A recombinant rabies virus expressing luciferase

A recombinant Rabies virus (RV) expressing firefly luciferase (rRV-luc) was generated by an improved reverse genetics system. Its biological properties were compared with those of the parental RV. The rRV-luc grew in BHK-21 cells similarly to RV, but its virulence for mice was weaker as shown by the lower infectious titers in brain. Rising infectious titers of rRV-luc during its passaging in BHK-21 cells indicated a virus adaptation, while the luciferase (luc) expression was stable. These results suggest that the recombinant RV carrying luc gene might prove a useful tool for further analysis of pathogenesis of RV in small animal models.

Thyroid hormone mediates otolith growth and development during flatfish metamorphosis

Flatfish begin life as bilaterally symmetrical larvae that swim up-right, then abruptly metamorphose into asymmetrically shaped juveniles with lateralized swimming postures. Flatfish metamorphosis is mediated entirely by thyroid hormone (TH). Changes in flatfish swim posture are thought to be regulated via vestibular remodeling, although the influence of TH on teleost inner ear development remains unclear. This study addresses the role of TH on the development of the three otolith end-organs (sacculus, utricle, and lagena) during southern flounder (Paralichthys lethostigma) metamorphosis. Compared with pre-metamorphosis, growth rates of the sacculus and utricle otoliths increase dramatically during metamorphosis in a manner that is uncoupled from general somatic growth. Treatment of P. lethostigma larvae with methimazol (a pharmacological inhibitor of endogenous TH production) inhibits growth of the sacculus and utricle, whereas treatment with TH dramatically accelerates their growth. In contrast with the sacculus and utricle otoliths that begin to form and mineralize during embryogenesis, a non-mineralized lagena otolith is first visible 10-12 days after hatching. The lagena grows during pre- and pro-metamorphosis, then abruptly mineralizes during metamorphic climax. Mineralization of the lagena, but not growth, can be induced with TH treatment, whereas treatment with methimazol completely inhibits lagena mineralization without inhibiting its growth. These findings suggest that during southern flounder metamorphosis TH exerts differential effects on growth and development among the three types of otolith.

Two-fold elevation of expression of FoxM1 transcription factor in mouse embryonic fibroblasts enhances cell cycle checkpoint activity by stimulating p21 and Chk1 transcription

OBJECTIVES

Forkhead Box M1 (FoxM1) transcription factor regulates expression of cell cycle effective genes and is stabilized by checkpoint kinase 2 (Chk2) to stimulate expression of DNA repair enzymes in response to DNA damage. This study intended to test whether FoxM1 is involved in cell cycle checkpoint pathways.

MATERIALS AND METHODS

Analysis of senescence and cell proliferation in FoxM1 transgenic (TG) mouse embryonic fibroblasts (MEFs) with 2-fold elevation of FoxM1, and overexpression or knockdown of FoxM1 in an inducible FoxM1 expression cell line, or FoxM1 siRNA. Chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assays (EMSA), and cotransfection to determine FoxM1 transcription targets, as well as RNase protection assays and western blot analysis, were performed.

RESULTS

Two-fold elevation of FoxM1 in FoxM1-TG-MEFs resulted in low levels of cell proliferation and increase in permanent cell cycle arrest at early passages (from passage 6 to 9). These phenotypes correlated with increased phosphorylation of p53 on Ser15, elevated expression of cell cycle inhibitor p21 and Chk1 at passage 3. FoxM1 was stabilized in response to DNA damage in MEFs and FoxM1 overexpression induced p21. Knockdown of FoxM1 resulted in decrease in Chk1. ChIP, EMSA and cotransfection assays confirmed that FoxM1 stimulated promoters of p21 and Chk1.

CONCLUSIONS

Chk1 and p21 are direct transcription targets of FoxM1 and FoxM1 participates in transcriptional responses to stress in normal cells.

Characterization of microRNAs involved in embryonic stem cell states

Studies of embryonic stem cells (ESCs) reveal that these cell lines can be derived from differing stages of embryonic development. We analyzed common changes in the expression of microRNAs (miRNAs) and mRNAs in 9 different human ESC (hESC) lines during early commitment and further examined the expression of key ESCenriched miRNAs in earlier developmental states in several species. We show that several previously defined hESC-enriched miRNA groups (the miR-302, -17, and -515 families, and the miR-371-373 cluster) and several other hESC-enriched miRNAs are down-regulated rapidly in response to differentiation. We further found that mRNAs up-regulated upon differentiation are enriched in potential target sites for these hESC-enriched miRNAs. Interestingly, we also observed that the expression of ESC-enriched miRNAs bearing identical seed sequences changed dynamically while the cells transitioned through early embryonic states. In human and monkey ESCs, as well as human-induced pluripotent stem cells (iPSCs), the miR-371-373 cluster was consistently up-regulated, while the miR-302 family was mildly down-regulated when the cells were chemically treated to regress to an earlier developmental state. Similarly, miR-302b, but not mmu-miR-295, was expressed at higher levels in murine epiblast stem cells (mEpiSC) as compared with an earlier developmental state, mouse ESCs. These results raise the possibility that the relative expression of related miRNAs might serve as diagnostic indicators in defining the developmental state of embryonic cells and other stem cell lines, such as iPSCs. These data also raise the possibility that miRNAs bearing identical seed sequences could have specific functions during separable stages of early embryonic development.

Serum peptidome patterns of human systemic lupus erythematosus based on magnetic bead separation and MALDI-TOF mass spectrometry analysis

OBJECTIVES

Currently few studies have been reported to utilize matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in rheumatic disease, especially in systemic lupus erythematosus (SLE). Our aim was to find differentially expressed disease-related and condition-specific peptides in sera from patients with SLE, as well as to develop and validate the peptide classification model for the diagnosis of SLE.

METHODS

Based on the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) 2000, 50 SLE patients were divided into two subgroups: 25 were defined as stable SLE (SLEDAI < or = 8) and 25 as active SLE (SLEDAI > 8). Twenty-five patients with rheumatoid arthritis (RA) and 24 healthy donors were also included and underwent analysis. We performed magnetic beads-based weak cation exchange chromatography (MB-WCX) for sample processing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for peptide profiling. ClinProt software 2.1 was used for data analysis and a genetic algorithm was modelled for class prediction.

RESULTS

A series of significant short peptides was detected. Classification models were developed to classify samples across normal controls, active SLE patients, and stable SLE patients, and achieved high capability of prediction and cross-validation. Blinded verification of the classification model showed 91.7% sensitivity in active SLE, 83.3% sensitivity in stable SLE, and 86.7% specificity in normal controls.

CONCLUSION

We have completed a preliminary study to describe the serum peptide profile of SLE and improve the diagnosis of SLE from an integrated perspective of peptide mass patterns.

Femtosecond-laser-written, stress-induced Nd:YVO4 waveguides preserving fluorescence and Raman gain

We report the formation of optical waveguides in the self-Raman Nd:YVO(4) laser crystal by femtosecond laser inscription. The confocal fluorescence and Raman images have revealed that the waveguide is constituted by a locally compressed area in which the original fluorescence and Raman gains of the Nd:YVO(4) system are preserved. Thus the obtained structures emerge as promising candidates for highly efficient self-Raman integrated laser sources.

Andrographolide regulates epidermal growth factor receptor and transferrin receptor trafficking in epidermoid carcinoma (A-431) cells

BACKGROUND AND PURPOSE

Andrographolide is the active component of Andrographis paniculata, a plant used in both Indian and Chinese traditional medicine, and it has been demonstrated to induce apoptosis in different cancer cell lines. However, not much is known about how it may affect the key receptors implicated in cancer. Knowledge of how andrographolide affects receptor trafficking will allow us to better understand new mechanisms by which andrographolide may cause death in cancer cells.

EXPERIMENTAL APPROACH

We utilized the well-characterized epidermal growth factor receptor (EGFR) and transferrin receptor (TfR) expressed in epidermoid carcinoma (A-431) cells as a model to study the effect of andrographolide on receptor trafficking. Receptor distribution, the total number of receptors and surface receptors were analysed by immunofluorescence, Western blot as well as flow-cytometry respectively.

KEY RESULTS

Andrographolide treatment inhibited cell growth, down-regulated EGFRs on the cell surface and affected the degradation of EGFRs and TfRs. The EGFR was internalized into the cell at an increased rate, and accumulated in a compartment that co-localizes with the lysosomal-associated membrane protein in the late endosomes.

CONCLUSION AND IMPLICATIONS

This study sheds light on how andrographolide may affect receptor trafficking by inhibiting receptor movement from the late endosomes to lysosomes. The down-regulation of EGFR from the cell surface also indicates a new mechanism by which andrographolide may induce cancer cell death.

Class IV-G and IV-S lupus nephritis in Chinese patients: a large cohort study from a single center

This study is to assess the difference between IV-G and IV-S in a large cohort of Chinese patients with lupus nephritis. The detailed data of patients with subclass IV-G and IV-S were retrospectively analyzed. Serum ANCA and anti-C1q antibodies were detected. A total of 172 cases were classified as class IV, including 152 cases with IV-G and 20 cases with IV-S. In IV-S, the level of haemoglobin was significantly higher (P = 0.024), proteinuria was milder (P = 0.003), serum creatinine was lower (P = 0.021), serum C3 was higher (P = 0.045) and the ratio of positive serum anti-cardiolipin antibodies was higher (P = 0.014). On pathological evaluation, the ratio of glomerular fibrinoid necrosis was significantly higher (P = 0.006) and the score of endocapillary hypercellualrity, interstitial inflammation and total activity indices was significantly lower (P < 0.001, P = 0.01, P = 0.006, respectively) in IV-S. The frequency of serum ANCA was significantly higher in IV-S than that in IV-G (20 vs 4.6%, P = 0.008). The frequencies of anti-C1q IgG1 and IgG3 subclass were significantly higher in IV-G (P = 0.006, P = 0.011, respectively). There are significant differences in clinical and pathological manifestations between IV-S and IV-G lupus nephritis which need further investigation.

Association between TIM-1 gene polymorphisms and allergic rhinitis in a Han Chinese population

BACKGROUND

TIM-1, a member of the T cell immunoglobulin and mucin (TIM) domain family, is involved in T-cell differentiation and has been implicated in allergic diseases. An association between TIM-1 and allergic rhinitis, however, has not been established.

OBJECTIVE

To investigate whether TIM-1 gene polymorphisms were associated with allergic rhinitis in a Han Chinese population.

METHODS

Two TIM-1 promoter single nucleotide polymorphisms (SNPs), -416G>C and -1454G>A, were examined in 185 allergic rhinitis patients of Han Chinese ethnicity using polymerase chain reaction (PCR) and restriction fragment length polymorphism. Additionally, exon 4 insertion/deletion polymorphisms in the TIM-1 gene were analyzed by PCR, polyacrylamide gel electrophoresis, and silver staining. The relationship between gene polymorphisms and serum specific IgE levels in this Han Chinese population was also evaluated.

RESULTS

We found that the -416G>C and -1454G>A SNPs were associated with allergic rhinitis susceptibility in this Han Chinese population. No statistically significant differences in the distribution of genotype or allele frequencies of 5383_5397ins/del and 5509_5511delCAA in exon 4 were observed. The -416G>C and -1454G>A SNPs were associated with the level of serum IgE specific to house dust mites in patients with allergic rhinitis.

CONCLUSIONS

These results suggest that TIM-1 gene polymorphisms (-416G>C and -1454G>A) are associated with allergic rhinitis susceptibility in a Han Chinese population.

Critical moisture content windows differ for the cryopreservation of pomelo (Citrus grandis) seeds and embryonic axes

Cryopreservation was attempted using a partial dehydration and freezing protocol on pomelo (Citrus grandis) seeds of ten cultivars and embryonic axes of one cultivar collected from Xishuangbanna. Although seeds of all ten cultivars could be dehydrated safely to 10 percent moisture content, further dehydration impaired seed viability with critical moisture contents ranging from 9 percent to 7 percent. Complete seedling regenerated from seeds frozen in a moisture window between 5-9 percent, and maximum seedling recovery varied between 22-86 percent. Cryopreservation of Jiajieyou cv. embryonic axes had a moisture window between 3-20 percent , much wider compared to whole seed cryopreservation, and maximum post-thaw emergence of 93 percent was achieved at 13 percent moisture content. Emergence differed only slightly from survival when whole seeds were cryopreserved, but for the embryonic axis cryopreservation at low moisture contents resulted in much lower emergence than survival. Possible causes of intraspecific variation in cryotolerance in pomelo seeds is discussed.

Reduced apoptosis of mouse macrophages induced by yscW mutant of Yersinia pestis results from the reduced secretion of YopJ and relates to caspase-3 signal pathway

The virulence of the pathogenic Yersinia species depends on a plasmid-encoded type III secretion system (T3SS) that injects six Yersinia outer protein (Yop) effector proteins into the cytosol of macrophages, leading to disruption of host defence mechanisms. Here, we report that a T3SS structural protein YscW of Yersinia pestis contributed to the induction of apoptosis of murine macrophages. The apoptotic percentage of macrophages, from both mouse peritoneal cavity and spleen, and of RAW264.7 cell line, caused by the yscW mutant strain was significantly lower than that by wild type (WT) Y. pestis and yscW complemented strain. Meanwhile, detection of caspase-3 activity in macrophages, a key apoptosis-inducing protein, showed coincident results with the changes of macrophage apoptosis induced by WT, yscW mutant and complemented strains, indicating that macrophage apoptosis was related to caspase-3 signal pathways. However, ectopic expression of YscW in RAW264.7 cells cannot increase the macrophage apoptosis and death, suggesting that YscW itself could not induce macrophage apoptosis directly. To get insight into the mechanism of this phenomenon, we investigated the secretion of YopJ, which has been thought to be the only Yop effector related to apoptosis, in WT, mutant and complemented strains, respectively. Results showed that in yscW mutant strain, secretion of YopJ was decreased significantly in the supernatant than that in WT or complemented strain. This means although YscW does not induce apoptosis directly, it can indirectly affect apoptosis through reducing the secretion of YopJ.

Molecular detection of three shrimp viruses and genetic variation of white spot syndrome virus in Hainan Province, China, in 2007

Abstract White spot syndrome virus (WSSV), Taura syndrome virus (TSV) and infectious hypodermal and haematopoietic necrosis virus (IHHNV) have been responsible for major pandemics affecting the shrimp farming industry. Shrimp samples were collected from eight farms in Hainan Province, China, during 2007 and analysed by polymerase chain reaction (PCR) or reverse transcriptase PCR methods to determine the prevalence of these viruses. From the eight sampling locations, only samples from one farm did not show any indication of infection with WSSV, TSV or IHHNV, while samples from one additional farm exhibited evidence of infection with TSV only. Surprisingly, evidence of co-infection with TSV and IHHNV was found among samples at two farms while evidence of co-infection with all three viruses (WSSV, TSV and IHHNV) was detected among shrimp samples at four farms. To further elucidate the molecular characteristics of WSSV in China, we further analysed genomic features of WSSV isolates based on the ORF23/24 variable region. From these data, we identified two novel WSSV strains which contain nucleotide deletions of 5657 and 11093 bp, respectively, when compared with the largest WSSV-TW isolate.

Tat-modified leptin is more accessible to hypothalamus through brain-blood barrier with a significant inhibition of body-weight gain in high-fat-diet fed mice

Obesity in human was found mainly due to the poor transportation of leptin through brain-blood barrier (BBB), called as leptin resistance. To produce a leptin capable of penetrating BBB, we have added Tat-PTD(9) to the C terminal of leptin to construct a fusion protein. The fusion Tat-leptin and native leptin genes were synthesized by single-step insertion of a polymerase chain reaction and expressed in Escherichia coli BL21 (Rosseta). The expressing products were purified and renatured by Ni-NTA affinity chromatography, and identified by the molecular size in SDS-PAGE gel and by its immunoreactivity to specific antibody with Western-blotting assay. To bio-functionally evaluate the fusion protein, Balb/c mice fed with high-fat diet (HFD) were given Tat-leptin, leptin or saline for 19 days. The immunohistochemical staining showed the increases in positive stains for the leptin in the region of hypothalamus of the HFD mice with either Tat-leptin or leptin as compared to saline group, but the staining intensity and frequency in the group with Tat-leptin were stronger and higher than those in the group with leptin. Furthermore, the most efficiency in preventing the body-weight gain caused by HFD was found in Tat-leptin group among these three groups. These results suggest that Tat-modified leptin may become a great potential candidate for the prevention or therapy of obese patients.

Breast cancer ErbB2 status in Asian women: A review of local literature

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Background: Breast cancer incidence is increasing throughout Asia. However, the characteristics of Asian breast cancer are not always well understood due to the limited availability of local data and their inadequate inclusion in global literature databases. Effective breast cancer treatment in this region requires a better understanding of Asian breast cancer biology, including ErbB2 status. Methods: We performed a literature search in seven Asian countries on breast cancer studies in which tumour ErbB2 overexpression was assessed. The keywords erbB2 OR HER2 OR ErbB-2 OR HER-2 AND breast cancer AND (country) were used to search PubMed, international and local conference abstracts and local-language journals from the year 2000 onwards. Where available, we selected up to five representative studies from each country on the basis of population size, multi-institution patient populations, institution reputation and journal impact factor. We excluded studies containing only mRNA, serum, or cell line data or those conducted on biased populations or in western countries on Asian populations. Results: ErbB2 data from 26 Asian breast cancer studies are summarized in the table . The mean or median age of the study populations ranged from 46–56 years, with one exception. In most studies that evaluated tumour ErbB2 and hormone status, ErbB2 over-expression correlated negatively with ER positivity. Conclusions: The larger studies in particular confirm that the proportion of ErbB2-positive breast cancer in Asia is generally similar to the 20–30% reported for western women. Definitions of ErbB2 positivity using IHC vary between institutions and FISH is not routinely performed in several Asian countries. This may contribute to the fact that reliable, representative data on breast tumour ErbB2 status is scarce in Malaysia, the Philippines, India and Thailand. The increased availability of accurate ErbB2 testing and data would aid improved treatment of ErbB2-positive breast cancer in these countries.

[Table: see text]

[Table: see text]