http://www.jbiomedsci.com The most accessed research articles published by Journal of Biomedical Science 2012-05-11T00:00:00Z This is an RSS newsfeed from BioMed Central It is intended to be used with an RSS reader. For more information about RSS newsfeeds from BioMed Central, visit http://www.biomedcentral.com/info/about/rss/ Background: It is essential to subculture the cells once cultured cells reach confluence. For this, trypsin is frequently applied to dissociate adhesive cells from the substratum. However, due to the proteolytic activity of trypsin, cell surface proteins are often cleaved, which leads to dysregulation of the cell functions. Methods: In this study, a triplicate 2D-DIGE strategy has been performed to monitor trypsin-induced proteome alterations. The differentially expressed spots were identified by MALDI-TOF MS and validated by immunoblotting. Results: 36 proteins are found to be differentially expressed in cells treated with trypsin, and proteins that are known to regulate cell metabolism, growth regulation, mitochondrial electron transportation and cell adhesion are down-regulated and proteins that regulate cell apoptosis are up-regulated after trypsin treatment. Further study shows that bcl-2 is down-regulated, p53 and p21 are both up-regulated after trypsinization. Conclusions: In summary, this is the first report that uses the proteomic approach to thoroughly study trypsin-induced cell physiological changes and provides researchers in carrying out their experimental design. http://www.jbiomedsci.com/content/17/1/36 Hsiang-Ling Huang Hsiang-Wei Hsing Tzu-Chia Lai Yi-Wen Chen Tian-Ren Lee Hsin-Tsu Chan Ping-Chiang Lyu Chieh-Lin Wu Ying-Chieh Lu Szu-Ting Lin Cheng-Wen Lin Chih-Ho Lai Hao-Teng Chang Hsiu-Chuan Chou Hong-Lin Chan Journal of Biomedical Science 2010, null:36 2010-05-11T00:00:00Z doi:10.1186/1423-0127-17-36 /content/figures/1423-0127-17-36-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 36 2010-05-11T00:00:00Z XML Background: Although diabetes mellitus (DM) can be treated with islet transplantation, a scarcity of donors limits the utility of this technique. This study investigated whether human mesenchymal stem cells (MSCs) from umbilical cord could be induced to differentiate into insulin-producing cells (IPCs). Secondly, we evaluated the effect of portal vein transplantation of these differentiated cells in the treatment of streptozotocin-induced diabetes in rats. Methods: MSCs from human umbilical cord were induced to differentiate into insulin-producing cells and evaluated by immunocytochemistry, reverse transcriptase, and real-time PCR, and ELISA. Differentiated cells were transplanted into the liver of diabetic rats using a Port-A catheter via the portal vein. Blood glucose levels were monitored weekly. Results: Human nuclei and C-peptide were detected in the rat liver by immunohistochemistry. Pancreatic beta-cell development-related genes were expressed in the differentiated cells. C-peptide release was increased after glucose challenge in vitro. Furthermore, after transplantation of differentiated cells into the diabetic rats, blood sugar level decreased. Insulin-producing cells containing human C-peptide and human nuclei were located in the liver. Conclusion: Thus, a Port-A catheter can be used to transplant differentiated insulin-producing cells from human MSCs into the portal vein to alleviate hyperglycemia among diabetic rats. http://www.jbiomedsci.com/content/19/1/47 Pei-Jiun Tsai Hwai-Shi Wang Yi-Ming Shyr Zen-Chung Weng Ling-Chen Tai Jia-Fwu Shyu Tien-Hua Chen Journal of Biomedical Science 2012, null:47 2012-04-30T00:00:00Z doi:10.1186/1423-0127-19-47 /content/figures/1423-0127-19-47-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 47 2012-04-30T00:00:00Z PDF Background: Chikungunya fever is a pandemic disease caused by the mosquito-borne Chikungunya virus (CHIKV). E1 glycoprotein mediation of viral membrane fusion during CHIKV infection is a crucial step in the release of viral genome into the host cytoplasm for replication. How the E1structure determines membrane fusion and whether other CHIKV structural proteins participate in E1 fusion activity remain largely unexplored. Methods: A bicistronic baculovirus expression system to produce recombinant baculoviruses for cell-based assay was used. Sf21 insect cells infected by recombinant baculoviruses bearing wild type or single-amino-acid substitution of CHIKV E1 and EGFP (enhanced green fluorescence protein) were employed to investigate the roles of four E1 amino acid residues (G91, V178, A226, and H230) in membrane fusion activity. Results: Western blot analysis revealed that the E1 expression level and surface features in wild type and mutant substituted cells were similar. However, cell fusion assay found that those cells infected by CHIKV E1-H230A mutant baculovirus showed little fusion activity, and those bearing CHIKV E1-G91D mutant completely lost the ability to induce cell-cell fusion. Cells infected by recombinant baculoviruses of CHIKV E1-A226V and E1-V178A mutants exhibited the same membrane fusion capability as wild type. Although the E1 expression level of cells bearing monomeric-E1-based constructs (expressing E1 only) was greater than that of cells bearing 26 S-based constructs (expressing all structural proteins), the sizes of syncytial cells induced by infection of baculoviruses containing 26 S-based constructs were larger than those from infections having monomeric-E1 constructs, suggesting that other viral structure proteins participate or regulate E1 fusion activity. Furthermore, membrane fusion in cells infected by baculovirus bearing the A226V mutation constructs exhibited increased cholesterol-dependences and lower pH thresholds. Cells bearing the V178A mutation exhibited a slight decrease in cholesteroldependence and a higher-pH threshold for fusion. Conclusions: Cells expressing amino acid substitutions of conserved protein E1 residues of E1-G91 and E1-H230 lost most of the CHIKV E1-mediated membrane fusion activity. Cells expressing mutations of less-conserved amino acids, E1-V178A and E1-A226V, retained membrane fusion activity to levels similar to those expressing wild type E1, but their fusion properties of pH threshold and cholesterol dependence were slightly altered. http://www.jbiomedsci.com/content/19/1/44 Szu-Cheng Kuo Ying-Ju Chen Yu-Ming Wang Pei-Yi Tsui Ming-Der Kuo Tzong-Yuan Wu Szecheng Lo Journal of Biomedical Science 2012, null:44 2012-04-21T00:00:00Z doi:10.1186/1423-0127-19-44 /content/figures/1423-0127-19-44-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 44 2012-04-21T00:00:00Z PDF Background: Cytochrome b5 performs central roles in various biological electron transfer reactions, where difference in the redox potential of two reactant proteins provides the driving force. Redox potentials of cytochromes b5 span a very wide range of ~400 mV, in which surface charge and hydrophobicity around the heme moiety are proposed to have crucial roles based on previous site-directed mutagenesis analyses. Methods: Effects of mutations at conserved hydrophobic amino acid residues consisting of the heme pocket of cytochrome b5 were analyzed by EPR and electrochemical methods. Cyclic voltammetry of the heme-binding domain of human cytochrome b5 (HLMWb5) and its site-directed mutants was conducted using a gold electrode pre-treated with β-mercarptopropionic acid by inclusion of positively-charged poly-L-lysine. On the other hand, static midpoint potentials were measured under a similar condition. Results: Titration of HLMWb5 with poly-L-lysine indicated that half-wave potential up-shifted to -19.5 mV when the concentration reached to form a complex. On the other hand, midpoint potentials of -3.2 and +16.5 mV were obtained for HLMWb5 in the absence and presence of poly-L-lysine, respectively, by a spectroscopic electrochemical titration, suggesting that positive charges introduced by binding of poly-L-lysine around an exposed heme propionate resulted in a positive shift of the potential. Analyses on the five site-specific mutants showed a good correlation between the half-wave and the midpoint potentials, in which the former were 16~32 mV more negative than the latter, suggesting that both binding of poly-L-lysine and hydrophobicity around the heme moiety regulate the overall redox potentials. Conclusions: Present study showed that simultaneous measurements of the midpoint and the half-wave potentials could be a good evaluating methodology for the analyses of static and dynamic redox properties of various hemoproteins including cytochrome b5. The potentials might be modulated by a gross conformational change in the tertiary structure, by a slight change in the local structure, or by a change in the hydrophobicity around the heme moiety as found for the interaction with poly-L-lysine. Therefore, the system consisting of cytochrome b5 and its partner proteins or peptides might be a good paradigm for studying the biological electron transfer reactions. http://www.jbiomedsci.com/content/17/1/90 Tomomi Aono Yoichi Sakamoto Masahiro Miura Fusako Takeuchi Hiroshi Hori Motonari Tsubaki Journal of Biomedical Science 2010, null:90 2010-12-04T00:00:00Z doi:10.1186/1423-0127-17-90 /content/figures/1423-0127-17-90-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 90 2010-12-04T00:00:00Z XML Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new perspective to neural therapy. The success of neural tissue engineering is mainly based on the regulation of cell behavior and tissue progression through the development of a synthetic scaffold that is analogous to the natural extracellular matrix and can support three-dimensional cell cultures. As the natural extracellular matrix provides an ideal environment for topographical, electrical and chemical cues to the adhesion and proliferation of neural cells, there exists a need to develop a synthetic scaffold that would be biocompatible, immunologically inert, conducting, biodegradable, and infection-resistant biomaterial to support neurite outgrowth. This review outlines the rationale for effective neural tissue engineering through the use of suitable biomaterials and scaffolding techniques for fabrication of a construct that would allow the neurons to adhere, proliferate and eventually form nerves. http://www.jbiomedsci.com/content/16/1/108 Anuradha Subramanian Uma Maheswari Krishnan Swaminathan Sethuraman Journal of Biomedical Science 2009, null:108 2009-11-25T00:00:00Z doi:10.1186/1423-0127-16-108 /content/figures/1423-0127-16-108-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 108 2009-11-25T00:00:00Z XML Resistance to conventional anticancer therapies in patients with advanced solid tumors has prompted the need of alternative cancer therapies. Moreover, the success of novel cancer therapies depends on their selectivity for cancer cells with limited toxicity to normal tissues. Several decades after Coley's work a variety of natural and genetically modified non-pathogenic bacterial species are being explored as potential antitumor agents, either to provide direct tumoricidal effects or to deliver tumoricidal molecules. Live, attenuated or genetically modified non-pathogenic bacterial species are capable of multiplying selectively in tumors and inhibiting their growth. Due to their selectivity for tumor tissues, these bacteria and their spores also serve as ideal vectors for delivering therapeutic proteins to tumors. Bacterial toxins too have emerged as promising cancer treatment strategy. The most potential and promising strategy is bacteria based gene-directed enzyme prodrug therapy. Although it has shown successful results in vivo yet further investigation about the targeting mechanisms of the bacteria are required to make it a complete therapeutic approach in cancer treatment. http://www.jbiomedsci.com/content/17/1/21 S Patyar R Joshi D Prasad Byrav A Prakash B Medhi B Das Journal of Biomedical Science 2010, null:21 2010-03-23T00:00:00Z doi:10.1186/1423-0127-17-21 /content/figures/1423-0127-17-21-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 21 2010-03-23T00:00:00Z XML Background: In the present study we identified a novel gene, Homo Sapiens Chromosome 1 ORF109 (c1orf109, GenBank ID: NM_017850.1), which encodes a substrate of CK2. We analyzed the regulation mode of the gene, the expression pattern and subcellular localization of the predicted protein in the cell, and its role involving in cell proliferation and cell cycle control. Methods: Dual-luciferase reporter assay, chromatin immunoprecipitation and EMSA were used to analysis the basal transcriptional requirements of the predicted promoter regions. C1ORF109 expression was assessed by western blot analysis. The subcellular localization of C1ORF109 was detected by immunofluorescence and immune colloidal gold technique. Cell proliferation was evaluated using MTT assay and colony-forming assay. Results: We found that two cis-acting elements within the crucial region of the c1orf109 promoter, one TATA box and one CAAT box, are required for maximal transcription of the c1orf109 gene. The 5' flanking region of the c1orf109 gene could bind specific transcription factors and Sp1 may be one of them. Employing western blot analysis, we detected upregulated expression of c1orf109 in multiple cancer cell lines. The protein C1ORF109 was mainly located in the nucleus and cytoplasm. Moreover, we also found that C1ORF109 was a phosphoprotein in vivo and could be phosphorylated by the protein kinase CK2 in vitro. Exogenous expression of C1ORF109 in breast cancer Hs578T cells induced an increase in colony number and cell proliferation. A concomitant rise in levels of PCNA (proliferating cell nuclear antigen) and cyclinD1 expression was observed. Meanwhile, knockdown of c1orf109 by siRNA in breast cancer MDA-MB-231 cells confirmed the role of c1orf109 in proliferation. Conclusions: Taken together, our findings suggest that C1ORF109 may be the downstream target of protein kinase CK2 and involved in the regulation of cancer cell proliferation. http://www.jbiomedsci.com/content/19/1/49 Shan-shan Liu Hong-xia Zheng Hua-dong Jiang Jie He Yang Yu You-peng Qu Lei Yue Yao Zhang Yu Li Journal of Biomedical Science 2012, null:49 2012-05-01T00:00:00Z doi:10.1186/1423-0127-19-49 /content/figures/1423-0127-19-49-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 49 2012-05-01T00:00:00Z PDF Background: Microglial cells are the predominant immune cells in malignant brain tumors, but tumors may release some factors to reduce their defensive functions. Restoration of the anti-cancer function of microglia has been proposed as a treatment modality for glioblastoma. We examined the effect of intra-cranially administered recombinant adeno-associated virus encoding interleukin-12 (rAAV2/IL12) on transfection efficiency, local immune activity and survival in a rat model of glioblastoma multiforme. Methods: F344 rats were injected with rAAV2/IL12 and implanted with syngeneic RG2 cells (glioblastoma cell line). Intracerebral interleukin-12 and interferon-γ concentrations were determined by ELISA. Activation of microglia was determined by expressions of ED1 and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) which were evaluated by Western blotting and immunohistochemistry. The proliferation of cancer cells was evaluated with Ki67 immunohistochemistry and apoptosis of cancer cells with TUNEL. Results: The brains treated with rAAV2/IL-12 maintained high expression of interleukin-12 and interferon-γ for at least two months. In syngeneic tumor model, brains treated with rAAV2/IL12 exhibited more infiltration of activated microglia cells as examined by ED1 and TRAIL stains in the tumor. In addition, the volume of tumor was markedly smaller in AAV2/IL12-treated group and the survival time was significantly longer in this group too. Conclusion: The intra-cerebrally administered rAAV2/IL-12 efficiently induces long lasting expression of IL-12, the greater infiltration of activated microglia cells in the tumor associated improved immune reactions, resulting in the inhibited growth of implanted glioblastoma and the increased survival time of these rats. http://www.jbiomedsci.com/content/19/1/45 Tsung-Lang Chiu Mei-Jan Wang Chin-Cheng Su Journal of Biomedical Science 2012, null:45 2012-04-22T00:00:00Z doi:10.1186/1423-0127-19-45 /content/figures/1423-0127-19-45-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 45 2012-04-22T00:00:00Z XML Background: The aim of the study was to investigate the effect of dietary supplementation with zinc and polyphenol compounds, i.e. resveratrol and genistein, on the effectiveness of chemically induced mammary cancer and the changes in the content of selected elements (Zn, Cu, Mg, Fe, Ca) in tumors as compared with normal tissue of the mammary gland. Methods: Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet and DMBA (7,12-dimethyl-1,2- benz[a]anthracene), were treated with zinc ions (Zn) or zinc ions + resveratrol (Zn + resveratrol) or zinc ions + genistein (Zn + genistein) via gavage for a period from 40 days until 20 weeks of age. The ICP-OES (inductively coupled plasma optical emission spectrometry) technique was used to analyze the following elements: magnesium, iron, zinc and calcium. Copper content in samples was estimated in an atomic absorption spectrophotometer. Results: Regardless of the diet (standard; Zn; Zn + resveratrol; Zn + genistein), DMBA-induced breast carcinogenesis was not inhibited. On the contrary, in the Zn + resveratrol supplemented group, tumorigenesis developed at a considerably faster rate. On the basis of quantitative analysis of selected elements we found - irrespectively of the diet applied - great accumulation of copper and iron, which are strongly prooxidative, with a simultaneous considerable decrease of the magnesium content in DMBA-induced mammary tumors. The combination of zinc supplementation with resveratrol resulted in particularly large differences in the amount of the investigated elements in tumors as compared with their content in normal tissue. Conclusions: Diet supplementation with zinc and polyphenol compounds, i.e. resveratrol and genistein had no effect on the decreased copper level in tumor tissue and inhibited mammary carcinogenesis in the rat. Irrespectively of the applied diet, the development of the neoplastic process in rats resulted in changes of the iron and magnesium content in the cancerous tissue in comparison with the healthy mammary tissue. The application of combined diet supplementation with zinc ions and resveratrol considerably promoted the rate of carcinogenesis and increased the number of DMBA-induced mammary tumors. http://www.jbiomedsci.com/content/19/1/43 Barbara Bobrowska-Korczak Dorota Skrajnowska Andrzej Tokarz Journal of Biomedical Science 2012, null:43 2012-04-16T00:00:00Z doi:10.1186/1423-0127-19-43 /content/figures/1423-0127-19-43-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 43 2012-04-16T00:00:00Z XML Background: Diallyl trisulfide (DATS) is one of the major constituents in garlic oil and has demonstrated various pharmacological activities, including antimicrobial, antihyperlipidemic, antithrombotic, and anticancer effects. However, the mechanisms of antiproliferative activity in leukemia cells are not fully understood. In this study, the apoptotic effects of DATS were investigated in human leukemia cells. Results: Results of this study indicated that treatment with DATS resulted in significantly inhibited leukemia cell growth in a concentration- and time-dependent manner by induction of apoptosis. In U937 cells, DATS-induced apoptosis was correlated with down-regulation of Bcl-2, XIAP, and cIAP-1 protein levels, cleavage of Bid proteins, activation of caspases, and collapse of mitochondrial membrane potential. The data further demonstrated that DATS increased intracellular reactive oxygen species (ROS) generation, which was attenuated by pretreatment with antioxidant N-acetyl-L-cysteine (NAC), a scavenger of ROS. In addition, administration of NAC resulted in significant inhibition of DATS-induced apoptosis by inhibiting activation of caspases. Conclusions: The present study reveals that the cytotoxicity caused by DATS is mediated by generation of ROS and subsequent activation of the ROS-dependent caspase pathway in U937 leukemia cells. http://www.jbiomedsci.com/content/19/1/50 Yung Hyun Choi Hyun Soo Park Journal of Biomedical Science 2012, null:50 2012-05-11T00:00:00Z doi:10.1186/1423-0127-19-50 /content/figures/1423-0127-19-50-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 50 2012-05-11T00:00:00Z PDF