Discovery and biological evaluation of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor

A novel series of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor is reported. Starting from a 3.4 microM high throughput screen hit, members of this series have been identified which are full agonists with functional potency <50 nM and oral bioavailability in mice.     

利用RAPD标记分析鸵鸟种群的遗传变异

为探讨分子遗传标记在鸵鸟（Struthio camelus)育种中的应用,利用RAPD技术分析了我国养殖的三个主要要鸵鸟品种内和品种间的遗传变异。蓝颈鸵鸟、澳洲灰和非洲黑三个品种在品种内和品种间显示出低水平的变异。品种间的遗传距离好地说胆了三个品种的育种改良过程。同时预示出用澳洲灰与其他品种鸵鸟进行杂交育种的可行性。选择的20条在鸡中能稳定扩增的RAPD引物其75％能在鸵鸟基因组中扩增出产物。显示出两种禽类DNA具有同源性、为今后利用鸡的微卫星引物对鸵鸟进行基因扫描（genome scan）分析奠定基础。     

The Polyclonal Antibodies Induced by VBP3 Complex Peptide Targeting Angiogenesis and Tumor Suppression

Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) play a critical role in tumor-associated angiogenesis and have become the targets of anti-tumor therapy. The BALB/c mice were immunized with VEGF/bFGF complex peptide (VBP3) constructed with different epitope peptides of human VEGF and bFGF. The results of the immunogenicity showed that the VBP3 could effectively stimulate immune response in mice and elicit the mice to produce high titer specific anti-VEGF and anti-bFGF antibodies (anti-VBP3 antibodies). The polyclonal anti-VBP3 antibodies separated from the mouse immune serum could effectively inhibit the proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) and block the proliferation and migration of lung cancer A549 cells. Besides, the anti-VBP3 antibodies could effectively inhibit tumor growth and tumor angiogenesis in BABL/c nude mice. The results demonstrated that the VBP3 complex peptide could elicit the body to produce the high titer anti-VEGF and anti-bFGF antibodies, which showed anti-tumor and anti-angiogenic effects in vitro and in vivo. The results revealed that the VBP3 complex peptide could be used as a potential peptide vaccine in tumor therapy.     

唐鱼β-actin基因近端和远端启动子的鉴定及其启动活性分析

利用高保真PCR技术获得唐鱼(Tanichthys albonubes)长为1.3 kb的卢肌动蛋白(β-actin)的端启动调控序列(TA,1.3 kb).在此基础上采用基因组步移技术(Genome walker)获得5'侧翼上游序列1.7 kb,再根据所获的近端启动子序列和上游序列设计引物,扩增获得全长为3.0 kb的唐鱼β-actin基因远端启动调控序列(TLA,3.0 kb).此1.3 kb和3.0 kb启动调控序列均包含3个转录活性元件:CAAT Box(-89～-85),CArG Box(-59～-49),TATA Box(-26～-20).利用启动子分析软件TRANSFAC 6.0分析,结果显示启动调控序列(-105～1261)国含有E-Box、NF-Y、Spl等多个重要转录因子结合位点,在远端启动调控序列(-1719～1261)中还含有更多的重要转录因子结合位点.将这两个序列分别定向克隆到红色荧光蛋白(Red fluorescent protein,RFP)表达载体中,构建重组表达载体pTLA-DsRed和pTA-DsRed,并分别注射到唐鱼受精卵中.结果显示转pTLA-DsRed基因唐鱼的阳性率较转pTA-DsRed的高,且所发出的红色荧光的强度也比后者的强.采用RT-PCR检测孵化后第15天的转基因唐鱼中RFP的mRNA,结果显示转pTLA-DsRed基因唐鱼中RFPmRNA的表达量比转pTA-DsRed基因唐鱼高35.7%.结果表明两种长度的启动调控序列均能有效驱使外源基因在唐鱼体内表达,且长度为3.0 kb的启动子序列具有更强的驱动活性.     

Enterocyte-Specific Inactivation of SIRT1 Reduces Tumor Load in the APC+/min Mouse Model

SIRT1 is a mammalian NAD⁺-dependent histone deacetylase implicated in metabolism, development, aging and tumorigenesis. Prior studies that examined the effect of enterocyte-specific overexpression and global deletion of SIRT1 on polyp formation in the intestines of APC^+/min mice, a commonly used model for intestinal tumorigenesis, yielded conflicting results, supporting either tumor-suppressive or tumor-promoting roles for SIRT1, respectively. In order to resolve the controversy emerging from these prior in vivo studies, in the present report we examined the effect of SIRT1 deficiency confined to the intestines, avoiding the systemic perturbations such as growth retardation seen with global SIRT1 deletion. We crossed APC^+/min mice with mice bearing enterocyte-specific inactivation of SIRT1 and examined polyp development in the progeny. We found that SIRT1-inactivation reduced total polyp surface (9.3 mm² vs. 23.3 mm², p = 0.01), average polyp size (0.24 mm² vs. 0.51 mm², p = 0.005) and the number of polyps >0.5 mm in diameter (14 vs. 23, p = 0.04), indicating that SIRT1 affects both the number and size of tumors. Additionally, tumors in SIRT1-deficient mice exhibited markedly increased numbers of cells undergoing apoptosis, suggesting that SIRT1 contributes to tumor growth by enabling survival of tumor cells. Our results indicate that SIRT1 acts as a tumor promoter in the APC^+/min mouse model of intestinal tumorigenesis.     

Cloning, sequencing, and expression of a Thermomonospora fusca protease gene in Streptomyces lividans.

The major Thermomonospora fusca YX extracellular protease gene (tfpA) was cloned into Escherichia coli and Streptomyces lividans and was sequenced. The open reading frame encoded 375 residues, including a 31-residue potential signal sequence, an N-terminal prosequence containing 150 residues, and the 194-residue mature protease that belongs to the chymotrypsin family. The protease was secreted by S. lividans, but evidence suggested that it was bound to an extracellular protease inhibitor. An inhibitor-deficient mutant was selected to produce protease for purification.     

Association Cluster Detector: a tool for heuristic detection of significance clusters in whole-genome scans

Whole genome scans analyze large sets of genetic markers, mainly single nucleotide polymorphisms, over the entire genome in order to find variants and regions associated with complex traits so these can be further investigated. Analyzing the results of such scans becomes difficult due to multiple testing problems and to the genomic distributions of recombination, linkage disequilibrium and true associations, which generate an extremely complex network of dependences between markers. Here we present Association Cluster Detector (ACD), a simple tool aiming to ease the analysis of the results of whole genome scans. ACD facilitates correction for multiple tests using several standard procedures and implements a sliding-window heuristic method that helps in detecting potentially interesting candidate regions by exploiting the property of non-random distribution of significantly associated markers. AVAILABILITY: The tool can be downloaded from http://www.upf.es/cexs/recerca/bioevo/softanddata.htm     

Gender differences in polysomnographic sleep in young healthy sleepers

Middle-aged and elderly populations exhibit gender differences in polysomnographic (PSG) sleep; however, whether young men and women also show such differences remains unclear. Thirty-one young healthy sleepers (16 men and 15 women, aged 18 to 30 yr, mean+/-SD, 20.5+/-2.4 yr) completed 3 consecutive overnight sessions in a sleep laboratory, after maintaining a stable sleep-wake cycle for 1 wk before study entry. Standard PSG sleep and self-rated sleepiness data were collected each night. Across nights, women showed better sleep quality than men: they fell asleep faster (shorter sleep onset latency) and had better sleep efficiency, with more time asleep and less time awake (all differences showed large effect sizes, d=0.98 to 1.12). By contrast, men were sleepier than women across nights. Both men and women demonstrated poorer overall sleep quality on the first night compared with the subsequent 2 nights of study. We conclude young adult healthy sleepers show robust gender differences in PSG sleep, like older populations, with better sleep quality in women than in men. These results highlight the importance of gender in sleep and circadian rhythm research studies employing young subjects and have broader implications for women's health issues relating to these topics.