Project description:Investigation of lithium effects in rat neural stem cells exposed to irradiation to mimic cranial radiotherapy in children. We investigated whether lithium is involved in halting or even preventing gene expression regulation in the model system.
Project description:Wnt signaling in essential for osteoblast differentiation and is activated by lithium via inhibition of glycogen synthase kinase 3beta. Although lithium has been shown to enhance osteoblast differentiation in mice models and accelerate bone repair, its effect in humans is not clear. Therefore, we performed gene expression profiling of human MSCs from 3 donors treated with lithium (5mM) for 7 days. Microarray profiling of lithium-stimulated hMSC revealed decreased expression of adipogenic genes (CEBPA, CMKLR1, HSD11B1) and genes involved in lipid biosynthesis. Interestingly, osteoclastogenic factors and immune responsive genes (IL7, IL8, CXCL1, CXCL12, CCL20) were also downregulated. Negative transcriptional regulators of the osteogenic program (TWIST1 and PBX1) were suppressed while genes involved in mineralization like CLEC3B and ATF4 were induced. These results suggest suppression of adipogenic program and induction of osteogenic genes.
Project description:In the present study approximately 1 to 2 mm3 prostate tumor AT1 was inoculated subcutaneously in the right hind leg of adult male Copenhagen rats. When the tumor diameter exceeded 15 mm, tumors of 5 and 4 rats were irradiated with carbon ion radiation of 37 or 16Gy respectively. Tumors of 5 other rats were irradiated with photon radiation of 37Gy. One animal irradiated with 37 Gy carbon ion radiation and one animal irradiated with photon radiation was sacrificed 12h, 30h, 72h, 7d and 14d after irradiation respectively. One animal irradiated with 16 Gy photon radiation was sacrificed 12h, 60h, 7d and 14d after irradiation respectively. Non-irradiated animals were sacrificed at 60h time point. Tumors were dissected and frozen in liquid nitrogen immediately. Total RNA from tumor material was isolated using the NucleoSpin RNA L kit (#740962.20, Macherey-Nagel). Differential gene expression analysis was performed on the Agilent whole rat genome Oligo Microarray (44k) platform by comparative two dye hybridisation with dye-swaps.
Project description:Wnt signaling in essential for osteoblast differentiation and is activated by lithium via inhibition of glycogen synthase kinase 3beta. Although lithium has been shown to enhance osteoblast differentiation in mice models and accelerate bone repair, its effect in humans is not clear. Therefore, we performed gene expression profiling of human MSCs from 3 donors treated with lithium (5mM) for 7 days. Microarray profiling of lithium-stimulated hMSC revealed decreased expression of adipogenic genes (CEBPA, CMKLR1, HSD11B1) and genes involved in lipid biosynthesis. Interestingly, osteoclastogenic factors and immune responsive genes (IL7, IL8, CXCL1, CXCL12, CCL20) were also downregulated. Negative transcriptional regulators of the osteogenic program (TWIST1 and PBX1) were suppressed while genes involved in mineralization like CLEC3B and ATF4 were induced. These results suggest suppression of adipogenic program and induction of osteogenic genes. Agilent one-color experiment, Organism: Human, Agilent-Custom Whole Genome Human 4x44k designed by Genotypic Technology Pvt. Ltd. (AMADID: 025085), Labeling kit: Agilent Quick-Amp labeling Kit (p/n5190-0442)
Project description:In the current global scenario there is always a possibility that a terrorist group might acquire material to produce a nuclear device. In the likelihood of a detonation of an improvised nuclear device (IND) the prompt radiation would consist of both photons (gamma rays) and neutrons. As neutrons generally have a high Relative Biological Effectiveness (RBE) for most physiological endpoints, it is important to understand the impact that neutrons would have on the biodosimetry methods that are being developed for medical triage purposes. We have previously reported transcriptomic response in human and mouse blood to neutron exposure and determined its RBE compared to photons for gene induction. In this report, we studied the effect of mixed neutron-photon radiation on gene expression in human peripheral blood in order to mimic an IND type radiation observed increase in number as well as expression level of genes with increasing percentage of neutron in mixed exposures which peaked at 25% neutron exposure which was maximum neutron percentage used for the study. We identified 156 genes that responded significantly to all the neutron-photon mixed exposures. These genes were found to be mainly involved in p53 signaling and DNA damage response. The 25% neutron exposure also showed maximum enrichment of known neutron associated gene ontology terms reported in the previous studies. Analysis of upstream regulators of gene expression showed strong activation of TP53, SLC29A1, PDCD1 and suppression of ANLN, AURK and ANXA2 across all exposures. While AGT was exclusively activated by neutron specific exposures. We confirmed the expression of genes which showed increased expression as a function of increased neutron percentage using quantitative real-time RT-PCR which matched with the microarray data. Thus, the data in this current study clearly indicates that gene expression can be used to estimate the percentage of the neutron component in mixed neutron-photon exposures.
Project description:It is elusive whether clonal selection of tumor cells in response to ionizing radiation (IR) is a deterministic or stochastic process. With high resolution clonal barcoding and tracking of over 400.000 HNSCC patient-derived tumor cells the clonal dynamics of tumor cells in response to IR was analysed. Fractionated IR induced a strong selective pressure for clonal reduction. This significantly exceeded uniform clonal survival probabilities indicative for a strong clone-to clone difference. within tumor cells. Survival to IR is driven by a deterministic clonal selection of a smaller population which commonly survives radiation, while increased clonogenic capacity is a result of clonal competition of cells which have been selected stochastically. The ratio of these parameters is amenable to radiation sensitivity which correlates to prognostic biomarkers of HNSCC. Evidence for the existence of a rare subpopulation with an intrinsically radiation resistant phenotype was found at a frequency of 0.6-3.3%. With cellular barcoding we introduce a novel functional heterogeneity associated qualitative readout for evaluating the contribution of stochastic and deterministic clonal selection processes in response to IR. To analyze transcriptomic changes of HNSCC cell lines after fractionated Photon IR (5x4Gy), RNAseq analysis was performed on irradiated cells in comparison to untreated control cells (EBI submission E-MTAB-9693)
Project description:Lithium is a first-line treatment for bipolar disorder, where it acts as a mood-stabilizing agent. Although its precise mechanism remains unclear, neuroimaging studies have shown that lithium accumulates in the hippocampus and that chronic use amongst bipolar disorder patients is associated with larger hippocampal volumes. Here, we tested the chronic effects of low (0.75 mM) and high (2.25 mM) doses of lithium on human hippocampal progenitor cells and used immunocytochemistry to investigate the effects of lithium on cell parameters implicated in neurogenesis. Corresponding RNA-sequencing and gene-set enrichment analyses were used to evaluate whether genes affected by lithium in our model overlap with those regulating the volume of specific layers of the dentate gyrus. We observed that high-dose lithium treatment in human hippocampal progenitors increased the generation of neuroblasts (P ≤ 0.01), neurons (P ≤ 0.01), and glia (P ≤ 0.001), alongside the expression of genes which regulate the volume of the molecular layer of the dentate gyrus. This study provides empirical support that adult hippocampal neurogenesis and gliogenesis are mechanisms that could contribute to the effects of lithium on human hippocampal volume.
Project description:The aim of our study is to investigate the effects of carbon ion and photon irradiation on A549 tumor cells and analyse how these effects are altered by PML knockdown. Therefore we created PML knockdown A549 cells (shPML) and irradiated them with either 2Gy carbon ion or 6Gy Photon (bioequivalent doses). 4 days after irradiation microarray analysis was performed. All experiments were performed in 3 biological replicates and control groups were transduced with an empty vector.