Invasion of Primary Glioma- and Cell Line-Derived Spheroids Implanted Into Corticostriatal Slice Cultures.

Invasion of primary glioma- and cell line-derived spheroids implanted into corticostriatal slice cultures.

Int J Clin Exp Pathol. 2013; 6(4): 546-60
Aaberg-Jessen C, Nørregaard A, Christensen K, Pedersen CB, Andersen C, Kristensen BW

Gliomas are highly invasive tumors and the pronounced invasive features of gliomas prevent radical surgical resection. In the search for new therapeutics targeting invasive glioma cells, in vivo-like in vitro models are of great interest. We developed and evaluated an in vivo-like in vitro model preserving the invasive features and stem cell features of glioma cells. Fluorescently labelled primary glioma spheroids and U87MG cell line-derived spheroids were implanted into organotypic rat corticostriatal slice cultures and the invasion was followed over time by confocal microscopy. The invasion was validated immunohistochemically with paraffin sections using a human-specific vimentin antibody. Moreover, the preservation of immature stem cell features was evaluated immunohistochemically using the stem cell markers CD133, Sox2, Bmi-1 and nestin. The confocal and immunohistochemical results showed that the primary glioma spheroid area was constant or decreasing after implantation, with a clear increase in the number of invading cells over time. In contrast, the U87MG spheroid area increased after implantation, with no convincing tumor cell invasion. High levels of Bmi-1 and nestin were found in all spheroids, whereas high levels of Sox2 and low to moderate levels of CD133 were only found in the primary spheroids. In conclusion, the invasion of gliomas is preserved using primary glioma spheroids. Some stem cell features are preserved as well, making this model useful in drug development elucidating both invasion and cancer stemness at the early in vitro level. HubMed – drug


Antimicrobial Resistance, Virulence Factors and Genetic Diversity of Escherichia coli Isolates from Household Water Supply in Dhaka, Bangladesh.

PLoS One. 2013; 8(4): e61090
Talukdar PK, Rahman M, Rahman M, Nabi A, Islam Z, Hoque MM, Endtz HP, Islam MA

BACKGROUND: Unsafe water supplies continue to raise public health concerns, especially in urban areas in low resource countries. To understand the extent of public health risk attributed to supply water in Dhaka city, Bangladesh, Escherichia coli isolated from tap water samples collected from different locations of the city were characterized for their antibiotic resistance, pathogenic properties and genetic diversity. METHODOLOGYPRINCIPAL FINDINGS: A total of 233 E. coli isolates obtained from 175 tap water samples were analysed for susceptibility to 16 different antibiotics and for the presence of genes associated with virulence and antibiotic resistance. Nearly 36% (n?=?84) of the isolates were multi-drug(?3 classes of antibiotics) resistant (MDR) and 26% (n?=?22) of these were positive for extended spectrum ?-lactamase (ESBL). Of the 22 ESBL-producers, 20 were positive for bla CTX-M-15, 7 for bla OXA-1-group (all had bla OXA-47) and 2 for bla CMY-2. Quinolone resistance genes, qnrS and qnrB were detected in 6 and 2 isolates, respectively. Around 7% (n?=?16) of the isolates carried virulence gene(s) characteristic of pathogenic E. coli; 11 of these contained lt and/or st and thus belonged to enterotoxigenic E. coli and 5 contained bfp and eae and thus belonged to enteropathogenic E. coli. All MDR isolates carried multiple plasmids (2 to 8) of varying sizes ranging from 1.2 to >120 MDa. Ampicillin and ceftriaxone resistance were co-transferred in conjugative plasmids of 70 to 100 MDa in size, while ampicillin, trimethoprim-sulfamethoxazole and tetracycline resistance were co-transferred in conjugative plasmids of 50 to 90 MDa. Pulsed-field gel electrophoresis analysis revealed diverse genetic fingerprints of pathogenic isolates. SIGNIFICANCE: Multi-drug resistant E. coli are wide spread in public water supply in Dhaka city, Bangladesh. Transmission of resistant bacteria and plasmids through supply water pose serious threats to public health in urban areas. HubMed – drug


Tacrolimus Inhibits NF-?B Activation in Peripheral Human T Cells.

PLoS One. 2013; 8(4): e60784
Vafadari R, Kraaijeveld R, Weimar W, Baan CC

The calcineurin inhibitor, tacrolimus (TAC), inhibits the protein phosphatase activity of calcineurin, leading to suppression of the nuclear translocation of NFAT and inhibition of T cell activation. Apart from NFAT also the transcription factor NF-?B plays a key functional role in T cell activation. Therefore, blockade of the NF-?B activation cascade by immunosuppressive drugs prevents immune activation. Here we studied whether TAC blocks NF-?B activation in peripheral human T cells. After anti-CD3/CD28-activation of T cells from healthy volunteers, NF-?B (p65) phosphorylation was measured by flow cytometry in CD3+ T cells, CD4+ helper T cells and CD8+ cytotoxic T cells in the absence and presence of TAC 10 ng/mL, sotrastaurin 500 nM (positive control) and mycophenolic acid 10 µg/mL (negative control; n?=?6). NF-?B transcriptional activity was measured by ELISA and intracellular TNF? protein, a downstream target, was measured by flow cytometry to assess the functional consequences of NF-?B blockade. Anti-CD3/28-activation induced NF-?B phosphorylation in CD3+ T cells, CD4+ T cells and CD8+ T cells by 34% (mean), 38% and 30% resp. (p<0.01). Sotrastaurin inhibited NF-?B activation in the respective T cell subsets by 93%, 95% and 86% (p<0.01 vs. no drug), while mycophenolic acid did not affect this activation pathway. Surprisingly, TAC also inhibited NF-?B phosphorylation, by 55% (p<0.01) in CD3+ T cells, by 56% (p<0.01) in CD4+ T cells and by 51% in CD8+ T cells (p<0.01). In addition, TAC suppressed NF-?B DNA binding capacity by 55% (p<0.05) in CD3+ T cells and TNF? protein expression was inhibited in CD3+ T cells, CD4+ T cells and CD8+ T cells by 76%, 71% and 93% resp. (p<0.01 vs. no drug), confirming impaired NF-?B signaling. This study shows the suppressive effect of TAC on NF-?B signaling in peripheral human T cell subsets, measured at three specific positions in the NF-?B activation cascade. HubMed – drug


Robust and Highly-Efficient Differentiation of Functional Monocytic Cells from Human Pluripotent Stem Cells under Serum- and Feeder Cell-Free Conditions.

PLoS One. 2013; 8(4): e59243
Yanagimachi MD, Niwa A, Tanaka T, Honda-Ozaki F, Nishimoto S, Murata Y, Yasumi T, Ito J, Tomida S, Oshima K, Asaka I, Goto H, Heike T, Nakahata T, Saito MK

Monocytic lineage cells (monocytes, macrophages and dendritic cells) play important roles in immune responses and are involved in various pathological conditions. The development of monocytic cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is of particular interest because it provides an unlimited cell source for clinical application and basic research on disease pathology. Although the methods for monocytic cell differentiation from ESCs/iPSCs using embryonic body or feeder co-culture systems have already been established, these methods depend on the use of xenogeneic materials and, therefore, have a relatively poor-reproducibility. Here, we established a robust and highly-efficient method to differentiate functional monocytic cells from ESCs/iPSCs under serum- and feeder cell-free conditions. This method produced 1.3×10(6)±0.3×10(6) floating monocytes from approximately 30 clusters of ESCs/iPSCs 5-6 times per course of differentiation. Such monocytes could be differentiated into functional macrophages and dendritic cells. This method should be useful for regenerative medicine, disease-specific iPSC studies and drug discovery. HubMed – drug