Effects of short-chain acyl-CoA dehydrogenase on cardiomyocyte apoptosis

AIM: To investigate the change of short-chain acyl-CoA dehydrogenase(SCAD) expression during cardiomyocyte apoptosis and to explore the relationship between SCAD and cardiomyocyte apoptosis.METHODS: The neonatal rat cardiomyocytes treated by tert-butyl hydroperoxide(tBHP) were used as the model of cardiomyocyte apoptosis. The cell viability, the expression of SCAD at mRNA and protein levels, the activity of SCAD and the content of free fatty acids were determined.RESULTS: The mRNA and protein expression of SCAD decreased in the cardiomyocyte apoptosis model. Compared with negative control group, SCAD expression and activity were both significantly decreased in siRNA-1186 group, but the content of free fatty acids were obviously increased in the cardiomyocytes. Meanwhile, SCAD siRNA treatment triggered the same apoptosis as cardiomyocytes treated with tBHP.CONCLUSION: Down-regulation of SCAD may play an important role in primary cardiomyocyte apoptosis. Increase in the expression of SCAD may become an important part in intervening cardiomyocyte apoptosis.     

水稻与油菜黄单胞菌菜豆致病变种非寄主互作体系中病原细菌过氧化氢的作用

 【目的】探讨互作体系中病原菌来源过氧化氢的作用。【方法】采用组织化学法通过透射电子显微镜技术观察水稻与油菜黄单胞菌菜豆致病变种互作体系中的过氧化氢积累的定位。【结果】突变体菌株细胞中烷基过氧化物还原酶亚基C的缺失导致胞内其余过氧化氢清除酶活性的补偿性显著上升,使胞内内源过氧化氢积累水平显著下降,并引起病原菌与水稻互作体系中的过氧化氢积累水平发生显著变化。【结论】病原细菌很可能是互作体系中过氧化氢的一个重要来源。病原细菌产生的过氧化氢很可能在非寄主互作中造成细菌周围植物细胞的损伤,对植物细胞具有潜在的毒性。     

花卉香味基因工程研究进展

概述了花卉香味基因工程研究进展以及产生短链醛和醇的脂氢过氧化物酶分子生物学研究现状,提出了脂氢过氧化物酶基因可以应用于花卉香味的改良。     

山羊PHGPx基因在不同组织中的表达特点及性腺中的定位

【目的】研究磷脂氢谷胱甘肽过氧化物酶(PHGPx)在山羊各种组织中的表达特点及在性腺中的定位情况。【方法】提取各种组织总RNA,应用实时荧光定量PCR方法检测各种组织PHGPx mRNA表达规律,利用免疫组化技术对睾丸和附睾PHGPx进行定位分析。【结果】PHGPx mRNA在各种组织表达水平由高到低依次为:睾丸心脑附睾肾肝肺脾背最长肌,在性腺和附睾中:睾丸附睾尾附睾头附睾体;免疫组化结果显示睾丸间质组织、生精细胞均有阳性产物,附睾头部平滑肌纤维表达弱阳性,附睾尾部附睾管中的单层柱状上皮表达呈强阳性。【结论】PHGPx在不同组织广泛表达,发挥重要的生物学功能,免疫组化结果直观显示了睾丸及附睾表达差异的部位,需深入研究其作用机制。     

有机过氧化物硫化天然胶乳的研究

研究了过氧化羟基异丙苯（氢过氧化枯烯）等有机过氧化物对天然胶乳硫化效果的影响,分析了不同引发剂的种类、用量以及不同硫化温度对硫化胶乳的影响。结果表明,以过氧化羟基异丙苯、四乙烯五胺、丙烯酸丁酯、少量的铁离子络合物为氧化—还原体系、聚氧乙烯十二烷基醚为乳化剂的硫化体系为低温下（４０℃）最佳硫化体系,物机性能均获得提高。它们的最适宜用量分别为：０．４５３、０．３０２、３、０．０６８ ｇ ／１００ ｇ干胶。与硫磺硫化体系的比较的结果表明：过氧化羟基异丙苯硫化体系的硫化胶膜耐热老化性能、胶乳稳定性、透明度均比硫磺硫化制成的硫化胶膜好,拉伸强度等与硫磺硫化的相近。      

采用叔丁基过氧化氢-连二亚硫酸钠氧化还原体系改善真丝纱线接枝后的泛黄性

为减轻真丝纱线接枝加工后表面泛黄的程度,以叔丁基过氧化氢(TBHP)-连二亚硫酸钠(SH)氧化还原体系引发单体甲基丙烯酰胺(MAA)接枝真丝纱线,并从引发剂分解及接枝反应的机理入手探讨接枝后真丝纱线泛黄的原因,研究接枝聚合工艺的最优条件。通过衰减全反射红外光谱(ATR-FTIR)测试表明,单体MAA可以在TBHP-SH的引发下接枝到真丝纱线的表面。以MAA为接枝单体时,引发剂的种类和用量是造成真丝接枝过程中泛黄的主要原因,引发剂TBHP中加入有还原和漂白作用的SH构成的氧化还原引发体系可有效改善泛黄现象。以真丝纱线的接枝增重率为考核指标,采用单因素试验优化的接枝反应工艺条件为:单体MAA的浓度为0.4 mol/L,引发剂TBHP与SH的摩尔比为1∶0.5,引发剂TBHP-SH与单体MAA的质量比为1∶16.7,接枝温度为80℃,接枝时间为90 min。在此工艺条件下,TBHP-SH引发MAA接枝真丝纱线的接枝增重率达到47.78%,真丝纱线的白度达到67.6。     

Lutein suppresses t-BHP-induced apoptosis in retinal ganglion cells

AIM: To investigate the protective effects of lutein on retinal ganglion cells in vitro. METHODS: The effect of lutein on tert-butyl hydroperoxide (t-BHP)-treated retinal ganglion cells (RGC-5 cell line) was determined. The protein expression of Brn-3 and MAP-2 was examined by the method of immunocytochemistry to identify the RGC-5 cells. The RGC-5 cells were induced by a 24 h exposure of t-BHP, and the cell viability was examined by MTT assay. The apoptotic ratio of the RGC-5 cells after exposed to t-BHP or/ and lutein treatment was analyzed by flow cytometry assay with Annexin V-FITC /PI staining. The activation of caspase-3 was detected by immunocytochemistry and the protein levels of Bcl-2, Bax, cleaved caspase-3, JNK and c-Jun were determined by Western blot. RESULTS: The RGC-5 cells expressed Brn-3 and MAP-2 proteins. Lutein treatment prevented t-BHP-induced RGC-5 cell apoptosis and increased the cell activity. Compared with control group, exposure of the RGC-5 cells to t-BHP decreased the expression of anti-apoptotic protein Bcl-2, increased the Bax/Bcl-2 ratio, up-regulated the level of cleaved caspase-3, also promoted the phosphorylation of JNK and c-Jun. Lutein partly reversed the effects of t-BHP on the RGC-5 cells mentioned above. CONCLUSION: Lutein protects RGC-5 cells against t-BHP-induced apoptosis by up-regulating Bcl-2 expression and inhibiting caspase-3 activation through modulating the JNK signaling pathway.     

Consequences for the bovine embryo of being derived from a spermatozoon subjected to oxidative stress

Objective To determine whether oxidative damage of ejaculated frozen–thawed sperm prior to oocyte insemination in vitro affects the competence of the resultant embryo to develop to the blastocyst stage. Method Extended frozen semen from bulls was thawed, subjected to Percoll gradient purification to obtain motile spermatozoa and mixed with medium containing the pro-oxidants menadione or tert-butyl hydroperoxide. After 3 h at 38.5°C, the sperm were washed and used to inseminate oocytes in vitro. Embryo development proceeded until 8 days after insemination. Results Treatment of sperm with 15 or 30 µmol/L menadione reduced the proportions of oocytes that cleaved and those that developed to the blastocyst stage; 30 µmol/L menadione reduced the proportion of cleaved embryos that developed to the blastocyst stage at day 8 after insemination. Oocytes inseminated with sperm treated with 150 or 300 µmol/L tert-butyl hydroperoxide had lower proportions of cleavage and blastocyst development, and the proportion of cleaved embryos becoming blastocysts was also reduced. Conclusion Oxidative damage to ejaculated sperm can compromise the ability of the sperm to cause oocyte cleavage and leads to formation of embryos with reduced competence for development.