Project description:CACO2 cells were exposed to four bacteria ( LGG, BB-12, Bifidobacterium infantis DSM33361(hereafter referred to as DSM33361), and Bifidobacterium breve Bif195 (hereafter called Bif195)), and control (untreated)
Project description:We introduce a new high-throughput transcriptomics (HTTr) platform comprised of a collagen sandwich primary rat hepatocyte culture and the TempO-Seq assay for screening and prioritizing potential hepatotoxicants. We selected 14 chemicals based on their risk of drug-induced liver injury (DILI) and tested them in hepatocytes at two treatment concentrations. HTTr data was generated using the TempO-Seq whole transcriptome and S1500+ assays. The HTTr platform exhibited high reproducibility between technical replicates (r>0.9) but biological replication was greater for TempO-Seq S1500+ (r>0.85) than for the whole transcriptome (r>0.7). Reproducibility between biological replicates was dependent on the strength of transcriptional effects induced by a chemical treatment. Despite targeting a smaller number of genes, the S1500+ assay clustered chemical treatments and produced gene set enrichment analysis (GSEA) scores comparable to those of the whole transcriptome. Connectivity mapping showed a high-level of reproducibility between TempO-Seq data and Affymetrix GeneChip data from the Open TG-GATES project with high concordance between the S1500+ gene set and whole transcriptome. Taken together, our results provide guidance on selecting the number of technical and biological replicates and support the use of TempO-Seq S1500+ assay for a high-throughput platform for screening hepatotoxicants.
Project description:Gliomas are the most devastating of primary adult malignant brain tumors. These tumors are highly infiltrative and can arise from cells with extensive self-renewal capability and chemoresistance, frequently termed glioma-propagating cells (GPCs). GPCs are thus the plausible culprits of tumor recurrence. Treatment strategies that eradicate GPCs will greatly improve disease outcome. Such findings support the use of GPCs as in vitro cellular systems for small molecule screening. However, the nuances in utilizing GPCs as a cellular screening platform are not trivial. These slow-growing cells are typically cultured as suspension, spheroid structures in serum-free condition supplemented with growth factors. Consequently, replenishment of growth factors throughout the screening period must occur to maintain cells in their undifferentiated state, as the more lineage-committed, differentiated cells are less tumorigenic. We will present a case study of a small molecule screen conducted with GPCs and explain how unique sphere activity assays were implemented to distinguish drug efficacies against the long-term, self-renewing fraction, as opposed to transient-amplifying progenitors, latter of which are detected in conventional viability assays. We identified Pololike kinase 1 as a regulator of GPC survival. Finally, we leveraged on public glioma databases to illustrate GPC contribution to disease progression and patient survival outcome. Total RNA from primary neurosphere culture of brain tumor specimens were hybridized in baseline condition. Specimens were obtained from 11 patients and replicate arrays were performed for all 11 neurosphere cultures.
Project description:Understanding the complex effects of genetic perturbations on cellular state and fitness in human pluripotent stem cells (hPSCs) has been challenging using traditional pooled screening techniques which typically rely on unidimensional phenotypic readouts. Here, we use barcoded open reading frame (ORF) overexpression libraries with a coupled single-cell RNA sequencing (scRNA-seq) and fitness screening approach, a technique we call SEUSS (ScalablE fUnctional Screening by Sequencing), to establish a comprehensive assaying platform. Using this system, we perturbed hPSCs with a library of developmentally critical transcription factors (TFs), and assayed the impact of TF overexpression on fitness and transcriptomic cell state across multiple media conditions. We further leveraged the versatility of the ORF library approach to systematically assay mutant gene libraries and also whole gene families. From the transcriptomic responses, we built genetic co-perturbation networks to identify key altered gene modules. Strikingly, we found that KLF4 and SNAI2 have opposing effects on the pluripotency gene module, highlighting the power of our method to characterize the effects of genetic perturbations. From the fitness responses, we identified ETV2 as a driver of reprogramming towards an endothelial-like state.
Project description:This SuperSeries is composed of the SubSeries listed below. Disease, injury, and aging induce pathological reactive astrocyte states that contribute to neurodegeneration. Modulating reactive astrocytes therefore represents an attractive therapeutic strategy. Here, we describe the development of an astrocyte phenotypic screening platform for identifying chemical modulators of astrocyte reactivity. Leveraging this platform for chemical screening, we identify HDAC3 inhibitors as effective suppressors of pathological astrocyte reactivity. We demonstrate that HDAC3 inhibition reduces molecular and functional characteristics of reactive astrocytes in vitro. Transcriptional and chromatin mapping studies show that HDAC3 inhibition disarms pathological astrocyte gene expression and function while promoting the expression of genes associated with beneficial astrocytes. Administration of RGFP966, a small molecule HDAC3 inhibitor, blocks reactive astrocyte formation and promotes neuroprotection in vivo in mice. Collectively, these results establish a platform for discovering modulators of reactive astrocyte states, inform the mechanisms that control astrocyte reactivity, and demonstrate the therapeutic benefits of modulating astrocyte reactivity for neurodegenerative diseases.
Project description:Disease, injury, and aging induce pathological reactive astrocyte states that contribute to neurodegeneration. Modulating reactive astrocytes therefore represents an attractive therapeutic strategy. Here, we describe the development of an astrocyte phenotypic screening platform for identifying chemical modulators of astrocyte reactivity. Leveraging this platform for chemical screening, we identify HDAC3 inhibitors as effective suppressors of pathological astrocyte reactivity. We demonstrate that HDAC3 inhibition reduces molecular and functional characteristics of reactive astrocytes in vitro. Transcriptional and chromatin mapping studies show that HDAC3 inhibition disarms pathological astrocyte gene expression and function while promoting the expression of genes associated with beneficial astrocytes. Administration of RGFP966, a small molecule HDAC3 inhibitor, blocks reactive astrocyte formation and promotes neuroprotection in vivo in mice. Collectively, these results establish a platform for discovering modulators of reactive astrocyte states, inform the mechanisms that control astrocyte reactivity, and demonstrate the therapeutic benefits of modulating astrocyte reactivity for neurodegenerative diseases.