B cell-activating factor belonging to the TNF family acts through separate receptors to support B cell survival and T cell-independent antibody formation

The TNF-related ligand, B cell-activating factor belonging to the TNF family (BAFF), is necessary for normal B cell development and survival, and specifically binds the receptors transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI), B cell maturation Ag (BCMA), and BAFF-R. Similarities between mice completely lacking BAFF and A/WySnJ strain mice that express a naturally occurring mutant form of BAFF-R suggest that BAFF acts primarily through BAFF-R. However, the nearly full-length BAFF-R protein expressed by A/WySnJ mice makes unambiguous interpretation of receptor function in these animals impossible. Using homologous recombination we created mice completely lacking BAFF-R and compared them directly to A/WySnJ mice and to mice lacking BAFF. BAFF-R-null mice exhibit loss of mature B cells similar to that observed in BAFF(-/-) and A/WySnJ mice. Also, mice lacking both TACI and BCMA simultaneously exhibit no B cell loss, thus confirming that BAFF-R is the primary receptor for transmitting the BAFF-dependent B cell survival signal. However, while BAFF-R-null mice cannot carry out T cell-dependent Ab formation, they differ from BAFF-deficient mice in generating normal levels of Ab to at least some T cell-independent Ags. These studies clearly demonstrate that BAFF regulates Ab responses in vivo through receptors in addition to BAFF-R.     

Evaluation of garlic intercropping for enhancing the biological control of Ralstonia solanacearum in flue-cured tobacco fields

Tobacco bacterial wilt, Ralstonia solanacearum, is an important disease affecting the root and stem. The disease causes extensive damage to flue-cured tobacco all over the word. Field trials were conducted in 2008 and 2009 at Longyan, Fujian Province, China, to evaluate garlic intercropping for enhancing the biological control of R. solanacearum in flue-cured tobacco fields. The results of the study demonstrate that tobacco bacterial wilt was clearly inhibited by intercropping garlic in 2008 and 2009. The appearance of the disease in intercropped fields was delayed for about 15 days. The total number of R. solanacearum in root system soils was significantly lower in intercropped fields than in monocultured fields in 2008. These numbers were between 138×10⁴ and 161×10⁴ cfu g^–1 dry soil in intercropped fields. The corresponding values in monocultured fields were 357×10⁴ cfu g^–1 dry soil. The monetary value of tobacco leaves was obviously higher in intercropped fields than in monocultured ones. The per cent increase in monetary values in the intercropped fields was between 14 and 34%. Consequently, intercropping tobacco with garlic might be very useful for enhancing biological control of R. solanacearum in flue-cured tobacco fields.     

Antitumor activity of diethynylfluorene derivatives of gold(I)

A list of diethynylfluorenes and their gold(I) derivatives have been studied for their antitumor activity as a function of their structure–activity relationships. End-capping the fluoren-9-one unit with gold(I) moieties could significantly strengthen the cytotoxic activity in vitro on three human cancer cell lines with induction of reactive oxygen species generation on Hep3B hepatocellular carcinoma cells and exhibit attractive antitumor activity from in vivo nude mice Hep3B xenograft model with limited adverse effects on vital organs including liver and kidney.     

转昆虫抗冻蛋白基因增强甘薯抗冻能力

为明确昆虫抗冻蛋白基因转入甘薯(Ipomoea batatas)后是否能提升其抗冻能力,进而为培育甘薯抗冻育种材料奠定基础,将黄粉虫(Tenebrio molitor)抗冻蛋白基因TmAFP导入植物基因表达质粒,经农杆菌介导的遗传转化获得抗冻甘薯新材料。以甘薯品种Huachano为受体材料建立甘薯植株高效再生体系,并采用不同成分的体细胞胚成熟培养基培养胚性悬浮细胞。胚性愈伤组织对除草剂的敏感性测试结果表明,转基因阳性植株筛选的最适培养基为MS+0.2 mg·L–12,4-D+0.8 mg·L^–1 GAP+100 mg·L^–1 Carb。将表达质粒分别转化Huachano后共获得7个胚性愈伤团并最终获得42株再生抗性植株,其中转pSUIBEV3-AFP有23个株系,转pCAMBIA-AFP有19个株系,经PCR、Southern杂交和RT-PCR检测后证实TmAFP基因已整合至甘薯基因组中并获得表达。将转基因甘薯及对照植株在–1℃下处理15小时后转移至室温,结果表明,转基因甘薯植株的抗冻能力显著提升。     

The effects of patchouli alcohol and combination with cisplatin on proliferation,apoptosis and migration in B16F10 melanoma cells

Melanoma is a highly metastatic cancer with a low incidence rate, but a high mortality rate. Patchouli alcohol (PA), a tricyclic sesquiterpene, is considered the main active component in Pogostemon cablin Benth, which improves wound healing and has anti-tumorigenic activity. However, the pharmacological action of PA on anti-melanoma remains unclear. Thus, the present study aimed to investigate the role of PA in the proliferation, cell cycle, apoptosis and migration of melanoma cells. These results indicated that PA selectively inhibited the proliferation of B16F10 cells in a dose- and time-dependent manner. It induced cell cycle arrest at the G₀/G₁ phase and typical morphological changes in apoptosis, such as chromatin condensation, DNA fragmentation and apoptotic bodies. In addition, PA reduced the migratory ability of B16F10 cells by upregulating E-cadherin and downregulating p-Smad2/3, vimentin, MMP-2 and MMP-9 expression. PA was also found to strongly suppress tumour growth in vivo. Furthermore, PA combined with cisplatin synergistically inhibited colony formation and migration of B16F10 cells and attenuated the development of resistance to treatment. Therefore, the results of this study indicate that PA may play a pivotal role in inducing apoptosis and reducing the migration of melanoma cells, and may thus be a potential candidate for melanoma treatment.     

Monitoring of Gene Expression Profiles and Isolation of Candidate Genes Involved in Pollination and Fertilization in Rice (Oryza Sativa L.) with a 10K cDNA Microarray

To monitor gene expression profiles during pollination and fertilization in rice at a genome scale, we generated 73,424 high-quality expressed sequence tags (ESTs) derived from the green/etiolated shoot and pistil (0-5 h after pollination, 5hP) of rice, which were subsequently used to construct a cDNA microarray containing ca. 10 000 unique rice genes. This microarray was used to analyze gene expression in pistil unpollinated (UP), 5hP and 5DAP(5 days after pollination), anther, shoot, root, 10-day-old embryo (10EM) and 10-day-old endosperm (10EN). Clustering analysis revealed that the anther has a gene-expression profile more similar to root than to pistil and most pistil-preferentially expressed genes respond to pollination and/or fertilization. There are 253 ESTs exhibiting differential expression (e +/- 2-fold changes) during pollination and fertilization, and about 70% of them can be assigned a putative function. We also recovered 20 genes similar to pollination-related and/or fertility-related genes previously identified as well as genes that were not implicated previously. Microarray and real-time PCR analyses showed that the array sensitivity was estimated at 1-5 copies of mRNA per cell, and the differentially expressed genes showed a high correlation between the two methods. Our results indicated that this cDNA microarray constructed here is reliable and can be used for monitoring gene expression profiles in rice. In addition, the genes that differentially expressed during pollination represent candidate genes for dissecting molecular mechanism of this important biological process in rice.     

Influence of the APOA5 locus on plasma triglyceride, lipoprotein subclasses, and CVD risk in the Framingham Heart Study

Several polymorphisms in the APOA5 gene have been associated with increased plasma triglyceride (TG) concentrations. However, associations between APOA5 and lipoprotein subclasses, remnant-like particles (RLPs), and cardiovascular disease (CVD) risk have been less explored. We investigated associations of five APOA5 single-nucleotide polymorphisms (SNPs; -1131T>C, -3A>G, 56C>G IVS3+ 476G>A, and 1259T>C) with lipoprotein subfractions and CVD risk in 1,129 men and 1,262 women participating in the Framingham Heart Study. Except for the 56C>G SNP, the other SNPs were in significant linkage disequilibria, resulting in three haplotypes (11111, 22122, and 11211) representing 98% of the population. SNP analyses revealed that the -1131T>C and 56C>G SNPs were significantly associated with higher plasma TG concentrations in both men and women. For RLP and lipoprotein subclasses, we observed gender-specific association for the -1131T>C and 56C>G SNPs. Female carriers of the -1131C allele had higher RLP concentrations, whereas in males, significant associations for RLPs were observed for the 56G allele. Moreover, haplotype analyses confirmed these findings and revealed that the 22122 and 11211 haplotypes exhibited different associations with HDL cholesterol concentrations. In women, the -1131C allele was associated with a higher hazard ratio for CVD (1.85; 95% confidence interval, 1.03-3.34; P = 0.04), in agreement with the association of this SNP with higher RLPs.     

Human Spotted Fever Group Rickettsioses Are Underappreciated in Southern Taiwan,Particularly for the Species Closely-Related to Rickettsia felis

Background

Despite increased identification of spotted fever group rickettsioses (SFGR) in animals and arthropods, human SFGR are poorly characterized in Taiwan.

Methods

Patients with suspected Q fever, scrub typhus, murine typhus, leptospirosis, and dengue fever from April 2004 to December 2009 were retrospectively investigated for SFGR antibodies (Abs). Sera were screened for Rickettsia rickettsii Abs by indirect immunofluorescence antibody assay (IFA), and those with positive results were further examined for Abs against R. rickettsii, R. typhi, R. felis, R. conorii, and R. japonica using micro-immunofluorescence (MIF) tests. Polymerase chain reaction (PCR) for detection of SFGR DNA was applied in those indicated acute infections. Case geographic distribution was made by the geographic information system software.

Results

A total of 413 cases with paired serum, including 90 cases of Q fever, 47 cases of scrub typhus, 12 cases of murine typhus, 6 cases of leptospirosis, 3 cases of dengue fever, and 255 cases of unknown febrile diseases were investigated. Using IFA tests, a total of 49 cases with 47 (11.4%) and 4 (1.0%) cases had sera potentially positive for R. rickettsii IgG and IgM, respectively. In the 49 cases screened from IFA, MIF tests revealed that there were 5 cases of acute infections (3 possible R. felis and 2 undetermined SFGR) and 13 cases of past infections (3 possible R. felis and 10 undetermined SFGR). None of the 5 cases of acute infection had detectable SFGR DNA in the blood specimen by PCR. Possible acute infection of R. felis was identified in both one case of Q fever and scrub typhus. The geographic distribution of SFGR cases is similar with that of scrub typhus.

Conclusions

Human SFGR exist and are neglected diseases in southern Taiwan, particularly for the species closely-related to R. felis.     

Complete Genome Sequence of Klebsiella oxytoca E718, a New Delhi Metallo-β-Lactamase-1-Producing Nosocomial Strain

We report the complete genome sequence of Klebsiella oxytoca E718, a New Delhi metallo-β-lactamase-1 (NDM-1)-producing strain isolated from a renal transplant patient. The genome contains a 6,097,032-bp chromosome and two multidrug resistance plasmids with sizes of 324,906 bp and 110,781 bp.     

Diverse post-translational modifications of the pannexin family of channel-forming proteins

The pannexin family of channel-forming proteins is composed of 3 distinct but related members called Panx1, Panx2, and Panx3. Pannexins have been implicated in many physiological processes as well as pathological conditions, primarily through their function as ATP release channels. However, it is currently unclear if all pannexins are subject to similar or different post-translational modifications as most studies have focused primarily on Panx1. Using in vitro biochemical assays performed on ectopically expressed pannexins in HEK-293T cells, we confirmed that all 3 pannexins are N-glycosylated to different degrees, but they are not modified by sialylation or O-linked glycosylation in a manner that changes their apparent molecular weight. Using cell-free caspase assays, we also discovered that similar to Panx1, the C-terminus of Panx2 is a substrate for caspase cleavage. Panx3, on the other hand, is not subject to caspase digestion but an in vitro biotin switch assay revealed that it was S-nitrosylated by nitric oxide donors. Taken together, our findings uncover novel and diverse pannexin post-translational modifications suggesting that they may be differentially regulated for distinct or overlapping cellular and physiological functions.