Modulation of autophagy for neuroprotection and functional recovery in traumatic spinal cord injury

Spinal cord injury(SCI) is a serious central nervous system trauma that leads to loss of motor and sensory functions in the SCI patients. One of the cell death mechanisms is autophagy, which is ‘self-eating' of the damaged and misfolded proteins and nucleic acids, damaged mitochondria, and other impaired organelles for recycling of cellular building blocks. Autophagy is different from all other cell death mechanisms in one important aspect that it gives the cells an opportunity to survive or demise depending on the circumstances. Autophagy is a therapeutic target for alleviation of pathogenesis in traumatic SCI. However, functions of autophagy in traumatic SCI remain controversial. Spatial and temporal patterns of activation of autophagy after traumatic SCI have been reported to be contradictory. Formation of autophagosomes following therapeutic activation or inhibition of autophagy flux is ambiguous in traumatic SCI studies. Both beneficial and harmful outcomes due to enhancement autophagy have been reported in traumatic SCI studies in preclinical models. Only further studies will make it clear whether therapeutic activation or inhibition of autophagy is beneficial in overall outcomes in preclinical models of traumatic SCI. Therapeutic enhancement of autophagy flux may digest the damaged components of the central nervous system cells for recycling and thereby facilitating functional recovery. Many studies demonstrated activation of autophagy flux and inhibition of apoptosis for neuroprotective effects in traumatic SCI. Therapeutic induction of autophagy in traumatic SCI promotes axonal regeneration, supporting another beneficial role of autophagy in traumatic SCI. In contrast, some other studies demonstrated that disruption of autophagy flux in traumatic SCI strongly correlated with neuronal death at remote location and impaired functional recovery. This article describes our current understanding of roles of autophagy in acute and chronic traumatic SCI, crosstalk between autophagy and apoptosis, therapeutic activation or inhibition of autophagy for promoting functional recovery, and future of autophagy in traumatic SCI.

Study on the Effects of Losartan on Cardiomyocyte Apoptosis and Gene Expression After Ischemia and Reperfusion in vivo in Rats

Summary: In order to study the effects of losartan on cardiomyocyte apoptosis following ischemia (0. 5 h) and reperfusion (48 h) in vivo and bcl-2 and bax gene expression, TUNEL staining method, immunohistochemistry and in situ hybridization histochemistry (ISHH) were used to monitor the apoptotic cells, mRNA and protein of gene expression, respectively. Image processing system was used to quantitively dispose the positive metric substance of both immunohistochemistry and ISHH through the average optical density (OD) value. The number of the apop- totic cells were 38±9 (control group), 0-1 (sham operation group) and 9±4 (losartan-treated group) in each visual field respectively with the difference among the groups being significant (P< 0. 001 ). OD values of bcl-2 (ISHH) were 0. 07425± 0. 02029 (control group ), 0. 05961± 0. 009932 (sham operation group) and 0. 07619±0. 01445 (losartan-treated group ) respectively, while OD values of bcl-2 (immunohistochemistry) were 0. 1374±0. 01367 (control group ), 0. 08510±0. 01862 (sham operation group) and 0. 1252±0. 02064 (losartan-treated group). hcl-2 gene expression was increased significantly in the control group and losartan-treated group as com- pared with sham operation group (P < 0. 05 ). OD value of bax (immunohistochemistry) was 09727±0. 02230 (control group), 0. 06182±0. 01430 (sham operation group) and 0. 06213± 0. 01420 (losartan-treated group). bax gene expression was decreased very significantly in losartan-treated group and sham operation group as compared with control group (P<0. 001 ). Bcl-2/ bax ratio was 1. 413 (control group), 1. 376 (sham operation group) and 2. 016 (losartan-treated group) respectively. The results indicated that losartan might inhibit cardiomyocyte apoptosis following ischemia and reperfusion. The mechanism might be that bax gene expression was inhibited to increase bcl-2/bax ratio.

Preclinical Verification of Modulated Electro-Hyperthermia —Part I. In Vitro Research

Modulated electro-hyperthermia (mEHT) targets tissue’s natural electric and thermal heterogeneities to heat the cancer cells selectively. The applied 13.56 MHz radiofrequency (RF) is a carrier of the low-frequency modulation. The high-frequency part was chosen to select the malignant lesion using the specialties of the tumor: the higher conductivity and dielectric constant of the tumor than its host. The electric field selects the tumor, and the low-frequency amplitude modulation polarizes and excites the transmembrane proteins of the malignant cells. The dominant absorption of the energy by the microscopic clusters of the membrane rafts acts like nanoparticle heating. Exciting the membrane produces various apoptotic signals. The processes were modeled using silico and phantom experiments, which proved the concept. The preclinical verification was made in vitro and in vivo, and in the end, clinical proofs validated the method. Our objective is to follow all the development steps from the laboratory to the clinics in a trilogy of articles. This present is the first part, which deals with in silico, phantom, and in vitro research.

Research Progress on Neuroprotective Effects of Salvianolic Acid B in an Animal Model of Parkinson s Disease

As an active ingredient extracted from Salvia miltiorrhiza,the neuroprotective effects of salvianolic acid B in Parkinson s disease include antioxidation,improvement of mitochondrial function,modulation of neuroinflammation,inhibition of apoptosis,promotion of neuronal differentiation and proliferation,and influence on intestinal flora.As an adjuvant drug,salbutamol B can be used in combination with conventional therapeutic drugs to enhance the efficacy and minimize the side effects,which provides a method and basis for the early diagnosis and treatment of Parkinson s disease in clinical practice.

Arylamine N-acetyltransferases: a new inhibitor of apoptosis in HepG2 cells

Objective: To explore how arylamine N-acetyltransferases (NATs) is related to cell apoptosis. Methods: NAT activity in apoptotic HepG2 cells was measured using high performance liquid chromatography (HPLC); the apoptosis rate of HepG2 cells acted upon by an NAT inhibitor was measured using flow cytometry. Results: NAT activity was lowered in apoptotic HepG2 cells; apoptosis rate induced by camptothecin (CAM) increased after inhibition of NAT activity in HepG2 cells. Conclusion: NAT can inhibit apoptosis in HepG2 cells.

Lamin A/C Modulate Apoptosis of Rat Vascular Smooth Muscle Cells During Cyclic Stretch Application

Objective The apoptosis of vascular smooth muscle cells(VSMCs)influenced by abnormal cyclic stretch is crucial for vascular remodeling during hypertension.We explored that the causes of mechano-responsive lamin A/C changingin aonormai cyclic stretcn and its roles in VSMC apoptosis.Methods and results Our previous vascular proteomics study revealed that LaminA/C is mechano-sensitive molecule.When VSMCs are subjected to cyclic stretch,the expression of LaminA/C is significantly changed which participates dysfunctions of VSMCs during hypertension.However,the molecular mechanism involved in regulation of LaminA/C expression and the role of LaminA/C in the VSMC apoptosis during cyclic stretch application are still unclear.In the present study,VSMCs were subjected to different amplitudes of cyclic steetch in vitro:5%cyclic stretch(physiological strain)or 15%cyclic stretch(pathological strain).The expression of 2 different selective cleavage isomers of LaminA/C,i.e.LaminA and LaminC,and the apoptosis of VSMCs were detected.The results showed that compared with 5%group,15%cyclic stretch significantly decreased the expression of LaminA and LaminC,and promoted the apoptosis of VSMCs.Using specific small interfering RNA(siRNA)transfection which targets on LMNA the encoding gene of LaminA/C,the expression of LaminA and LaminC in VSMCs was significantly decreased,and the apoptosis was significantly increased.In order to study the molecular mechanism involved in cyclic stretch regulating the expression of LaminA/C,we focused on the microRNA(miR).Bioinformatics analysis showed that the 3’untranslated region(3’UTR)of LMNA has two potential binding sites to miR-124-3p.Double luciferase reported system revealed that both sites have binding abilities to miR-124-3p.Under static condition,miR-124-3p inhibitor significantly up-regulated the expression levels of LaminA and LaminC,while the miR-124-3p mimics significantly down-regulated them.RT-PCR results showed that 15%cyclic stretch significantly up-regulated the expression of miR-124-3p compared with 5%cyclic stretch.Furthermore,in order to study the role of changeed LaminA/C in VSMC apoptosis,LMNA-specific siRNA was transfected to repress the expression of LaminA/C in VSMCs,and Protein/DNA microarray was used to detecte the activity of transcription factors.The transcription factors whose activity were changed significantly(increase or decrease more than 2 times)were analyzed by cluster analysis and ingenurity pathway analysis(IPA).Six transcription factors associated with apoptosis were screened,in which TP53 was activated by the specific siRNA transfection and the other 5 were inavtived,including TP53,CREB1,MYC,STAT1/5/6 and JUN.Using abdominal aorta coarctation hypertensive model,the change of miR-124-3p in VSMCs was explored in vivo.A marked increase of miR-124-3p in thoracic aorta was revealed compared with the sham-operated controls,and in situ FISH revealed that this increase was mainly in the VSMCs.Conclusions The present study suggest that abnormally increased cyclic stretch(15%)up-regulates the expression of miR-124-3p in VSMCs,which subsequently targets on the 3’UTR of LMNA and decreases the expression of nuclear envelope protein LaminA/C;the repressed LaminA/C may play an important role in the apoptosis of VSMCs by regulating the activity of virious transcription factors,such as TP53,CREB1,MYC,STAT1/5/6 and JUN.The present study may provide a new insight into understanding the molecular mechanisms of vascular remodeling.

Effects of intensity modulated radiation therapy + local hyperthermia on the cancer cell apoptosis and invasion in liver cancer lesion

Objective: To investigate the effects of intensity modulated radiation therapy + local hyperthermia on the cancer cell apoptosis and invasion in liver cancer lesion. Methods:A total of 94 patients with middle-advanced primary liver cancer who were diagnosed and treated in this hospital between November 2015 and February 2017 were divided into control group (n=47) and experimental group (n=47) by random number table method. Control group received intensity modulated radiation therapy and experimental group received intensity modulated radiation therapy + local hyperthermia. Both groups accepted peritoneal lesion biopsy before and after treatment, and the expression of apoptosis and invasion genes in specimen tissue were detected by fluorescence quantitative PCR. Results: There was no statistically significant difference in apoptosis and invasion gene expression between the two groups of patients before treatment. After treatment, apoptosis genes Fas, caspase-3, Bax and p53 mRNA expression in lesion tissue of experimental group were higher than those of control group whereas FasL and Bcl-2 mRNA expression were lower than those of control group;invasion genes Cofilin-1, Bmi-1, STAT3 and SOX18 mRNA expression in lesion tissue of experimental group were lower than those of control group whereas Tip30 and TP53IP1 mRNA expression were higher than those of control group. Conclusion: intensity modulated radiation therapy + local hyperthermia can effectively promote cancer cell apoptosis and inhibit its invasion activity in patients with middle and advanced primary liver cancer.

Modulating effects of survivin antisense oligonucleotide on changes of apoptosis and cell cycle of human hepatocellular carcinoma cell line SMMC-7721

To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent.Electron microscopy,flow cytometry and RT-PCR were used to detect the changes in cell ultrastructure,apoptosis,cell cycle and the expression of cyclinB1 mRNA,respectively.Results After transfection of survivin ASODN,the expression of cyclinB1 mRNA in the cells significantly increased and increase in G2-M arrest and apoptosis appeared.Meanwhile,the cell ultrastructure had apoptotic changes such as chromatin condensation and apoptotic body formation.Conclusion Survivin ASODN can induce the expression of cyclinB1 that may result in G2-M arrest.Consequently,apoptosis is triggered.Survivin ASODN transfection might be an improtant new treatment for HCC.14 refs,2 figs,1 tab.

高车前素通过调控Orai1介导的Ca^(2+)内流对IL-1β诱导的软骨细胞凋亡的影响

目的探讨高车前素(His)对IL^(-1)β诱导的软骨细胞凋亡的影响,并初步阐明其作用机制。方法分离大鼠膝骨关节软骨细胞,采用10 ng·mL^(-1)IL^(-1)β处理软骨细胞建立骨关节炎细胞模型,并采用不同浓度(5、10、20μmol·L^(-1))His处理24 h。采用CCK-8检测细胞增殖活性;ELISA法检测细胞培养液中炎症因子IL-6和TNF-α水平;流式细胞术检测细胞凋亡水平及细胞内Ca^(2+)浓度;Western blot检测细胞内Bax、Bcl-2、cleaved-Caspase-3、钙释放激活钙通道调节分子1(Orai1)及内质网应激相关蛋白CHOP、GRP78表达水平。将Orai1过表达质粒(pcDNA-Orai1)转染至软骨细胞中,采用10 ng·mL^(-1)IL^(-1)β联合20μmol·L^(-1)His处理24 h后,流式细胞术检测细胞凋亡水平;Fluo-4/AM荧光探针标记法检测细胞内Ca^(2+)浓度。结果10 ng·mL^(-1)IL^(-1)β可降低大鼠软骨细胞增殖活性,诱导软骨细胞凋亡,提高细胞培养液中IL-6和TNF-α水平以及细胞内Ca^(2+)浓度,上调细胞中Bax、cleaved-Caspase-3、Orai1、CHOP和GRP78等蛋白表达水平,下调Bcl-2蛋白表达水平。His可提高IL^(-1)β处理的软骨细胞增殖活性,抑制IL^(-1)β诱导的软骨细胞凋亡,并降低细胞培养液中IL-6和TNF-α水平以及细胞内Ca^(2+)浓度,下调细胞中Bax、cleaved-Caspase-3、Orai1、CHOP和GRP78等蛋白表达水平,上调Bcl-2蛋白表达水平。Orai1过表达可逆转His对IL^(-1)β诱导的软骨细胞凋亡及胞内Ca^(2+)浓度的影响。结论His可抑制IL^(-1)β诱导的软骨细胞凋亡,其作用机制可能与下调Orai1介导Ca^(2+)内流引起的内质网应激凋亡途径有关。

Hyperthermia combined with chemotherapy vs chemotherapy in patients with advanced pancreatic cancer:A multicenter retrospective observational comparative study

BACKGROUND Several studies report the useful therapeutic results of regional hyperthermia in association with chemotherapy(CHT) and radiotherapy for the treatment of pancreatic cancer. Modulated electrohyperthermia(mEHT) is a new hyperthermia technique that induces immunogenic death or apoptosis of pancreatic cancer cells in laboratory experiments and increases tumor response rate and survival in pancreatic cancer patients, offering beneficial therapeutic effects against this severe type of cancer.AIM To assess survival, tumor response and toxicity of mEHT alone or combined with CHT compared with CHT for the treatment of locally advanced or metastatic pancreatic cancer.METHODS This was a retrospective data collection on patients affected by locally advanced or metastatic pancreatic cancer(stage Ⅲ and IV) performed in 9 Italian centers, members of International Clinical Hyperthermia Society-Italian Network. This study included 217 patients, 128(59%) of them were treated with CHT(no-mEHT) and 89(41%) patients received mEHT alone or in association with CHT. mEHT treatments were performed applying a power of 60-150 watts for 40-90 min, simultaneously or within 72 h of administration of CHT.RESULTS Median patients’ age was 67 years(range 31-92 years). mEHT group had a median overall survival greater than non-mEHT group(20 mo, range 1.6-24, vs 9 mo, range 0.4-56.25, P < 0.001). mEHT group showed a higher number of partial responses(45% vs 24%, P = 0.0018) and a lower number of progressions(4% vs 31%, P < 0.001) than the no-mEHT group, at the three months follow-up. Adverse events were observed as mild skin burns in 2.6% of mEHT sessions.CONCLUSION mEHT seems safe and has beneficial effects on survival and tumor response of stage Ⅲ-IV pancreatic tumor treatment. Further randomized studies are warranted to confirm or not these results.

羟基喜树碱通过激活NF-κB诱导人乳腺癌Bcap-37细胞凋亡

目的:探讨NF-κB信号转导途径在羟基喜树碱诱导人乳腺癌Bcap-37细胞凋亡中所起的作用。方法:突变IκB-α-pcDNA3.1(-)质粒转染Bcap-37细胞,并用G418进行阳性克隆选择;采用MTT法测定细胞的增殖活力,琼脂糖凝胶电泳观察细胞凋亡,流式细胞仪进行细胞周期分析,Western blotting法和DIG-EMSA研究细胞凋亡途径。结果:羟基喜树碱对Bcap-37有明显的生长抑制作用,琼脂糖凝胶电泳检测到典型的DNA梯状条带;羟基喜树碱可通过降解IκBα蛋白进而激活NF-κB,并使NF-κB发生核移位;羟基喜树碱没有激活突变IκB-α-pcDNA3.1(-)质粒转染细胞的NF-κB,并且转染细胞凋亡受到抑制。结论:羟基喜树碱对Bcap-37有明显的生长抑制和诱导凋亡作用;NF-κB信号转导途径在羟基喜树碱诱导人乳腺癌Bcap-37细胞凋亡中起着促进凋亡的作用。

积雪草甙诱导肿瘤细胞凋亡及增强长春新碱的抗肿瘤作用

背景与目的:中药积雪草的三萜类成分积雪草甙(asiaticoside,ATS)具有促进胶原蛋白合成作用,对创伤愈合有较好的疗效。近年有文献报道积雪草甙有一定的抗肿瘤活性。本文研究积雪草甙诱导肿瘤细胞凋亡及其与长春新碱(vincristine,VCR)的协同作用。方法:采用MTT法检测积雪草甙单用或合用VCR对KB、KBv200、MCF-7和MCF-7/ADM细胞的增殖抑制作用,流式细胞术分析KB细胞周期和凋亡率的变化,琼脂糖凝胶电泳、荧光显微镜和Westernblot方法观察KB细胞凋亡和细胞周期相关性质改变。结果:积雪草甙对KB、KBv200、MCF-7和MCF-7/ADM细胞的IC50分别为(1.11±0.13)、(1.82±0.08)、(1.58±0.15)mg/ml和(3.25±0.46)mg/ml,且KBv200和MCF-7/ADM细胞对积雪草甙表现出与相应的亲本细胞相近的药物敏感性。经积雪草甙处理后的KB细胞表现出凋亡细胞特征性的改变。积雪草甙与VCR合用对多种肿瘤细胞均有显著协同作用,合并用药组KB细胞凋亡率、Bcl-2蛋白磷酸化水平明显高于单用组,且仅有合用组检测到活化后的caspase-3蛋白。积雪草甙与VCR合用组KB细胞阻滞于S-G2/M期的比率和CyclinB1蛋白的表达水平高于单用组,P34cdc2蛋白表达略有降低。结论:积雪草甙可诱导肿瘤细胞凋亡并与长春新碱显示协同作用,有可能作为生化调节剂应用于肿瘤化?

喜树碱诱导的草地贪夜蛾Sf9细胞凋亡

传统植物源杀虫剂喜树碱具有优异的抑制昆虫生长发育活性,其诱导昆虫细胞凋亡的作用方式和机制尚不明确,极大地限制了喜树碱在植物保护领域的应用开发。本研究以1μmol/L喜树碱诱导草地贪夜蛾Spodopterafrugiperda Sf9细胞呈现细胞皱缩、微绒毛消失和染色质边集等典型细胞凋亡早期超微结构形态特征,中期凋亡小体逐渐出现并急剧增多,DNA电泳分析可见清晰DNA片段化凋亡特征。流式细胞术分析表明1μmol/L喜树碱诱导Sf9细胞12h凋亡率达到最大值39.67%,是对照的13.13倍,随后减小。喜树碱诱导Sf9细胞凋亡在12h和24h时Sf caspase-1分别出现两个活性高峰,表明其作为效应因子在细胞凋亡级联反应过程中具有影响作用。喜树碱显著抑制Sf9细胞拓扑异构酶Ⅰ活性,阻断解旋负超螺旋pBR322DNA,导致DNA损伤进而启动细胞凋亡级联反应使Sfcaspase-1活性增加,提示其信号转导过程是细胞凋亡诱导机制之一。本研究通过分析喜树碱的诱导昆虫Sf9细胞凋亡,对揭示喜树碱诱导昆虫细胞凋亡的作用机制具有重要启示和帮助。

植物源物质诱导的斜纹夜蛾细胞凋亡

为了研究植物源物质对斜纹夜蛾Spodoptera litura离体培养细胞系SL-1的凋亡诱导作用,采用倒置相差显微镜观察了印楝素、喜树碱等9种物质各自对SL-1凋亡小体的浓度效应及时序性。结果表明：印楝素0.1～5.0μg/mL和喜树碱0.5～20.0μmol/L处理SL-1,24～48h后均产生大量典型的凋亡小体;茶皂素、蓖麻碱、黄樟油、丹皮酚、烟碱、苦参碱和博落回碱0.1～20.0μg/mL处理SL-1后,整个观察期72h内均无明显凋亡小体出现,凋亡诱导作用不明显。印楝素0.75μg/mL诱导SL-1细胞凋亡,从凋亡小体判断,处理后0～36h属细胞凋亡早期,36～60h属细胞凋亡中期,60h后为细胞凋亡晚期。喜树碱5.0μmol/L诱导SL-1细胞凋亡,处理后0～24h属细胞凋亡前期,24～54h属细胞凋亡中期,54h后进入细胞凋亡晚期。初步认为印楝素和喜树碱对SL-1有凋亡诱导作用,并具有一定的浓度依赖性和时序性。

3-甲基腺嘌呤对喜树碱诱导的宫颈癌Hela细胞凋亡的影响

目的:本研究探讨自噬抑制剂3-甲基腺嘌呤(3-methyladenine,3-MA)对喜树碱(Camptothecin,CPT)诱导的Hela细胞凋亡的影响。方法:用四甲基偶氮唑盐比色法(MTT方法)检测CPT对Hela细胞作用的最佳药物浓度和时间,以及不同药物对Hela细胞增殖活性的影响;用免疫印迹及免疫荧光检测不同药物作用于Hela细胞后,Hela细胞自噬标志蛋白微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)、p62及凋亡相关蛋白的变化;DAPI核染色观察细胞凋亡。结果:CPT作用于Hela细胞后,Hela细胞增殖活性明显下降,并且可诱导自噬现象的发生。CPT和3-MA联合作用较单独CPT作用Hela细胞的增殖活性降低,细胞自噬水平下降,凋亡率明显升高。结论:CPT在诱导Hela细胞凋亡的同时可诱导自噬,通过3-MA抑制自噬可增强Hela细胞对CPT作用的敏感性。

不同杀虫成分对Sf9细胞凋亡的影响

通过倒置显微形态观察凋亡小体、DNA琼脂糖凝胶电泳确证的模型,研究了8种代表性杀虫成分对草地贪夜蛾Spodoptera frugiperda离体培养细胞系Sf9的凋亡诱导效果,以探讨不同杀虫成分对昆虫细胞凋亡的影响.结果表明,印楝素0.15-1.50μg/mL处理后72 h内、喜树碱0.35-3.50μg/mL处理后36 h,Sf9细胞产生大量典型凋亡小体,处理时间延长或剂量加大则以造成细胞坏死为主;DNA电泳产生典型的DNA Ladder,表明印楝素和喜树碱对Sf9具有明显的细胞凋亡诱导作用.印楝素1.5μg/mL诱导处理Sf9细胞凋亡高峰期为处理后24-48 h,喜树碱0.35-3.50μg/mL诱导处理Sf9细胞凋亡高峰期为处理后12 h.苦参碱、氟铃脲、毒死蜱、灭多威、氯氰菊酯以0.1-10.0μg/mL及昆虫蜕皮激素20-羟基蜕皮酮（20-hydroxyecdysone）以0.048-4.800μg/mL处理后72 h内对Sf9均无明显的细胞凋亡诱导作用.杀虫剂对昆虫细胞凋亡诱导效应随供试化合物、细胞种类、处理剂量、处理时间而异.

喜树碱抗肿瘤作用机制研究进展

喜树碱(Camptothec in CPT)能稳定拓扑异构酶Ⅰ和DNA的共价化合物,形成了三元可解离复合物,通过复制冲突模型造成DNA损伤,最终导致细胞死亡。但是DNA损伤后引起凋亡的具体分子机制还不清楚。本文简述喜树碱的可能多种抗肿瘤机制,包括不同细胞凋亡通路、信号通路,细胞周期,以及端粒损伤作用。并且CPT的作用可能是剂量和时间依赖的双相性,其抗肿瘤的作用机制也有根本上的不同。

重组人TFAR19蛋白对羟基喜树碱诱导人7721肝癌细胞凋亡的增敏作用

目的 :探讨新的人凋亡相关基因产物TFAR19蛋白对羟基喜树碱诱导人 772 1肝癌细胞凋亡的增敏作用。方法 :将不同浓度的rhTFAR19蛋白单独或与羟基喜树碱 (hydroxycamptothecin ,HCPT)同时加入处于指数生长期的 772 1肝癌细胞中共同培养 ,通过透射电镜、DNA片段化分析、PI及AnnexinV标记进行流式细胞仪分析 ,观察细胞的形态学和细胞凋亡的变化。结果 :不同质量浓度的rhTFAR19蛋白单独作用于 772 1肝癌细胞未见明显凋亡 ,但同时加 5mg·L-1的羟基喜树碱后 ,各质量浓度组均观察到细胞凋亡 ,并且显示了明确的量效关系 :5mg·L-1的HCPT加 5mg·L-1rhTFAR19蛋白的细胞凋亡率为 2 9.5 8% ,而加 2 0mg·L-1rhTFAR19蛋白的细胞凋亡率为6 3 .77%。结论 :rhTFAR19蛋白对HCPT诱导的细胞凋亡有明显的剂量依赖性促进作用 ,临床用HCPT行局部化疗时 ,若加rhTFAR19蛋白 ,可能会在不增加化疗药物毒性的情况下 。

喜树碱诱导Jurkat细胞线粒体膜电势和线粒体质量变化的研究

目的:研究喜树碱(camptothecin,CPT)诱导Jurkat细胞凋亡过程中线粒体膜电势和线粒体质量的变化。方法:用喜树碱处理Jurkat细胞,利用Annexin V-FITC/PI双染流式细胞术研究细胞早期凋亡,PI染色流式细胞术测细胞周期,Annexin V-PE/DiOC6(3)双染流式细胞术检测线粒体膜电势(△ψm),NAO染色流式细胞术检测线粒体质量。结果:在10μmol.L-1CPT诱导下,6 h时Jurkat细胞早期凋亡的细胞比率(22.59±1.04)%显著高于对照组(3.93±0.73)%(P<0.01)。CPT组坏死比率(2.48±0.53)%与对照组(2.78±0.63)%无显著差异(P>0.05);并可使细胞出现明显的凋亡峰。晚期凋亡的细胞比率为(13.58±0.97)%显著高于对照组(3.18±0.51)%(P<0.01),CPT组G0/G1期细胞比率(48.14±0.96)%,明显高于对照组(44.09±0.43)%(P<0.01)。CPT组线粒体发生明显去极化现象,AnnexinV+DiOC6(3)-的细胞比率为(19.47±0.69)%,而对照组比率为(4.21±0.40)%,差异显著(P<0.01)。同时,CPT组线粒体质量显著低于对照组:CPT组NAO+细胞比率为(74.77±1.66)%,对照组为(92.24±1.41)%(P<0.01)。结论:CPT诱导Jurkat细胞凋亡过程中线粒体去极化作用增强并且线粒体质量下降,表明该凋亡过程与线粒体途径密切相关。

药物诱导胃癌细胞凋亡的初步探索

目的:了解羟基喜树碱和氧化砷体外诱导胃癌细胞凋亡的能力.探索最佳诱导时间和剂量.并初步阐明其作用机制。方法:利用HE染色法、流式细胞仪和DNA末端原位标记染色法(TUNEL)观察羟基喜树碱和氧化砷在体外对胃癌细胞MKN-28(高分化腺癌)。SGC-7901(中分化腺癌)。MKN-45(低分化腺癌)的作用 结果:药物作用48小时后,羟基喜树碱0.01mg/ml组胃癌细胞MKN-28、SGC-7901、MKN-45的凋亡率分别为30.26％、21.88％和12.35％,氧化砷10μmol/L组胃癌细胞MKN-28、SGC-7901、MKN-45的凋亡率分别为22.52％、13.83％和9.68％其中羟基喜树碱在细胞周期的S期诱导胃癌细胞发生凋亡,而氧化砷则主要作用于G2/M期。