Effects of terpinen-4-ol fumigation on protein levels of detoxification enzymes in Tribolium confusum

Terpinen-4-ol has high fumigating activity to stored-grain pests including Tribolium confusum. To understand the detoxification of terpinen-4-ol in insects, proteomic analysis was performed to identify related proteins and pathways in response to terpinen-4-ol fumigation in T. confusum. By using isobaric tags for relative and absolute quantitation (iTRAQ)-based strategy, 4,618 proteins were obtained from T. confusum adults in the present study. Comparative proteomic analysis showed that 148 proteins were upregulated and 137 proteins were downregulated in beetles under the LC₅₀ of terpinen-4-ol treatment for 24 hr. According to functional classifications, differentially expressed proteins (DEPs) were enriched in xenobiotic metabolism pathways. In the detoxification pathway, the levels of 25 cytochrome P450s, 5 glutathione S-transferases, and 2 uridine diphosphate (UDP)-glucuronosyltransferases were changed, most of which were upregulated in T. confusum exposed to terpinen-4-ol. The results indicated that terpinen-4-ol was potentially metabolized and detoxified by enzymes like P450s in T. confusum.     

MicroRNA研究进展

近年来,在许多真核生物中发现了一类能时序调控发育的、长度约为22个核苷酸（nt）的非编码小分子RNA,称为microRNA(miRNA)。它由RNaseⅢ蛋白Drosha和Dicer共同酶解作用产生,由Exportin-5转运出核,通过与small interfering RNA(siRNA)相似的机制,导致mRNA降解,或者与mRNA的3’端非翻译区结合,阻遏转录后翻译。miRNA在发育和某些人类疾病发生中有着重要作用。     

重组SARS病毒N蛋白可与SARS患者血清发生特异反应

N蛋白是SARS CoV病毒基因组编码病毒核衣壳蛋白 ,它不同于现已知的任何蛋白质 .对它的深入研究对揭示SARS -CoV的致病机理和疫苗及诊断试剂的研制有重要意义 .灭活的病毒经逆转录后 ,用根据已知的病毒的基因组序列所设计的引物PCR扩增N蛋白基因 .扩增出的基因经序列分析表明和已知的序列完全一致 ,共编码 4 2 2个氨基酸残基 .将N蛋白基因克隆入原核表达载体pET2 8a构建成表达质粒pET2 8a N .表达质粒转化大肠杆菌BL2 1 (DE3) ,并用IPTG诱导后 ,获得了高表达N蛋白的重组菌株 .目的蛋白经一步金属离子螯合层析纯化后获得了纯度超过 90 %的样品 .Western印迹及ELISA分析表明 ,SARS患者体内有特异性的针对N蛋白的抗体 ,并具有较高的特异性 .这为临床上诊断SARS患者提供了新方法 ,并为SARS疫苗的研制提供了研究思路     

TNF‐α induces up‐regulation of MicroRNA‐27a via the P38 signalling pathway,which inhibits intervertebral disc degeneration by targeting FSTL1

The mechanism of intervertebral disc degeneration is still unclear, and there are no effective therapeutic strategies for treating this condition. miRNAs are naturally occurring macromolecules in the human body and have many biological functions. Therefore, we hope to elucidate whether miRNAs are associated with intervertebral disc degeneration and the underlying mechanisms involved. In our study, differentially expressed miRNAs were predicted by the GEO database and then confirmed by qPCR and in situ hybridization. Apoptosis of nucleus pulposus cells was detected by flow cytometry and Bcl2, Bax and caspase 3. Deposition of extracellular matrix was assessed by Alcian blue staining, and the expression of COX2 and MMP13 was detected by immunofluorescence, Western blot and qPCR. Moreover, qPCR was used to detect the expression of miR27a and its precursors. The results showed that miR27a was rarely expressed in healthy intervertebral discs but showed increased expression in degenerated intervertebral discs. Ectopic miR27a expression inhibited apoptosis, suppressed the inflammatory response and attenuated the catabolism of the extracellular matrix by targeting FSTL1. Furthermore, it seems that the expression of miR27a was up‐regulated by TNF‐α via the P38 signalling pathway. So we conclude that TNF‐α and FSTL1 engage in a positive feedback loop to promote intervertebral disc degeneration. At the same time, miR27a is up‐regulated by TNF‐α via the P38 signalling pathway, which ameliorates inflammation, apoptosis and matrix degradation by targeting FSTL1. Thus, this negative feedback mechanism might contribute to the maintenance of a low degeneration load and would be beneficial to maintain a persistent chronic disc degeneration.     

Shifting from population-wide to personalized cancer prognosis with microarrays

The era of personalized medicine for cancer therapeutics has taken an important step forward in making accurate prognoses for individual patients with the adoption of high-throughput microarray technology. However, microarray technology in cancer diagnosis or prognosis has been primarily used for the statistical evaluation of patient populations, and thus excludes inter-individual variability and patient-specific predictions. Here we propose a metric called clinical confidence that serves as a measure of prognostic reliability to facilitate the shift from population-wide to personalized cancer prognosis using microarray-based predictive models. The performance of sample-based models predicted with different clinical confidences was evaluated and compared systematically using three large clinical datasets studying the following cancers: breast cancer, multiple myeloma, and neuroblastoma. Survival curves for patients, with different confidences, were also delineated. The results show that the clinical confidence metric separates patients with different prediction accuracies and survival times. Samples with high clinical confidence were likely to have accurate prognoses from predictive models. Moreover, patients with high clinical confidence would be expected to live for a notably longer or shorter time if their prognosis was good or grim based on the models, respectively. We conclude that clinical confidence could serve as a beneficial metric for personalized cancer prognosis prediction utilizing microarrays. Ascribing a confidence level to prognosis with the clinical confidence metric provides the clinician an objective, personalized basis for decisions, such as choosing the severity of the treatment.     

Contributions of cysteine residues in Zn2 to zinc fingers and thiol-disulfide oxidoreductase activities of chaperone DnaJ

Escherichia coli DnaJ, possessing both chaperone and thiol-disulfide oxidoreductase activities, is a homodimeric Hsp40 protein. Each subunit contains four copies of a sequence of -CXXCXGXG-, which coordinate with two Zn(II) ions to form an unusual topology of two C4-type zinc fingers, C144DVC147Zn(II)C197NKC200 (Zn1) and C161PTC164Zn(II)C183PHC186 (Zn2). Studies on five DnaJ mutants with Cys in Zn2 replaced by His or Ser (C183H, C186H, C161H/C183H, C164H/183H, and C161S/C164S) reveal that substitutions of one or two Cys residues by His or Ser have little effect on the general conformation and association property of the molecule. Replacement of two Cys residues by His does not interfere with the zinc coordination. However, replacement of two Cys by Ser results in a significant decrease in the proportion of coordinated Zn(II), although the unique zinc finger topology is retained. The mutants of C183H, C186H, and C161S/C164S display full disulfide reductase activity of wild-type DnaJ, while C161H/C183H and C164H/183H exhibit severe defect in the activity. All of the mutations do not substantially affect the chaperone activity. The results indicate that the motif of -CXXC- is critical to form an active site and indispensable to the thiol-disulfide oxidoreductase activity of DnaJ. Each -CXXC- motif in Zn2 but not in Zn1 functions as an active site.     

魔芋无土栽培营养液配方研究初报

分别采用全MS、1/2MS、1/5MS、1/10MS(含大量元素、微量元素和铁盐)、1/10MS大量元素营养液(不含微量元素和铁盐)定期浇灌用蛭石栽培的不同级别的魔芋,前50d生长状况没有差异,50-80d以1/2MS-1/10MS营养液为佳,80-110d时1-5MS-1/10MS生长较好;魔芋在缺乏微量元素的营养液中后期生长不良,提前倒苗;产量分析结果表明:35g以上的种芋以1/2MS最高,35g以下的种芋以1/10MS最高,魔芋的耐盐浓度在2.25‰以下,高盐浓度对块茎的形成有毒害作用,造成产量大幅度下降,添加微量元素和铁有较好的增产作用。     

水稻插入突变库构建研究进展

水稻是单子叶植物基因组研究的一种模式植物 ,其全基因组测序已经完成 ,在此基础上开展功能基因组的研究。水稻插入突变体库的建立是功能基因组研究的一个重要内容 ,在此基础上也能进行正向遗传学及反向遗传学的研究。水稻插入突变体库构建的方法有T DNA插入突变、Ac Ds系统插入突变、Tos1 7插入突变。分别介绍三种方法的原理及其在水稻突变体库构建中的应用和研究进展。