Silencing of Bcl-2 gene expression by siRNA transfection in- hibits the protective effect of fluvastatin against cell apoptosis in human aortic endothelial cells

Objective To study the protective effect of fluvastatin,one of the HMG-CoA reductase inhibitors (statins),against oxygen radical-induced oxidative damages in human aortic endothelial cell,and the role of Bcl-2 in this protection.Methods Human aortic endothelial cells with or without Bcl-2 siRNA transfection were subjected to 1-100 nM of fluvastatin and 100 la hydrogen peroxide for 24 hours.Bcl-2 mRNA and protein expression were measured by Taqman quantitative PCR and Western blotting.Cell apoptosis was measured by normal and fluorescent microscopy and Cell Death Detection ELISA.Results In the Bcl-2-expressed cells,fluvastatin significantly reversed hydrogen peroxide-induced microscopic apoptosis and apoptotic DNA fragmentation,which were accompanied by a markedly upregulation of Bcl-2 expression by fluvastatin.However,the endothelial protection by fluvastatin was completely lost in Bcl-2 siRNA transfected cells.Conclusion Fluvastatin protects human endothelial cells against oxygen radical-induced cell apoptosis in vitro,and this protection seemed to be mediated in a Bcl-2 dependent pathway.(J Geriatr Cardil 12008;5:33-38)

Correlation between expression of gastrin, somatostatin and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma

AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma.METHODS: Sixty-two large intestine cancer tissue samples were randomly and retrospectively selected from patients with large intestine carcinoma. Immunohistochemical staining for bcl-2, bax, GAS, SS was performed according to the standard streptavidin-biotin-peroxidase (S-P) method.According to the semi-quantitative integral evaluation, SS and GAS were divided into three groups as follows. Scores1-3 were defined as the low expression group, 4-8 as the intermediate expression group, 9-16 as the high expression group. Bax and bcl-2 protein expressions in different GAS and SS expression groups of large intestine carcinoma were assessed.RESULTS: The positive expression rate of bax had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 9.246; P＜0.05,x2GAS = 6.981). The positive expression rate of bax in SS high (80.0%, 8/10) and intermediate (76.5%, 13/17)expression groups was higher than that in low expression group (40.0%, 14/35) (P＜0.05, x2high vs low = 5.242; P＜0.05,x2middle vs low = 6.097). The positive expression rate of bax in GAS high expression group (27.3%, 3/8) was lower than that in low expression group (69.4%, 25/36) (P＜0.05,x2 = 4.594). However, bax expression in GAS intermediate expression group (46.7%, 7/15) was lower than that in low expression group, but not statistically significant. The positive expression rate of bcl-2 had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 7.178; P＜0.05, x2GAS = 13.831). The positive expression rate of bcl-2 in GAS high (90.9%, 10/11)and intermediate (86.7%, 13/15) expression groups was higher than that in low expression group (44.4%, 16/36)(P＜0.05,x2high vs low = 5.600; P＜0.05, x2 middle vs low = 7.695).However, the positive expression rate of bcl-2 in SS high (40.0%, 4/10) and intermediate (47.1%, 8/9) expression groups was lower than that in low expression group (77.1%, 27/35)(P＜0.05, x2 high vs low = 4.710; P＜0.05, x2 middle vs low = 4.706).There was a significant positive correlation between the integral ratio of GAS to SS and the integral of bcl-2 (P＜0.01,r=0.340). However, there was a negative correlation between the integral ratio of GAS to the SS and bax the integral of (P＜0.05, r = -0.299).CONCLUSION: The regulation and control of gastrin,somatostatin in cell apoptosis of large intestine carcinoma may be directly related to the abnormal expression of bcl-2, bax.

Effects of Bcl-2 Gene Interference on the Apoptosis,Proliferation and Progesterone Secretion of Goose Follicular Granulosa Cells

Based on published sequences for chicken Bcl-2,three siRNAs（small interfering RNA）were designed,and expression vectors were constructed and transfected into goose granulosa cells cultured in vitro.Bcl-2 protein,apoptosis and proliferation of granulosa cells,48 h after the transf ection,were analyzed by flow cytometry,and progesterone（P）secreted into the culture medium was measured by radioimmunoassay.In addition,apoptosis and Bcl-2 protein level were assessed in untreated granulosa cells from the four largest preovulatory follicles（F1F4）,the smallest preovulatory follicles（SPF）,small yellow follicles（SYF）and atretic follicles.The highest level of Bcl-2 protein was observed in granulosa cells from SPF,and levels in cells from healthy follicles were significantly higher than those of atretic follicles（P【0.05）.Bcl-2 protein levels in cells subjected to RNAi were significantly lower than those of controls（P【0.05）,while apoptosis indices（AI）,proliferation indices（PI）and P secretion in the RNAi treatments were higher than those of controls（P【0.05）.

Simvastatin inhibits apoptosis of endothelial cells induced by sepsis through upregulating the expression of Bcl-2 and downregulating Bax

BACKGROUND: Many studies have showed that apoptosis of endothelial cells plays a curial role in the progress of sepsis. But the role of simvastatin in apoptosis of endothelial cells induced by sepsis is not clear. The present study aimed to investigate the role of simvastatin in apoptosis of endothelial cells induced by sepsis and its mechanism.METHODS: Human umbilical vein endothelial cells(HUVECs) were randomly divided into three groups: control group, sepsis serum intervention group(sepsis group) and simvastatin+sepsis serum intervention group(simvastatin group). After 24-hour incubation with corresponding culture medium, the relative growth rate of HUVECS in different groups was detected by MTT assay; the apoptosis of HUVECs was detected by Hoechst33258 assay and fl ow cytometry; and the expression of the Bcl-2 and Bax genes of HUVECs was detected by PCR.RESULTS: Compared with the sepsis group, HUVECs in the simvastatin group had a higher relative growth rate. Apoptotic HUVECs decreased significantly in the simvastatin group in comparison with the sepsis group. Expression of the Bcl-2 gene in HUVECs decreased obviously, but the expression of the Bax gene increased obviously after 24-hour incubation with sepsis serum; however, the expression of the Bcl-2 and Bax genes was just the opposite in the simvastatin group.CONCLUSIONS: Our study suggests that simvastatin can inhibit apoptosis of endothelial cells induced by sepsis through upregulating the expression of Bcl-2 and downregulating Bax. It may be one of the mechanisms for simvastatin to treat sepsis.

Expression of bcl-2 gene increases in apoptosis of vascular endothelial cells induced by rattlesnake venom

Apoptosis of vascular endothelial cells (VEC) has been induced by deprivation of survival factors (aFGF and serum) and by rattlesnake venom. The expression of bcl-2 gene has been examined by Northern blotting in the two apoptosis inducing systems. Our results show that the expression of bcl-2 has not been detected in normal culture cells and in apoptotic cells induced by deprivation of survival factors. But in apoptotic cells induced by rattlesnake venom (10 μg/mL), the expression of bcl-2 increases, and its mRNA exhibits two bands. The data first suggest that increasing expression and splitting of bcl-2 mRNA may play an important role in apoptosis of VEC induced by rattlesnake venom, and this finding is helpful to understanding the role of bcl-2 in regulation of apoptosis.

^(103)Pd-induced apoptosis of proliferative smooth muscle cells in bile ducts of dogs:significance and effects on related genes

BACKGROUND:With the objective of developing a locally- produced radioactive stent,the present study used in vivo animal experiments to explore apoptosis of proliferative smooth muscle cells resulting from facilitation of the expression of genes caused byγ-radiation in order to prevent bile duct restenosis.We therefore explored the effects and significance ofγ-radiation on the activity of caspase-3,Fas and Bcl-2 genes in apoptosis of proliferative smooth muscle cells in the bile duct walls of dogs. METHODS:Twelve dogs were randomly divided into 2 groups(6 in each group).A postinjury bile duct stenosis model was established and radioactive 103 Pd( 103 palladium) or ordinary bile duct stents were implanted into the bile ducts.HE staining,RT-PCR and immunohistochemistry were used to detect the proliferation and apoptosis of bile duct smooth muscle cells in proliferative endomembrane and the expression of related caspase-3,Bcl-2 and Fas genes. RESULTS:The expression of caspase-3 and Fas genes in the bile duct tissues of dogs with radioactive stents was higher than that of dogs with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the bile ducts.The expression of the Bcl-2 gene in the bile duct tissues of dogs with radioactive stents was lower than that in those with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the dogs with low Bcl-2 gene expression. CONCLUSIONS:Radiation increases the activity of caspase-3 and Fas genes and is associated with apoptosis. The radioactive 103 Pd stent may facilitate apoptosis of proliferative smooth muscle cells in the bile ducts of dogs by activating these genes.The Bcl-2 gene expression level is correlated with the occurrence of apoptosis and the radiosusceptibility of cells.

Detection of apoptotic cells and immunohistochemical study of bcl-2 and p53 gene protein in primary gastric mucosa-associated lymphoid tissue (MALT) lymphoma

To identify the apoptotic cells in gastric MALT lymphoma and its relationship between bcl-2 and p53 gene expression. Methods: TdT-mediated dUTP biotin Nick End labeling (TUNEL) and immuno-histochemistry ABC method were used to display apoptotic cells and the gene protein expression of bcl-2 and p53 independently. Results: Apoptotic indices (AI) in high-grade MALT lymphomas were significantly higher than in mixed-grade group and low-grade group (P<0.05). Bcl-2 was expressed in 83% of low-grade tumors, 61.6% of the median-grade tumors and 43.7% of high-grade tumors. An inverse correlation was observed between the expression of bcl-2 and apoptotic indices. Only 27 cases were p53 positive. The frequency of p53 positivity was significantly increased as the histologic grade advanced (P<0.05). There was also an inverse correlation between the expression of bcl-2 and p53. Conclusion: Apoptosis may be important in tumors development and transmission. p53 and bcl-2 were important regulatory genes of apoptosis and may be associated with transformation from low- grade to high-grade lymphomas.

Effect of Bushenyisui Formula on brain tissue apoptosis and Bcl-2 in beta-amyloid protein-induced Alzheimer's disease rat models

OBJECTIVE： To investigate the effect of Bushenyisui Formula on cell apoptosis and positive B cell lym- phoma （Bcl-2） in the Brain of rat models of Alzheim- er＇s disease （AD） induced by beta-amyloid protein （All3） and the mechanism underlying the effect. METHODS： Total of 40 SD rats, 20 females and 20 males, were randomly assigned to 4 groups, con- trolled group （A）, model group （B）, conventional treatment group （C） and Bushenyisui Formula treat- ment （BYFT） group （D）, 10 rats in each group. AI3 1-42 was injected into the bilateral hippocampus of the rats in group B, C and D to create the models of AD. Sham operation was performed on the rats of group A in the same way by injecting equal volume of 0.9% sodium chloride solution into their bilateral hippocampus. 5 days after operation, Bushenyisui Formula was intraperitoneally administered at a dose of 450 mg/kg to the rats of group D （QD） for 20 days. Equal volume of 0.9% sodium chloride solution was intraperitoneally injected into the rats of group B with the same procedure. C suspension （20 mg/mL） was intraperitoneally injected into the rats of group B with the same procedure. The number of apoptot- ic cells in Brain and the positive Bcl-2 were count- ed. The changes of learning and memory abilities were evaluated using Y-maze. RESULTS： Right after the establishment of the mod- els, group B, C and D compared to group A respec- tively, the outcomes of Y-maze were significantly different from that of group A, which suggested ob- vious learning and memory disorder in those groups （P〈0.01）. After treatment, the times of elec- tronic shocks of group C and D were significantly less than that of group B （P〈0.05）, and the numbers of apoptotic cells and positive Bcl-2 were signifi- cantly different from those of group B, apoptotic sells＇ number of group C and D smaller than that of group B and the number of positive Bcl-2 greater than that of group B. CONCLUSION： Bushenyisui Formula could increase the number of Bcl-2 in brain, which improved the function of nervous system pertaining to learning and memory abilities.

Relationship between expression and distribution of cyclooxygenase-2 and bcl-2 in human gastric adenocarcinoma

AIM: To explore expression and distribution features of COX-2 and bcl-2 in human gastric adenocarcinoma tissues and to study its biological significance.METHODS: Totally 36 human gastric carcinoma samples were enrolled in this study (cardiac adenocarcinoma 16 cases, distal gastric adenocarcinoma 20 cases). The expressions of COX-2 and bcl-2 in cancerous tissues and corresponding para-cancerous tissues were investigated by immunohistochemistry using COX-2 polyclonal antibody and bcl-2 monoclonal antibody. The normal gastric mucosa tissues were used as control.RESULTS: The expressions of COX-2 and bcl-2 in gastric carcinoma were significantly higher than that in the paracancerous tissues (77.8% vs 47.2%, P＜0.01, 80.56% vs 58.33%, P＜0.05). The expression of COX-2 in cardiac adenocarcinoma was remarkably higher than that in the distal gastric carcinoma (93.8% vs 65.0%, P＜0.01). The expression of COX-2 was mainly localized in the cytoplasm of tumor cells and partly in the nucleus. There is a transition of the COX-2 cytoplasmic positivity to nucleic in tumor cells with the increase of gastric carcinoma pathological grade. Interstitial macrophages, fibroblasts and vascular endothelial cells also expressed COX-2. The tissues with higher expression of COX-2 also expressed high level of bcl-2 protein.CONCLUSION: Abnormal expression pattern of COX-2within the tissues of human gastric cancer is correlated with tumor location and lymph node metastasis. COX-2may regulate expression of apoptosis suppressor gene (bcl-2) through interaction of tumor cells and stromal cells and play an important role in the generation and development of tumors, which will be of great help in developing new methods for antitumor therapy.

Effect of basic fibroblast growth factor and danshen on bcl-2 and p53 mRNA expression in the brain of rats exposed to repeated, high, positive acceleration (+Gz)

BACKGROUND： Both animal experiments and clinical studies have shown that basic fibroblast growth factor （bFGF） and danshen （Salvia miltiorrhiza） can exhibit protective effects on ischemia-reperfusion cerebral injury. OBJECTIVE： To test whether bFGF and danshen can protect cerebral injury induced by exposure to repeated, high, positive acceleration （＋Gz） in an animal model and to analyze the possible mechanisms. DESIGN, TIME AND SETTING： Randomized controlled animal study. The experiment was performed at the Research Center for Molecular Biology, Air-force General Hospital of Chinese PLA from April to August 2000. MATERIALS： A total of 20 clean grade, healthy, Sprague Dawley rats of both genders, weighing （200 ± 15） g, were provided by our experimental animal center. Rats were randomly divided into 5 groups： the control group, ＋Gz exposure group, bFGF group, danshen group, and saline group, with 4 animals per group. bFGF （Beijing Bailuyuan Biotechnology Co. Ltd.） and danshen solution （Shanghai Zhongxi Pharmaceutical Co. Ltd.） were used. METHODS： All rats were fixed on a rotary arm of a centrifugal apparatus （2 m in radius） with their heads oriented towards the center of the apparatus. Except for rats in the control group, the value of ＋Gz exposure was ＋14 Gz with an acceleration rate of 1.5 G/s. The peak force lasted for 45 seconds. ＋Gz exposure was performed three times with intervals of 30 minutes. Rats in the control group received the same ＋Gz procedure, but the G value was ＋1 Gz. Rats in bFGF group and danshen group were intraperitoneally injected with 100 μg/kg bFGF or 15 g/kg danshen solution, respectively, at 30 minutes prior to centrifugation and immediately after centrifugation. Rats in saline group were injected with the same volume of saline. Six hours after exposure, rats were decapitated. One hemisphere was preserved in liquid nitrogen for RNA extraction and the other was processed for apoptosis detection. MAIN OUTCOME MEASURES： mRNA levels of bcl-2 and p53 were measured by semi-quantitative reverse-transcription polymerase chain reaction. Apoptotic cell death was detected by terminal deoxynuleotidyl transferase-mediated dUTP nick end labeling. RESULTS： Changes in mRNA expression of bcl-2 and p53 and apoptotic cells were observed in rat brain six hours after repeated ＋Gz exposures, bFGF and danshen were able block the changes of bcl-2 and p53 expression and inhibit apoptotic cell death. CONCLUSION： The data suggest that apoptosis and changes in bcl-2 and p53 expression in the rat brain can be induced by repeated ＋Gz exposures. Apoptosis is, therefore, one of the molecular mechanisms of brain damage induced by repeated ＋Gz exposures, bFGF and danshen were of the equal potency in preventing brain injury induced by repeated ＋Gz exposures.

RADIATION-INDUCED APOPTOSIS OF TWO NASOPHARANGEALCARCINOMA CELL LINES

Objective: To study apoptosis induced by radiation in two nasopharyngeal carcinoma (NPC) cell lines, CNE and CNE-2. Methods: Hoechst 33342 staining, immuno-histochemical staining, RT-PCR, DNA dot blotting and Southern blotting were used to identify apoptosis. Results: A single dose of X-irradiation resulted in apoptosis, the apoptotic index (AI) was time- and dose-dependent. Different apoptotic responses existed in the two cell lines. Immunohistochemical staining showed that bcl-2 protein was strongly positive in CNE but negative in CNE-2. However, RT-PCR revealed p53 mRNA in CNE-2 but not in CNE. P53 and bcl-2 genes were both present in the two cell lines as shown by DNA blotting, but the 2.8 kb fragment of the p53 gene was much lower than the 5.6 kb fragment on CNE which was clearly shown in Southern hybridization, suggestive of partial deletion of p53 gene in CNE. Conclusion: Apoptotic response to radiation is different in two NPC cell lines. CNE is more radioresistant than CNE-2. Overexpression of bcl-2 protein and partial deletion of p53 gene may explain their difference in radiosensitivity.

Prognostic role of sensitive-to-apoptosis gene expression in rectal cancer

AIM:To investigate the association between prognosis of rectal cancer treated with chemoradiotherapy(CRT) and expression of sensitive-to-apoptosis(SAG),B-cell lymphoma-extra large(Bcl-X L) and Bcl-2 homologous antagonist/killer(Bak).METHODS:Real-time quantitative polymerase chain reaction was used to determine the expression of proteins of interest,namely SAG,Bcl-X L,Bak and β-actin,in rectal carcinoma patients who had a follow-up period of 3 years after CRT.Biopsy specimens were excised from the rectal tumor preceding CRT.RESULTS:SAG,Bcl-X L and Bak proteins showed significant correlations with each other.In multivariate analysis,patients with high vs low SAG expression showed a statistically significant difference in 2-year survival rates:56% vs 73%,respectively(P = 0.056).On the other hand,there were no significant correlations between the expression levels of all three genes and metastatic rates or tumor responses to CRT.Mean overall survival in the patients with elevated SAG expression was 27.1 mo ± 3.9 mo [95% confidence interval(CI):19.3-34.9],and in patients with reduced expression,it was 32.1 mo ± 2.5 mo(95% CI:27.3-36.9).The corresponding values for Bcl-X L were 28.0 mo ± 4.1 mo(95% CI:19.9-36.1) and 31.7 mo ± 2.9 mo(95% CI:26.0-37.5),and those for Bak were 29.8 mo ± 3.7 mo(95% CI:22.5-37.2) and 30.6 mo ± 2.4 mo(95% CI:25.5-35.0),respectively.CONCLUSION:Two-year survival rates significantly correlated with low SAG expression,and SAG may be a candidate gene for good prognosis,independent of therapeutic response of different individuals.

Telomerase activity and expression of the telomerase catalytic subunit gene in non small cell lung cancer: correlation with decreased apoptosis and clinical prognosis

To investigate the level of telomerase activation (TA) and telomerase catalytic subunit (hEST 2) gene mRNA in patients with non small cell lung cancer, and determine whether they are associated with tumor cell apoptosis, stage, and clinical outcome Methods Primary tumor specimens from 58 patients untreated with chemotherapy and 10 cases of histologically benign and adjacent lung tissue were analyzed TA and hEST 2 were measured by means of a modified telomerase repeat amplification protocol (TRAP) assay and in situ hybridization (ISH), respectively Terminal deoxynucleotidyl transferase (TdT) mediated biotin dUTP nick end labeling (TUNEL) was used to evaluate apoptotic cells Reverse transcription polymerase chain reaction (RT PCR) was used to detect bcl 2 mRNA expression Results TA and hEST 2 were detected in 45 (77 6%) and 43 (74 1%) of 58 tumor specimens, respectively, and not detected in specimens of adjacent and benign lung tissue One case expressed hEST 2 as a weak positive Statistically significant positive association was found between the level of TA and hEST 2( r =0 85, P =0 001) TA and hEST 2 were associated with tumor stage, but not associated with tumor grade, gender and patient age Positive rate of bcl 2 mRNA was 38 (65 5%) of 58 tumor specimens The mean apoptotic index in the bcl 2 positive group (9 5±1 3) was lower than that in the bcl 2 negative one (19 8±2 1, P <0.05), suggesting that apoptotic index may be inversely associated with bcl 2 expression ( r =-0 48, P =0 041) Bcl 2 expression in the TA and hEST 2 positive group (92 1% and 89 4%) was higher than that in the negative one (50 0% and 45 0%, P =0 043 and P =0 032, respectively) The apoptotic index was lower in the TA or hEST 2 positive group (8 2±1 4, 10 7±1 1) than in the negative one (20 5±1 6, 24 2±2 1, P <0 05) A statistically significant inverse association was found between TA or hEST 2 and apoptotic index ( r =-0 45, P =0 02 and r = -0 51, P =0 001, respectively) Positive correlation was also detected between TA or hEST 2 and bcl 2 expression ( r =0 86, P =0 01 and r =0 73, P =0 024, respectively) The level of hEST 2 mRNA and apoptotic index were associated with clinical outcome in a multivariate cox regression analysis Conclusions High TA and hEST 2 were frequently detected in primary non small cell lung cancer untreated with chemotherapy, having high bcl 2 expression and a low tumor cell apoptotic rate This suggests that both TA and hEST 2 are correlated with the deregulation of apoptosis hEST 2 and apoptotic index have prognostic significance in patients with non small cell lung cancer

Visualized and cascade-enhanced gene silencing by smart DNAzyme-graphene nanocomplex

BCL-2 gene as well as its products is recognized as a promising target for the molecular targeted therapy of tumors.However,due to certain defense measures of tumor cells,the therapeutic effect based on the gene silencing of BCL-2 is greatly reduced.Here we fabricate a smart response nucleic acid therapeutic that could silence the gene effectively through a dual-targeted and cascade-enhanced strategy.In brief,nano-graphene oxide(GO),working as a nano-carrier,is loaded with a well-designed DNAzyme,which can target and silence the BCL-2 mRNA.Furthermore,upon binding with the BCL-2 mRNA,the enzymatic activity of the DNAzyme can be initiated,cutting a substrate oligonucleotide to produce an anti-nucleolin aptamer AS1411.Nucleolin,a nucleolar phosphoprotein,is known as a stabilizer of BCL-2 mRNA.Via binding and inactivating the nucleolin,AS1411 can destabilize BCL-2 mRNA.By this means of simultaneously targeting mRNA and its stabilizer in an integrated system,effective silencing of the BCL-2 gene of tumor cells is achieved at both the cellular and in vivo levels.After being dosed with this nucleic acid therapeutic and without any chemotherapeutics,apoptosis of tumor cells at the cellular level and apparent shrinkage of tumors in vivo are observed.By labeling a molecular beacon on the substrate of DNAzyme,visualization of the enzymatic activity as well as the tumor in vivo can be also achieved.Our work presents a pure bio-therapeutic strategy that has positive implications for enhancing tumor treatment and avoiding side effects of chemotherapeutics.

Apoptosis of human colon carcinoma HT-29 cells induced by ceramide

AIM： To investigate the effect of exogenous ceramideinduced apoptosis on human colon carcinoma HT-29 cells. METHODS： Light microscope, transmission electron microscope and fluorescence microscope were used to observe the morphology change of apoptosis in HT-29 cells. Agarose gel electrophoresis was performed to detect the DNA fragment. Mitochondrial function was detected by MTT assay, mRNA expression of Bcl-2 family gene members was determined by reverse transcription polymerase chain reaction （RT-PCR） assay. RESULTS： After C2-ceramide treatment, typical characteristics of apoptosis, such as nuclear chromatin breakage, apoptotic body and DNA ladder, could be observed. After exposure to 50μmol/L C2-ceramide for 12 and 24 h, cell apoptosis was 64.1% and 81.3% respectively, which had a time-and dose-effect relationship. Mitochondrial function started to decrease from 6 h after exposure to ceramide. Meanwhile, ceramide up-regulated or down-regulated the mRNA expression of Bcl-2 family gene members. CONCLUSION： Ceramide induces apoptosis of human colon carcinoma HT-29 cells by affecting the expression of Bcl-2 family gene members and impacting the mitochondrial function.

应用RNAi沉默STAT3基因促裸鼠移植瘤细胞凋亡及对Bax/Bcl-2基因表达的影响

目的应用RNAi技术沉默信号转导子与转录活化子3(STAT3)基因,探讨其对人乳腺癌裸鼠移植瘤的细胞凋亡及其对Bax/Bcl2基因表达的影响。方法于雌裸鼠皮下种植MCF7细胞,肿瘤长至一定大小时,随机分为盐水对照(A)组、空质粒对照(B)组及实验(C)组。于肿瘤局部分别注射盐水、psilencer1.0U6空质粒和psilencer1.0U6STAT3siRNA重组质粒。当A组肿瘤长至足够大时处死全部动物,取肿瘤,测其大小及重量,行HE及免疫组化染色,同时用Westernblot检测STAT3,Bax,Bcl2基因的表达水平。结果C组肿瘤瘤块的体积和重量明显小于A,B组(P<0.01)。免疫组化及HE显示C组肿瘤中心区出现大面积细胞坏死及细胞凋亡征象,STAT3免疫组化呈阴性,而A,B组无此现象。Westernblot显示C组STAT3的表达明显低于A,B组(P<0.01),而Bax的表达明显高于A,B组(P<0.05),各组Bcl2的表达水平差异无显著性(P<0.05)。结论应用RNAi技术沉默STAT3基因可以降低人乳腺癌裸鼠移植瘤中STAT3的表达,同时引起Bax基因的表达上调,导致细胞凋亡进而抑制肿瘤的生长。

Effect of Lichong decoction on expression of Bcl-2 and Bcl-2-associated X protein mRNAs in hysteromyoma model rat

OBJECTIVE:To study on effects of Lichong decoction on expression of apoptosis-controlling genes,Bcl-2 and Bcl-2-associated X protein(Bax) mRNAs in hysteromyoma tissue of the hysteromyoma model rat.METHODS:Fifty Wistar female rats were randomly divided into a normal group,a model group,a Lichong decoction group,a Guizifuling capsule group and a Mifepristone group.The hysteromyoma rat model was established by intraperitoneal injection of exogenous estrin and progestogens.Pathological examination of uterine tissue,uterine coefficient and uterine transverse diameter were made under optic microscope and expressions of Bcl-2 and Bax mRNAs in uterine tissue in the groups were detected with real-time fluorescent quantitative polymerase chain reaction(PCR) technique.RESULTS:After treatment,under microscope it was found that in the Lichong decoction group myometrium thinned,muscle fiber slightly overgrowth or long and thin,regular arrangement,inserting phenomenon of inner circular muscle and external longitudinal muscle was occasionally or not seen in the Lichong decoction group.The uterine coefficient and the uterine transverse diameter significantly decreased(P<0.01),and Bcl-2 mRNA expression significantly decreased(P<0.01) and Bax mRNA expression significantly increased in hysteromyoma tissue(P<0.01) in the Lichong decoction group as compared with the model group.CONCLUSION:Therapeutic effects of Lichong decoction on hysteromyoma is related with decrease of Bcl-2 mRNA expression and increase of Bax mRNA expression.

Effects of penehyclidine hydrochloride on apoptosis of lung tissues in rats with traumatic acute lung injury

Objective： To investigate the effects ofpenehyclidine hydrochloride on apoptosis of lung tissue cells and its mechanism in acute lung injury following blunt chest trauma in rats. Methods： Sprague Dawley （SD） rats （n=54） weighing （250-25） g were divided equally and randomly into three groups： normal control group （C group, n= 18）, trauma model group （T group, n= 18） and penehyclidine hydrochloride treatment group （P group, n=18）. Each group was further divided into three subgroups according to the time points of 3, 12 and 24 hours after experiment （at each time point, n=6 for each subgroup）. Rats of P group were intraperitoneally injected with penehyclidine hydrochloride for 2 mg/kg immediately after blunt chest trauma and rats in its 24 hours subgroup were once again injected with penehyclidine hy- drochloride in the same dose 12 hours after injury. Lung tissue samples were collected at every time point and cell apoptosis in lung tissues were measured by TUNEL. Apoptotic index （AI） was calculated, expressions of bax and bcl-2 were detected by immunohistochemical staining of SABC, and lung tissue sections were taken for light and electron microscopic observation. Results： As compared with C group, at every time point, AI and expressions ofbax and bcl-2 in T group were higher （P〈0.05）, and the ratio of bcl-2/bax markedly decreased （P〈0.05）, especially in the 24 hours subgroup. The ratio in T group （0.468±0.007） was lower than that in C group （1.382±0.058, t=12.5, P〈0.01）. Lung tissue injuries were significant under a light microscope, and the number of apoptotic cells increased obviously under a transmission electron microscope. As compared with T group at the same phase, AI and expression of bax decreased in P group （P〈0.05 and P〈0.01）, while the expression of bcl-2 increased significantly （P〈0.01）, and the ratio of bcl-2/bax markedly increased （P〈0.05）, especially in the 24 hours subgroup. The ratio in P group （1.012-0.070） was much higher than that in T group （0.468±0.007, t=-8.3, P〈0.01）. The injury of lung tissues was relieved, and apoptosis of cells decreased obviously under a transmission electron microscopic observation. Conclusions： Apoptosis and expressions ofbax and bcl-2 in lung tissues might be involved in the pathogenesis of lung injury induced by blunt chest trauma. Penehyclidine hydrochloride can alleviate lung injuries by inhibiting apoptosis of lung tissue cells, during which effects ofpenehyclidine hydrochloride on regulating expressions ofbax and bcl-2 may play an important role.

Endoplasmic reticulum stress is involved in acetylated low-density lipoprotein induced apoptosis in THP-1 differentiated macrophages

Background Cardiovascular disease is a major cause of mortality and morbidity in patients with chronic kidney disease Macrophage death in advanced atherosclerosJs promotes necrosis and plaque destabilization. In vitro data from peritoneal macrophages show apoptosis triggered through endoplasmic reticulum （ER） stress caused by free cholesterol accumulation plays an important role. Here we used THP-1 cells differentiated by 100 ng/ml of phorbol 12-myristate 13-acetate （PMA） for five days as an in vitro model, to investigate if acetylated low-density lipoprotein （AcLDL） loading could also induce apoptosis and its underlying mechanisms. Methods Oil red O staining was used to examine the lipid droplets. Confocal microscopy was used to visualize the uptake of AcLDL. Hoechst 33258 stain and the caspase 3,7 assay were used to detect apoptosis. High performance liquid chromatography was used in the intracellular free cholesterol （FC） and cholesterol ester （CE） assay. Western blotting was used to demonstrate the protein level. Real-time PCR was used to detect the changes of mRNAs. ER free cholesterol was also assayed. Results Confocal microscopy showed THP-1 cells differentiated by 100 ng/ml of PMA for five days uptake more AcLDL than differentiated for two days. Hoechst 33258 stain showed AcLDL could induce apoptosis in THP-1 macrophages in a time and dose dependent manner. Exposure of THP-1 macrophages to 100 ug/ml of AcLDL for 24 hours resulted in a significant increase in caspase 3,7 activity, a significant increase in FC and CE mass of 1.5 and 2.4-fold, meanwhile, a significant increase in transcription factor C/EBP homologous protein and a decrease in Bcl-2 both in protein and mRNA levels were observed with an 8-fold rise of free cholesterol in the ER. Conclusion ER stress is involved in AcLDL induced apoptosJs in THP-1 macrophages with free cholesterol accumulation in the ER.

RNA干扰抑制SiHaB2细胞中Bcl-2基因的表达

Bcl-2基因作为细胞凋亡的一个潜在抑制剂调节细胞的死亡,抑制恶性肿瘤细胞中Bcl-2基因的表达可促进肿瘤细胞的凋亡。采用RNA干扰技术,合成了含有21个核苷酸的小双链干扰RNA(siRNA-Bcl-2),并构建了含有19个核苷酸基因的质粒载体(pSilencer2.1-U6-Bcl-2),把合成的siRNA-Bcl-2和pSilencer2.1-U6-Bcl-2分别转导入Bcl-2高表达的细胞株SiHaB2中,通过Western印迹检测,免疫荧光法检测及DNA梯(ladder)检测,可观察到在导入siRNA-Bcl-2和pSilencer2.1-U6-Bcl-2的SiHaB2细胞被培养72h后,可以明显抑制Bcl-2蛋白的表达。