山东崑嵛山两栖动物的多样性

Arthur P.Jacot(1923)报道过山东内陆的两栖动物,此后,王兴春等(1997)和陆宇燕等(1999)进行过报道.而山东省两栖动物的区系和地理区划尚无系统研究.本文在对山东省胶东半岛最大的山系--昆嵛山进行初步考察的基础上,仅就该地区的两栖动物组成和区系特征进行分析讨论,为研究山东省两栖爬行动物地理区划提供参考.     

Loss of Core 1-derived O-Glycans Decreases Breast Cancer Development in Mice

Mucin-type core 1-derived O-glycans, one of the major types of O-glycans, are highly expressed in mammary gland epithelium. Abnormal O-glycans such as Tn antigen are found in over 90% of breast cancers; however, the in vivo role of these aberrant O-glycans in the etiology of breast cancer is unclear. We generated mice with mammary epithelial specific deletion of core 1-derived O-glycans. By crossing with two spontaneous mouse breast cancer models, we determined that loss of core 1-derived O-glycans delays the onset and progression of breast cancer development. Deficiency of core 1 O-glycosylation impaired the localization of Muc1, a major O-glycoprotein, on the apical surfaces of mammary epithelium. Signaling mediated by Muc1, which is critical for breast cancer development, was also defective in the absence of core 1 O-glycans. This study reveals an unexpected role of core 1-derived O-glycans in breast cancer development in mice.     

An analysis approach to identify specific functional sites in orthologous proteins using sequence and structural information: Application to neuroserpin reveals regions that differentially regulate inhibitory activity

The analysis of sequence conservation is commonly used to predict functionally important sites in proteins. We have developed an approach that first identifies highly conserved sites in a set of orthologous sequences using a weighted substitution‐matrix‐based conservation score and then filters these conserved sites based on the pattern of conservation present in a wider alignment of sequences from the same family and structural information to identify surface‐exposed sites. This allows us to detect specific functional sites in the target protein and exclude regions that are likely to be generally important for the structure or function of the wider protein family. We applied our method to two members of the serpin family of serine protease inhibitors. We first confirmed that our method successfully detected the known heparin binding site in antithrombin while excluding residues known to be generally important in the serpin family. We next applied our sequence analysis approach to neuroserpin and used our results to guide site‐directed polyalanine mutagenesis experiments. The majority of the mutant neuroserpin proteins were found to fold correctly and could still form inhibitory complexes with tissue plasminogen activator (tPA). Kinetic analysis of tPA inhibition, however, revealed altered inhibitory kinetics in several of the mutant proteins, with some mutants showing decreased association with tPA and others showing more rapid dissociation of the covalent complex. Altogether, these results confirm that our sequence analysis approach is a useful tool that can be used to guide mutagenesis experiments for the detection of specific functional sites in proteins. Proteins 2015; 83:135–152. © 2014 Wiley Periodicals, Inc.     

JSI-124 Suppresses Invasion and Angiogenesis of Glioblastoma Cells In Vitro

Glioblastoma multiforme (GBM) is one of the utmost malignant tumors. Excessive angiogenesis and invasiveness are the major reasons for their uncontrolled growth and resistance toward conventional strategies resulting in poor prognosis. In this study, we found that low-dose JSI-124 reduced invasiveness and tumorigenicity of GBM cells. JSI-124 effectively inhibited VEGF expression in GBM cells. In a coculture study, JSI-124 completely prevented U87MG cell–mediated capillary formation of HUVECs and the migration of HUVECs when cultured alone or cocultured with U87MG cells. Furthermore, JSI-124 inhibited VEGF-induced cell proliferation, motility, invasion and the formation of capillary-like structures in HUVECs in a dose-dependent manner. JSI-124 suppressed VEGF-induced p-VEGFR2 activity through STAT3 signaling cascade in HUVECs. Immunohistochemistry analysis showed that the expression of CD34, Ki67, p-STAT3 and p-VEGFR2 protein in xenografts was remarkably decreased. Taken together, our findings provide the first evidence that JSI-124 effectively inhibits tumor angiogenesis and invasion, which might be a viable drug in anti-angiogenesis and anti-invasion therapies.     

Effect of EGCG On Fe(III)‐induced conformational transition of silk fibroin,a model of protein related to neurodegenerative diseases

The abnormal aggregation of amyloid proteins is reported to play a critical role in the etiology of neurodegenerative disorders. Studies have shown that excessive ferric irons are associated with the misfolding of amyloid proteins, and that (‐)‐epigallocatechin gallate (EGCG) is a good metallic ion chelator with inhibitory effect on the aggregation of amyloid proteins. EGCG has been thus considered as a potential drug candidate for the treatment of neurodegenerative diseases. However, the mechanism of action for EGCG in inhibition of aggregation of amyloid proteins is still remaining unclear. Silk fibroin (SF) shares similarities with amyloid proteins in some amino acid sequences and fibrillation kinetics. In this work, therefore, we used SF as a model of protein to investigate the effects of Fe(III) and EGCG on conformational transition by using turbidity assay, thioflavin T (ThT) fluorescence spectroscopy, Raman spectroscopy, and atomic force microscope (AFM). We demonstrated that low concentration of Fe(III) ions promoted the formation of β‐sheet conformers, while high concentration of Fe(III) ions inhibited further aggregation of SF. EGCG could significantly inhibit the conformational transition of SF when induced by Fe(III), and decrease the amount of β‐sheet conformers dose‐dependently. The findings provide important information regarding to EGCG as a potential agent for the prevention and treatment of neurodegenerative diseases. Fe(III) can accelerate the conformation transition of silk fibrion (SF) from random coil into β‐sheet, while (‐)‐epigallocatechin gallate (EGCG) inhibits Fe(III)‐induced β‐sheet aggregation of SF., 2016. © 2015 Wiley Periodicals, Inc. Biopolymers 105: 100–107, 2016     

Toward a phylogeny and biogeography of Diaphanosoma (Crustacea: Cladocera)

Aquatic Ecology - Diaphanosoma s.l., with 40+? described species, is the largest genus of the Sididae and the Ctenopoda, similar in many ways to the anomopod genus Daphnia. Here, we offer a c...     

雷公藤内生细菌的促生作用及其对雷公藤甲素生成的影响

从健康雷公藤植株体内分离得到23株内生细菌,对其有益生物学特征及对小麦萌发能力的影响进行评价,得出3株益生效果显著的内生细菌.这3株内生细菌均能产生植物生长素和铁载体,其中LG3、LJ10具有溶磷特性,LG3、LY4具有固氮功能并同时具有1-氨基环丙烷-1-羧酸脱氨酶(ACC脱氨酶)活性.经细菌16S rDNA序列鉴定及同源性分析发现, LG3、LY4属于肠杆菌属,LJ10属于泛菌属.回接试验表明,3株内生细菌不但能够促进雷公藤植株的生长,还能显著提高不同器官内雷公藤甲素的含量.