highly expressed in CRC tissues. Knockdowning of USP39 gene can inhibit cell proliferation and promote cell apoptosis.
Objective To observe the effects of SARS-CoV-2 infection on the morphology, proliferation, apoptosis, cell cycle, and immune response function of mouse retinal photoreceptor cells (661w cells). MethodsA cell experiment. Logarithmic growth phase 661w cells were cultured in vitro and transfected with angiotensin-converting enzyme 2 (ACE2) overexpressing lentivirus to construct ACE2 overexpressing 661w cells that could be infected with SARS-CoV-2 pseudovirus (hereafter referred to as ‘pseudovirus’). The 661w cells were divided into three groups: the normal group (untreated), the siACE2 group (overexpressing ACE2 and not infected with the pseudovirus) and the infected group (overexpressing ACE2 and infected with the pseudovirus), in which the infected group was 5 TU/ml pseudovirus group, 15 TU/ml pseudovirus group, 30 TU/ml pseudovirus group and 50 TU/ml pseudovirus group, and the cells were infected with the pseudovirus for 12, 24, 48 and 72 h, respectively. The infected group was infected with 5 TU/ml pseudovirus group, 15 TU/ml pseudovirus group, 30 TU/ml pseudovirus group and 50 TU/ml pseudovirus group, respectively, for 12, 24, 48 and 72 h. Fluorescence microscopy was used to observe the transfection efficiency of ACE2; protein immunoblotting (Western blot) was used to detect the relative expression level of ACE2 in the cells; light microscope was used to observe the morphology of the cells in the normal and the infected groups; cell proliferation was detected by Cell Counting Kit-8 (CCK8) assay; flow cytometry was used to detect the cell cycle; Western blot and real-time quantitative polymerase chain reaction (qPCR) were used to detect the relative expression of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), B lymphocytoma-2 (Bcl-2), Bcl-2-associated X-protein (Bax) proteins and mRNA in the cells of siACE2 group, infected group (30 TU/ml pseudovirus group); qPCR was used to detect the relative expression of nuclear factor (NF)- κB1 and NF-κB2, as well as NF- kB enhancer (P65) and precursor protein (P100) in cells of the siACE2 group and the infected group (30 TU/ml pseudovirus group). One-way ANOVA was used for comparison between multiple groups; t-test was used for comparison between two groups. Results Compared with the siACE2 group, the cells in the infected group showed different degrees of crumpling, and with the increase of the concentration and time of pseudovirus induction, the crumpling of the cells worsened, and the number of cells decreased. Compared with the normal group, the cells in the infected group showed a gradual decrease in cell viability with the prolongation of pseudovirus induction time, and the difference was no statistically significant (F=0.840, 0.412, 1.498, 1.138; P＞0.05), and the apoptotic index of the cells induced in the 30 and 50 TU/ml pseudovirus group was significantly elevated, and the difference was statistically significant (F=2.523, 6.716, 3.477, 3.421; P＜0.05). At 72 h of pseudovirus induction, compared with the siACE2 group, the G1 phase cells in the 30 TU/ml pseudovirus group were significantly increased, and the difference was statistically significant (t=3.812, P＜0.05); the relative expression of IL-6, TNF-α, Bax protein and mRNA in the cells was up-regulated (t=7.601, 6.039, 3.088, 5.193, 6.427, 7.667; P＜0.05), the relative expression of Bcl-2 protein and mRNA was down-regulated (t=3.614, 6.777; P＜0.05), and the relative expression of NF-κB1, NF-κB2, P65, and P100 mRNA was significantly up-regulated with statistically significant differences (t=3.550, 3.074, 3.307, 4.218; P＜0.05). ConclusionSARS-CoV-2 infection may inhibit photoreceptor cell proliferation, promote apoptosis and cycle blockade by activating the NF-κB signalling pathway.
Objective To observe the effects of δ-opioid receptor agonists D-Ala2-D-Leu5-enkephali （DADLE） on hepatocyte apoptosis and expressions of bcl-2 and caspase-3 in septic rat, and to investigate the possible mechanism by which DADLE protects the liver in sepsis. Methods Sepsis was reproduced in rats by cecum ligation and puncture (CLP). Fifty-four SD rats (either male or female) were randomly divided into CLP group (n=18), DADLE group (n=18) and sham operation (SO) group (n=18). The rats were respectively killed at different time (2 h, 4 h and 6 h after operation). Hepatocyte apoptosis was detected by TdT-mediated dUTP Nick End Labeling (TUNEL). The expressions of bcl-2 and caspase-3 protein were detected by immunohistochemistry. And the changes of pathology in hepatic tissue were detected by light microscope. Results The hepatic pathological lesion of rats in CLP group was obviously serious compared with SO group, while it was obviously improved in DADLE group. The apoptosis index of rat hepatocytes in CLP group significantly increased compared with SO group, and further it was prominent at 4 h （P＜0.01). The apoptosis index of rat hepatocytes at each time of DADLE group was significantly decreased compared with CLP group （P＜0.01）. Expression of caspase-3 protein in liver tissues of CLP group significantly increased compared with SO group （P＜0.01）, while the expression of bcl-2 protein significantly decreased （P＜0.05）. Expression of caspase-3 protein in liver tissues of DADLE group significantly decreased compared with the CLP group （P＜0.01）, while the expression of bcl-2 protein significantly increased （P＜0.05）. There was positive correlation between expression of caspase-3 in liver tissues and apoptosis index of hepatocyte (r=0.83, P＜0.01) and negative correlation between expression of bcl-2 in liver tissues and apoptosis index of hepatocyte (r=-0.65, P＜0.01). Conclusions The findings indicate that δ-opioid receptor agonists DADLE can obviously improve hepatic pathological changes of septic rats. And its protective mechanism contains down regulation of caspase-3 expression, upregulation of bcl-2 expression and thus the apoptosis of hepatocyte is repressed.
ObjectiveTo study the role of survivin gene in the research work of tumor. MethodsLiteratures about the molecular structure, function, mechanism,distribution of survivin gene and its role in the treatment of tumor were reviewed.ResultsSurvivin was a new member of inhibitor of apoptosis protein family, expressed in almost all the human tumors independent to the expression of bcl2. The expression of survivin was significantly correlated with the poor prognosis of tumor patients. Survivin inhibited the apoptosis of tumor cells via inhibiting the activity of caspase3, the effector molecule of the apoptosis signal transduction pathway. Inhibition of the expression of survivin gene could block its effect of inhibiting apoptosis and consequently get a therapeutic effect of tumors.ConclusionSurvivin is commonly expressed in human tumor tissues. It can be identified as an important prognostic parameter of poor outcome and a new therapeutic target in cancer.
Objective To study the effect of 5-fluorouracil (5-FU) induced apoptosis of the rectal carcinoma cell line HR8348 in vitro and the relationship between apoptosis induced by 5-FU and the expression of bcl-2，bcl-xl，bax and p53,and to investigate the possible mechanism of apoptosis of rectal carcinoma cell line HR8348 induced by 5-FU.Methods After treatment with 5-FU for 24 h,the apoptotic index was detected by methyl green and pyronine Y staining and by terminal deoxynucleotidyl transferase (TdT)mediated dUTP nick end labeling (TUNEL).The bcl-2,bcl-xl,bax and p53 gene expression of HR8348 cells were examined by immunohistochemical method.Results After treatment with 5-FU,the apoptotic index of experiment group was significantly increased,there was significant difference as compared with the control.Exposed to 5-FU for 12 h,24 h and 36 h,the expression of bcl-2 of HR8348 cell line remained unchanged,but the expression of bcl-xl slightly diminished,while the expression of bax was remarkly increased,the expression of p53 was not detected in both experiment and control groups.Conclusion This results indicate that 5-FU may induce apoptosis of rectal carcinoma cell line HR8348 and the possible mechanism of apoptosis induction is through upregulation of bax expression and the change of bax to bcl-xl ratio.
Objective To investigate the mechanism of the resistance of pancreatic cancer cells to tumor necrosis factor related apoptosis inducing ligand (TRAIL)mediated apoptosis. MethodsThe expression of TRAIL receptor-4 (TRAIL-R4) in normal pancreas tissue and pancreatic cancer was analyzed by using Northern blotting, Western blotting and immunohistochemistry.ResultsTRAIL-R4 mRNA and protein were expressed at moderate to high levels in human pancreatic cancer, but demonstrated weak to negative in the normal pancreas. Moreover, pancreatic cancer cells showed b TRAIL-R4 immunostaining throughout the tumor mass. Conclusion TRAIL-R4 levels are significantly different in pancreatic cancer in comparison to the normal pancreas. These findings give new insights into the resistance mechanisms of pancreatic cancer cells towards TRAILmediated apoptosis.