Proteomics analysis of acetylated protein in clear cell renal cell carcinoma

AIM To comprehensively analyze clear cell renal cell carcinoma （ccRCC）-associated acetylated proteins, acetylation sites and differentially expressed proteins （DEPs）, and to identify potential molecular markers and therapeutic targets for clinical application. METHODS The open search strategy was applied to re-analyze the mass spectrometric data of ccRCC clinical tissue samples including 8 pairs of cancer and paracancerous tissues. Mass spectrometric data of ccRCC containing 8 pairs of cancer and paracancerous tissues were downloaded from ProteomeXchange proteomics database, and subjected to database searching for the identification of acetylated proteins and acetylation sites. The DEPs were analyzed by power law global error model （PLGEM） algorithm and uploaded to cluster analysis, GO enrichment and KEGG pathway analysis. The expression of acetylated proteins was verified by Western blot using specific lysine acetylation antibody. RESULTS A total of 464 DEPs were identified by non-labeled quantitative proteomics, including 104 up-regulated and 360 down-regulated proteins. The GO enrichment and KEGG pathway analysis showed that the up-regulated proteins were mainly involved in the processes of vasoconstriction, complement and coagulation cascade system, and platelet activation. More importantly, a total of 503 acetylated proteins including 1 397 acetylation sites were identified. We found that the protein acetylation level in ccRCC was significantly down-regulated as compared with paracancerous tissues, which was verified by Western blot analysis. We also found that the acetylation levels of glutathione S-transferase kappa 1 （GSTK1） at sites K158, K163 and K165 were decreased in ccRCC as compared with paracancerous tissues. CONCLUSION The proteins involved in complement and coagulation cascade, vasoconstriction and platelet activation may play an important role in ccRCC malignant progression. The total acetylation level was significantly decreased in ccRCC tissues, suggesting an overall suppression of acetylation in renal cancer. Deacetylation of GSTK1 is likely a key molecular event in the renal malignant progression and a potential clinical biomarker.     

Developmental and tissue-specific changes in oxidative parameters and antioxidant systems in tomato fruits grown under salt stress

In tomato plants, salt stress has been induced to improve the quality of fruit. In general, plants under salt stress produce reactive oxygen species (ROS). Plants have their own ROS scavenging systems (antioxidant systems). In tomato plants, salt-induced changes in antioxidant systems have been examined extensively in leaves and roots; however, detailed information about salt-stressed fruits is not available. We examined the salt-induced changes in the antioxidant systems of the pericarp (containing epidermis) and pulp (containing seeds, placenta, and locule) during fruit ripening. Salt treatments were applied by adding 100 mM NaCl to the nutrient solution. In the pericarp and pulp, lipid peroxidation and hydrogen peroxide content were not increased by salt stress during ripening, indicating the absence of salt-induced oxidative stress. In the pericarp, the activities of superoxide dismutase (EC 1.15.1.1) and ascorbate (ASA)–glutathione (GSH) cycle-related enzymes increased with salt stress at the turning stage. Thus, at the turning stage, the antioxidant system may contribute to the enzymatic reaction involved ASA–GSH cycle. However, during the red and over-ripe fruit stages, salt stress produces little effect on antioxidant enzymes. In addition, the concentrations of antioxidants, such as the reduced form of ASA and GSH, increased during ripening in the control fruit, but those in the salt-stressed fruit remained unchanged. Therefore, the antioxidant system may contribute to the nonenzymatic reactions such as ASA and GSH taking place during the red and over-ripe fruit stages. In contrast, in the pulp, salt stress produces little effect on antioxidants and antioxidant enzymes. These results indicate that the salt-stressed fruit has protection mechanisms against salt-induced oxidative stress during ripening in both the pericarp and pulp. Salt-induced changes in antioxidant systems differed between the pericarp and pulp.     

Seasonal and cultivar differences in salt-induced changes in antioxidant system in tomato

Salt stress has been applied to improve the quality of tomato, but detailed information about the changes in antioxidant systems in salt-stressed fruit is not available. In this study, we examined the effect of salt stress on oxidative parameters, antioxidant content and antioxidant enzymes in two tomato cultivars during two cropping seasons. Salt stress was applied by adding 100 mM NaCl to the nutrient solution. We show that tomato fruits have antioxidant systems to protect themselves from salt-induced oxidative stress. This finding is supported by the lipid peroxidation and hydrogen peroxide levels, which remained unchanged under salt stress conditions. However, these antioxidant systems depend on cultivars and cropping seasons. In the summer crop, the antioxidant systems in salt-stressed ‘House Momotaro’ can be attributed to the enzymatic reactions of ascorbate peroxidase (EC 1.11.1.11) and glutathione reductase (EC 1.6.4.2), while those in salt-stressed ‘Mini Carol’ can be attributed to their non-enzymatic reactions of ascorbate and glutathione. In the winter crop, the antioxidant systems were not influenced by salt stress in either cultivar. However, the proline content increased in both cropping seasons and cultivars. The seasonal and cultivar differences of salt-induced changes in the antioxidant systems may result from cultivar differences in antioxidant capacities and the interaction between salt stress and growth conditions such as temperature and solar radiation.     

小麦在铜、镉胁迫下体内含巯基物质对解毒机制的研究

将小麦幼苗分别放在含有100μmol/L Cu2 的培养液和100μmol/L Cd2 的培养液中培养,观察其体内重金属含量、丙二醛(MDA)、植物螯合肽(PC)和谷胱甘肽(GSH)的变化。试验结果表明,在铜、镉胁迫下,小麦体内重金属含量逐渐增加,尤以根中增加明显,约75倍,而叶中增加较少,为2~5倍;无论是在根中还是在叶中,镉的含量都高于铜的含量;铜、镉胁迫下小麦叶片膜脂过氧化程度都高于根部无论是铜胁迫还是镉胁迫下,小麦体内叶片的GSH含量均高于根部,而PC含量均低于根部。     

紫外线和60Coγ射线联合诱变选育高产谷胱甘肽酵母菌

以实验室保存的酵母菌为出发菌株,通过紫外线、60Coγ射线照射及氯化锌平板筛选高产谷胱甘肽酵母菌菌株。采用四氧嘧啶法测定GSH含量,结果显示摇瓶实验菌体胞内谷胱甘肽的含量达到1.39%,较出发菌株提高了250%。传代试验证明,其遗传性能稳定。     

富硒茶对大鼠抗氧化功能的影响

用基础低硒饲料饲养大鼠 ,以自来水 (对照 )、Na2 SeO3 溶液、低硒茶水和富硒茶水作试验处理 ,实验 7周后分析血液及肝脏中谷胱甘肽过氧化物酶 (GSH Px)活性、超氧化物歧化酶 (SOD)活性和血液、肝脏的含硒量 ,丙二醛 (MDA)的含量。结果表明 :富硒茶显著增加大鼠血液和肝脏的含硒量 ,降低MDA含量 ,提高血液的SOD活性。富硒茶处理大鼠血液的GSH Px活性是对照和低硒茶叶的 1 3倍 ,肝脏GSH Px活性可达 1 4倍 ,富硒茶在提高肝脏和血液的GSH Px活性和SOD活性 ,降     

植物谷胱甘肽研究进展

谷胱甘肽是植物中普遍存在的硫醇,在还原硫的贮存和运输、蛋白质合成及植物抗逆性方面均有重要作用。介绍了谷胱甘肽的测定方法和在植物中的生理作用,概述了谷胱甘肽在小麦、水稻、烟草、果树及蔬菜上的研究进展。并提出了对谷胱甘肽在植物体内合成、降解、运输的调控机制及对植物抗氧化作用机理研究的重要性。     

高温胁迫对不同黄瓜品种幼苗中抗坏血酸代谢的影响

对高温胁迫条件下黄瓜幼苗叶片中的抗坏血酸以及与之代谢相关物质的含量和酶活性变化进行了研究。结果表明,高温处理1 d,津春4号和农城3号的抗坏血酸总含量均急剧下降,降幅分别为50.8%和37.1%,处理2 d时总谷胱甘肽含量降至最低,降幅分别为36.9%和39.5%,之后逐渐上升,抗坏血酸过氧化物酶（Ascorbic peroxidase,AAP）活性经1 d胁迫后分别增加67.4%和39.6%,抗坏血酸氧化酶（Ascorbic ox-idase,AAO）活性胁迫4 d时分别降低44.0%和35.0%,另外,脱氢抗坏血酸还原酶（DHAR）和单脱氢抗坏血酸还原酶（MDAR）活性也有所增加。抗坏血酸含量与谷胱甘肽含量间呈显著的正相关关系,与AAP及AAO活性之间均呈显著负相关关系。耐高温品种抗坏血酸和谷胱甘肽含量的变化幅度较小,AAP,AAO,MDAR和DHAR等酶活性变化幅度较大。     

发酵法生产谷胱甘肽的研究进展

谷胱甘肽是一种重要的生理活性三肽,对维持生物体内合适的氧化还原环境起着关键作用,被广泛应用于医药、食品和化妆品等领域。微生物发酵法是目前谷胱甘肽生产的主要方法。综述了发酵法生产谷胱甘肽中优良菌株选育、发酵过程优化与控制等,并对发酵法合成谷胱甘肽需解决的问题进行了展望。     

转CrylAc+CpTI双价基因棉对烟粉虱主要解毒酶活性的影响

测定了取食转双价基因棉SGK321及其亲本棉SY321后烟粉虱伪蛹体内羧酸酯酶、乙酰胆碱酯酶、谷胱甘肽S-转移酶等主要解毒酶的活性。结果表明:与SY321烟粉虱种群相比,SGK321对烟粉虱体内羧酸酯酶、乙酰胆碱酯酶、谷胱甘肽S-转移酶活性均值无显著影响,但两个种群中这些酶活性个体分布存在不同程度的差异。与SY321烟粉虱种群相比,SGK321烟粉虱种群α-NA羧酸酯酶活性在<30 mOD/(mgprotein.min)区间分布频率较高,而在30~40 mOD/(mg protein.min)区间较低;SGK321烟粉虱种群乙酰胆碱酯酶活性在2~4 U/mg protein区间内分布频率略低,而在>4 U/mg protein区间内分布频率上升了10个百分点;SGK321烟粉虱种群谷胱甘肽S-转移酶活性在80~140 U/mg protein活性区间内分布频率略有下降,在140~170 U/mg protein区间内分布频率上升了15个百分点。