scholarly journals The TAF10-containing TFIID and SAGA transcriptional complexes are dispensable for early somitogenesis in the mouse embryo

2016 ◽  
Author(s):  
Paul Bardot ◽  
Stéphane D. Vincent ◽  
Marjorie Fournier ◽  
Alexis Hubaud ◽  
Mathilde Joint ◽  
...  
Keyword(s):  
Cell Fate ◽  
Mouse Embryo ◽  
Control Cell ◽  
Paraxial Mesoderm ◽  
Mrna Levels ◽  
Lateral Plate ◽  
Mesoderm Development ◽  
Regulated Gene Expression ◽  
A Minor

AbstractDuring development, tightly regulated gene expression programs control cell fate and patterning. A key regulatory step in eukaryotic transcription is the assembly of the pre-initiation complex (PIC) at promoters. The PIC assembly has mainly been studiedin vitro, and little is known about its composition during development.In vitrodata suggests that TFIID is the general transcription factor that nucleates PIC formation at promoters. Here we show that TAF10, a subunit of TFIID and of the transcriptional co-activator SAGA, is required for the assembly of these complexes in the mouse embryo. We performedTaf10conditional deletions during mesoderm development and show thatTaf10loss in the presomitic mesoderm (PSM) does not prevent cyclic gene transcription or PSM segmental patterning, while lateral plate differentiation is profoundly altered. During this period, global mRNA levels are unchanged in the PSM, with only a minor subset of genes dysregulated. Together, our data demonstrate that the TAF10-containing canonical TFIID and SAGA complexes, are dispensable for early paraxial mesoderm development, arguing against the generic role in transcription proposed for these fully assembled holo complexes.

scholarly journals Understanding paraxial mesoderm development and sclerotome specification for skeletal repair

2020 ◽  
Vol 52 (8) ◽  
pp. 1166-1177 ◽  
Author(s):  
Shoichiro Tani ◽  
Ung-il Chung ◽  
Shinsuke Ohba ◽  
Hironori Hojo
Keyword(s):  
Molecular Mechanisms ◽  
Skeletal Development ◽  
Deep Understanding ◽  
Basic Research ◽  
Paraxial Mesoderm ◽  
Lateral Plate ◽  
Developmental Processes ◽  
Mesoderm Development

Abstract Pluripotent stem cells (PSCs) are attractive regenerative therapy tools for skeletal tissues. However, a deep understanding of skeletal development is required in order to model this development with PSCs, and for the application of PSCs in clinical settings. Skeletal tissues originate from three types of cell populations: the paraxial mesoderm, lateral plate mesoderm, and neural crest. The paraxial mesoderm gives rise to the sclerotome mainly through somitogenesis. In this process, key developmental processes, including initiation of the segmentation clock, formation of the determination front, and the mesenchymal–epithelial transition, are sequentially coordinated. The sclerotome further forms vertebral columns and contributes to various other tissues, such as tendons, vessels (including the dorsal aorta), and even meninges. To understand the molecular mechanisms underlying these developmental processes, extensive studies have been conducted. These studies have demonstrated that a gradient of activities involving multiple signaling pathways specify the embryonic axis and induce cell-type-specific master transcription factors in a spatiotemporal manner. Moreover, applying the knowledge of mesoderm development, researchers have attempted to recapitulate the in vivo development processes in in vitro settings, using mouse and human PSCs. In this review, we summarize the state-of-the-art understanding of mesoderm development and in vitro modeling of mesoderm development using PSCs. We also discuss future perspectives on the use of PSCs to generate skeletal tissues for basic research and clinical applications.

scholarly journals The LINC complex transmits integrin-dependent tension to the nuclear lamina and represses epidermal differentiation

2020 ◽  
Author(s):  
Emma Carley ◽  
Rachel K. Stewart ◽  
Abigail Zieman ◽  
Iman Jalilian ◽  
Diane. E. King ◽  
...  
Keyword(s):  
Cell Fate ◽  
Control Cell ◽  
Nuclear Lamina ◽  
Epidermal Differentiation ◽  
Keratinocyte Differentiation ◽  
Linc Complex ◽  
Force Transmission ◽  
Cell Fate Decisions

AbstractWhile the mechanisms by which chemical signals control cell fate have been well studied, how mechanical inputs impact cell fate decisions are not well understood. Here, using the well-defined system of keratinocyte differentiation in the skin, we examine whether and how direct force transmission to the nucleus regulates epidermal cell fate. Using a molecular biosensor, we find that tension on the nucleus through Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes requires integrin engagement in undifferentiated epidermal stem cells, and is released during differentiation concomitant with decreased tension on A-type lamins. LINC complex ablation in mice reveals that LINC complexes are required to repress epidermal differentiation in vivo and in vitro and influence accessibility of epidermal differentiation genes, suggesting that force transduction from engaged integrins to the nucleus plays a role in maintaining keratinocyte progenitors. This work reveals a direct mechanotransduction pathway capable of relaying adhesion-specific signals to regulate cell fate.

scholarly journals Redundant Roles of Tead1 and Tead2 in Notochord Development and the Regulation of Cell Proliferation and Survival

2008 ◽  
Vol 28 (10) ◽  
pp. 3177-3189 ◽  
Author(s):  
Atsushi Sawada ◽  
Hiroshi Kiyonari ◽  
Kanako Ukita ◽  
Noriyuki Nishioka ◽  
Yu Imuta ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Paraxial Mesoderm ◽  
Mouse Development ◽  
Lateral Plate ◽  
Growth Defects ◽  
Mouse Mutants ◽  
Severe Growth

ABSTRACT Four members of the TEAD/TEF family of transcription factors are expressed widely in mouse embryos and adult tissues. Although in vitro studies have suggested various roles for TEAD proteins, their in vivo functions remain poorly understood. Here we examined the role of Tead genes by generating mouse mutants for Tead1 and Tead2. Tead2 −/− mice appeared normal, but Tead1 −/−; Tead2 −/− embryos died at embryonic day 9.5 (E9.5) with severe growth defects and morphological abnormalities. At E8.5, Tead1 −/−; Tead2 −/− embryos were already small and lacked characteristic structures such as a closed neural tube, a notochord, and somites. Despite these overt abnormalities, differentiation and patterning of the neural plate and endoderm were relatively normal. In contrast, the paraxial mesoderm and lateral plate mesoderm were displaced laterally, and a differentiated notochord was not maintained. These abnormalities and defects in yolk sac vasculature organization resemble those of mutants for Yap, which encodes a coactivator of TEAD proteins. Moreover, we demonstrated genetic interactions between Tead1 and Tead2 and Yap. Finally, Tead1 −/−; Tead2 −/− embryos showed reduced cell proliferation and increased apoptosis. These results suggest that Tead1 and Tead2 are functionally redundant, use YAP as a major coactivator, and support notochord maintenance as well as cell proliferation and survival in mouse development.

scholarly journals Mouse embryo geometry drives formation of robust signaling gradients through receptor localization

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhechun Zhang ◽  
Steven Zwick ◽  
Ethan Loew ◽  
Joshua S. Grimley ◽  
Sharad Ramanathan
Keyword(s):  
Cell Fate ◽  
Mouse Embryo ◽  
Basolateral Membrane ◽  
Embryonic Stem ◽  
Bmp Signaling ◽  
Receptor Localization ◽  
Bmp Receptors ◽  
Early Mouse

Abstract Morphogen signals are essential for cell fate specification during embryogenesis. Some receptors that sense these morphogens are known to localize to only the apical or basolateral membrane of polarized cell lines in vitro. How such localization affects morphogen sensing and patterning in the developing embryo remains unknown. Here, we show that the formation of a robust BMP signaling gradient in the early mouse embryo depends on the restricted, basolateral localization of BMP receptors. The mis-localization of receptors to the apical membrane results in ectopic BMP signaling in the mouse epiblast in vivo. With evidence from mathematical modeling, human embryonic stem cells in vitro, and mouse embryos in vivo, we find that the geometric compartmentalization of BMP receptors and ligands creates a signaling gradient that is buffered against fluctuations. Our results demonstrate the importance of receptor localization and embryo geometry in shaping morphogen signaling during embryogenesis.

Porcine nuclear transfer using somatic donor cells altered to express male germ cell function

2009 ◽  
Vol 21 (7) ◽  
pp. 882 ◽  
Author(s):  
Sangho Roh ◽  
Hye-Yeon Choi ◽  
Sang Kyu Park ◽  
Cheolhee Won ◽  
Bong-Woo Kim ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Fate ◽  
Nuclear Transfer ◽  
Cell Function ◽  
Control Cell ◽  
Donor Cell ◽  
Male Germ Cell ◽  
Cell Group ◽  
Cell Extracts

Recent studies reported that the direct transformation of one differentiated somatic cell type into another is possible. In the present study, we were able to modulate the cell fate of somatic cells to take on male germ cell function by introducing cell extracts derived from porcine testis tissue. Fibroblasts were treated with streptolysin O, which reversibly permeabilises the plasma membrane, and incubated with testis extracts. Our results showed that the testis extracts (TE) could activate expression of male germ cell-specific genes, implying that TE can provide regulatory components required for altering the cell fate of fibroblasts. Male germ cell function was sustained for more than 10 days after the introduction of TE. In addition, a single TE-treated cell was injected directly into the cytoplasm of in vitro-matured porcine oocytes. The rate of blastocyst formation was significantly higher in the TE-treated nuclear donor cell group than in the control cell group. The expression level of Nanog, Sox9 and Eomes was drastically increased when altered cells were used as donor nuclei. Our results suggest that TE can be used to alter the cell fate of fibroblasts to express male germ cell function and improve the developmental efficiency of the nuclear transfer porcine embryos.

Bioinspired in vitro microenvironments to control cell fate: Focus on macromolecular crowding

2021 ◽  
Author(s):  
Dimitrios I. Zeugolis
Keyword(s):  
Cell Fate ◽  
Cell Expansion ◽  
Ex Vivo ◽  
Control Cell ◽  
Macromolecular Crowding ◽  
Cell Phenotype ◽  
Cell Culture Systems ◽  
And Function ◽  
Phenotypic Drift

The development of therapeutic regenerative medicine and accurate drug discovery cell-based products requires effective, with respect to obtaining sufficient numbers of viable, proliferative and functional cell populations, cell expansion ex vivo. Unfortunately, traditional cell culture systems fail to recapitulate the multifaceted tissue milieu in vitro, resulting in cell phenotypic drift, loss of functionality, senescence and apoptosis. Substrate-, environmental- and media- induced approaches are under intense investigation as a means to maintain cell phenotype and function whilst in culture. In this context, herein, the potential of macromolecular crowding, a biophysical phenomenon with considerable biological consequences, is discussed.

Neuroectodermal fate of epiblast cells in the distal region of the mouse egg cylinder: implication for body plan organization during early embryogenesis

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 87-98 ◽  
Author(s):  
G.A. Quinlan ◽  
E.A. Williams ◽  
S.S. Tan ◽  
P.P. Tam
Keyword(s):  
Cell Fate ◽  
Neural Tube ◽  
Primitive Streak ◽  
Distal Region ◽  
Small Population ◽  
Surface Ectoderm ◽  
Minor Contribution ◽  
Stage Embryo ◽  
A Minor

The developmental fate of cells in the distal region (distal cap) of the epiblast was analysed by fate mapping studies. The displacement and differentiation of cells labelled in situ with carbocyanine dyes and lacZ-expressing cells grafted to the distal cap were studied over a 48-hour period of in vitro development. The distal cap epiblast differentiates predominantly into neurectodermal cells. Cells at the anterior site of the distal cap colonise the fore-, mid- and hindbrain and contribute to non-neural ectoderm cells of the amnion and craniofacial surface ectoderm. Those cells in the most distal region of the epiblast contribute to all three brain compartments as well as the spinal cord and the posterior neuropore. Cells at the posterior site of the distal cap are mainly localised to the caudal parts of the neural tube. A minor contribution to the embryonic (paraxial and lateral) and extraembryonic (allantoic and yolk sac) mesoderm is also found. Epiblast cells located outside the distal cap give rise to surface ectoderm and other non-ectodermal derivatives, with only a minor contribution to the neuroectoderm. Results of this study provide compelling evidence that the precursor population of the neural tube is contained in the distal cap epiblast of the early-primitive-streak-stage embryo. Furthermore, the regionalisation of cell fate within this small population suggest that a preliminary craniocaudal patterning may have occurred in the neural primordium before neurulation.

scholarly journals Control of skeletal morphogenesis by the Hippo-YAP/TAZ pathway

Development ◽  
2020 ◽  
Vol 147 (21) ◽  
pp. dev187187
Author(s):  
Hannah K. Vanyai ◽  
Fabrice Prin ◽  
Oriane Guillermin ◽  
Bishara Marzook ◽  
Stefan Boeing ◽  
...  
Keyword(s):  
Cell Fate ◽  
Target Genes ◽  
Control Cell ◽  
Tissue Growth ◽  
Double Knockout ◽  
Cartilage Growth ◽  
Chondrocyte Proliferation ◽  
Specific Expression

ABSTRACTThe Hippo-YAP/TAZ pathway is an important regulator of tissue growth, but can also control cell fate or tissue morphogenesis. Here, we investigate the function of the Hippo pathway during the development of cartilage, which forms the majority of the skeleton. Previously, YAP was proposed to inhibit skeletal size by repressing chondrocyte proliferation and differentiation. We find that, in vitro, Yap/Taz double knockout impairs murine chondrocyte proliferation, whereas constitutively nuclear nls-YAP5SA accelerates proliferation, in line with the canonical role of this pathway in most tissues. However, in vivo, cartilage-specific knockout of Yap/Taz does not prevent chondrocyte proliferation, differentiation or skeletal growth, but rather results in various skeletal deformities including cleft palate. Cartilage-specific expression of nls-YAP5SA or knockout of Lats1/2 do not increase cartilage growth, but instead lead to catastrophic malformations resembling chondrodysplasia or achondrogenesis. Physiological YAP target genes in cartilage include Ctgf, Cyr61 and several matrix remodelling enzymes. Thus, YAP/TAZ activity controls chondrocyte proliferation in vitro, possibly reflecting a regenerative response, but is dispensable for chondrocyte proliferation in vivo, and instead functions to control cartilage morphogenesis via regulation of the extracellular matrix.

scholarly journals Coordinate activation of lysosomal, Ca2+-activated and ATP-ubiquitin-dependent proteinases in the unweighted rat soleus muscle

1996 ◽  
Vol 316 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Daniel TAILLANDIER ◽  
Eveline AUROUSSEAU ◽  
Dominique MEYNIAL-DENIS ◽  
Daniel BECHET ◽  
Marc FERRARA ◽  
...  
Keyword(s):  
Soleus Muscle ◽  
Enzyme Activities ◽  
Muscle Wasting ◽  
Hindlimb Suspension ◽  
Mrna Levels ◽  
Protein Breakdown ◽  
Equal Distribution ◽  
Rat Soleus Muscle ◽  
A Minor

Nine days of hindlimb suspension resulted in atrophy (55%) and loss of protein (53%) in rat soleus muscle due to a marked elevation in protein breakdown (66%, P < 0.005). To define which proteolytic system(s) contributed to this increase, soleus muscles from unweighted rats were incubated in the presence of proteolytic inhibitors. An increase in lysosomal and Ca2+-activated proteolysis (254%, P < 0.05) occurred in the atrophying incubated muscles. In agreement with the measurements in vitro, cathepsin B, cathepsins B+L and m-calpain enzyme activities increased by 111%, 92% and 180% (P < 0.005) respectively in the atrophying muscles. Enhanced mRNA levels for these proteinases (P < 0.05 to P < 0.001) paralleled the increased enzyme activities, suggesting a transcriptional regulation of these enzymes. However, the lysosomal and Ca2+-dependent proteolytic pathways accounted for a minor part of total proteolysis in both control (9%) and unweighted rats (18%). Furthermore the inhibition of these pathways failed to suppress increased protein breakdown in unweighted muscle. Thus a non-lysosomal Ca2+-independent proteolytic process essentially accounted for the increased proteolysis and subsequent muscle wasting. Increased mRNA levels for ubiquitin, the 14 kDa ubiquitin-conjugating enzyme E2 (involved in the ubiquitylation of protein substrates) and the C2 and C9 subunits of the 20 S proteasome (i.e. the proteolytic core of the 26 S proteasome that degrades ubiquitin conjugates) were observed in the atrophying muscles (P < 0.02 to P < 0.001). Analysis of C9 mRNA in polyribosomes showed equal distribution into both translationally active and inactive mRNA pools, in either unweighted or control rats. These results suggest that increased ATP-ubiquitin-dependent proteolysis is most probably responsible for muscle wasting in the unweighted soleus muscle.

scholarly journals Paraxial mesoderm organoids model development of human somites

2021 ◽  
Author(s):  
Christoph Budjan ◽  
Shichen Liu ◽  
Adrian Ranga ◽  
Senjuti Gayen ◽  
Olivier Pourquie ◽  
...  
Keyword(s):  
Model Development ◽  
Cell Number ◽  
Paraxial Mesoderm ◽  
Critical Parameters ◽  
Mesoderm Development ◽  
Human Spinal Cord ◽  
Somite Formation ◽  
Functional Features

During the development of the vertebrate embryo, segmented structures called somites are periodically formed from the presomitic mesoderm (PSM), and give rise to the vertebral column. While somite formation has been studied in several animal models, it is less clear how well this process is conserved in humans. Recent progress has made it possible to study aspects of human paraxial mesoderm development such as the human segmentation clock in vitro using human pluripotent stem cells (hPSCs), however, somite formation has not been observed in these monolayer cultures. Here, we describe the generation of human paraxial mesoderm (PM) organoids from hPSCs (termed Somitoids), which recapitulate the molecular, morphological and functional features of paraxial mesoderm development, including formation of somite-like structures in vitro. Using a quantitative image-based screen, we identify critical parameters such as initial cell number and signaling modulations that reproducibly yielded somite formation in our organoid system. In addition, using single-cell RNA sequencing and 3D imaging, we show that PM organoids both transcriptionally and morphologically resemble their in vivo counterparts and can be differentiated into somite derivatives. Our organoid system is reproducible and scalable, allowing for the systematic and quantitative analysis of human spinal cord development and disease in vitro.

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