FAS/ActD通过线粒体途径引起细胞阻滞诱导人宫颈癌HeLa细胞凋亡

为了探讨FAS抗体与放线菌素D(actinomycin D,ActD)联合作用诱导人宫颈癌HeLa细胞凋亡的分子机制,通过MTT法检测细胞活力,利用流式细胞仪检测细胞凋亡和细胞周期,从而研究FAS/ActD抑制细胞增殖的作用. 结果表明,FAS/ActD能明显降低HeLa细胞的活力,并且通过G1/G0期阻滞和S期阻滞诱导HeLa细胞凋亡. 此外,Western印迹分析进一步显示,FAS/ActD还能引起Bcl-2蛋白表达降低, Bax蛋白表达增加,Bid蛋白发生断裂激活,导致细胞质中Cyto-c释放的增加,并激活在细胞凋亡的执行过程中起着关键作用的caspase 9和caspase 3. 以上结果提示,FAS抗体与ActD的联合作用可能经线粒体途径引起细胞周期阻滞,从而诱导HeLa细胞凋亡. 该研究为宫颈癌的免疫治疗提供了新的思路.     

澳洲茄碱诱导胆管癌QBC939细胞凋亡及作用机制

研究澳洲茄碱对人胆管癌上皮细胞系QBC939凋亡的诱导与作用机制。采用MTT法检测不同浓度澳洲茄碱对QBC939细胞的增殖抑制作用;流式细胞术检测澳洲茄碱对QBC939细胞的凋亡诱导情况;Western blot检测澳洲茄碱对QBC939细胞中凋亡相关蛋白(Bax、Bcl-2、caspase3、caspase7、PARP、cleaved PARP)的表达影响。结果发现澳洲茄碱以浓度依赖方式能够抑制QBC939细胞的增殖;澳洲茄碱能够显著诱导QBC939细胞的凋亡;澳洲茄碱可以上调Bax、caspase3、caspase7和cleaved PARP蛋白表达,下调Bcl-2和PARP蛋白表达。表明澳洲茄碱能够通过改变凋亡相关蛋白表达,诱导胆管癌QBC939细胞的凋亡,这对于研发和治疗胆管癌相关药物具有一定的潜在价值。     

蛋白酶体抑制剂MG132诱导K562和HeLa细胞凋亡程度存在明显差异

蛋白酶体抑制剂MG132诱导人白血病细胞K562和宫颈癌细胞HeLa凋亡,用3个不同浓度的蛋白酶体抑制剂MG132处理人白血病细胞K562和宫颈癌细胞HeLa,通过MTT检测、annexin Ⅴ/ PI 双染法、流式细胞术、酶标仪和Western 印迹分别检测MG132对K562细胞和HeLa细胞的生长效应、细胞凋亡率、细胞内活性氧(ROS)水平和caspase-3活性变化的影响.蛋白酶体抑制剂MG132诱导K562细胞凋亡明显,对HeLa细胞诱导凋亡不明显.结果表明,蛋白酶体抑制剂MG132特异性诱导不同肿瘤细胞凋亡的程度存在明显差异.     

PrP106-126多肽诱导凋亡细胞中14-3-3β的降解

本研究将PrP106-126多肽和HeLa细胞共孵育4h和8h,采用Hoechst染色分析发现PrP106-126诱导凋亡细胞细胞核出现不同程度的染色质浓集,固缩及碎裂的细胞凋亡征象。Western blotting检测发现PrP106-126诱导细胞中的多聚ADP核糖聚合酶(poly ADP-ribose polymerase,PARP)降解,提示PrP106-126通过caspase3途径引起细胞凋亡现象。PrP106-126诱导的细胞中14-3-3β在不同孵育时间也出现降解,而Real-time PCR检测14-3-3β mRNA未发生变化。本研究证明PrP106-126通过caspase3诱导HeLa细胞凋亡,并可导致抗凋亡蛋白14-3-3β的降解而加速凋亡的形成。     

水飞蓟宾诱导肺腺癌Anip973细胞凋亡的分子机制研究

目的：探讨水飞蓟宾诱导肺腺癌Anip973细胞系细胞凋亡的分子机制。方法：采用MTT法、倒置显微镜和电子显微镜等形态学检测以及流式细胞仪（FCM）技术检测、DNALadder分析、凋亡分子PARP的表达检测细胞凋亡,同时进行凋亡相关蛋白Bax、Bcl-2、caspase-3和caspase-9表达活性分析。结果：（1）水飞蓟宾对人肺腺癌Anip973细胞系细胞的增殖有显著抑制作用;（2）水飞蓟宾作用Anip973细胞48h后,随着浓度的增加,倒置显微镜下可见细胞数目减少,胞体变小、变圆,到高浓度时出现较多的死亡细胞;（3）扫描电镜观察发现,随着水飞蓟宾作用浓度的增加,Anip973细胞中出现增多的凋亡细胞,凋亡细胞表现出典型的超微结构特征;（4）流式细胞仪检测的结果发现,随着药物作用时间的延长,Anip973细胞的G1期细胞比例增多,S期细胞明显减少,G2期细胞略有减少,并出现明显的凋亡峰。（5）水飞蓟宾作用后的Anip973细胞出现明显的DNALadder和PARP降解增加等凋亡特征;（6）水飞蓟宾作用后,Anip973细胞中的凋亡相关蛋白Bax表达增加、caspase-3和caspase-9酶活性增加,而Bcl-2表达降低。结论：水飞蓟宾在体外有抑制人肺腺癌细胞Anip973的增殖作用,并通过激活线粒体依赖的caspase凋亡通路,诱导其凋亡。     

脂联素抑制t-BHP诱导的内皮细胞凋亡作用及其可能机制探讨

目的：探讨重组脂联素对第三丁基过氧化氢（t-BHP）诱导的人脐静脉内皮细胞（HUVECs）凋亡的影响及其相关的分子机制。方法：以HUVECs作为研究对象,给予t-BHP处理,模拟体外HUVECs氧化损伤细胞凋亡模型。在此基础上,用携带重组脂联素基因的腺病毒转染HUVECs,观察重组脂联素对t-BHP诱导的HUVECs凋亡的影响。用MTT法检测细胞增殖活力。Hochest/PI荧光染色检测细胞凋亡率。Western blot检测细胞凋亡相关蛋白p-JNK、JNK和Caspase 3表达水平的变化。结果：100 μmol/L的t-BHP作用8 h可诱导HUVECs发生凋亡。与对照组相比,t-BHP组p-JNK、active caspase 3表达增多（P<0.01）。HUVECs高表达重组脂联素基因后,可明显抑制t-BHP诱导的HUVECs凋亡（P<0.01）,下调t-BHP诱导的p-JNK、active caspase 3表达。结论：持续t-BHP氧化损伤可诱导HUVECs发生凋亡。重组脂联素可有效抑制t-BHP诱导的HUVECs凋亡,其机制与p-JNK、active caspase 3的表达下调有关。     

阿司匹林诱导人恶性睾丸生殖细胞瘤NTera-2细胞凋亡

阿司匹林,又称乙酰水杨酸,已证实有抑制肿瘤细胞增殖、诱导肿瘤细胞凋亡和抑制血管生成等多种抗癌功能.除已知对环氧合酶COX-2的活性有抑制外,阿司匹林抗癌分子机制尚不十分清楚.已报道阿司匹林可以降低多种癌症发生风险,但应用于人类睾丸肿瘤治疗的研究报道很少.本文研究了阿司匹林对人恶性睾丸肿瘤NTera-2细胞凋亡的机制.通过MTT方法检测细胞活力,发现阿司匹林以时间和剂量依赖方式抑制NTera-2细胞增殖.不同浓度阿司匹林处理NTera-2细胞后,采用Hoechest 33258染色方法和Annexin V-FITC/PI流式法分别检测NTera-2细胞的形态学变化、凋亡小体形成、细胞凋亡水平;RT-PCR结果显示,NTera-2细胞中Fas和caspase-8的表达以阿司匹林剂量依赖性上升;蛋白印迹结果显示,FasL的蛋白表达水平下降并活化caspase-8、caspase-3蛋白表达,PARP出现剪切体. 进一步的实验证明,caspase广谱抑制剂Z-VAD-FMK能够减弱阿司匹林诱导NTera-2细胞凋亡. 结果显示,阿司匹林能明显抑制NTera-2细胞活力,并通过激活caspase 通路诱导NTera-2细胞的凋亡,为进一步利用阿司匹林治疗人类睾丸肿瘤的研究奠定基础.     

miR-9靶向调控PTEN在HPV16+及HPV18+宫颈癌细胞凋亡中的作用

研究微小RNA-9(microRNA-9,miR-9)靶向调控人第10号染色体缺失的磷酸酶及张力蛋白同源蛋白（Recombinantphosphataseandtensinhomolog,PTEN）在人乳头瘤病毒（Humanpapillomavirus,HPV）16+及HPV18+宫颈癌细胞凋亡中的作用。收集宫颈癌组织及正常宫颈组织，培养HPV16+SiHa细胞、HPV18+HeLa细胞、HPV阴性C33A细胞及正常宫颈上皮H8细胞，检测miR-9、PTEN的表达水平。SiHa细胞和HeLa细胞进行分组转染后检测增殖抑制率、凋亡率、PTEN及miR-9表达水平。结果显示高危型HPV阳性及阴性的宫颈癌组织中miR-9的表达水平高于正常宫颈组织、PTEN的表达水平低于正常宫颈组织（P<0.05）且高危型HPV阳性宫颈癌组织中miR-9、PTEN表达的变化更显著；SiHa细胞、HeLa细胞中miR-9的表达水平高于C33A细胞和H8细胞、PTEN的表达水平低于C33A细胞和H8细胞（P<0.05）；敲低miR-9表达后，SiHa细胞、HeLa细胞的PTEN表达水平、增殖抑制率、凋...     

重组荞麦胰蛋白酶抑制剂对人肝癌细胞的凋亡及半胱氨酸天冬酶活性的影响

先前的研究表明,基因重组荞麦胰蛋白酶抑制剂 (rBTI) 具有诱导不同肿瘤细胞凋亡的作用.为了揭示其诱导肿瘤细胞凋亡的可能机理,从基因水平上探讨与凋亡有关的分子事件,本研究用不同浓度的 rBTI 体外作用于人肝癌细胞 HepG2 后,采用 MTT 比色法检测抑制剂对epG2 细胞的抑制率,用 DNA 凝胶电泳和细胞核的形态学观察检测 HepG2 细胞的凋亡.结果表明,rBTI 在体外能够明显抑制 HepG2 细胞的增长,并诱导细胞凋亡.另外,细胞凋亡与Bcl-2/Bax mRNA 水平有关.通过 RT-PCR 检测发现,细胞经过rBTI处理后,抗凋亡基因Bcl-2 mRNA 水平下调,促凋亡基因 Bax mRNA 有所上调,而对照 GAPDH 无变化.对 HepG2细胞中 Fas/Fas 配体及半胱氨酸天冬酶（caspase）的研究证明,细胞经过 rBTI 处理后,对死亡受体 Fas mRNA没有影响; rBTI 可明显激活caspase-3 和 caspase-9 酶活性, 对caspase-8 活性几乎无影响.上述结果表明,rBTI 对HepG2 细胞具有明显的诱导凋亡作用,其诱导细胞凋亡的机制与 caspase-3 依赖性凋亡调节信号通路有关,未涉及 Fas/Fas 配体途径.     

DNA损伤诱导的长链非编码RNA-UCA1促进HeLa细胞增殖

尿路上皮癌抗原1 (UCA1)是一种长链非编码RNA,在多种肿瘤内高表达.然而,其在宫颈癌细胞和组织中的表达报告颇不一致,且功能尚未确定.本文探索UCA1在宫颈癌HeLa细胞中的生物学功能.实时定量PCR（qRT-PCR）结果显示,UCA1、p21和p53 mRNA在阿霉素（doxorubicin,DOX）或γ射线照射的HeLa细胞中表达上调|相反,敲减p53表达则可抑制DOX诱导的UCA1上调.表明DNA损伤诱导的UCA1可能与p53有关.转染结合CCK8检测HeLa细胞增殖活力结果显示,与对照比较,过表达UCA1促进HeLa细胞增殖,干扰UCA1表达则减缓细胞增殖.此外,流式细胞术结果显示,过表达UCA1导致阿霉素诱导的凋亡率下降;siRNA抑制UCA1表达后引起细胞G2/M期比例上升,S期下降,且阿霉素诱导的细胞凋亡率上升.上述结果说明,DNA损伤诱导的UCA1可促进HeLa细胞增殖,减少细胞凋亡.然而,是否DNA损伤诱导的UCA1上调依赖p53尚需进一步实验证明.     

抗Caspase-3核酶M1RNA的制备与体内外活性鉴定

为评价抗caspase 3核酶在阻抑细胞凋亡发生中的潜在价值 ,以RNaseP催化亚基M1RNA为模板 ,设计合成 3个特异性针对人caspase 3的核酶pM1 GS716、pM1 GS337和pM1 GS2 35 ,并对它们的体内外切割活性进行探讨 .3 2 P标记的caspase 3基因片段体外转录物作为靶RNA ,体外切割实验表明 ,pM1 GS716和pM1 GS337均有切割活性 ,其中pM1 GS716的切割效率可达到 93% .3个核酶转染HeLa细胞 ,评价其在体内的切割活性 .在TNF α作用下 ,转染pM1 GS716的HeLa细胞内caspase 3mRNA下降了 75 % ,蛋白含量下降了 6 9% ,caspase 3蛋白酶活性下降了 5 2 % .Hoechst 332 5 8染色表明 ,细胞凋亡率较对照明显下降 (分别为 2 1 6± 0 7%和 4 9 4± 0 2 % ,P <0 0 1) .提示体外制备的pM1 GS716具有良好的特异催化切割活性 ,有望通过切割caspase 3而抑制细胞凋亡 .     

Assessment of the antiproliferative and apoptotic roles of sulfonamide carbonic anhydrase IX inhibitors in HeLa cancer cell line

Carbonic anhydrase IX (CA IX) has recently been validated as an antitumor/antimetastatic drug target. In this study, we examined the underlying molecular mechanisms and the anticancer activity of sulfonamide CA IX inhibitors against cervical cancer cell lines. The effects of several sulfonamides on HeLa, MDA-MB-231, HT-29 cancer cell lines, and normal cell lines (HEK-293, PNT-1A) viability were determined. The compounds showed high cytotoxic and apoptotic activities, mainly against HeLa cells overexpressing CA IX. We were also examined for intracellular reactive oxygen species (ROS) production; intra-/extracellular pH changes, for inhibition of cell proliferation, cellular mitochondrial membrane potential change and for the detection of caspase 3, 8, 9, and CA IX protein levels. Of the investigated sulfonamides, one compound was found to possess high cytotoxic and anti-proliferative effects in HeLa cells. The cytotoxic effect occurred via apoptosis, being accompanied by a return of pHe/pHi towards normal values as for other CA IX inhibitors investigated earlier.     

ExoS of Pseudomonas aeruginosa induces apoptosis through a Fas receptor/caspase 8-independent pathway in HeLa cells

Pseudomonas aeruginosa infection is a serious complication in immunocompromised individuals and in patients with cystic fibrosis. We have previously shown that the type III secreted effector ExoS triggers apoptosis in various cultured cell lines via its ADP-ribosyltransferase (ADPRT) activity. The apoptosis process was further shown to involve intrinsic signalling pathway requiring c-Jun N-terminal kinase (JNK)-initiated mitochondrial pathway. In the present study, we investigated the role of Fas pathway activation in P. aeruginosa-induced apoptosis. P. aeruginosa infection resulted in caspase 8 cleavage in HeLa cells, which was inhibited by overexpression of a dominant negative version of Fas-associated death domain (FADD), suggesting that Fas pathway was activated. In fact, confocal laser scanning microscopy showed that P. aeruginosa induced clustering of FasR. In addition, the ADPRT activity of the ExoS was required for the induction of FasR clustering and caspase 8 cleavage. However, blocking the FasR-FasL interaction by antagonistic antibodies to FasR or to FasL had no effect on P. aeruginosa-induced caspase 8 and caspase 3 activation, neither did the silencing of FasR by small interfering RNA (siRNA), suggesting that caspase 8 activation through the FADD bypasses FasR/FasL-mediated signalling. Thus, FADD-mediated caspase 8 activation involves intracellular ExoS in an ADPRT-dependent manner. Furthermore, silencing of caspase 8 by siRNA did not interfere with P. aeruginosa-induced apoptosis, whereas it rendered HeLa cells markedly increased resistance towards FasL-induced apoptosis. In conclusion, our findings indicate that ExoS of P. aeruginosa induces apoptosis through a mechanism that is independent of Fas receptor/caspase 8 pathway.     

Contribution of caspase(s) to the cell cycle regulation at mitotic phase

Caspases have been suggested to contribute to not only apoptosis regulation but also non-apoptotic cellular phenomena. Recently, we have reported the involvement of caspase-7 to the cell cycle progression at mitotic phase by knockdown of caspase-7 using small interfering RNAs and short hairpin RNA. Here we showed that chemically synthesized broad-spectrum caspase inhibitors, which have been used to suppress apoptosis, prevented the cell proliferation in a dose-dependent manner, and that the subtype-specific peptide-based caspase inhibitor for caspase-3 and -7, but not for caspase-9, inhibited cell proliferation. It was also indicated that the BIR2 domain of X-linked inhibitor of apoptosis protein, functioning as an inhibitor for caspase-3 and -7, but not the BIR3 domain which plays as a caspase-9 inhibitor, induced cell cycle arrest. Furthermore, flow cytometry revealed that the cells treated with caspase inhibitors arrested at G(2)/M phase. By using HeLa.S-Fucci (fluorescent ubiquitination-based cell cycle indicator) cells, the prevention of the cell proliferation by caspase inhibitors induced cell cycle arrest at mitotic phase accompanying the accumulation of the substrates for APC/C, suggesting the impairment of the APC/C activity at the transition from M to G(1) phases. These results indicate that caspase(s) contribute to the cell cycle regulation at mitotic phase.     

Spatiotemporal activation of caspase‐dependent and ‐independent pathways in staurosporine‐induced apoptosis of p53wt and p53mt human cervical carcinoma cells

Background information. Caspase‐dependent and ‐independent death mechanisms are involved in apoptosis in a variety of human carcinoma cells treated with antineoplastic compounds. Our laboratory has reported that p53 is a key contributor of mitochondrial apoptosis in cervical carcinoma cells after staurosporine exposure. However, higher mitochondrial membrane potential dissipation and greater DNA fragmentation were observed in p53^wt (wild‐type p53) HeLa cells compared with p53^mt (mutated p53) C‐33A cells. Here, we have studied events linked to the mitochondrial apoptotic pathway. Results. Staurosporine can induce death of HeLa cells via a cytochrome c/caspase‐9/caspase‐3 mitochondrial‐dependent apoptotic pathway and via a delayed caspase‐independent pathway. In contrast with p53^wt cells, p53^mt C‐33A cells exhibit firstly caspase‐8 activation leading to caspase‐3 activation and Bid cleavage followed by cytochrome c release. Attenuation of PARP‐1 [poly(ADP‐ribose) polymerase‐1] cleavage as well as oligonucleosomal DNA fragmentation in the presence of z‐VAD‐fmk points toward a major involvement of a caspase‐dependent pathway in staurosporine‐induced apoptosis in p53^wt HeLa cells, which is not the case in p53^mt C‐33A cells. Meanwhile, the use of 3‐aminobenzamide, a PARP‐1 inhibitor known to prevent AIF (apoptosis‐inducing factor) release, significantly decreases staurosporine‐induced death in these p53^mt carcinoma cells, suggesting a preferential implication of caspase‐independent apoptosis. On the other hand, we show that p53, whose activity is modulated by pifithrin‐α, isolated as a suppressor of p53‐mediated transactivation, or by PRIMA‐1 (p53 reactivation and induction of massive apoptosis), that reactivates mutant p53, causes cytochrome c release as well as mitochondrio—nuclear AIF translocation in staurosporine‐induced apoptosis of cervical carcinoma cells. Conclusions. The present paper highlights that staurosporine engages the intrinsic mitochondrial apoptotic pathway via caspase‐8 or caspase‐9 signalling cascades and via caspase‐independent cell death, as well as through p53 activity.     

羊栖菜多糖通过激活Caspase途径诱导Lovo细胞凋亡

研究了羊栖菜多糖（Sargassum Fusiforme Polysaccharides,SFPS）诱导人大肠癌lovo细胞凋亡及凋亡过程中caspase-3、caspase-8、caspase-9的活性变化。MTT法检测SFPS对lovo细胞增殖的抑制率;通过电镜、琼脂糖凝胶电泳、流式细胞术鉴定细胞凋亡;应用Western印迹法测定caspase-3酶原和caspase-9的变化;RToPCR检测caspase-3 mRNA表达;caspase-3,caspase-8、caspase-9活性检测试剂盒观察caspase-3、caspase-8、caspase-9的活性改变。结果显示,SFPS对lovo细胞增殖有显著抑制作用,经形态变化、DNA条带和流式细胞分析,可见明显的细胞凋亡特征。SFPS处理lovo细胞后,发现caspase-3酶原蛋白表达降低,caspase-3 mRNA高表达,并具有剂量和时间的依赖性。而在检测蛋白中,也发现caspase-9被激活进而形成具有活性的片段。另外,caspase的活性检测也进一步发现caspase-3、caspase-9的活性逐步增高。实验结果提示SFPS在体外诱导lovo胞凋亡,这可能是SFPS抑制肿瘤增殖的机制之一,并且是通过激活启动caspase-9,进而激活下游效应caspase-3的级联反应来实现的。     

Flavonoid compound breviscapine suppresses human osteosarcoma Saos‐2 progression property and induces apoptosis by regulating mitochondria‐dependent pathway

This study was aimed to investigate the ability of a flavonoid compound breviscapine (BVP) to suppress growth and elicit apoptosis in human osteosarcoma (OS) Saos‐2 cells. The cells were cultured in vitro and treated with three concentrations of BVP (80, 160, and 320 μg/ml). Moreover, C57 mice were injected with Saos‐2 cells to establish a subcutaneous xenograft model, and they were subsequently treated with three doses of BVP via intraperitoneal injection. The viability of the cells was examined by the Cell Counting Kit‐8 method. The apoptotic cells were assessed by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The tumor volume and weight were monitored from day 3 through day 21 after the last injection. The expression of bax, bcl‐2, and cytochrome c (cyt c) mRNA was detected by a real‐time polymerase chain reaction. The protein levels of bax, bcl‐2, cyt c, caspase 3, and caspase 9 were evaluated by Western blot. The expression and distribution of bcl‐2 and bax in tissues were detected by immunohistochemistry. Compared with the control group, BVP treatment inhibited cell proliferation and induced apoptosis of Saos‐2 cells in vitro. Consistently, treatment of mice bearing transplanted tumors with BVP suppressed the growth of OS tumors and promoted cell apoptosis; it also reduced tumor volume and weight. Mechanistically, BVP‐induced apoptosis was mediated by the mitochondria‐dependent pathway, as evidenced by the increased expression of bax and cyt c and the decreased expression of bcl‐2, as well as activation of caspase 9 and caspase 3 in vitro and in vitro. Collectively, BVP inhibits growth and promotes apoptosis of OS by activating the mitochondrial apoptosis pathway.     

The phospholipid scramblase PLSCR1 increases UV induced apoptosis primarily through the augmentation of the intrinsic apoptotic pathway and independent of direct phosphorylation by protein kinase C delta

Cell death by apoptosis can be caused by the DNA mutagen UV light whose exposure causes the direct activation of both the caspase 9 regulated cell damage intrinsic pathway and the caspase 8 regulated plasma membrane extrinsic pathway. We determined that increased activity of the plasma membrane phospholipid scramblase, PLSCR1, amplified UV mediated apoptosis primarily through the activation of the intrinsic apoptotic pathway. The caspase 8 inhibitor z-IETD-fmk was not as effective an inhibitor of PLSCR1 augmented UV induced apoptosis compared to treatment with caspase 3, caspase 9, or pan-caspase inhibitors. The inability of the caspase 8 inhibitor to decrease UV induced apoptosis was dependent on PLSCR1, as UV induced apoptosis was decreased by a similar amount in the control cells in the presence of inhibitors of caspase 8, caspase 9, caspase 3, or the pan-caspase inhibitor. PKC-delta directly phosphorylates human PLSCR1 resulting in increased PLSCR1 scramblase activity. PKC-delta can also be activated by caspase mediated cleavage resulting in the release of a constitutively active kinase domain. We observed that replacing the PKC-delta phosphorylation site of PLSCR1 with an alanine did not affect the ability of PLSCR1 to enhance UV induced apoptosis implying that PKC-delta does not directly phosphorylate PLSCR1 to increase plasma membrane scramblase activity during apoptosis. Cells transfected with a PLSCR1 mutant that contained an alanine substitution at its known PKC-delta phosphorylation site underwent UV induced apoptosis at a level similar to those transfected with wild type PLSCR1. The combined results indicate that UV exposure in cells possessing PLSCR1 increases apoptosis primarily by enhancement of the intrinsic apoptotic pathway, and also imply that the increased apoptosis observed upon exposure to UV light is not through direct phosphorylation of PLSCR1 by PKC-delta.     

短链脂肪酸作用下伤寒沙门菌诱导巨噬细胞凋亡机制的探讨

目的了解短链脂肪酸(SCFA)作用伤寒沙门菌诱导巨噬细胞凋亡机制。方法将SCFA作用伤寒沙门菌感染巨噬细胞8 h后,检测TNF-α、caspase3、caspase8、caspase9及NO的产生量,同时检测加入caspase3、caspase8、caspase9抑制剂和TNF-α抗体后的细胞凋亡率。结果作用8 h后caspase3、caspase8及NO、TNF-α的产生量均高于对照组(P0.01)。caspase3、caspase8抑制剂和TNF-α抗体均能不同程度抑制SCFA作用伤寒沙门菌诱导的巨噬细胞凋亡(P0.01)。结论 SCFA作用伤寒沙门菌诱导巨噬细胞凋亡可以通过NO及TNF-α介导,caspase3和caspase8参与的外源性凋亡途迳。