Project description:This study was undertaken with two major goals in mind: i) To investigate the potential for interspecies hydrogen transfer between a hemicellulytic rumen bacterium (B. proteoclasticus) and a methanogenic achaea (M. ruminantium) Microscopic examination had previously shown B. proteoclasticus in co-culture with M. ruminantium rapidly formed cell to cell co-aggregates. ii) To examine the expression of genes involved in methanogenesis under more rumen-like conditions.
Project description:Background: Experimental studies have suggested that stem cells (SC) may exert their beneficial effects on the ischemic heart by paracrine activation of antiapoptotic pathways. In order to identify potential cardioprotective mediators, we performed a systematic analysis of the differential gene expression of lin-/c-kit+ SC after coculture with cardiomyocytes (CM). Methods: SC were separated from murine bone marrow and labeled with the green fluorescent CFDA. SC were then cocultivated with neonatal rat ventricular CM (NRVCM). After 48 h, we performed two cell sorting steps to generate a highly purified population of conditioned SC (>99%) and isolated the RNA. Next, we performed a genome-wide microarray analysis of cocultured vs. monocultured SC with Illumina Chips (Coculture n=3; Monoculture n=3). Our systematic analysis of differentially expressed genes focused on products that are secretable, membrane-bound and potentially involved in antiapoptotic signal transduction. Results: Our analysis resulted in 3 genes (out of more than 1000 differentially regulated genes) that met the criteria mentioned above and which could also be confirmed by RT-PCR. We found CCL-12 (12x, p<0.05), MIF (2x, p<0.05) and connexin 40 (4.5x; p<0.05) upregulated in our coculture model. An ELISA of cell culture supernatants was performed to proof secretability of candidate genes and showed that supernatants of coculture experiments have higher CCL-12 concentrations than monoculture experiments (20 pg/ml vs. 4 pg/ml; p<0.01). Next, we stimulated NRVCM with concentrated coculture supernatants which resulted in a significantly higher phosphorylation of AKT (p<0.01). Finally, NRVCM were labeled with Annexin-V and apoptosis of NRVCM in a co- and monoculture was measured by FACS. Thereby, we observed a reduction in apoptotic NRVCM in the coculture model (12% vs. 25%; p<0.05). Conclusion: Our results provide evidence that coculture of SC with NRVCM leads to an upregulation of antiapoptotic genes and a paracrine-mediated increase in the phosphorylation of AKT. This results in less apoptotis in cocultured NRVCM. We therefore conclude, that cell-cell interactions lead to a modified gene expression in SC that may in part explain the cardioprotective effects of stem cell therapy. We analysed six RNA samples extracted from three cocultures and three monocultures. Every sample represents an independant biological experiment, derived from individual preparations of cardiac myocytes and bone marrow stem cells.
Project description:Cell-to-cell interactions between tumor cells and their microenvironment are critical determinants of tumor tissue biology and therapeutic responses. Interactions between glioblastoma (GBM) cells and endothelial cells (ECs) establish a purported stem cell niche. We hypothesized that genes that mediate these interactions would be important, particularly as therapeutic targets. Using a novel computational approach to deconvoluting expression data from mixed physical coculture of GBM cells and ECs, we identified upregulation of the cAMP specific phosphodiesterase PDE7B in GBM cells in response to ECs. We further found that elevated PDE7B expression occurs in most GBM cases and has a negative effect on survival. PDE7B overexpression resulted in the expansion of a stem-like cell subpopulation, increased tumor aggressiveness, and increased growth in an intracranial GBM model. This deconvolution algorithm provides a new tool for cancer biology, and these results identify PDE7B as a therapeutic target in GBM. 3 replicates from U87 monocultures, 3 replicates from HBMEC monocultures, 3 replicates from U87-HBMEC cocultures
Project description:This study aims to to compare the gene transcription profiles of endothelial cells and stem cells, when they are cultured alone or when they are cultured together. Thus there are two major questions - how do the cells differ, and how do the cells influence each other's gene expression. Thus there are 4 types of sample: endothelial cell monoculture, endothelial cell coculture, stem cells monoculture, stem cell coculture. There are also 4 biological replicates (independent experiments) leading to 16 array data files.
Project description:Background: Experimental studies have suggested that stem cells (SC) may exert their beneficial effects on the ischemic heart by paracrine activation of antiapoptotic pathways. In order to identify potential cardioprotective mediators, we performed a systematic analysis of the differential gene expression of lin-/c-kit+ SC after coculture with cardiomyocytes (CM). Methods: SC were separated from murine bone marrow and labeled with the green fluorescent CFDA. SC were then cocultivated with neonatal rat ventricular CM (NRVCM). After 48 h, we performed two cell sorting steps to generate a highly purified population of conditioned SC (>99%) and isolated the RNA. Next, we performed a genome-wide microarray analysis of cocultured vs. monocultured SC with Illumina Chips (Coculture n=3; Monoculture n=3). Our systematic analysis of differentially expressed genes focused on products that are secretable, membrane-bound and potentially involved in antiapoptotic signal transduction. Results: Our analysis resulted in 3 genes (out of more than 1000 differentially regulated genes) that met the criteria mentioned above and which could also be confirmed by RT-PCR. We found CCL-12 (12x, p<0.05), MIF (2x, p<0.05) and connexin 40 (4.5x; p<0.05) upregulated in our coculture model. An ELISA of cell culture supernatants was performed to proof secretability of candidate genes and showed that supernatants of coculture experiments have higher CCL-12 concentrations than monoculture experiments (20 pg/ml vs. 4 pg/ml; p<0.01). Next, we stimulated NRVCM with concentrated coculture supernatants which resulted in a significantly higher phosphorylation of AKT (p<0.01). Finally, NRVCM were labeled with Annexin-V and apoptosis of NRVCM in a co- and monoculture was measured by FACS. Thereby, we observed a reduction in apoptotic NRVCM in the coculture model (12% vs. 25%; p<0.05). Conclusion: Our results provide evidence that coculture of SC with NRVCM leads to an upregulation of antiapoptotic genes and a paracrine-mediated increase in the phosphorylation of AKT. This results in less apoptotis in cocultured NRVCM. We therefore conclude, that cell-cell interactions lead to a modified gene expression in SC that may in part explain the cardioprotective effects of stem cell therapy.
Project description:Using data from microarray experiments we investigated a coculture of D. vulgaris Hildenborough and Methanococcus maripaludis. Using data from microarray experiments we investigated a coculture of D. vulgaris Hildenborough and Methanococcus maripaludis.
Project description:Stromal-epithelial interactions play a fundamental role in tissue homeostasis, controlling cell proliferation and differentiation. Not surprisingly, aberrant stromal-epithelial interactions contribute to malignancies. The goals and objectives of this study were 1.) to characterize and validate the molecular identity of human primary epithelial and stromal/mesenchymal breast cells maintained long-term in novel ex vivo culture conditions in serum free medium. 2.) To analyze changes in gene expression profiles of normal human primary epithelial and stromal/mesenchymal breast cells upon long-term ex vivo co-culture when compared to corresponding monocultures 3.) To study the dynamic reciprocity between normal human primary epithelial and stromal/mesenchymal breast cells. 4.) To identify critical molecular pathways and biomarkers controlling epithelial and/or stromal cell growth and quiescence. Human primary epithelial progenitor cells and mesenchymal stem cells bearing fluorescent tags were either co-cultured in novel ex vivo culture conditions on ECM coated meshes in serum free medium (M5) or cultured as monocultures in the same conditions for 30 days. The cultures were then dissociated and epithelial and stromal/mesenchymal cells from either co-cultures or monocultures separated by FACS. Gene expression profiling of epithelial or stromal/mesenchymal cells was performed. Clean gene expression profiles from three different epithelial and stromal/mesenchymal cell extracts either grown in co-cultures or monocultures were successfully obtained.
Project description:Propionate accumulation is an important bottleneck for anaerobic degradation of organic matter. We hypothesized that propionate conversion by a novel coculture of Syntrophobacter fumaroxidans and Geobacter sulfurreducens can be an alternative strategy for propionate oxidation coupled to Fe(III) reduction. In this study, we successfully cocultured S. fumaroxidans and G. sulfurreducens on propionate and Fe(III). Proteomic analyses of this coculture provided insights into the underlying mechanisms of propionate metabolism pathway and interspecies electron transfer mechanism. Our study can be further useful in understanding syntrophic propionate degradation in bioelectrochemical and anaerobic digestion systems.