Roles of Protein Kinase C and Fructose in Hepatic Injury Caused by Obstructive Jaundice

Summary： The regulating mechanism in hepatic injury caused by obstructive jaundice （OJ） was examined in this study. Rat hepatocytes were harvested by in situ collagenase perfusion and subjected to primary culture. The heptocytes were pre-treated with various concentrations of protein kinase C （PKC） agonist PMA and its inhibitor chelerythrine and cultured for 20 min. After the treatment, 50μmol/L glycochenodeoxycholate （GCDC） was added and the cells were cultured for an additional 24 h. Cells were then detected by flow cytometry （FCM） and TUNEL. After hepatocytes were treated with different concentrations of fructose and 100μM GCDC, the cells were examined by FCM and TUNEL. Experimental obstructive jaundice （BDL） was induced by double ligation of the bile duct. After BDL, the rats were fed with or without fructos and sacrificed 3, 7, 14 and 21 days after the ligation. The apoptotic status was observed in liver of all rats with TUNEL and PKC protein in liver of OJ was studied by immunohistochemical method. Our results showed that PMA increased GCDC-induced apoptosis and chelerythrine decreased GCSX-induced apoptosis in a concentration-dependent manner. After the treatment with fructose of different concentrations, 100μM GCDC decreased the apoptotic rate and the apoptotic rate decreased with the increase of fructose concentration. The apoptotic rate of liver was related to the time of OJ. Without the treatment of fructose, PKC and apoptosis index （AI） were highest 14 days after the bile duct ligation. With the treatment of fructose, apoptosis index （AI） and PKC were decreased from the 14th day after the bile duct ligation. It is concluded that PKC is involved in the regulation of apoptosis in the liver cells with OJ and plays important roles in the development and progression of liver injury caused by OJ. Fructose can protect hepatocytes in the bile salt-induced apoptosis by regulating PKC.     

Transient retinal ischemia-reperfusion in rats

Objective To investigate the effect of transient ischemia-reperfusion on the retina in rats. Methods Retinal ischemia-reperfusion was induced in rats by increasing the intraocular pressure.After 1 or 5 minutes of ischemia, retinal neuronal cell death at diffesent periods of reperfusion was studied using the TdT-deoxynucleotide terminal nick-end labeling (TUNEL) method and light microscopy.Retinal IL-1β and TNFα were quantified by an enzyme-linked immunosorbent assay (ELISA). Results A few migrating leukocytes were noticed in the retina after transient retinal ischemia-reperfusion. Rare TUNEL-positive (T+) cells were noticed in the outer granular layer or the rod and cone layer, and not in ganglion cell layer in control eyes, but they were significantly increased in the outer granular layer, the inner granular layer, and ganglion cell layer in the eyes treated with 1 or 5 minutes of retinal ischemia-reperfusion (P<0.05).Retinal IL-1β was significantly increased at 6 hours after reperfusion in the eyes treated with 1 or 5 minutes ischemia over the control eyes (P<0.05), but retinal TNFα was not significantly increased (P>0.05 ). Conclusion Transient retinal ischemia-reperfusion for only 1 or 5 minutes of ischemia can induce the upregulation of retinal IL-1β and apoptosis of retinal neuronal cells.This kind of apoptosis in individual cells, however, was not sufficient to affect the whole retinal function.     

Therapeutic effect of bFGF on retina ischemia-reperfusion injury

Background Basic fibroblast growth factor (bFGF) plays important roles in retina degeneration, light injury, mechanical injury, especially in retina ischemia-reperfusion injury (RIRI). This study was to investigate the therapeutical effect of bFGF on RIRI and its mechanisms.Methods Experimental RIRI was induced by increasing intraocular pressure (IOP) in the eyes of 48 rats. These rats were divided into normal control, ischemia-reperfusion and bFGF-treated groups.Histological and ultrastructural changes of in the retina of different groups were observed, and the number of retinal ganglion cells (RGCs) was quantitatively analyzed under microscopy. Apoptotic cells were detected using the TdT-dUTP terminal nick-end labeling (TUNEL) method. The expression of caspase-3 was determined by streptavidin peroxidase (SP) immunohistochemistry. Atomic absorption spectrum method was used to evaluate the intracellular calcium changes.Results At the early stage of retinal ischemia-reperfusion injury, retina edema in the treated group was significantly eliminated compared with the untreated ischemic animals. RGCs in the bFGF-treated group was more than those in the untreated ischemic group during the post-reperfusion stages. In ischemic group, apoptotic cells could be found at 6th hours after reperfusion and reached the peak at 24th hours. At 72th hours no apoptotic cells could be found. The changes in caspase-3 expression had a similar manner. The intracellular calcium of rat retina began to increase at lth hour, reached the peak at 24 hours, and began to decease at 72th hours. The change of the three markers in the treatment group showed a similar pattern, but they were all relatively less obvious.Conclusion Apoptosis may play a vital role in RIRI. bFGF may has therapeutical effects on RIRI by inhibiting the increase of intracellular calciums and caspase-3 expression.     

Effects of 3-aminobenzamide on expressions of poly（ADP ribose） polymerase and apoptosis inducing factor in cardiomyocytes of rats with acute myocardial infarction

Background Poly（ADP-ribose） polymerase （PARP） plays an important role in cell survival and death. However, the mechanisms involved are not fully understood. Therefore, we investigated the effect of inhibition of PARP on acute myocardial infarction （AMI） at different time points in rats. Methods AMI was induced in rats by ligating the left anterior descending coronary artery. One group received 3-aminobenzamide （3-AB, a kind of PARP inhibitor） （30 mg/kg） by intraperitoneal injection. The changes of ultramicrostructure of cardiocytes in infarction region were noted, PARP cleavage was measured by Western blotting, and expressions of protein of PARP and apoptosis inducing factor （AIF） were measured by immunohistochemical staining after treatment with 3-AB for 2 hours, 4 hours, 6 hours, 1 week, 4 weeks and 8 weeks. Results Few damages to the ultramicrostructure of cardiocytes were observed after treatment with 3-AB. PARP cleavage was detected as early as 4 hours and markedly increased by 6 hours following AMI without 3-AB, but was not found until 6 hours following AMI treated with 3-AB. There were significant differences between 3-AB and AMI groups at the same time points. The expression of PARP was observed gradually increased, but that of AIF was suppressed for 6 hours after treatment of 3-AB, compared with AMI groups in positive cells at the same time points. There was significantly less cleavage of PARP and more PARP expression in 3-AB treated group compared with AMI and control groups at all matched time points. Conclusions Our results suggest that 3-AB inhibits degradation of PARP, increases the expression of PARP protein, and suppresses the expression of AIF protein. Inhibition of PARP activity may protect cardiocytes in rats with AMI and reduce apoptosis.     

Early activation of caspase-1 after retinal ischemia and reperfusion injury in mice

Background Caspases are important in the signaling pathway of cellular apoptosis. Caspase-3 protein expression has been shown to increase and parallel to neuronal apoptosis in retinal ischemia injury. This study was to determine whether caspase-1 is involved in neuronal cell death or in retinal ischemia and repeffusion injury.Methods In twenty-one adult mice, ischemia was induced by increasing the intraocular pressure.The animals were sacrificed at 1 hour, 3 hours, 6 hours, 1 day, 3 days and 7 days after reperfusion.Frozen sections were used for caspase-1 immunostaining and TUNEL labeling.Results In normal retina, no caspase-1 positive cells were seen. One hour after ischemia,numerous positive cells were noted in the ganglion cell layer (GCL) and inner side of inner nuclear layer (INL). At 3 hours, caspase-1 positive cells continued to increase and peaked at 6 hours, then decreased significantly at 1 day. TUNEL positive cells were detected at 3 hours and peaked at 1 day after ischemia. Double labeling of caspase-1 and TUNEL only showed few cells with co-localization after ischemia.Conclusion Caspase-1 immunoreactivity preceds to the TUNEL labeling in the GCL and INL after retinal ischemia and reperfusion injury and its early activation may play an important role in the initiation of neuronal apoptosis.     

Tacolimus postconditioning alleviates apoptotic cell death in rats after spinal cord ischemia-reperfusion injury via up-regulating protein-serine-threonine kinases phosphorylation

The effects of tacrolimus postconditioning on protein-serine-threonine kinases （Akt） phos- phorylation and apoptotic cell death in rats after spinal cord ischemia-reperfusion injury were investi- gated. Ninety male SD rats were randomly divided into sham operation group, ischemia-reperfusion group and tacrolimus postconditioning group. The model of spinal cord ischemia was established by means of catheterization through femoral artery and balloon dilatation. The spinal cord was reperfused 20 min after ischemia via removing saline out of balloon. The corresponding spinal cord segments were excised and determined for Akt activity in spinal cord tissue by using Western blotting at 5, 15, and 60 min after reperfusion respectively. Spinal cord tissue sections were stained immunohistochemically for detection of the phosphorylated Akt expression at 15 min after reperfusion. Flow cytometry was applied to assess apoptosis of neural cells, and dry-wet weights method was employed to measure water content in spinal cord tissue at 24 h after reperfusion. The results showed that the activities of Akt in tarcolimus postconditioning group were significantly higher than those in ischemia-reperfusion group at 5, 15, and 60 min after reperfusion （P〈0.05, P〈0.01）. The Akt activities reached the peak at 15 min after reperfu- sion in ischemia-reperfusion group and tacrolimus postconditioning group. The percentage of apoptotic cells and water content in spinal cord tissue were significantly reduced （P〈0.01） in tacrolimus postcon- ditioning group as compared with those in ischemia-reperfusion group at 24 h after reperfusion. It is concluded that tacrolimus postconditioning can increase Akt activity in spinal cord tissue of rats, inhibit apoptosis of neural cells as well as tissue edema, and thereby alleviate spinal cord ischemia-reperfusion injury.     

ANTI-PROLIFERATION EFFECT OF ORIDONIN ON HL-60 CELLS AND ITS MECHANISM

Objcetive To investigate the anti-proliferation effect of oridonin on leukemic HL-60 cells and its mechanism. Methods HL-60 cells in vitro in culture medium were given different concentrations of oridonin. The inhibitory rate of cells were measured by microculture tetrazolium (MTT) assay, cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the activity of telomerase was detected using telomere repeat amplification protocol (TRAP) PCR-ELISA before and after apoptosis occurred. Results Oridonin could decrease telomerase activity, inhibit growth of HL-60 cells, and cause apoptosis significantly. The suppression was both in time- and dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by hoechst 33258 fluorescence staining especially after cells were treated 48-60 hours by oridonin. Conclusions Oridonin has apparent anti-proliferation and apoptotic effects on HL-60 cells in vitro, decreasing telomerase activity of HL-60 cells may be one of its most important mechanisms. These results will provide strong laboratory evidence of oridonin for clinical treatment of acute leukemia.     

Effects of nuclear translocation of tissue transglutaminase and the release of cytochrome C on hepatocyte apoptosis

Objective To assess the effects of nuclear translocation of tissue transglutaminase (TTG) and the release of cytochrome C on hepatocyte apoptosis and to reveal the mechanism of signal transcluction of early apoptosis in injured hepatocytes.Methods Hepatocytes isolated from tissue transglutaminase gene knock-out mice and rats were stimulated with ethanol. Proteins from whole cell, cytoplasm and nuclei were extracted for determination of TTG activity by ^14C-putrescine incorporation. Distribution of TTG throughout the entire cell, as well as just nucleus was observed under a confocal scanning microscope. The amount of cytochrome C released from mitochonclria was determined by ELISA. Cell apoptosis was observed by fluorescent cytochemistry.Results TTG activity in whole cells and nuclei was significantly increased after the hepatocytes were treated with ethanol. Cytochrome C release was remarkably increased in the cells isolated from rat and wild-type mouse after treatment with ethanol but not in TTG gene knock-out mice. Cellular apoptosis appeared in hepatocytes isolated from rats and wild-type mice but not in the hepatocytes from TTG gene knock-out mice after stimulation with ethanol.Conclusions Increased TTG in hepatocytes can be translocated into the nucleus and promote release of mitochonclrial cytochrome C into the cytoplasm. Passing through a series of signal pathways, hepatocyte apoptosis is induced eventually.     

NF-κB/IκBα在MNU致实验性大鼠视网膜损伤中的变化

目的 观察核因子KappaB（NF-κB）在N-甲基-N-亚硝脲（MNU）诱导大鼠视网膜光感受器细胞凋亡中的的变化,探讨MNU损伤视网膜的机制。方法 给生后50d的雌性SD大鼠一次腹腔注射MNU60mg／kg．分别在MNU处理不同时间后处死动物。光学显微镜观察视网膜的形态学变化;TUNEL试剂盒检测光感受器细胞凋亡：Western blotting分析NF-κB。结果 MNU处理后24h,视网膜光感受器细胞核固缩和光感受器细胞层外节部定向障碍：7d后．外颗粒层和光感受层几乎完全消失。光感受器细胞凋亡在MNU处理后24h达高峰。在凋亡发生的过程中,仅在MNU作用12h和24h后,胞核内有低水平的p65蛋白。相反,胞浆和胞核内的KB蛋白水平呈时间依赖性地显著增加。结论 NF-κB／IKBa信号通路的激活可能介导了MNU所致的视网膜损伤。     

N-甲基-N-亚硝脲对大鼠光感受器细胞毒性作用的形态学改变

目的:观察N-甲基-N-亚硝脲(N—methyl—N—nitrosourea，MNU)对SD大鼠光感受器细胞毒性作用的形态学改变。方法：雌性SD大鼠76只，分12组，正常对照组4只，其余组各6只。于大鼠生后50d，分别一次腹腔注射MNU 40mg／kg、60mg／kg和80mg／kg。在MNU处理后24h、48h、3d和7d，处死大鼠，取眼球，做组织学检查。结果：不同剂量的MNU均引起视网膜损伤，其损伤的程度与MNU剂量呈正比。作用24h后，可见不同程度的视网膜光感受器细胞核固缩和光感受器细胞外节部定向障碍；48h或3d后，可见光感受器细胞丧失；7d后，外颗粒层和光感受层仅剩下少数几层或几乎完全消失。结论：MNU对大鼠视网膜光感受器细胞有选择性的毒性作用，该作用呈剂量和时间依赖性。     

实验性光损伤大鼠视网膜光感受器细胞凋亡的研究

目的：观察较强可见光所致大鼠视网膜光感受器细胞凋亡现象，探讨视网膜光化学损伤发病机制。方法：取健康成年SD大鼠50只，随机分成正常对照组（CON）、光损伤后1天（D1）、3天（D3）、5天（D5）、7天（D7）组，每组10只。各组大鼠在12h明12h暗环境中饲养7天，然后暗适应36h。D1、D3、D5、D7组大鼠采用4178Lux照度的可见光进行12h间歇光照射，连续3天，总计36h，然后在正常环境中分别饲养1天、3天、5天、7天。10％水合氯醛麻醉大鼠，摘取眼球，制备视网膜石蜡切片及超薄切片，行HE染色、TUNEL法标记及重金属染色，光镜、透射电镜观察，MIAS-1000图像分析系统检测。结果：正常大鼠视网膜组织结构层次清楚，外核层排列规则，染色质电子密度均匀。TUNEL法染色阴性。光照后1天，外核层开始变薄，其厚度减少11.88％。核染色质开始固缩。可见少量TUNEL法标记的阳性细胞核，染色质向核膜下聚集，呈现典型的凋亡细胞表现。光照后3天，外核层厚度减少26.80％。电镜下核染色质向中心聚集。TUNEL法标记的凋亡细胞增加。光照后5天，外核层厚度减少39.76％。TUNEL法标记的凋亡细胞更。光照后7天，外核层厚度和TUNEL法标记的凋亡细胞数与光照后5天基本相似。视网膜色素上皮细胞、节细胞及内核层均无明显变化。也未了现炎症细胞。结论：实验性光损伤导致大鼠光感受器丧失，光感受器丧失的性质为细胞凋亡。实验结果初步证实光感受器细胞凋亡是实验性大鼠视网膜光损伤的重要机制。     

二十二碳六烯酸抑制大鼠视网膜光感受器细胞凋亡

目的:观察二十二碳六烯酸(DHA)对N-甲基-N-亚硝基脲(MNU)所致视网膜光感受器细胞凋亡的影响,为其临床应用提供理论依据.方法:35只雌性SD大鼠随机分为7组,每组5只.除正常组外,其余各组均于出生后35 d开始灌胃,DHA组和造模组每日分别灌服含有一定量DHA的脱脂牛奶或等体积的脱脂牛奶,持续15 d后行腹腔注射MNU 40 mg/kg.分别于造模后12,24,48 h全麻后处死相应动物,取眼球行光镜观察及用末端脱氧核苷酸转移酶介导dUTP缺口末段标记(TUNEL)法检测各组大鼠视网膜细胞的凋亡.结果:光镜下显示中周部视网膜在造模后24 h开始出现光感受器细胞排列紊乱,少量核固缩,48 h后光感受器细胞已大量溶解,而DHA组光感受器细胞的形态均接近正常,仅见排列紊乱、稀疏.造模组光感受器细胞在造模后12,24,48h的凋亡百分率(AD分别为(5.3±1.1)％、(60.6±4.1)％、(97.1±1.9)％,DHA组在造模后12,24,48 h的AI分别为(4.3±1.4)％、(44.5±7.8)％和(78.7±5.8)％,24 h和48 h后造模组和DHA组间比较均有统计学差异(P＜0.05).结论:二十二碳六烯酸40 mg/(kg·d)可以有效抑制视网膜光感受器细胞的凋亡.     

牛磺酸对大鼠视网膜光损伤保护作用的实验研究

目的 探讨牛磺酸对大鼠视网膜光损伤和视细胞凋亡的保护作用及其作用机制。方法 所有大鼠被随机分为牛磺酸用药组、阳性对照组、正常对照组。通过持续光照射24h，形成视网膜光损伤模型。光照后3d，通过光镜观察视网膜组织病理学结构，流式细胞仪测定细胞凋亡的情况。结果 组织病理学结果显示，阳性对照组视网膜结构破坏严重，感光细胞内外节消失，外核层变薄，细胞核明显减少，而牛磺酸用药组无明显改变。牛磺酸治疗组视网膜细胞凋亡数明显低于阳性对照组(P＜0．05)。结论 牛磺酸对视网膜光损伤具有保护作用，其可能的机制是通过抑制视细胞的凋亡。     

RCS大鼠感光细胞凋亡与Bcl-2蛋白的表达

目的 探讨遗传性视网膜色素变性中感光细胞凋亡及其可能的基因调控机制。方法 对RCS大鼠及对照SD大鼠的视网膜组织结构进行光镜观察、细胞凋亡及Bcl-2蛋白免疫组织化学检测。结果 RCS大鼠生后15d视网膜的感光细胞视杆层及外节增厚，视杆层的厚度在25d达到高峰。感光细胞的数目在25d时有所下降，到出生后60d，仅少许感光细胞存留。出生后25～40d，RCS大鼠视网膜可见外核层TUNEL染色阳性的感光细胞，阳性细胞数35d最多。30-40d内核层和节细胞层可见Bcl-2蛋白免疫组化阳性表达细胞，35d时内核层阳性表达细胞数最多。外核层一直未见明显Bcl-2蛋白阳性表达细胞。结论 RCS大鼠视网膜变性过程中。感光细胞发生了凋亡。Bcl-2原癌基因可能不参与感光细胞的保护机制。     

实验性光损伤大鼠视网膜病理改变的电镜观察

目的：观察实验性光损伤大鼠视网膜组织病理学特点。方法：取健康成年SD大鼠40只，随机分成正常对照组（CON）、光损伤后１天（D1）、３天（D3）、５天（D５）组，每组１０只。D1、D3、D5组大鼠采用4178Lux照度的可见光进行１２小时间歇光照射，连续３天，总计36小时，然后在正常环境中分别饲养1天、３天、５天。灌流固定，摘取眼球，制成超薄切片，应用电镜技术方法进行研究。结果：正常大鼠视网膜组织结构层次清楚，染色均匀，细胞形态规整。光照后１天，光感受器外节膜盘叠状结构解离，外核层核染色质开始固缩。光照后３天，视网膜内节线粒体肿胀，空泡性变，外核层核染色质向中心聚集，呈岛状。光照后５天，视网膜光损伤达到高峰，视网膜内、外节空泡变明显增多，外核层出现细胞核碎裂，边集，光感受器细胞内线粒体空泡变，核膜皱缩，内陷。光照后各组大鼠视网膜色素上皮、内核层及节细胞未见明显改变。结论：实验性光损伤大鼠视网膜组织病理特点是光感受器的退行性变。     

白藜芦醇对实验性脑缺血的保护作用

目的探讨不同剂量白藜芦醇对局灶性脑缺血梗死体积和脑水肿的影响及对核因子-KB(NF-kB)p65表达的影响。方法采用大鼠大脑中动脉闭塞模型,用红四氮唑(TTC)染色显示脑梗死范围,脑水肿的测定用干湿重法,使用免疫组织化学技术观察NF-kBp65的表达。结果白藜芦醇剂量为10^-^7、10^-^6g／kg时有效降低脑梗死体积,10^-^7、10^-^6g／kg白藜芦醇能明显减轻脑水肿程度,在10^-^7g／kg浓度时白藜芦醇能抑制NF-kBp65的表达。结论白藜芦醇具有缺血脑保护作用,其作用与NF-kB的抑制有关。     

睾丸扭转复位后生精上皮细胞核转录因子表达的改变及其凋亡

目的探讨睾丸扭转2h复位后第3天睾丸生精上皮细胞核转录因子(NF-κB)表达的改变及其凋亡的关系。方法用24只雄性SD大鼠建立左侧睾丸扭转复位模型。分为Ⅰ、Ⅱ和Ⅲ组,每组8只。Ⅰ组动物睾丸扭转复位后用柳氮磺胺吡啶灌胃;Ⅱ组动物睾丸扭转复位后用等量的生理盐水灌胃;Ⅲ组动物假手术后用等量的生理盐水灌胃。分别用Western蛋白印迹和免疫组织化学原位检测睾丸生精上皮细胞中NF-κB的表达情况;TUNEL法检测生精上皮细胞凋亡情况。结果Ⅱ组动物睾丸扭转复位后第3天扭转侧睾丸生精上皮细胞胞质NF-κB蛋白质(9·4±2·68)表达与Ⅰ、Ⅲ组扭转侧睾丸生精上皮细胞胞质NF-κB表达(分别为:12±2·2;11·1±3)相比下降水平差异无统计学意义,胞核NF-κB表达升高水平差异有统计学意义(3组分别为8·4±3·1;21·1±3·6;6·0±2·3)。免疫组织化学原位检测Ⅰ和Ⅲ组扭转侧睾丸生精上皮细胞中NF-κB的表达以胞质为主,Ⅱ组扭转侧睾丸生精上皮细胞中NF-κB的表达以细胞核为主,而且NF-κB阳性细胞比例较其他两组阳性率显著上升(三组分别为15·6%±2·6%,66·1%±3·8%,10·8%±2·7%)。Ⅰ组(7·7%±2·0%)和Ⅲ组(5·9%±1·7%)扭转侧睾丸生精上皮细胞凋亡指数差异不明显;Ⅱ组扭转侧睾丸生精上皮细胞凋亡水平(37·2%±3·3%)跟以上两组相比升高有显著性差异。结论睾丸扭转2h复位后第3d,睾丸生精上皮细胞NF-κB蛋白已被激活,从胞质转移至核内,启动生精上皮细胞凋亡过程。NF-κB蛋白质的激活是导致睾丸扭转复位后生精上皮细胞特别是精原细胞和各级精母细胞凋亡增加的重要环节。     

siRNA介导的NF-κB P65沉默诱导肝癌细胞SMMC7721凋亡

目的 研究siRNA介导的NF-κBP65沉默诱导肝癌细胞凋亡相关机制。方法实验以肝癌SMMC772l细胞株为材料,分为空白对照（Con）、脂质体对照（LP）以及siRNA干扰实验（siRNA）3组。以体外转录法合成dsRNA,并用脂质体转染SMMC7721细胞株;Westernblotting检测NF．KBP65表达水平,MTT检测细胞增殖情况,Annexin V-PI法检测细胞凋亡,免疫组化检测Bcl-2和Bax表达。结果与Con和LP组相比,siRNA具有抑制SMMC7721细胞NF-κBP65表达的作用,NF-κBP65表达抑制率分别达到64．74％和34．52％。siRNA明显抑制SMMC．7721细胞的增殖,并诱导细胞凋亡,晚期凋亡细胞分别是Con组和LP组的8倍和7倍。siRNA引起Bcl-2表达下调,而Bax表达上调。结论siRNA可以有效抑制NF-κBP65蛋白表达,并通过调节Bcl-2和Bax诱导SMMC7721细胞的凋亡。