scholarly journals X-chromosome upregulation is dynamically linked to the X-inactivation state

2020 ◽  
Author(s):  
Antonio Lentini ◽  
Christos Coucoravas ◽  
Nathanael Andrews ◽  
Martin Enge ◽  
Qiaolin Deng ◽  
...  
Keyword(s):  
Stem Cells ◽  
X Chromosome ◽  
Embryonic Stem ◽  
Mrna Levels ◽  
X Chromosomes ◽  
Dosage Balance ◽  
Mechanistic Basis ◽  
Early Mouse ◽  
Key Events

AbstractMammalian X-chromosome dosage balance is regulated by X-chromosome inactivation (XCI) and X-chromosome upregulation (XCU), but the dynamics of XCU as well as the interplay between the two mechanisms remain poorly understood. Here, we mapped XCU throughout early mouse embryonic development at cellular and allelic resolution, revealing sex- and lineage-specific dynamics along key events in X-chromosome regulation. Our data show that XCU is linearly proportional to the degree of XCI, indicating that dosage compensation ensues based on mRNA levels rather than number of active X chromosomes. In line with this, we reveal that the two active X chromosomes in female naïve embryonic stem cells are not hyperactive as previously thought. In all lineages, XCU was underlain by increased transcriptional burst frequencies, providing a mechanistic basis in vivo. Together, our results demonstrate unappreciated flexibility of XCU in balancing X-chromosome expression, and we propose a general model for allelic dosage balance, applicable for wider mechanisms of transcriptional regulation.

scholarly journals Histone H3 Lysine 36 Trimethylation Is Established over theXistPromoter by AntisenseTsixTranscription and Contributes to RepressingXistExpression

2015 ◽  
Vol 35 (22) ◽  
pp. 3909-3920 ◽  
Author(s):  
Tatsuya Ohhata ◽  
Mika Matsumoto ◽  
Martin Leeb ◽  
Shinwa Shibata ◽  
Satoshi Sakai ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
X Chromosome ◽  
Antisense Rna ◽  
Histone H3 ◽  
Embryonic Stem ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
X Chromosomes ◽  
Histone H3.3

One of the two X chromosomes in female mammals is inactivated by the noncodingXistRNA. In mice, X chromosome inactivation (XCI) is regulated by the antisense RNATsix, which repressesXiston the active X chromosome. In the absence ofTsix, PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) is established over theXistpromoter. Simultaneous disruption ofTsixand PRC2 leads to derepression ofXistand in turn silencing of the single X chromosome in male embryonic stem cells. Here, we identified histone H3 lysine 36 trimethylation (H3K36me3) as a modification that is recruited byTsixcotranscriptionally and extends over theXistpromoter. Reduction of H3K36me3 by expression of a mutated histone H3.3 with a substitution of methionine for lysine at position 36 causes a significant derepression ofXist. Moreover, depletion of the H3K36 methylaseSetd2leads to upregulation ofXist, suggesting H3K36me3 as a modification that contributes to the mechanism ofTsixfunction in regulating XCI. Furthermore, we found that reduction of H3K36me3 does not facilitate an increase in H3K27me3 over theXistpromoter, indicating that additional mechanisms exist by whichTsixblocks PRC2 recruitment to theXistpromoter.

scholarly journals Induction of Pluripotent Stem Cells from a Manifesting Carrier of Duchenne Muscular Dystrophy and Characterization of Their X-Inactivation Status

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yuko Miyagoe-Suzuki ◽  
Takashi Nishiyama ◽  
Miho Nakamura ◽  
Asako Narita ◽  
Fusako Takemura ◽  
...  
Keyword(s):  
Stem Cells ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
X Inactivation ◽  
Female Carrier ◽  
Stem Cell Markers ◽  
X Chromosomes

Three to eight percent of female carriers of Duchenne muscular dystrophy (DMD) develop dystrophic symptoms ranging from mild muscle weakness to a rapidly progressive DMD-like muscular dystrophy due to skewed inactivation of X chromosomes during early development. Here, we generated human induced pluripotent stem cells (hiPSCs) from a manifesting female carrier using retroviral or Sendai viral (SeV) vectors and determined their X-inactivation status. Although manifesting carrier-derived iPS cells showed normal expression of human embryonic stem cell markers and formed well-differentiated teratomas in vivo, many hiPS clones showed bi-allelic expression of the androgen receptor (AR) gene and loss of X-inactivation-specific transcript and trimethyl-histone H3 (Lys27) signals on X chromosomes, suggesting that both X chromosomes of the hiPS cells are in an active state. Importantly, normal dystrophin was expressed in multinucleated myotubes differentiated from a manifesting carrier of DMD-hiPS cells with XaXa pattern. AR transcripts were also equally transcribed from both alleles in induced myotubes. Our results indicated that the inactivated X chromosome in the patient’s fibroblasts was activated during reprogramming, and XCI occurred randomly during differentiation.

scholarly journals A system for imaging the regulatory noncoding Xist RNA in living mouse embryonic stem cells

2011 ◽  
Vol 22 (14) ◽  
pp. 2634-2645 ◽  
Author(s):  
Karen Ng ◽  
Nathalie Daigle ◽  
Aurélien Bancaud ◽  
Tatsuya Ohhata ◽  
Peter Humphreys ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
X Chromosome ◽  
Single Point ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Chromatin Domain ◽  
Dynamic Binding ◽  
X Chromosomes ◽  
Xist Rna

In mammals, silencing of one of the two X chromosomes in female cells compensates for the different number of X chromosomes between the sexes. The noncoding Xist RNA initiates X chromosome inactivation. Xist spreads from its transcription site over the X chromosome territory and triggers the formation of a repressive chromatin domain. To understand localization of Xist over one X chromosome we aimed to develop a system for investigating Xist in living cells. Here we report successful visualization of transgenically expressed MS2‑tagged Xist in mouse embryonic stem cells. Imaging of Xist during an entire cell cycle shows that Xist spreads from a single point to a steady state when the chromosome is covered with a constant amount of Xist. Photobleaching experiments of the established Xist cluster indicate that chromosome‑bound Xist is dynamic and turns over on the fully Xist covered chromosome. It appears that in interphase the loss of bound Xist and newly produced Xist are in equilibrium. We also show that the turnover of bound Xist requires transcription, and Xist binding becomes stable when transcription is inhibited. Our data reveal a strategy for visualizing Xist and indicate that spreading over the chromosome might involve dynamic binding and displacement.

scholarly journals Delayed DNA replication in haploid human embryonic stem cells

2021 ◽  
Author(s):  
Matthew Micheal Edwards ◽  
Michael V. Zuccaro ◽  
Ido Sagi ◽  
Qiliang Ding ◽  
Dan Vershkov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dna Replication ◽  
Embryonic Stem Cells ◽  
X Chromosome ◽  
Human Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Replication Timing ◽  
Genetic System ◽  
X Chromosomes ◽  
Genomic Regions

Haploid human embryonic stem cells (ESCs) provide a powerful genetic system but diploidize at high rates. We hypothesized that diploidization results from aberrant DNA replication. To test this, we profiled DNA replication timing in isogenic haploid and diploid ESCs. The greatest difference was the earlier replication of the X chromosome in haploids, consistent with the lack of X chromosome inactivation. Surprisingly, we also identified 21 autosomal regions that had dramatically delayed replication in haploids, extending beyond the normal S phase and into G2/M. Haploid-delays comprised a unique set of quiescent genomic regions that are also under-replicated in polyploid placental cells. The same delays were observed in female ESCs with two active X chromosomes, suggesting that increased X chromosome dosage may cause delayed autosomal replication. We propose that incomplete replication at the onset of mitosis could prevent cell division and result in re-entry into the cell cycle and whole genome duplication.

scholarly journals Delayed DNA replication in haploid human embryonic stem cells

2021 ◽  
Author(s):  
Matthew M. Edwards ◽  
Michael V. Zuccaro ◽  
Ido Sagi ◽  
Qiliang Ding ◽  
Dan Vershkov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dna Replication ◽  
Embryonic Stem Cells ◽  
X Chromosome ◽  
Human Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Replication Timing ◽  
Genetic System ◽  
X Chromosomes ◽  
Genomic Regions

Haploid human embryonic stem cells (ESCs) provide a powerful genetic system but diploidize at high rates. We hypothesized that diploidization results from aberrant DNA replication. To test this, we profiled DNA replication timing in isogenic haploid and diploid ESCs. The greatest difference was the earlier replication of the X Chromosome in haploids, consistent with the lack of X-Chromosome inactivation. We also identified 21 autosomal regions that had delayed replication in haploids, extending beyond the normal S phase and into G2/M. Haploid-delays comprised a unique set of quiescent genomic regions that are also underreplicated in polyploid placental cells. The same delays were observed in female ESCs with two active X Chromosomes, suggesting that increased X-Chromosome dosage may cause delayed autosomal replication. We propose that incomplete replication at the onset of mitosis could prevent cell division and result in re-entry into the cell cycle and whole genome duplication.

scholarly journals MOF-associated complexes ensure stem cell identity and Xist repression

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Tomasz Chelmicki ◽  
Friederike Dündar ◽  
Matthew James Turley ◽  
Tasneem Khanam ◽  
Tugce Aktas ◽  
...  
Keyword(s):  
Stem Cells ◽  
X Chromosome ◽  
Embryonic Stem ◽  
X Chromosomes ◽  
Cellular Processes ◽  
Neuronal Progenitors ◽  
Msl Complex ◽  
Regulatory Potential ◽  
Safe Mechanism ◽  
Fail Safe

Histone acetyl transferases (HATs) play distinct roles in many cellular processes and are frequently misregulated in cancers. Here, we study the regulatory potential of MYST1-(MOF)-containing MSL and NSL complexes in mouse embryonic stem cells (ESCs) and neuronal progenitors. We find that both complexes influence transcription by targeting promoters and TSS-distal enhancers. In contrast to flies, the MSL complex is not exclusively enriched on the X chromosome, yet it is crucial for mammalian X chromosome regulation as it specifically regulates Tsix, the major repressor of Xist lncRNA. MSL depletion leads to decreased Tsix expression, reduced REX1 recruitment, and consequently, enhanced accumulation of Xist and variable numbers of inactivated X chromosomes during early differentiation. The NSL complex provides additional, Tsix-independent repression of Xist by maintaining pluripotency. MSL and NSL complexes therefore act synergistically by using distinct pathways to ensure a fail-safe mechanism for the repression of X inactivation in ESCs.

scholarly journals mRNA-Driven Generation of Transgene-Free Neural Stem Cells from Human Urine-Derived Cells

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1043 ◽  
Author(s):  
Phil Jun Kang ◽  
Daryeon Son ◽  
Tae Hee Ko ◽  
Wonjun Hong ◽  
Wonjin Yun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Human Urine ◽  
Neurological Disorders ◽  
Therapeutic Potential ◽  
Embryonic Stem ◽  
Global Gene Expression ◽  
Patient Specific ◽  
Human Neural Stem Cells

Human neural stem cells (NSCs) hold enormous promise for neurological disorders, typically requiring their expandable and differentiable properties for regeneration of damaged neural tissues. Despite the therapeutic potential of induced NSCs (iNSCs), a major challenge for clinical feasibility is the presence of integrated transgenes in the host genome, contributing to the risk for undesired genotoxicity and tumorigenesis. Here, we describe the advanced transgene-free generation of iNSCs from human urine-derived cells (HUCs) by combining a cocktail of defined small molecules with self-replicable mRNA delivery. The established iNSCs were completely transgene-free in their cytosol and genome and further resembled human embryonic stem cell-derived NSCs in the morphology, biological characteristics, global gene expression, and potential to differentiate into functional neurons, astrocytes, and oligodendrocytes. Moreover, iNSC colonies were observed within eight days under optimized conditions, and no teratomas formed in vivo, implying the absence of pluripotent cells. This study proposes an approach to generate transplantable iNSCs that can be broadly applied for neurological disorders in a safe, efficient, and patient-specific manner.

scholarly journals Induced Pluripotent Stem Cells (iPSCs) in Vascular Research: from Two- to Three-Dimensional Organoids

2021 ◽  
Author(s):  
Anja Trillhaase ◽  
Marlon Maertens ◽  
Zouhair Aherrahrou ◽  
Jeanette Erdmann
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Induced Pluripotent Stem Cells ◽  
Stem Cell Research ◽  
Pluripotent Stem Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
3D Models ◽  
Induced Pluripotent

AbstractStem cell technology has been around for almost 30 years and in that time has grown into an enormous field. The stem cell technique progressed from the first successful isolation of mammalian embryonic stem cells (ESCs) in the 1990s, to the production of human induced-pluripotent stem cells (iPSCs) in the early 2000s, to finally culminate in the differentiation of pluripotent cells into highly specialized cell types, such as neurons, endothelial cells (ECs), cardiomyocytes, fibroblasts, and lung and intestinal cells, in the last decades. In recent times, we have attained a new height in stem cell research whereby we can produce 3D organoids derived from stem cells that more accurately mimic the in vivo environment. This review summarizes the development of stem cell research in the context of vascular research ranging from differentiation techniques of ECs and smooth muscle cells (SMCs) to the generation of vascularized 3D organoids. Furthermore, the different techniques are critically reviewed, and future applications of current 3D models are reported. Graphical abstract

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