OBJECTIVE: To investigate apoptosis of chondrocytes cultured in vitro and related expression of caspase-3. METHODS: Apoptosis of chondrocytes were detected by flow cytometry analysis and TUNEL staining. The expression of caspase-3 was determined by RT-PCR and Western blot, and caspase-3 protein activity was determined by ELISA. RESULTS: Apoptosis was observed in chondrocytes cultured in vitro from passage 1 to passage 4 at various degrees. The percentage of apoptosis of chondrocytes on day 7 was much higher than that on day 3 (15.7% +/- 0.3% vs 8.9% +/- 0.6%, P lt; 0.01). caspase-3 mRNA and protein expressed in chondrocytes during whole culture process. Along with the culture time extension in vitro, caspase-3 expression and protein activity up-regulated, coincident with apoptosis of chondrocyte. caspase-3 was activated and a fragment of 20 kDa was detected after 7 days of culture. CONCLUSION: caspase-3 is involved in apoptosis of chondrocytes cultured in vitro.
Objective To explore the effect of artemisinin on the apoptosis of pancreas acinar cells in acute pancreatitis (AP), and to study whether artemisinin can relieve the severity of AP. Methods ① In vivo experiment: twenty one Wistar rats were divided into the following 3 groups randomly: the normal control group, the AP group and the artemisinin group. The model of AP was established by injecting cerulein into the peritoneal cavity of rat. After establishment of AP in the artemisinin group, artemisinin was injected into the peritoneal cavity. Meanwhile normal saline was injected into the peritoneal cavity of rats of the normal control group and the AP group. The apoptosis of pancreas acinar cell was detected by terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The activity of myeloperoxidase was detected by absorption spectrometry. ② In vitro experiment: the pancreas acinar cells of normal rats were isolated through twostep enzyme digestion, and cultured. These acinar cells were divided into 3 groups: the normal control group, the AP group and the artemisinin group. Then, the cells of AP group were cocultured with cerulein, and those of the artemisinin group were cocultured with cerulein and artemisinin. The apoptosis of pancreas acinar cells were detected by AO dyeing and the measurement of the activity of caspase3. And the activity of LDH and AMS in the culture medium of each group were measured. Results ① In vivo: the apoptosis index of the artemisinin group was sigificantly increased and the activity of myeloperoxidase was obviously decreased compared with the AP group (P＜0.05). ② In vitro: the apoptosis index and the activity of caspase3 of the artemisinin group were significantly increased compared with the AP group (P＜0.05); the activities of LDH and AMS of the artemisinin group were more decreased than those of the AP group (P＜0.05). Conclusion Artemisinin could contribute to the apoptosis of rat pancreas acinar cells, decrease the releasing of trypsogen, alleviate the activation of neutrophil and relieve the severity of AP.
Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12，24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)
OBJECTIVE: To investigate the effect of vasostomy on apoptosis in the male rat spermatogenic cells after vasoligation. METHODS: Model of vasoligation and vasostomy in male rat was established, and then terminal deoxynucleotidyl transferase-mediated dUTP nick labelling technique to detect the apoptosis of spermatogenic cells at 4, 8, 12, 16 weeks after vasostomy. RESULTS: The number of apoptotic cells in vasostomy group was significantly lower than that of vasoligation group since 8 weeks after vasostomy(P lt; 0.05). The number of apoptotic cells in 8 and 12 weeks after vasostomy were significantly higher than that in prevasoligation(P lt; 0.05). 16 weeks after vasostomy, the number of apoptotic cells restored to the level same as that in prevasoligation stage. CONCLUSION: Vasostomy can reverse the apoptosis of spermatogenic cells due to vasoligation.
ObjectiveTo explore the new gene therapy method for tumor, the recombinant Caspase3 gene (rcaspase3) eukaryotic expression plasmid was constructed by molecular biologic method. MethodsThe eukaryotic expression plasmid pcDNA3.1(+)/rCaspase3 was constructed by rearrangement of the large subunit and small subunit of Caspase3 and it was transfected into pancreatic carcinoma cells(PCⅡ). After being transfected, the expression of rCaspase3 mRNA in pancreatic carcinoma cells was detected by RTPCR and it’s apoptotic activity was detected by FCM. ResultsThe sequence of rCaspase3 showed that the recombinant molecules (rCaspase3) now had its’ small subunit preceding its’ large subunit. After pancreatic carcinoma cells being transfected with the pcDNA3.1(+)/rCaspase3 by liposomes, a 894 bp strap was observed by RTPCR. No strap was found in control groups. A transparent hypodiploid karyotype peak was found by FCM.ConclusionThe plasmid of pcDNA3.1(+)/rCaspase3 has been constructed successfully. rCaspase3 has apoptotic activity and can be used as target gene in gene therapy for pancreatic carcinoma.
Objective To observe the effect of a wide range of concentration of arsenic trioxide on hepatoma cell line BEL-7402 with variable duration. Methods The cell activity and morphologic changes were studied after treated with different concentration. The apoptosis were detected by flow cytometry assay and DNA Gel electrophoresis. Results The effect of arsenic trioxide on hepatoma cell lines were dependent on the time and concentration obviously. Hepatoma cells cultured with different concentration presented apoptosis features: i.e. intact cell membrane, chromatin condensation, nucleic fragmentation and apoptotic body formation; flow cytometry analysis showed an arrestment at G2/M phase and a subG1 cell peak, DNA gel electrophoresis showed a marked DNA ladder. Conclusion Arsenic trioxide can obviously inhibit the growth of hepatoma cell lines through inducing hepatoma cell apoptosis.
Objective To study the effect of water soluble chitosan (WSC) on the apoptosis of peritoneal macrophage induced by lipopolysaccharides (LPS), and discuss the mechanism. Methods Peritoneal macrophages were divided to three groups: phosphate buffered saline (PBS) group, LPS group and LPS plus WSC group. At hour 24, apoptosis cell and active caspase-3 were detected by flow cytometry; nitric oxide (NO) was determined with Griess reagent. Results There were more apoptosis cells in the LPS group than the PBS group. The percentage of apoptosis cells was significantly decreased in the LPS plus WSC group than the LPS group. The expression of active caspase-3 and the secretion of NO were also inhibited by WSC after LPS intervention. Conclusion WSC inhibits apoptosis of peritoneal macrophage induced by LPS.
Objective To investigate the inhibitory effects of RNA interference (RNAi) expression vector on the expression of survivin in pancreatic cancer cell PANC-1. Methods The protein and mRNA expressions of survivin were examined with immunofluorescence and RT-PCR. The survivin gene was cloned into the T-vector and sequenced. The RNAi expression vectors targeting survivin, named si-svv-1 and si-svv-2 respectively according to whether they harbored a mutation or no mutation, were constructed and transfected into PANC-1 cells with liposome. The expression of survivin mRNA was detected with RT-PCR. Apoptosis of PANC-1 cells was analyzed with DNA ladder and FACS. Results There was a high degree expression of survivin in PANC-1 cells. The expression of survivin was not inhibited by RNAi expression vectors si-svv-1, but inhibited about (72.43±8.04)% by si-svv-2 and the apoptosis rate of PANC-1 cells increased to （12.36±1.44）% after 72 h. Conclusion The RNAi expression vector can effectively inhibit the expression of survivin in pancreatic cancer cell PANC-1 cells and induce the apoptosis in PANC-1 cells.
Objective To investigate the effect of Wnt/β-catenin signal pathway on the apoptosis in steroid-induced avascular necrosis of femoral head (SANFH) in rats. Methods Seventy-two male Sprague Dawley rats (weighing, 200-230 g) were randomly divided into the control group (group A, n=24), the model group (group B, n=24), and the intervening group (group C, n=24). The rats in groups B and C were injected with lipopolysaccharide and methylprednisolone (MPS) to establish the SANFH model. The rats in group C were injected intramuscularly with human recombinant secreted frizzled related protein 1 (SFRP1) [1 μg/(kg·d)] at the first time of MPS administration for 30 days. The rats in group A received saline injection at the same injection time of group B. The general condition of rats in groups B and C was observed during modeling and after modeling. At 2, 4, and 8 weeks after last injection of MPS, 8 rats were sacrificed to harvest the femoral head. Histological staining was performed to evaluate osteonecrosis. Apoptosis was detected via TUNEL staining. The expressions of Wnt/β-cate nin pathway signaling molecules (activated β-catenin and c-Myc) were detected by immunohistochemistry and Western blot. Results Six rats were added in groups B and C because of 6 deaths. The other rats survived to the end of experiment. Normal bone structure was observed in group A; osteonecrosis of bone structure disturbance and disruption of the trabecula were found with time in groups B and C. Group C had the highest empty lacuna rate and apoptosis rate, followed by groups B and A, showing significant difference between groups (P < 0.05). The expression levels of activated β-catenin and c-Myc were significantly lower in group C than groups A and B (P < 0.05), and in group B than group A (P < 0.05). Conclusion Wnt/β-catenin signal pathway is involved in the pathogenesis in early SANFH model and its possible mechanism is to affect the cell cycle and cell apoptosis by the regulation of c-Myc expression.
Objective To observe the proapoptotic effect ofthe homogenate of different parts of pig’s full thickness dermal wounds on cultured fibroblasts. Methods The tissues were dissected from the wound center and subneoepithelium separately 15 days after homogenization and sterilization, the specimens stored at -70℃. The forth passage of the fibroblasts were cultured for 16 hours in different culture solutions and were grouped into 7 groups: DMEM containing 5% fetal bovine serum as Group Ⅰ, DMEM containing 5% homogenate of tissue from wound center as GroupⅡ, DMEM containing 5% homogenate of tissue from subneoepithelium as Group Ⅲ, the culture solution of Group Ⅱmixed with 10 μg/ml GM6001 in Group Ⅳ, with the culturing medium of Group Ⅲplus 10 μg/ml GM6001 as Group Ⅴ, the culture solution of Group Ⅱ mixed with 10 ng/ml aFGF as Group Ⅵ, and the culture solution of Group Ⅲ mixed with 10 ng/ml aFGF as Group Ⅶ. In all groups except Group Ⅰ, the fibroblasts of the 6 pigs were treated with the homogenate derived from the same animal respectively. After being incubated in Annexin Ⅴ-FITC and PI, cells were analyzed by Flow Cytometry and the rate of apoptotic cells was acquired. The data were analyzed by SPSS 11.0 using Leastsignificant Difference test(LSD). Results The apoptotic rate of the 7 groups were as follows:4.39%±0.41% in Group Ⅰ，10.98%±1.42% in Group Ⅱ，13.47%±1.44% in Group Ⅲ，7.2%±0.46% in Group Ⅳ，12.1%±0.85% in Group Ⅴ，3.9%±0.63% in Group Ⅵ，9.8%±0.50% in Group Ⅶ； there were significant differences between every two groups except Group Ⅰand Group Ⅵ. Conclusion Homogenate of the tissue derived from the subneoepithelium has greater proapoptotic effect than that from the wound center; the proapoptotic effect of homogenate of the tissue both under neoepithelium and in wound center can be significantly alleviated by acid fibroblast growth factor, partly because of MMPs.