http://www.jbiomedsci.com The latest 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: 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 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: Whereas brain death is a vitally important clinical phenomenon, our contemporary understanding on its underlying cellular mechanisms remains elusive. This study evaluated whether the ubiquitin-proteasome system (UPS) in the rostral ventrolateral medulla (RVLM), a neural substrate that our laboratory identified previously to be intimately related to brain death, is engaged in this fatal process. Methods: We performed proteomics, Western Blot, real-time PCR, ELISA and pharmacological experiments in conjunction with a clinically relevant experimental endotoxemia model of brain death based on intravenous administration of Escherichia coli lipopolysaccharide in adult male Sprague-Dawley rats. Results: Proteomics, Western blot and enzyme activity analyses demonstrated that polyubiquitination was preserved and de-ubiquitination by ubiquitin C-terminal hydrolase isozyme-L1 (UCH-L1) was sustained, alongside increased monoubiquitin availability or proteasome activity in RVLM over the course of experimental endotoxemia. However, real-time PCR revealed no significant alteration in proteasome subunit alpha type-1, ubiquitin or UCH-L1 at mRNA level. Functionally, whereas microinjection into the bilateral RVLM of proteasome inhibitors (lactacystin or proteasome inhibitor II) potentiated survival, an inhibitor of ubiquitin-recycling (ubiquitin aldehyde) or an UCH-L1 inhibitor exacerbated mortality. Conclusions: We proposed previously that the progression towards brain death entails a tug-of-war between pro-death and pro-life programs in RVLM. It is conceivable that ubiquitination or de-ubiquitination in RVLM participate in brain death by regulating the degradation of the proteins involved in those programs. http://www.jbiomedsci.com/content/19/1/48 Carol Wu Julie Chan Jimmy Chou Samuel Chan Alice Chang Journal of Biomedical Science 2012, null:48 2012-04-30T00:00:00Z doi:10.1186/1423-0127-19-48 /content/figures/1423-0127-19-48-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 48 2012-04-30T00:00:00Z PDF 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: CAP/Capulet (Capt), Slingshot (Ssh) and Cofilin/Twinstar (Tsr) are actin-binding proteins that restrict actin polymerization. Previously, it was shown that low resolution analyses of loss-of-function mutations in capt, ssh and tsr all show ectopic F-actin accumulation in various Drosophila tissues. In contrast, RNAi depletion of capt, tsr and ssh in Drosophila S2 cells all affect actin-based lamella formation differently. Whether loss of these three related genes might cause the same effect in the same tissue remains unclear. Methods: Loss-of-function mutant clones were generated using the MARCM or EGUF system whereas overexpression clones were generated using the Flip-out system. Immunostaining were then performed in eye imaginal discs with clones. FRAP was performed in cultured eye discs. Results: Here, we compared their loss-of-function phenotype at single-cell resolution, using a sheet of epithelial cells in the Drosophila eye imaginal disc as a model system. Surprisingly, we found that capt and ssh, but not tsr, mutant cells within and posterior to the morphogenetic furrow (MF) shared similar phenotypes. The capt/ssh mutant cells possessed: (1) hexagonal cell packing with discontinuous adherens junctions; and (2) largely complementary accumulation of excessive phosphorylated myosin light chain (p-MLC) and F-actin rings at the apical cortex. We further showed that the capt/ssh mutant phenotypes depended on the inactivation of protein kinase A (PKA) and activation of Rho. Conclusions: Although Capt, Ssh and Tsr were reported to negatively regulate actin polymerization, we found that Capt and Ssh, but not Tsr, share overlapping functions during eye morphogenesis. http://www.jbiomedsci.com/content/19/1/46 Chiao-Ming Lin Pei-Yi Lin Yu-Chiao Li Jui-Chou Hsu Journal of Biomedical Science 2012, null:46 2012-04-30T00:00:00Z doi:10.1186/1423-0127-19-46 /content/figures/1423-0127-19-46-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 46 2012-04-30T00:00:00Z 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: 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: 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: Shikonin, a phytochemical purified from Lithospermum erythrorhizon, has been shown to confer diverse pharmacological activities, including accelerating granuloma formation, wound healing, anti-inflammation and others, and is explored for immune-modifier activities for vaccination in this study. Transdermal gene-based vaccine is an attractive approach for delivery of DNA transgenes encoding specific tumor antigens to host skin tissues. Skin dendritic cells (DCs), a potent antigen-presenting cell type, is known to play a critical role in transmitting and orchestrating tumor antigen-specific immunities against cancers. The present study hence employs these various components for experimentation.MethodThe mRNA and protein expression of RANTES were detected by RT-PCR and ELISA, respectively. The regional expression of RANTES and tissue damage in test skin were evaluated via immunohistochemistry assay. Fluorescein isothiocyanate sensitization assay was performed to trace the trafficking of DCs from the skin vaccination site to draining lymph nodes. Adjuvantic effect of shikonin on gene gun-delivered human gp100 (hgp100) DNA cancer vaccine was studied in a human gp100-transfected B16 (B16/hgp100) tumor model. Results: Among various phytochemicals tested, shikonin induced the highest level of expression of RANTES in normal skin tissues. In comparison, mouse RANTES cDNA gene transfection induced a higher level of mRANTES expression for a longer period, but caused more extensive skin damage. Topical application of shikonin onto the immunization site before gene gun-mediated vaccination augmented the population of skin DCs migrating into the draining lymph nodes. A hgp100 cDNA gene vaccination regimen with shikonin pretreatment as an adjuvant in a B16/hgp100 tumor model increased cytotoxic T lymphocyte activities in splenocytes and lymph node cells on target tumor cells. Conclusion: Together, our findings suggest that shikonin can effectively enhance anti-tumor potency of a gene-based cancer vaccine via the induction of RANTES expression at the skin immunization site. http://www.jbiomedsci.com/content/19/1/42 Hui-Ming Chen Pi-Hsueh Wang Kandan Aravindaram Yun-Hsiang Chen Hsiu-Hui Yu Wen-Chin Yang Ning-Sun Yang Journal of Biomedical Science 2012, null:42 2012-04-12T00:00:00Z doi:10.1186/1423-0127-19-42 /content/figures/1423-0127-19-42-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 42 2012-04-12T00:00:00Z XML Many neurodegenerative disorders, although related by their destruction of brain function, display remarkable cellular and/or regional pathogenic specificity likely due to a deregulated functionality of the mutant protein. However, neurodegenerative disease genes, for example huntingtin (HTT), the ataxins, the presenilins (PSEN1/PSEN2) are not simply localized to neurons but are ubiquitously expressed throughout peripheral tissues; it is therefore paramount to properly understand the earliest precipitating events leading to neuronal pathogenesis to develop effective long-term therapies. This means, in no unequivocal terms, it is crucial to understand the gene's normal function. Unfortunately, many genes are often essential for embryogenesis which precludes their study in whole organisms. This is true for HTT, the β-amyloid precursor protein (APP) and presenilins, responsible for early onset Alzheimer's disease (AD). To better understand neurological disease in humans, many lower and higher eukaryotic models have been established. So the question arises: how reasonable is the use of organisms to study neurological disorders when the model of choice does not contain neurons? Here we will review the surprising, and novel emerging use of the model organism Dictyostelium discoideum, a species of soil-living amoeba, as a valuable biomedical tool to study the normal function of neurodegenerative genes. Historically, the evidence on the usefulness of simple organisms to understand the etiology of cellular pathology cannot be denied. But using an organism without a central nervous system to understand diseases of the brain? We will first introduce the life cycle of Dictyostelium, the presence of many disease genes in the genome and how it has provided unique opportunities to identify mechanisms of disease involving actin pathologies, mitochondrial disease, human lysosomal and trafficking disorders and host-pathogen interactions. Secondly, I will highlight recent studies on the function of HTT, presenilin γ-secretase and Hirano bodies conducted in Dictyostelium. I will then outline the limitations and future directions in using Dictyostelium to study disease, and finally conclude that given the evolutionary conservation of genes between Dictyostelium and humans and the organisms' genetic tractability, that this system provides a fertile environment for discovering normal gene function related to neurodegeneration and will permit translational studies in higher systems. http://www.jbiomedsci.com/content/19/1/41 Michael Myre Journal of Biomedical Science 2012, null:41 2012-04-10T00:00:00Z doi:10.1186/1423-0127-19-41 /content/figures/1423-0127-19-41-toc.gif Journal of Biomedical Science 1423-0127 ${item.volume} 41 2012-04-10T00:00:00Z XML