| 1. |
- Sahara, Makoto, et al.
(författare)
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Population and single-cell analysis of human cardiogenesis reveals unique LGR5 ventricular progenitors in embryonic outflow tract
- 2019
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Ingår i: Developmental Cell. - Stockholm : Karolinska Institutet, Dept of Cell and Molecular Biology. - 1534-5807 .- 1878-1551.
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Tidskriftsartikel (refereegranskat)abstract
- The morphogenetic process of mammalian cardiac development is complex and highly regulated spatiotemporally by multipotent cardiac stem/progenitor cells (CPCs). Mouse studies have been informative for understanding mammalian cardiogenesis; however, similar insights have been poorly established in humans. Here, we report comprehensive gene expression profiles of human cardiac derivatives from multipotent CPCs to intermediates and mature cardiac cells by population and single-cell RNA-seq using human embryonic stem cell-derived and embryonic/fetal heart-derived cardiac cells micro-dissected from specific heart compartments. Importantly, we discover a uniquely human subset of cono-ventricular region-specific CPCs, marked by LGR5. At 4 to 5 weeks of fetal age, the LGR5+ population appears to emerge specifically in the proximal outflow tract of human embryonic hearts and thereafter promotes cardiac development and alignment through expansion of the ISL1+TNNT2+ intermediates. The current study contributes to a deeper understanding of human cardiogenesis, which may uncover the putative origins of certain human congenital cardiac malformations.
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| 2. |
- Wagner, Ines, et al.
(författare)
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Serum proteases potentiate BMP-induced cell cycle re-entry of dedifferentiating muscle cells during newt limb regeneration
- 2017
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Ingår i: Developmental Cell. - Stockholm : Karolinska Institutet, Dept of Cell and Molecular Biology. - 1534-5807 .- 1878-1551.
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Tidskriftsartikel (refereegranskat)abstract
- Limb amputation in the newt induces myofibers to dedifferentiate and re-enter the cell cycle to generate proliferative myogenic precursors in the regeneration blastema. Here we show that bone morphogenetic proteins (BMPs) and mature BMPs that have been further cleaved by serum proteases induce cell cycle entry by dedifferentiating newt muscle cells. Protease-activated BMP4/7 heterodimers that are present in serum strongly induced myotube cell cycle re-entry with protease cleavage yielding a 30-fold potency increase of BMP4/7 compared with canonical BMP4/7. Inhibition of BMP signaling via muscle-specific dominant-negative receptor expression reduced cell cycle entry in vitro and in vivo. In vivo inhibition of serine protease activity depressed cell cycle re-entry, which in turn was rescued by cleaved-mimic BMP. This work identifies a mechanism of BMP activation that generates blastema cells from differentiated muscle.
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| 3. |
- Baek, Sungmin, et al.
(författare)
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The Alternative Splicing Regulator Nova2 Constrains Vascular Erk Signaling to Limit Specification of the Lymphatic Lineage
- 2019
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Ingår i: Developmental Cell. - : CELL PRESS. - 1534-5807 .- 1878-1551. ; 49:2, s. 279-292
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Tidskriftsartikel (refereegranskat)abstract
- The correct assignment of cell fate within fields of multipotent progenitors is essential for accurate tissue diversification. The first lymphatic vessels arise from pre-existing veins after venous endothelial cells become specified as lymphatic progenitors. Prox1 specifies lymphatic fate and labels these progenitors; however, the mechanisms restricting Prox1 expression and limiting the progenitor pool remain unknown. We identified a zebrafish mutant that displayed premature, expanded, and prolonged lymphatic specification. The gene responsible encodes the regulator of alternative splicing, Nova2. In zebrafish and human endothelial cells, Nova2 selectively regulates pre-mRNA splicing for components of signaling pathways and phosphoproteins. Nova2-deficient endothelial cells display increased Mapk/Erk signaling, and Prox1 expression is dynamically controlled by Erk signaling. We identify a mechanism whereby Nova2-regulated splicing constrains Erk signaling, thus limiting lymphatic progenitor cell specification. This identifies the capacity of a factor that tunes mRNA splicing to control assignment of cell fate during vascular differentiation.
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| 4. |
- Bahrampour, Shahrzad, et al.
(författare)
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Neural Lineage Progression Controlled by a Temporal Proliferation Program.
- 2017
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Ingår i: Developmental Cell. - : Cell Press. - 1534-5807 .- 1878-1551. ; 43:3, s. 332-348
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Tidskriftsartikel (refereegranskat)abstract
- Great progress has been made in identifying transcriptional programs that establish stem cell identity. In contrast, we have limited insight into how these programs are down-graded in a timely manner to halt proliferation and allow for cellular differentiation. Drosophila embryonic neuroblasts undergo such a temporal progression, initially dividing to bud off daughters that divide once (type I), then switching to generating non-dividing daughters (type 0), and finally exiting the cell cycle. We identify six early transcription factors that drive neuroblast and type I daughter proliferation. Early factors are gradually replaced by three late factors, acting to trigger the type I→0 daughter proliferation switch and eventually to stop neuroblasts. Early and late factors regulate each other and four key cell-cycle genes, providing a logical genetic pathway for these transitions. The identification of this extensive driver-stopper temporal program controlling neuroblast lineage progression may have implications for studies in many other systems.less thanbr /greater than (Copyright © 2017 Elsevier Inc. All rights reserved.)
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| 5. |
- Boije, Henrik, et al.
(författare)
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The Independent Probabilistic Firing of Transcription Factors : A Paradigm for Clonal Variability in the Zebrafish Retina
- 2015
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 34:5, s. 532-543
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Tidskriftsartikel (refereegranskat)abstract
- Early retinal progenitor cells (RPCs) in vertebrates produce lineages that vary greatly both in terms of cell number and fate composition, yet how this variability is achieved remains unknown. One possibility is that these RPCs are individually distinct and that each gives rise to a unique lineage. Another is that stochastic mechanisms play upon the determinative machinery of equipotent early RPCs to drive clonal variability. Here we show that a simple model, based on the independent firing of key fate-influencing transcription factors, can quantitatively account for the intrinsic clonal variance in the zebrafish retina and predict the distributions of neuronal cell types in clones where one or more of these fates are made unavailable.
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| 6. |
- Böiers, Charlotta, et al.
(författare)
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A Human IPS Model Implicates Embryonic B-Myeloid Fate Restriction as Developmental Susceptibility to B Acute Lymphoblastic Leukemia-Associated ETV6-RUNX1
- 2018
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 44:3, s. 7-377
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Tidskriftsartikel (refereegranskat)abstract
- ETV6-RUNX1 is associated with childhood acute B-lymphoblastic leukemia (cALL) functioning as a first-hit mutation that initiates a clinically silent pre-leukemia in utero. Because lineage commitment hierarchies differ between embryo and adult, and the impact of oncogenes is cell-context dependent, we hypothesized that the childhood affiliation of ETV6-RUNX1 cALL reflects its origins in a progenitor unique to embryonic life. We characterize the first emerging B cells in first-trimester human embryos, identifying a developmentally restricted CD19−IL-7R+ progenitor compartment, which transitions from a myeloid to lymphoid program during ontogeny. This developmental series is recapitulated in differentiating human pluripotent stem cells (hPSCs), thereby providing a model for the initiation of cALL. Genome-engineered hPSCs expressing ETV6-RUNX1 from the endogenous ETV6 locus show expansion of the CD19−IL-7R+ compartment, show a partial block in B lineage commitment, and produce proB cells with aberrant myeloid gene expression signatures and potential: features (collectively) consistent with a pre-leukemic state. Böiers, Richardson et al. explore the potential for a developmental susceptibility to childhood acute lymphoblastic leukemia. Characterization of earliest B cell progenitors in human fetal liver identified a unique progenitor compartment that can be recapitulated using human pluripotent stem cells to model the impact of the pre-leukemia-initiating oncogene ETV6-RUNX1.
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| 7. |
- Eroglu, E, et al.
(författare)
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Heart Regeneration 4.0: Matrix Medicine
- 2017
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Ingår i: Developmental cell. - : Elsevier BV. - 1878-1551 .- 1534-5807. ; 42:1, s. 7-8
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Tidskriftsartikel (refereegranskat)
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| 8. |
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| 9. |
- Hennigs, Lars
(författare)
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Organizer-Derived WOX5 Signal Maintains Root Columella Stem Cells through Chromatin-Mediated Repression of CDF4 Expression
- 2015
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 33, s. 576-588
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Tidskriftsartikel (refereegranskat)abstract
- Stem cells in plants and animals are maintained pluripotent by signals from adjacent niche cells. In plants, WUSCHEL HOMEOBOX (WOX) transcription factors are central regulators of stem cell maintenance in different meristem types, yet their molecular mode of action has remained elusive. Here we show that in the Arabidopsis root meristem, the WOX5 protein moves from the root niche organizer, the quiescent center, into the columella stem cells, where it directly represses the transcription factor gene CDF4. This creates a gradient of CDF4 transcription, which promotes differentiation opposite to the WOX5 gradient, allowing stem cell daughter cells to exit the stem cell state. We further show that WOX5 represses CDF4 transcription by recruiting TPL/TPR co-repressors and the histone deacetylase HDA19, which consequently induces histone deacetylation at the CDF4 regulatory region. Our results show that chromatin-mediated repression of differentiation programs is a common strategy in plant and animal stem cell niches.
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| 10. |
- Karim, Mahmoud Abdul, et al.
(författare)
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Rab-Effector-Kinase Interplay Modulates Intralumenal Fragment Formation during Vacuole Fusion
- 2018
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Ingår i: Developmental Cell. - : Cell Press. - 1534-5807 .- 1878-1551. ; 47:1, s. 80-97.e6
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Tidskriftsartikel (refereegranskat)abstract
- Upon vacuolar lysosome (or vacuole) fusion in S. cerevisiae, a portion of membrane is internalized and catabolized. Formation of this intralumenal fragment (ILF) is important for organelle protein and lipid homeostasis and remodeling. But how ILF formation is optimized for membrane turnover is not understood. Here, we show that fewer ILFs form when the interaction between the Rab-GTPase Ypt7 and its effector Vps41 (a subunit of the tethering complex HOPS) is interrupted by a point mutation (Ypt7-D44N). Subsequent phosphorylation of Vps41 by the casein kinase Yck3 prevents stabilization of trans-SNARE complexes needed for lipid bilayer pore formation. Impairing ILF formation prevents clearance of misfolded proteins from vacuole membranes and promotes organelle permeability and cell death. We propose that HOPS coordinates Rab, kinase, and SNARE cycles to modulate ILF size during vacuole fusion, regulating lipid and protein turnover important for quality control and membrane integrity.
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