Project description:The small molecule Halofuginone (HF) is a potent regulator of extracellular matrix (ECM ) gene expression and is unique in its therapeutic potential. While the basis for HF effects is unknown, inhibition of TGFb signaling and activation of the AAR have been linked to HF transcriptional control of a number of ECM components and amelioration of fibrosis and alleviation of autoimmune disease by regulation of Th17 cell differentiation, respectively. The aim of this study was to generate a global expression profile of HF targets in epithelial cells to identify potential mediators of HF function in this cell type. We report that HF modulation of the ECM remodeling protein Mmp13 in epithelial cells is separable from previously reported effects of HF on TGFß signal inhibition, and use microarray expression analysis to correlate this with transcriptional responses characteristic of the Integrated Stress Response (ISR). Our findings suggest a common mechanism underlying HF anti-fibrotic and anti-angiogenic effects in parenchymal cells and HF effects on Th17 differentiation. Moreover, our results point away from a central role of TGFb signaling in the HF mechanism of action and suggest a new approach to small molecule based regulation of the ECM transcriptional program in vivo. NMuMG mammary epithelial cells were treated with 10 nM Halofuginone or 10 nM MAZ1310 (a non-functional analog of Halofuginone used as a control) for 8 hours. Each treatment was performed in biological triplicate. Following RNA extraction, we used Phalanx Mouse Whole Genome OneArray to measure mRNA abundance of Halofuginone-treated and MAZ1310 control samples. Each array was performed in triplicate. Expression of transcripts in Halofuginone versus MAZ1310 treated cells was examined.
Project description:T cell differentiation to the Th17 effector subset requires stimulation through the T cell and co-stimulatory receptors, together with cytokine stimulation by TGFb and IL-6. The small molecule halofuginone (HF) inhibits Th17 cell development and induces a pattern of stress-regulated gene expression that mimics amino acid starvation. We used global transcript profiling to ask how halofuginone modulates gene expression induced during T cell activaiton and Th17 differentiation Experiment Overall Design: Purified mouse CD4+ CD25- T cells were activated under Th17 polarizing cytokine conditions and treated with either halofuginone or its inactive derivative, MAZ1310, for 3- or 6-hours.
Project description:This study was designed to evaluate similarities and differences between transcriptional responses of developing Th17 cells to the prolyl-tRNA synthetase inhibitor, halofuginone, and the mTOR inhibitor, rapamycin. Further comparisons between wild-type and Gcn2-/- Th17 cells allow for investigation into which gene modules regulated by halofuginone or rapamycin treatment require Gcn2. Murine CD4+ CD25- T cells were magnetically isolated from wild-type or Gcn2-/- T cells. These cells were activated through anti-CD3/ anti-CD28 antibodies and polarized into Th17 cells using TGFb plus IL-6. 10 nM halofuginone, 10 nM rapamycin, or vehicle control (DMSO) were added to cultures at the time of activation. Cells were harvested at 4, 18, or 72 hours post-activation and differentiation. RNA was isolated from each sample and used for microarray analysis. Each culture condition and time-point was repeated twice in independent experiments using cells isolated from different wild-type or Gcn2-/- mice. Vehicle versus halofuginone, vehicle versus rapamycin, halofuginone versus rapamycin. Gcn2-/- versus wild-type T cells treated with vehicle, halofuginone, or rapamycin.
Project description:BRCA2 mutation carriers preferentially develop luminal-like breast cancers, but it remains unclear how BRCA2 mutations affect mammary epithelial subpopulations. Here, we report that Brca2mut/WT mammary organoids subjected to replication stress activated a transcriptional response that selectively expands Brca2mut/WT luminal cells lacking hormone receptor expression (HR-). While CyTOF analyses revealed comparable epithelial compositions among wildtype and Brca2mut/WT mammary glands, Brca2mut/WT HR- luminal cells exhibited greater organoid formation and preferentially survived and expanded under replication stress. ScRNA-seq analysis corroborated the expansion of HR- luminal cells which express elevated levels of Tetraspanin-8 (Tspan8) and Thrsp mRNA, and pathways implicated in replication stress survival including Type I interferon responses. Notably, CRISPR/Cas9-mediated deletion of Tspan8 or Thrsp prevented Brca2mut/WT HR- luminal cell expansion. Our findings indicate that Brca2mut/WT cells have an activate a transcriptional response after replication stress that preferentially favours outgrowth of HR- luminal cells through the expression of interferon-responsive and mammary alveolar genes.
Project description:Microarray gene expression profiling reveals that PHGDH inhibition by NCT-503 activates a metabolic stress response characterized by downregulation of cell cycle genes and induction of stress response genes.
Project description:The small molecule Halofuginone (HF) is a potent regulator of extracellular matrix (ECM ) gene expression and is unique in its therapeutic potential. While the basis for HF effects is unknown, inhibition of TGFb signaling and activation of the AAR have been linked to HF transcriptional control of a number of ECM components and amelioration of fibrosis and alleviation of autoimmune disease by regulation of Th17 cell differentiation, respectively. The aim of this study was to generate a global expression profile of HF targets in epithelial cells to identify potential mediators of HF function in this cell type. We report that HF modulation of the ECM remodeling protein Mmp13 in epithelial cells is separable from previously reported effects of HF on TGFß signal inhibition, and use microarray expression analysis to correlate this with transcriptional responses characteristic of the Integrated Stress Response (ISR). Our findings suggest a common mechanism underlying HF anti-fibrotic and anti-angiogenic effects in parenchymal cells and HF effects on Th17 differentiation. Moreover, our results point away from a central role of TGFb signaling in the HF mechanism of action and suggest a new approach to small molecule based regulation of the ECM transcriptional program in vivo.
Project description:To study the effect of pregnancy on mouse mammary epithelial subpopulations, epthelial cells derived from virgin or pregnant (12.5 day pregnant) mice were isolated using fluorescence-activated cell sorting. After elimination of haematopoietic and endothelial cells, two distinct epithelial subpopulations were sorted using antibodies against CD29 and CD24. Based on the immunohistochemical phenotype, and in vivo and in vitro functional assays, these subpopulations were identified as mammary stem cell enriched (CD29hiCD24+) and luminal (CD29loCD24+) respectively (ref: Shackleton et al, Nature 2006). Microarray profiling was used to compare gene expression profiles of the two subpopulations in 12.5 day pregnant and virgin mice.