Project description:Non-Erosive Reflux Disease (NERD) is one of the most prominent and common forms of gastroesophageal reflux disease (GERD). We performed transcriptomic analysis (RNA sequencing) of esophageal biopsies from patients with NERD and healthy controls to increase understanding of complex cellular and molecular pathways in NERD.
Project description:Objective: Long non-coding RNAs (lncRNA) regulate gene transcription and diverse cellular functions. We previously defined a novel core inflammatory and metabolic ileal gene signature in treatment naïve pediatric Crohn Disease (CD), however, genome-wide characterization of lncRNA expression was lacking. We now extend our analyses to define a more comprehensive view that includes lncRNA. Design: Using RNAseq, we performed a systematic profiling of lncRNAs and protein-coding genes expression in 177 ileal biopsies. Co-expression analysis was used to identify functions and tissue-specific expression. RT-PCR was used to test lncRNAs regulation by IL-1β in Caco-2 enterocytes model. Results: We characterize a widespread dysregulation of 459 lncRNA in the ileum of treatment naïve pediatric CD patients. Unsupervised and supervised classifications using the 459 lncRNA showed comparable patients’ grouping as the 2160 dysregulated protein-coding genes, linking lncRNA to CD pathogenesis. Co-expression and functional annotation enrichment analyses across several tissues and cell types showed that the up-regulated LINC01272 is associated with a myeloid pro-inflammatory signature while the down-regulated HNF4A-AS1 exhibits association with an epithelial metabolic signature. We further validated expression and regulation of prioritized lncRNA upon IL-1β exposure in differentiated Caco-2 cells. Finally, we identified significant correlations between LINC01272 and HNF4A-AS1 expression and more severe mucosal injury. Conclusion: We define differentially expressed lncRNA in the ileum of treatment naive pediatric CD. We show lncRNA utility to correctly classify disease or healthy states and demonstrate their regulation in response to an inflammatory signal. These lncRNA, after mechanistic exploration, may serve as potential new targets for RNA-based interventions.
Project description:Translational control plays a central role in regulation of gene expression and can lead to significant divergence between mRNA- and protein-abundance. The translational landscape of early mammalian development and its impact on cellular proteome, however, remains largely un-explored. Here we used genome-wide approaches combined with time-course analysis to measure the mRNA-abundance, mRNA-translation rate and protein expression during the transition of naïve into primed embryonic stem cells (ESCs). We found that the ground state ESCs cultured with GSK3- and MEK-inhibitors and LIF (2iL) display higher ribosome density on a selective set of mRNAs. These mRNAs show reduced translation during the exit from ground state pluripotency and transition to serum/LIF (SL) culture or upon commitment to primed epiblast-like stem cells (EpiLSCs). Strikingly, integrative analysis with cellular proteome indicate a strong translational buffering of this set of mRNAs in 2iL-ESCs leading to stable protein expression levels. Our data reveal that the global alteration of cellular proteome is largely accompanied by transcriptional rewiring. Furthermore, we identified a set of genes (including UHRF1 and KRAS) that undergo selective post-translational regulation during the transition of naïve into primed pluripotency and linked the observed changes to upstream GSK- and MEK/MAPK-signaling pathways using single inhibitor treated ESCs. Thus, we provide a comprehensive and detailed overview of the global changes in gene expression during the transition of naïve to primed pluripotency and dissect the relative contributions of RNA-transcription, translation and regulation of protein stability in controlling protein abundance.
Project description:Immune system plays a dual role in cancer by either targeting or supporting neoplastic cells at various stages of disease, including metastasis. Yet, the exact immune-related transcriptome profiles of breast cancer cells and their evolution during dissemination remain undiscovered. This study aimed at exploring immune-related transcriptomic landscape of primary tumors and lymph node metastasis of chemotherapy-naïve breast cancer patients.
Project description:Human embryonic stem cells (hESCs) typically exhibit "primed" pluripotency, analogous to stem cells derived from the mouse post-implantation epiblast. This has led to a search for growth conditions that support self-renewal of hESCs akin to hypomethylated naïve epiblast cells in human pre-implantation embryos. We have discovered that reverting primed hESCs to a hypomethylated naïve state or deriving a new hESC line under naïve conditions results in the establishment of Stage Specific Embryonic Antigen 4 (SSEA4) negative hESC lines with a transcriptional program resembling the human pre-implantation epiblast. In contrast, we discovered that the methylome of naïve hESCs in vitro is distinct from the human epiblast in vivo with loss of DNA methylation at primary imprints and a lost "memory" of the methylation state of the human oocyte. This failure to recover the naïve epiblast methylation landscape appears to be a consistent feature of self-renewing hypomethylated naïve hESCs in vitro.
Project description:The transition of pluripotent stem cells (PSCs) from primed to naïve states constitutes a prototypical example of cellular plasticity. The naïve state can be stabilized by defined chemical cocktails that block extracellular signals, notably including the MEK pathway. However, little is known regarding the underlying transcriptional mechanisms. Here, we report that the transcriptional landscape of the naïve state can be mimicked in mouse and human PSCs by stimulating transcriptional enhancers. This is attained by inhibiting the CDK8 and CDK19 kinases, which are negative regulators of Mediator, a critical component of enhancer function. Mechanistically, CDK8/19i triggers a global increase in the recruitment of RNA Pol II at promoters and enhancers, hyperactivating enhancers and their target genes. Lastly, the emergence of naïve pluripotency in the pre-implantation epiblast coincides with a marked reduction in CDK8/19 activity, and CDK8/19i blocks its subsequent developmental progression. These findings suggest that naïve pluripotency during development includes hyperactivation of enhancers and can be captured in vitro, either by blunting extracellular signaling, or by stimulating enhancer-driven transcription. These principles may apply to other cellular transitions.
Project description:Non-alcoholic steatohepatitis (NASH) is a rising health challenge, with no approved drugs. We used a computational drug repositioning strategy to uncover a novel therapy for NASH, identifying a GABA-B receptor agonist, AZD3355 (lesogaberan) previously evaluated as a therapy for esophageal reflux. AZD3355’s potential efficacy in NASH was tested in human stellate cells. Transcriptomic analysis of these responses identified key regulatory nodes impacted by AZD3355.