利巴韦林对猫细小病毒感染诱导F81猫肾细胞中凋亡相关基因表达的影响

试验将F81猫肾细胞随机分为对照组、药物组(猫细小病毒(FPV)+利巴韦林)、病毒组(FPV感染),采用实时荧光定量PCR的方法,检测Bcl-2、Bcl-xl、Bax和Caspase 3等凋亡相关基因的相对表达量。结果显示,与对照组相比,病毒组细胞凋亡增加,抗凋亡基因Bcl-2 mRNA表达受到抑制,Bax mRNA和 Caspase 3 mRNA的相对表达量均有不同程度的上调。药物组细胞的抗凋亡基因Bcl-2和Bcl-xl的表达水平显著高于病毒组(P<0.05),且总体呈上调状态,但72 h时Bcl-xl表达量减少;而药物组的促凋亡基因Bax和Caspase 3的表达量显著低于病毒组(P<0.05),48 h前,Bax 的表达量呈递减状态,72 h时检测结果显示药物组Bax表达量相比对照组显著上调(P<0.05),但仍显著低于病毒组(P<0.05);与对照组相比,病毒组和药物组Caspase 3的表达量在72 h时显著上调(P<0.05)。综上所述,利巴韦林可在基因水平通过上调抗凋亡基因Bcl-2和Bcl-xl和下调促凋亡基因Bax和Caspase 3的表达来抑制FPV感染诱导的F81猫肾细胞凋亡发生。     

Induction of Apoptosis and Antitumor Activity of Eel Skin Mucus,Containing Lactose-Binding Molecules,on Human Leukemic K562 Cells

For innate immune defense, lower animals such as fish and amphibian are covered with skin mucus, which acts as both a mechanical and biochemical barrier. Although several mucus sources have been isolated and studied for their biochemical and immunological functions, the precise mechanism(s) of action remains unknown. In the present study, we additionally found the eel skin mucus (ESM) to be a promising candidate for use in anti-tumor therapy. Our results showed that the viability of K562 cells was decreased in a dose-dependent manner by treatment with the isolated ESM. The cleaved forms of caspase-9, caspase-3 and poly adenosine diphosphate-ribose polymerase were increased by ESM. The levels of Bax expression and released cytochrome C were also increased after treatment with ESM. Furthermore, during the ESM mediated-apoptosis, phosphorylation levels of ERK1/2 and p38 but not JNK were increased and cell viabilities of the co-treated cells with ESM and inhibitors of ERK 1/2 or p38 were also increased. In addition, treatment with lactose rescued the ESM-mediated decrease in cell viability, indicating lactose-containing glycans in the leukemia cells acted as a counterpart of the ESM for interaction. Taken together, these results suggest that ESM could induce mitochondria-mediated apoptosis through membrane interaction of the K562 human leukemia cells. To the best of our knowledge, this is the first observation that ESM has anti-tumor activity in human cells.     

Isolation and Assessment of the in Vitro Anti-Tumor Activity of Smenothiazole A and B,Chlorinated Thiazole-Containing Peptide/Polyketides from the Caribbean Sponge,Smenospongia aurea

The study of the secondary metabolites contained in the organic extract of Caribbean sponge Smenospongia aurea led to the isolation of smenothiazole A (3) and B (4), hybrid peptide/polyketide compounds. Assays performed using four solid tumor cell lines showed that smenothiazoles exert a potent cytotoxic activity at nanomolar levels, with selectivity over ovarian cancer cells and a pro-apoptotic mechanism.     

Astaxanthin Attenuates Early Acute Kidney Injury Following Severe Burns in Rats by Ameliorating Oxidative Stress and Mitochondrial-Related Apoptosis

Early acute kidney injury (AKI) is a devastating complication in critical burn patients, and it is associated with severe morbidity and mortality. The mechanism of AKI is multifactorial. Astaxanthin (ATX) is a natural compound that is widely distributed in marine organisms; it is a strong antioxidant and exhibits other biological effects that have been well studied in various traumatic injuries and diseases. Hence, we attempted to explore the potential protection of ATX against early post burn AKI and its possible mechanisms of action. The classic severe burn rat model was utilized for the histological and biochemical assessments of the therapeutic value and mechanisms of action of ATX. Upon ATX treatment, renal tubular injury and the levels of serum creatinine and neutrophil gelatinase-associated lipocalin were improved. Furthermore, relief of oxidative stress and tubular apoptosis in rat kidneys post burn was also observed. Additionally, ATX administration increased Akt and Bad phosphorylation and further down-regulated the expression of other downstream pro-apoptotic proteins (cytochrome c and caspase-3/9); these effects were reversed by the PI3K inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002. Moreover, the protective effect of ATX presents a dose-dependent enhancement. The data above suggested that ATX protects against early AKI following severe burns in rats, which was attributed to its ability to ameliorate oxidative stress and inhibit apoptosis by modulating the mitochondrial-apoptotic pathway, regarded as the Akt/Bad/Caspases signalling cascade.     

Cell Death Inducing Microbial Protein Phosphatase Inhibitors—Mechanisms of Action

Okadaic acid (OA) and microcystin (MC) as well as several other microbial toxins like nodularin and calyculinA are known as tumor promoters as well as inducers of apoptotic cell death. Their intracellular targets are the major serine/threonine protein phosphatases. This review summarizes mechanisms believed to be responsible for the death induction and tumor promotion with focus on the interdependent production of reactive oxygen species (ROS) and activation of Ca²⁺/calmodulin kinase II (CaM-KII). New data are presented using inhibitors of specific ROS producing enzymes to curb nodularin/MC-induced liver cell (hepatocyte) death. They indicate that enzymes of the arachidonic acid pathway, notably phospholipase A2, 5-lipoxygenase, and cyclooxygenases, may be required for nodularin/MC-induced (and presumably OA-induced) cell death, suggesting new ways to overcome at least some aspects of OA and MC toxicity.     

细胞凋亡机制研究进展

细胞凋亡是细胞生命活动中的基本现象,是当今生命科学研究的热点。文章通过检索国内外主要数据库,对细胞死亡受体途径、线粒体途径及交织旁路途径进行简要综述。文章可为后续该领域研究提供借鉴,更好的解决实际问题。     

急性病毒性坏死病毒IAP-86基因的克隆、表达及抗凋亡研究

在已经完成的栉孔扇贝急性病毒性坏死病毒(acute viral necrosis virus,AVNV)全基因组序列测序与分析的基础上,设计特异性引物,克隆得到了ORF86编码的杆状病毒凋亡抑制蛋白基因(IAP-86)。IAP-86基因与pET32a(+)质粒连接构建得到重组质粒pET32a-IAP86,将重组质粒转化到E.coil BL21(DE3)中,使用异丙基-β-D-硫代半乳糖苷(IPTG)诱导蛋白表达,SDS-PAGE检测显示表达蛋白分子量约为40 ku,经Western-blotting和质谱分析证明,该蛋白即为IAP-86融合蛋白,Co2+柱纯化后得到了纯化的IAP-86融合蛋白。将重组的IAP-86蛋白用FITC标记,荧光显微镜下观察,发现重组的IAP-86蛋白最终能够与栉孔扇贝血淋巴细胞的细胞核和细胞质结合。细胞凋亡检测实验发现,重组的IAP-86蛋白能够在一定程度上抑制栉孔扇贝血淋巴细胞凋亡,凋亡抑制率为7%。本实验应用原核表达成功得到了IAP-86蛋白,并证明IAP-86对栉孔扇贝细胞的凋亡有一定抑制作用,这为进一步研究AVNV的侵染机制提供依据。     

绣球菌多糖诱导K562、THP-1细胞凋亡的研究

本文的目的是研究绣球菌多糖对K562、THP-1细胞凋亡的诱导作用。利用MTT比色法测定绣球菌多糖对K562、THP-1细胞增殖的抑制作用;通过吖啶橙染色观察K562、THP-1细胞形态学上的改变;同时利用DNA琼脂糖凝胶电泳检测细胞凋亡的情况。实验结果表明：经绣球菌多糖处理后,K562、THP-1细胞的生长受到了显著抑制,最大抑制率分别为46.57%和59.82%;K562、THP-1细胞出现了典型的细胞凋亡形态学特征;同时,琼脂糖凝胶电泳呈现DNA梯形条带。由此说明,绣球菌多糖可在体外抑制K562、THP-1细胞生长并诱导其凋亡。     

R-Phycoerythrin Induces SGC-7901 Apoptosis by Arresting Cell Cycle at S Phase

R-Phycoerythrin (R-PE), one of the chemical constituents of red algae, could produce singlet oxygen upon excitation with the appropriate radiation and possibly be used in photodynamic therapy (PDT) for cancer. Documents reported that R-PE could inhibit cell proliferation in HepG2 and A549 cells, which was significative for cancer therapy. This is due to the fact that R-PE could kill cancer cells directly as well as by PDT. However, little is known about the cytotoxicity of R-PE to the SGC-7901 cell. In this study, it has been found that R-PE could inhibit SGC-7901 proliferation and induce cell apoptosis, which was achieved by arresting the SGC-7901 cell at S phase. CyclinA, CDK2 and CDC25A are proteins associated with the S phase, and it was found that R-PE could increase the expression of cyclin A protein and decrease the expression of CDK2 and CDC25A proteins. Thus, it was concluded that R-PE reduced the CDK2 protein activated through decreasing the CDC25A factor, which reduced the formation of Cyclin-CDK complex. The reduction of Cyclin-CDK complex made the SGC-7901 cells arrest at the S phase. Therefore, R-PE induced apoptosis by arresting the SGC-7901 cell at S phase was successful, which was achieved by the expression of the CDC25A protein, which reduced the CDK2 protein actived and the formation of Cyclin-CDK complex.