Project description:Nucleotide repeat expansion disorders, a group of genetic diseases characterized by the expansion of specific DNA sequences, pose significant challenges to treatment and therapy development. Here, we present a precise and programmable method called prime editor–mediated correction of nucleotide repeat expansion (PE-CORE) for correcting pathogenic nucleotide repeat expansion. PE-CORE leverages a prime editor and paired pegRNAs to achieve targeted correction of repeat sequences. We demonstrate the effectiveness of PE-CORE in HEK293T cells and patient-derived induced pluripotent stem cells (iPSCs). Specifically, we focus on spinal and bulbar muscular atrophy and spinocerebellar ataxia type, two diseases associated with nucleotide repeat expansion. Our results demonstrate the successful correction of pathogenic expansions in iPSCs and subsequent differentiation into motor neurons. Specifically, we detect distinct downshifts in the size of both the mRNA and protein, confirming the functional correction of the iPSC-derived motor neurons. These findings highlight PE-CORE as a precision tool for addressing the intricate challenges of nucleotide repeat expansion disorders, paving the way for targeted therapies and potential clinical applications.
Project description:Dynamic control of gene expression is crucial for most aspects of cell physiology and at its core is RNA polymerase II (RNAPII). Using 53 RNAPII point mutants, we generated a point mutant epistatic miniarray profile (pE-MAP) comprising ~60,000 quantitative genetic interactions in Saccharomyces cerevisiae. This enabled functional assignment of RNAPII sub-domains, including connections to protein complexes. Using splicing microarrays and point mutants altering elongation rates in vitro, we found an inverse relationship between RNAPII speed and in vivo splicing efficiency. Furthermore, the pE-MAP classified groups of fast and slow mutants that favor upstream and downstream start site selection, respectively. Finally, the pE-MAP identified Sub1 as a positive transcription factor regulating start site selection and splicing. These data reveal striking coordination of polymerization rate with transcription initiation and splicing, suggesting transcription rate is tuned to coordinate multiple gene expression steps. The pE-MAP approach provides a powerful strategy to understand other multi-functional machines at amino acid resolution.
Project description:The mechanism by which transcription factor (TF) network instructs cell-type-specific transcriptional programs to drive primitive endoderm (PrE) progenitors to commit to parietal endoderm (PE) versus visceral endoderm (VE) cell fates remains poorly understood. To address the question, we analyzed the single-cell transcriptional signatures defining PrE, PE, and VE cell states during the onset of the PE-VE lineage bifurcation. By coupling with the epigenomic comparison of active enhancers unique to PE and VE cells, we identified GATA6, SOX17, and FOXA2 as central regulators for the lineage divergence. Transcriptomic analysis of cXEN cells, an in vitro model for PE cells, after the acute depletion of GATA6 or SOX17 demonstrated that these factors induce Mycn, imparting the self-renewal properties of PE cells. Concurrently, they suppress the VE gene program, including key genes like Hnf4a and Ttr, among others. We proceeded with RNA-seq analysis on cXEN cells with FOXA2 knockout, in conjunction with GATA6 or SOX17 depletion. We found FOXA2 acts as a potent suppressor of Mycn while simultaneously activating the VE gene program. The antagonistic gene regulatory activities of GATA6/SOX17 and FOXA2 in promoting alternative cell fates, and their physical co-bindings at the enhancers provide molecular insights to the plasticity of the PrE lineage. Finally, we show that the external cue, BMP signaling, promotes the VE cell fate by activation of VE TFs and repression of PE TFs including GATA6 and SOX17. These data reveal a putative core gene regulatory module that underpins PE and VE cell fate choice.
Project description:We have developed a novel in vitro protocol for the derivation of bona fide Pharyngeal Endoderm (PE) cells from hESCs. We demonstrated that our PE cells robustly express Pharyngeal Endoderm markers, they are transcriptionally similar to PE cells isolated from in vivo mouse development and represent a transcriptionally homogeneous population. Importantly, we elucidated the contribution of Retinoic Acid in promoting a transcriptional and epigenetic rewiring of PE cells. In addition, we defined the epigenetic landscape of PE cells by combining ATAC-Seq and ChIP-Seq of histone marks.
Project description:We have developed a novel in vitro protocol for the derivation of bona fide Pharyngeal Endoderm (PE) cells from hESCs. We demonstrated that our PE cells robustly express Pharyngeal Endoderm markers, they are transcriptionally similar to PE cells isolated from in vivo mouse development and represent a transcriptionally homogeneous population. Importantly, we elucidated the contribution of Retinoic Acid in promoting a transcriptional and epigenetic rewiring of PE cells. In addition, we defined the epigenetic landscape of PE cells by combining ATAC-Seq and ChIP-Seq of histone marks.
Project description:We have developed a novel in vitro protocol for the derivation of bona fide Pharyngeal Endoderm (PE) cells from hESCs. We demonstrated that our PE cells robustly express Pharyngeal Endoderm markers, they are transcriptionally similar to PE cells isolated from in vivo mouse development and represent a transcriptionally homogeneous population. Importantly, we elucidated the contribution of Retinoic Acid in promoting a transcriptional and epigenetic rewiring of PE cells. In addition, we defined the epigenetic landscape of PE cells by combining ATAC-Seq and ChIP-Seq of histone marks.
Project description:We have developed a novel in vitro protocol for the derivation of bona fide Pharyngeal Endoderm (PE) cells from hESCs. We demonstrated that our PE cells robustly express Pharyngeal Endoderm markers, they are transcriptionally similar to PE cells isolated from in vivo mouse development and represent a transcriptionally homogeneous population. Importantly, we elucidated the contribution of Retinoic Acid in promoting a transcriptional and epigenetic rewiring of PE cells. In addition, we defined the epigenetic landscape of PE cells by combining ATAC-Seq and ChIP-Seq of histone marks. This SuperSeries is composed of the SubSeries listed below.
Project description:Introduction: To determine the miRNA expression profile in placentas complicated by Preeclampsia (PE) and compare it to uncomplicated pregnancies. Methods: Sixteen placentas from women with PE, including 11 with early onset PE (EOPE) and 5 with late onset PE (LOPE), as well as 8 from uncomplicated pregnancies were analyzed using miRNA microarrays. For statistical analyses the MATLAB® simulation environment was applied. The over-expression of miR-518a-5p was verified using Quantitative Real-Time Polymerase Chain Reaction. Results: Overall, 44 miRNAs were found deregulateddysregulated in PE complicated placentas. Statistical analysis revealed that miR-431, miR-518a-5p and miR-124* were over-expressed in EOPE complicated placentas as compared to controls whereas miR-544 and miR-3942 were down-regulated in EOPE. When comparing the miRNA expression profile in cases with PE and PE- growth restricted fetuses (FGR), miR-431 and miR-518a-5p were found over-expressed in pregnancies complicated by FGR. Additionally, up- regulation of miR-124, miR-423-3p and miR-518a-5p was associated with proteinuria. Discussion: Specific miRNAs can differentiate EOPE and LOPE from uncomplicated pregnancies representing putative PE-specific diagnostic biomarkers. Among them, miR-518a-5p emerged as a potential diagnostic indicator for EOPE cases as well as for FGR and proteinuria associated PE complicated placentas designating its potential link to the severity of the disease.
Project description:In pregnancies involving preeclampsia (PE), there is evidence that the fetal-placental unit is under oxidative stress. Here we examined primary cell lines generated from umbilical cords (UC) delivered by mothers who had either a normal pregnancy or experienced early onset PE to determine whether the two had distinguishable phenotypes. While all UC provided outgrowths when established in 4 % O2, success was less assured for PE cords under ambient (20 % O2) conditions (P < 0.05). Moreover, proliferation rates of established PE lines, although similar to controls in 4 % O2, were significantly lower in 20 % O2. PE lines grown in 4 % O2 were also more susceptible to the pro-oxidant diethylmaleate than control lines, and unlike controls, were not protected by glutathione. Transcriptome profiling revealed only a few differentially regulated genes between PE lines and controls in 4 % O2 conditions, but confirmed the more severely stressed phenotype of the PE lines under 20 % O2. We conclude that the primary UC cell lines generated from PE births maintain a susceptibility to oxidative stress that is stable over many cell divisions, but whether the basis of this vulnerability is genetic or epigenetic remains unclear. RNA was isolated from early passages (< p5) of UC fibroblast lines (15 PE and 9 CTL lines, grown in T25 flasks) when they reached ~90% confluency in 4 % O2 conditions. In order to collect RNA from cells under 20 % O2, cell lines at either p 4, 5, or 6 were switched from 4 % O2 conditions to 20 % O2 conditions when they were approximately 20 % confluent. When they reached ~90% confluency (generally 2 days in 4 % O2 and 3-4 days in 20 % O2 conditions), medium was removed and RNA STAT60 (I ml; Tel-Test, Friendswood, TX) was immediately added to each T25 flask and RNA extracted by following the manufacturer’s instructions. The samples of RNA were submitted to University Texas Southwestern Medical Center Microarray Core Facility (https://microarray.swmed.edu/) and microarray analysis performed with Illumina HumanHT-12 v4 expression BeadChips. Raw intensity data were background subtracted by using BeadStudio software and analyzed further by GeneSpring 12.6 software (Agilent Technologies Inc., Santa Clara CA), according to the advanced workflow protocol: percentile shift and filter by flags (detected).