DSpace collection: 期刊論文

Visible Light-Regulated Gene Expression and Neurite Outgrowth of Nerve Cells

Tue, 27 Mar 2012 10:21:05 GMT

title: Visible Light-Regulated Gene Expression and Neurite Outgrowth of Nerve Cells abstract: The neurite outgrowth and gene expression of PC12 cells on collagen-coated glass plates under light-emitting diode (LED) irradiation and mixed light irradiation were investigated at several wavelengths (470, 525, 600, and 630 nm). We found that visible light regulated the neurite outgrowth of PC12 cells. Therefore, we investigated the expression level of p75NTR and TrkA in PC12 cells in order to evaluate whether gene expression in PC12 cells changed according to the wavelength of light used to irradiate these cells. When the PC12 cells were irradiated with mixed light or LED light for 10 min or 30 h in the presence of nerve growth factor (NGF), p75NTR expression was downregulated compared to that in PC12 cells cultured in the dark with NGF in the culture medium. Light irradiation influenced the expression of TrkA in the PC12 cells cultured with or without NGF. Light irradiation of PC12 cells regulated the expression of specific genes as well as neurite outgrowth.

The Novel Protein Suppressed in Lung Cancer Down-Regulated in Lung Cancer Tissues Retards Cell Proliferation and Inhibits the Oncokinase Aurora-A

Tue, 27 Mar 2012 10:21:03 GMT

title: The Novel Protein Suppressed in Lung Cancer Down-Regulated in Lung Cancer Tissues Retards Cell Proliferation and Inhibits the Oncokinase Aurora-A abstract: Introduction: In an attempt to search for genes with abnormal expression in cancers, Suppressed in Lung Cancer (SLAN, also known as KIAA0256) is found underexpressed in human lung cancer tissues by quantitative real-time PCR (Q-RT-PCR). The study set out to characterize SLAN protein and explore its cellular functions. Methods: SLAN or its specific short hairpin RNA, full length or various deletion mutants were overexpressed in 293T or lung cancer cell lines, and cell proliferation, cell cycle, mitosis progression, and spindle configuration were surveyed. Results: SLAN and its deletion mutants are localized to many subcellular locations such as endoplasmic reticulum (ER), nucleus, nucleolus, spindle pole and midbody, suggesting SLAN may function as a multifunctional protein. Overexpression of SLAN per se or its short hairpin RNAs (shRNAs) inhibits or accelerates cell proliferation through prolonging or shortening mitosis. Time-lapse microscopic recording reveals that cells overexpressing exogenous SLAN are arrested in mitosis or cannot undergo cytokinesis. SLAN 2-551 mutants drastically arrest cells in mitosis, where alpha- and gamma-tubulin are disorganized. SLAN employs C-terminal to interact with Aurora-A, a key mitosis regulator and an oncogenic kinase associated with a wide range of human cancers. SLAN negatively regulates the activity of Aurora-A by directly inhibiting kinase activity in vitro or reducing the level of active Aurora-A in cells. SLAN is frequently reduced in lung cancer tissues overexpressing Aurora-A, arguing for the necessity to suppress SLAN during the Aurora-A-associated cancer formation. Conclusions: Taken together, we have identified a novel protein SLAN downregulated in lung caner, having multiple subcellular localization including spindle matrix and midbody, inhibiting cell proliferation and Aurora-A.

Rectal swab sampling followed by an enrichment culture-based real-time PCR assay to detect Salmonella enterocolitis in children

Tue, 27 Mar 2012 10:21:02 GMT

title: Rectal swab sampling followed by an enrichment culture-based real-time PCR assay to detect Salmonella enterocolitis in children abstract: Although routine bacterial culture is the traditional reference standard method for the detection of Salmonella infection in children with diarrhoea, it is a time-consuming procedure that usually only gives results after 3-4 days. Some molecular detection methods can improve the turn-around time to within 24 h, but these methods are not applied directly from stool or rectal swab specimens as routine diagnostic methods for the detection of gastrointestinal pathogens. In this study, we tested the feasibility of a bacterial enrichment culture-based real-time PCR assay method for detecting and screening for diarrhoea in children caused by Salmonella. Our results showed that the minimum real-time PCR assay time required to detect enriched bacterial culture from a swab was 3 h. In all children with suspected Salmonella diarrhoea, the enrichment culture-based real-time PCR achieved 85.4% sensitivity and 98.1% specificity, as compared with the 53.7% sensitivity and 100% specificity of detection with the routine bacterial culture method. We suggest that rectal swab sampling followed by enrichment culture-based real-time PCR is suitable as a rapid method for detecting and screening for Salmonella in paediatric patients.

Identification of Lactoferricin B Intracellular Targets Using an Escherichia coli Proteome Chip

Tue, 27 Mar 2012 10:21:00 GMT

title: Identification of Lactoferricin B Intracellular Targets Using an Escherichia coli Proteome Chip abstract: Lactoferricin B (LfcinB) is a well-known antimicrobial peptide. Several studies have indicated that it can inhibit bacteria by affecting intracellular activities, but the intracellular targets of this antimicrobial peptide have not been identified. Therefore, we used E. coli proteome chips to identify the intracellular target proteins of LfcinB in a high-throughput manner. We probed LfcinB with E. coli proteome chips and further conducted normalization and Gene Ontology (GO) analyses. The results of the GO analyses showed that the identified proteins were associated with metabolic processes. Moreover, we validated the interactions between LfcinB and chip assay-identified proteins with fluorescence polarization (FP) assays. Sixteen proteins were identified, and an E. coli interaction database (EcID) analysis revealed that the majority of the proteins that interact with these 16 proteins affected the tricarboxylic acid (TCA) cycle. Knockout assays were conducted to further validate the FP assay results. These results showed that phosphoenolpyruvate carboxylase was a target of LfcinB, indicating that one of its mechanisms of action may be associated with pyruvate metabolism. Thus, we used pyruvate assays to conduct an in vivo validation of the relationship between LfcinB and pyruvate level in E. coli. These results showed that E. coli exposed to LfcinB had abnormal pyruvate amounts, indicating that LfcinB caused an accumulation of pyruvate. In conclusion, this study successfully revealed the intracellular targets of LfcinB using an E. coli proteome chip approach.