现代设施农业中香石竹根区土壤生物酶因子时空变化研究

[目的]为了对香石竹病害监测、预防方面提供一些基础理论依据。[方法]通过定位监测,研究香石竹种植区正常株与发病株根际土壤酶活性的时空变化特征。[结果]土壤酶活性变化与土传病害发生具有一定的关联性。[结论]多酚氧化酶、磷酸酶、脲酶可以作为预测、指示土传病害发生的表征,脱氢酶、木聚糖酶也可以作为夏季预测、指示土传病害发生的表征。

Bioinformatics Analysis of Chalconesynthase Gene in Morus

[Objective] This study aimed to explore the molecular mechanism of mulberry pigment metabolism regulation. [Method] Chalconesynthase（CHS） gene was cloned from Morus（Moraceae） in silico. The amino acid sequence, physical and chemical properties, transmembrane structural domain, hydrophobicity/hydrophilicity,subcellular localization, secondary and tertiary structure of protein were predicted and analyzed by bioinformatics tools. [Result] The cDNA sequence of CHS gene was 1 365bp by splicing using the software DNAstar and it contained a complete ORF including 1 170 bp which encoded 389 amino acids. Bioinformatic analysis showed that CHS gene included specific peptide sequence RLMMYQQGCFAGGTVLR of chalcone synthase superfamily, but has no signal peptide, belonging to the non-secretory proteins, located inside of cytoplasm. Its molecular evolution is more conservative.[Conclusion] The results above provided foundation for the further studies of structure and function of CHS protein.

Expression of endothelial nitric oxide synthase and vascular endothelial growth factor in association with neovascularization in human primary astrocytoma

Objective: To investigate the relationship between the expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and angiogenesis in primary astrocytoma. Methods: Thirty-seven primary astrocytomas and 4 astrocytic hyperplasia samples were collected and divided into three groups according to histological grade. The expression of eNOS, VEGF and factorⅧ related antigen (FⅧRAg) were assayed by immunohistochemistry. Microvascular density was assessed by FⅧRAg immunoreactivity. The intensity of immunoreactivity was graded according to the percentage of positive tumor cells. Results: No eNOS and VEGF were expressed in the astrocytes and vascular endothelium in astrocytic hyperplasia. The expression of eNOS or VEGF was light in low-grade astrocytoma and strong in glioblastoma. eNOS expression in astrocytoma was very positively correlated with VEGF. eNOS and VEGF expression in anaplastic astrocytoma was median in contrast to the low grade astrocytoma and glioblastoma. Lower microvascular density was found in low grade astrocytoma than that in higher grade malignant ones. The expressions of eNOS and VEGF were correlated with microvascular density and tumor malignancy. Conclusion: This finding suggests that eNOS and VEGF may have cooperative effect in tumor angiogenesis and play an important role in the pathogenesis of primary astrocytoma.

HDACs,histone deacetylation and gene transcription: from molecular biology to cancer therapeutics

Histone deacetylases （HDACs） and histone acetyl transferases （HATs） are two counteracting enzyme families whose enzymatic activity controls the acetylation state of protein lysine residues, notably those contained in the N-terminal extensions of the core histones. Acetylation of histones affects gene expression through its influence on chromatin conformation. In addition, several non-histone proteins are regulated in their stability or biological function by the acetylation state of specific lysine residues. HDACs intervene in a multitude of biological processes and are part of a multiprotein family in which each member has its specialized functions. In addition, HDAC activity is tightly controlled through targeted recruitment, protein-protein interactions and post-translational modifications. Control of cell cycle progression, cell survival and differentiation are among the most important roles of these enzymes. Since these processes are affected by malignant transformation, HDAC inhibitors were developed as antineoplastic drugs and are showing encouraging efficacy in cancer patients.

Significance of regenerating islet-derived type Ⅳ gene expression in gastroenterological cancers

The regenerating islet-derived members （Reg）, a group of small secretory proteins, which are involved in cell proliferation or differentiation in digestive organs, are upregulated in several gastrointestinal cancers, functioning as trophic or antiapoptotic factors. Regenerat- ing islet-derived type Ⅳ （RegⅣ）, a member of the Reg gene family, has been reported to be overexpressed in gastroenterological cancers. RegIV overexpression in tumor cells has been associated with carcinogen- esis, cell growth, survival and resistance to apoptosis. Cancer tissue expressing RegIV is generally associated with more malignant characteristics than that with- out such expression, and RegⅣ is considered a novel prognostic factor as well as diagnostic marker in some gastroenterological cancers. We previously investigated the expression levels of RegⅣ mRNA of 202 surgical colorectal cancer specimens with quantitative real-time reverse-transcriptase polymerase chain reaction and reported that a higher level of RegⅣ gene expression was a significant independent predictor of colorec- tal cancer. The biologic functions of RegⅣ protein in cancer tissue, associated with carcinogenesis, anti- apoptosis and invasiveness, are being elucidated by molecular investigations using transfection techniques or neutralizing antibodies of RegIV, and the feasibility of antibody therapy targeting RegIV is being assessed. These studies may lead to novel therapeutic strate- gies for gastroenterological cancers expressing RegⅣ. This review article summarizes the current information related to biological functions as well as clinical impor- tance of RegⅣ gene to clarify the significance of Reg~ expression in gastroenterological cancers.

Troglitazone inhibits cell proliferation by attenuation of epidermal growth factor receptor signaling independent of peroxisome proliferator-activated receptor γ

Peroxisome proliferator-activated receptors （PPAR） belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone （TGZ）, can inhibit cell proliferation and promote cell differentiation independent of PPARy. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by targeting the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinasesignaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro- liferation by promoting EGFR degradation and attenuating Akt phosphorylation.

Protective effect of dihydropteridine reductase against oxidative stress is abolished with A278C mutation

Objective: To evaluate the antioxidation of dihydrobiopterin reductase and to explore the effect of A278C mutation of the quinoid dihydropteridine reductase(QDPR) gene on its antioxidant activity. Methods: First, plasmids with different genes(wild and mutant QDPR) were constructed. After gene sequencing, they were transfected into human kidney cells(HEK293T). Then, the intracellular production of reactive oxygen species(ROS) and tetrahydrobiopterin(BH4) was detected after cells were harvested. Activations of nicotinamide adenine dinucleotide phosphate oxidase 4(NOX4), glutathione peroxidase 3(GPX3), and superoxide dismutase 1(SOD1) were analyzed to observe the oxidative stress after transfection. The expression of the neuronal nitric oxide synthase(n NOS) gene was analyzed by semiquantitative reverse-transcription polymerase chain reaction(RT-PCR). We also detected the activation of transforming growth factor β1(TGF-β1) by enzyme-linked immunosorbent assay(ELISA) to observe the connection of TGF-β1 and oxidative stress. Results: The exogenous wild-type QDPR significantly decreased the expression of n NOS, NOX4, and TGF-β1 and induced the expression of SOD1 and GPX3, but the mutated QDPR lost this function and resulted in excessive ROS production. Our data also suggested that the influence on the level of BH4 had no significant difference between mutated and the wild-type QDPR transfection. Conclusions: Wild-type QDPR played an important role in protecting against oxidative stress, but mutant QDPR failed to have these beneficial effects.

Differential gene expression profile of Buyanghuanwu decoction in rats with ventricular remodeling post-myocardial infarction

OBJECTIVE: To investigate the effect of Buyanghuanwu decoction(BYHWD) on gene expression in ventricular remodeling post-myocardial infarction in rats.METHODS: Animal models of myocardial infarction were established by permanent ligation of the left anterior descending coronary artery. Echocardiography measurements were performed after the treatment of BYHWD(18 g·kg-1 collagen was observ·d-1) for 90 days.Myocardialed by mallory trichrome staining. Capillary density was quantified by using Factor rentially expⅧre immunohistochemical staining.Diffessed genes were explored by a short-read sequencing technology combined with a tag-based digital gene expression profiling(DGE)system. Real-time quantitative polymerase chain reaction detecting system(q PCR) was used to validate the sequencing results. After assembling the gene information from Sham, model and BYHWD groups, we constructed three DGE libraries based on each group. The sequencing of three libraries generated 66 000-73 000 unique tags, which were mapped to reference sequences for annotation of expressed genes.RESULTS: Among them, 511 and 352 differentially expressed genes were found in comparison with sham/model and model/BYHWD, respectively. Fifty-five genes exhibited reversed direction of gene expression differences between Sham/Model and Model/BYHWD groups. We found that transforming growth factor beta receptor-1, junctophilin-2,monocyte chemotactic protein 1, neuropeptide Y,arachidonate 5-Lipoxygenase, arachidonate 15-Lipoxygenase were significantly modulated, which suggested the involvement of these genes in BYHWD treatment.CONCLUSION: The DGE profiling data provide comprehensive gene expression information at the transcriptional level that could facilitate our understanding of the pharmacological mechanisms of BYHWD in ventricular remodeling post-myocardial infarction.