scholarly journals Yap/Taz-TEAD ACTIVITY LINKS MECHANICAL CUES TO CELL PROGENITOR BEHAVIOR DURING HINDBRAIN SEGMENTATION

2018 ◽  
Author(s):  
Adrià Voltes ◽  
Covadonga F Hevia ◽  
Chaitanya Dingare ◽  
Simone Calzolari ◽  
Javier Terriente ◽  
...  
Keyword(s):  
Cell Fate ◽  
Cell Lineage ◽  
Tissue Growth ◽  
Specific Cell ◽  
Cell Behaviors ◽  
Mechanical Signals ◽  
Matrix Cell ◽  
Physical Cues

SUMMARYCells perceive their microenvironment through chemical and physical cues. However, how mechanical signals are interpreted during embryonic tissue deformation resulting in specific cell behaviors is largely unexplored. The Yap/Taz family of transcriptional co-activators has emerged as an important regulator of tissue growth and regeneration, responding to physical cues from the extracellular matrix, cell shape and actomyosin cytoskeleton. In this work, we unveiled the role of Yap/Taz-TEAD activity as sensor of mechanical signals in the regulation of the progenitor behavior of boundary cells during hindbrain compartmentalization. Monitoring in vivo Yap/Taz-activity during hindbrain segmentation we discovered that boundary cells respond to mechanical cues in a cell-autonomous manner through Yap/Taz-TEAD activity. Cell-lineage analysis revealed that Yap/Taz-TEAD boundary cells decrease their proliferative activity when Yap/Taz-TEAD ceased, preceding changes of cell fate: from proliferating progenitors to differentiated neurons. Functional experiments demonstrated the pivotal role of Yap/Taz-TEAD signaling in maintaining the progenitor features in the hindbrain boundary cell population.

scholarly journals Tgfβ signaling is critical for maintenance of the tendon cell fate

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Guak-Kim Tan ◽  
Brian A Pryce ◽  
Anna Stabio ◽  
John V Brigande ◽  
ChaoJie Wang ◽  
...  
Keyword(s):  
Cell Fate ◽  
Essential Role ◽  
Cell Lineage ◽  
Type Ii ◽  
Critical Importance ◽  
Tgfβ Signaling ◽  
Differentiation Markers ◽  
Tendon Cell

Studies of cell fate focus on specification, but little is known about maintenance of the differentiated state. In this study, we find that the mouse tendon cell fate requires continuous maintenance in vivo and identify an essential role for TGFβ signaling in maintenance of the tendon cell fate. To examine the role of TGFβ signaling in tenocyte function the TGFβ type II receptor (Tgfbr2) was targeted in the Scleraxis-expressing cell lineage using the ScxCre deletor. Tendon development was not disrupted in mutant embryos, but shortly after birth tenocytes lost differentiation markers and reverted to a more stem/progenitor state. Viral reintroduction of Tgfbr2 to mutants prevented and even rescued tenocyte dedifferentiation suggesting a continuous and cell autonomous role for TGFβ signaling in cell fate maintenance. These results uncover the critical importance of molecular pathways that maintain the differentiated cell fate and a key role for TGFβ signaling in these processes.

scholarly journals EBF1 is expressed in pericytes and contributes to pericyte cell commitment

2021 ◽  
Author(s):  
Francesca Pagani ◽  
Elisa Tratta ◽  
Patrizia Dell’Era ◽  
Manuela Cominelli ◽  
Pietro Luigi Poliani
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Mesenchymal Stem Cells ◽  
B Cell ◽  
Cell Fate ◽  
Early Stage ◽  
Cell Lineage ◽  
Cell Maturation ◽  
Cell Commitment

AbstractEarly B-cell factor-1 (EBF1) is a transcription factor with an important role in cell lineage specification and commitment during the early stage of cell maturation. Originally described during B-cell maturation, EBF1 was subsequently identified as a crucial molecule for proper cell fate commitment of mesenchymal stem cells into adipocytes, osteoblasts and muscle cells. In vessels, EBF1 expression and function have never been documented. Our data indicate that EBF1 is highly expressed in peri-endothelial cells in both tumor vessels and in physiological conditions. Immunohistochemistry, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and fluorescence-activated cell sorting (FACS) analysis suggest that EBF1-expressing peri-endothelial cells represent bona fide pericytes and selectively express well-recognized markers employed in the identification of the pericyte phenotype (SMA, PDGFRβ, CD146, NG2). This observation was also confirmed in vitro in human placenta-derived pericytes and in human brain vascular pericytes (HBVP). Of note, in accord with the key role of EBF1 in the cell lineage commitment of mesenchymal stem cells, EBF1-silenced HBVP cells showed a significant reduction in PDGFRβ and CD146, but not CD90, a marker mostly associated with a prominent mesenchymal phenotype. Moreover, the expression levels of VEGF, angiopoietin-1, NG2 and TGF-β, cytokines produced by pericytes during angiogenesis and linked to their differentiation and activation, were also significantly reduced. Overall, the data suggest a functional role of EBF1 in the cell fate commitment toward the pericyte phenotype.

Pax5 determines B- versus T-cell fate and does not block early myeloid-lineage development

Blood ◽  
2003 ◽  
Vol 101 (11) ◽  
pp. 4342-4346 ◽  
Author(s):  
Claudiu V. Cotta ◽  
Zheng Zhang ◽  
Hyung-Gyoon Kim ◽  
Christopher A. Klug
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Fate ◽  
Nk Cell ◽  
Cell Lineage ◽  
Blood Analysis ◽  
Hematopoietic Stem ◽  
Peripheral Blood Analysis

Abstract Progenitor B cells deficient in Pax5 are developmentally multipotent, suggesting that Pax5 is necessary to maintain commitment to the B-cell lineage. Commitment may be mediated, in part, by Pax5 repression of myeloid-specific genes. To determine whether Pax5 expression in multipotential cells is sufficient to restrict development to the B-cell lineage in vivo, we enforced expression of Pax5 in hematopoietic stem cells using a retroviral vector. Peripheral blood analysis of all animals reconstituted with Pax5-expressing cells indicated that more than 90% of Pax5-expressing cells were B220+ mature B cells that were not malignant. Further analysis showed that Pax5 completely blocked T-lineage development in the thymus but did not inhibit myelopoiesis or natural killer (NK) cell development in bone marrow. These results implicate Pax5 as a critical regulator of B- versus T-cell developmental fate and suggest that Pax5 may promote commitment to the B-cell lineage by mechanisms that are independent of myeloid gene repression.

scholarly journals Successive specification of Drosophila neuroblasts NB 6-4 and NB 7-3 depends on interaction of the segment polarity genes wingless, gooseberry and naked cuticle

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3253-3261 ◽  
Author(s):  
Nirupama Deshpande ◽  
Rainer Dittrich ◽  
Gerhard M. Technau ◽  
Joachim Urban
Keyword(s):  
Cell Fate ◽  
Cell Lineage ◽  
Positional Information ◽  
Dorsoventral Patterning ◽  
Expression Domain ◽  
Direct Role ◽  
Segment Polarity Genes ◽  
Segment Polarity ◽  
Unique Identity

The Drosophila central nervous system derives from neural precursor cells, the neuroblasts (NBs), which are born from the neuroectoderm by the process of delamination. Each NB has a unique identity, which is revealed by the production of a characteristic cell lineage and a specific set of molecular markers it expresses. These NBs delaminate at different but reproducible time points during neurogenesis (S1-S5) and it has been shown for early delaminating NBs (S1/S2) that their identities depend on positional information conferred by segment polarity genes and dorsoventral patterning genes. We have studied mechanisms leading to the fate specification of a set of late delaminating neuroblasts, NB 6-4 and NB 7-3, both of which arise from the engrailed (en) expression domain, with NB 6-4 delaminating first. In contrast to former reports, we did not find any evidence for a direct role of hedgehog in the process of NB 7-3 specification. Instead, we present evidence to show that the interplay of the segmentation genes naked cuticle (nkd) and gooseberry (gsb), both of which are targets of wingless (wg) activity, leads to differential commitment to NB 6-4 and NB 7-3 cell fate. In the absence of either nkd or gsb, one NB fate is replaced by the other. However, the temporal sequence of delamination is maintained, suggesting that formation and specification of these two NBs are under independent control.

scholarly journals A Genome-Wide RNA Interference Screen Identifies a Differential Role of the Mediator CDK8 Module Subunits for GATA/ RUNX-Activated Transcription in Drosophila

2010 ◽  
Vol 30 (11) ◽  
pp. 2837-2848 ◽  
Author(s):  
Vanessa Gobert ◽  
Dani Osman ◽  
Stéphanie Bras ◽  
Benoit Augé ◽  
Muriel Boube ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Rna Interference ◽  
Cell Fate ◽  
Gata Factor ◽  
Hematopoietic System ◽  
Crystal Cell ◽  
Genome Wide ◽  
A Genome

ABSTRACT Transcription factors of the RUNX and GATA families play key roles in the control of cell fate choice and differentiation, notably in the hematopoietic system. During Drosophila hematopoiesis, the RUNX factor Lozenge and the GATA factor Serpent cooperate to induce crystal cell differentiation. We used Serpent/Lozenge-activated transcription as a paradigm to identify modulators of GATA/RUNX activity by a genome-wide RNA interference screen in cultured Drosophila blood cells. Among the 129 factors identified, several belong to the Mediator complex. Mediator is organized in three modules plus a regulatory “CDK8 module,” composed of Med12, Med13, CycC, and Cdk8, which has long been thought to behave as a single functional entity. Interestingly, our data demonstrate that Med12 and Med13 but not CycC or Cdk8 are essential for Serpent/Lozenge-induced transactivation in cell culture. Furthermore, our in vivo analysis of crystal cell development show that, while the four CDK8 module subunits control the emergence and the proliferation of this lineage, only Med12 and Med13 regulate its differentiation. We thus propose that Med12/Med13 acts as a coactivator for Serpent/Lozenge during crystal cell differentiation independently of CycC/Cdk8. More generally, we suggest that the set of conserved factors identified herein may regulate GATA/RUNX activity in mammals.

Vertebrate retinal ganglion cells are selected from competent progenitors by the action of Notch

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3637-3650 ◽  
Author(s):  
C.P. Austin ◽  
D.E. Feldman ◽  
J.A. Ida ◽  
C.L. Cepko
Keyword(s):  
Cell Fate ◽  
Ganglion Cells ◽  
Notch Pathway ◽  
Cell Types ◽  
Projection Neurons ◽  
Specific Cell ◽  
Vitro Assay ◽  
Notch Activity

The first cells generated during development of the vertebrate retina are the ganglion cells, the projection neurons of the retina. Although they are one of the most intensively studied cell types within the central nervous system, little is known of the mechanisms that determine ganglion cell fate. We demonstrate that ganglion cells are selected from a large group of competent progenitors that comprise the majority of the early embryonic retina and that differentiation within this group is regulated by Notch. Notch activity in vivo was diminished using antisense oligonucleotides or augmented using a retrovirally transduced constitutively active allele of Notch. The number of ganglion cells produced was inversely related to the level of Notch activity. In addition, the Notch ligand Delta inhibited retinal progenitors from differentiating as ganglion cells to the same degree as did activated Notch in an in vitro assay. These results suggest a conserved strategy for neurogenesis in the retina and describe a versatile in vitro and in vivo system with which to examine the action of the Notch pathway in a specific cell fate decision in a vertebrate.

LncRNA GAS5 suppresses the proliferation and invasion of osteosarcoma cells via the miR-23a-3p/PTEN/PI3K/AKT pathway

2020 ◽  
Author(s):  
Jianmin Liu ◽  
Ming Chen ◽  
Longyang Ma ◽  
Xingbo Dang ◽  
Gongliang Du
Keyword(s):  
Tumor Suppressor ◽  
Tumor Growth ◽  
Akt Pathway ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Cell Behaviors ◽  
Human Osteosarcoma ◽  
Proliferation And Invasion

Abstract Background: Accumulating evidence has shown that lncRNA growth arrest special 5 (GAS5) is a well‑known tumor suppressor in the pathogenesis of a variety of human cancers. However, the detailed role of GAS5 in osteosarcoma is largely unclear. Here, we explore the role of GAS5 in progression of osteosarcoma. Methods: The expression level of GAS5 was detected in human osteosarcoma tissues and matched adjacent tissues, as well as osteosarcoma cell lines and non-malignant osteoblast cells. Then, in vitro gain- and loss-of-function experiments, with the pcDNA-GAS5 expression vector and GAS5-siRNA, were performed in U2OS and HOS cells to determine the effect of GAS5 on osteosarcoma cell proliferation and invasion. Subsequently, we searched potential miRNA targets with bioinformatics analysis and confirmed their interaction by using luciferase reporter gene and RNA pull-down assays. The function and mechanism of miR-23a-3p in proliferation and invasion was also investigated in U2OS and HOS cells. Furthermore, rescue experiments were performed to verify the involvement of miR-23a-3p and its target gene in GAS5-mediated cell behaviors. Finally, a xenograft nude mouse model was established by subcutaneous injection with U2OS cells overexpressing GAS5 or not, and the effect of GAS5 on tumor growth in vivo was evaluated. Results: GAS5 was downregulated in human osteosarcoma tissues and cell lines. Overexpression of GAS5 could significantly suppress, and downregulation of GAS5 promoted, proliferation and invasion of osteosarcoma cells. GAS5 could directly bind with and downregulated miR-23a-3p that post-transcriptionally downregulated the tumor suppressor PTEN and positively regulated proliferation and invasion of osteosarcoma cells. Rescue experiments confirmed the involvement of miR-23a-3p and PTEN in GAS5-mediated cell behaviors by modifying the phosphatidylinositol-3-kinases/protein-serine-threonine kinase (PI3K/AKT) pathway. GAS5 could inhibit tumor growth in vivo . Conclusion: GAS5 functions as a competing endogenous RNA , sponging miR-23a-3p, to promote PTEN expression and suppress cell growth and invasion in osteosarcoma by regulating the PI3K/AKT pathway.

Directing Stem Cell Fate in 3D Through Cell Inert and Adhesive Diblock Copolymer Domains

2013 ◽  
Author(s):  
Somyot Chirasatitsin ◽  
Priyalakshmi Viswanathan ◽  
Giuseppe Battaglia ◽  
Adam J. Engler
Keyword(s):  
Extracellular Matrix ◽  
Stem Cell ◽  
Cell Adhesion ◽  
Cell Fate ◽  
Diblock Copolymer ◽  
Stem Cell Differentiation ◽  
Stem Cell Fate ◽  
Cell Behaviors ◽  
Cell Structures

Adhesions are important cell structures required to transduce a variety of chemical and mechanics signals from outside-in and vice versa, all of which regulate cell behaviors, including stem cell differentiation (1). Though most biomaterials are coated with an adhesive ligand to promote adhesion, they do not often have a uniform distribution that does not match the heterogeneously adhesive extracellular matrix (ECM) in vivo (2). We have previously shown that diblock copolymer (DBC) mixtures undergo interface-confined de-mixing to form nanodomins of one copolymer in another (3). Here we demonstrate how diblock copolymer mixtures can be made into foams with nanodomains to better recapitulate native ECM adhesion regions and influence cell adhesion.

scholarly journals Taurocholate Induces Connective Tissue Growth Factor Expression in Hepatocytes Through ERK-YAP Signaling

2018 ◽  
Vol 50 (5) ◽  
pp. 1711-1725
Author(s):  
Bin Yu ◽  
Guan-nan Jin ◽  
Mei Ma ◽  
Hui-fang Liang ◽  
Bi-xiang Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Western Blotting ◽  
Tissue Growth ◽  
Hepatic Cell ◽  
Erk Signaling ◽  
Rt Pcr ◽  
Hepatic Cell Lines

Background/Aims: Cholestasis is characterized by intrahepatic accumulation of cytotoxic bile acids (BAs), ultimately leading to fibrosis and cirrhosis, but the precise role of BAs in cholestasis-induced liver fibrosis remains largely elusive. In this study, we investigated the role and the potential mechanisms of BAs during cholestasis in vivo and in vitro. Methods: The effect of BAs during cholestasis was studied in bile duct ligation (BDL) rat models in vivo. We performed immunohistochemistry, Western blotting, and quantitative RT-PCR to investigate the expression of connective tissue growth factor (CTGF/CCN2) in rat liver during cholestasis. The hepatic cell lines AML12 and BRL were stimulated with taurocholate (TC) and the level of CTGF/CCN2, and activation of ERK, Akt, p38 MAPK, JNK, YAP, and TGF-β/Smad signaling were examined using Western blotting. Next, to elucidate the mechanism underlying bile acid-induced CTGF/CCN2, we treated the cells with MEK1/2 inhibitor (U0126), YAP function inhibitor (verteporfin), p38 kinase inhibitor (SB203580), Akt inhibitor (MK2206), and small interfering RNA (siRNA) targeting mek1, erk, and yap in cooperation with TC. Besides, we confirmed the activation of these signaling pathways in BDL and sham rat livers by immunohistochemistry, Western blotting, and quantitative RT-PCR. Results: In this study, we confirmed that the expression of CTGF/CCN2 was increased in BDL-induced rodent cholestatic liver fibrosis. In addition, we showed that TC, the main component of BAs, enhanced the synthesis of CTGF/ CCN2 in AML12 and BRL hepatic cell lines. Moreover, we demonstrated that TC activated ERK, Akt, and YAP signaling in hepatocytes, but the precise roles of these signaling cascades in the expression of CTGF/CCN2 were different: TC-induced expression of CTGF/CCN2 was mediated by ERK-YAP signaling, whereas Akt signaling inhibited ERK signaling and YAP and subsequently the expression of CTGF/CCN2 in hepatocytes. Furthermore, YAP functioned as a downstream regulator of ERK signaling in TC-induced CTGF/CCN2 expression in hepatocytes. Conclusion: Our report provides evidence for the role of conjugated BAs in liver fibrosis and suggests that the production of CTGF/CCN2, induced by conjugated BAs via ERK-YAP axis activation, may be a therapeutic target in cholestasis-induced liver fibrosis.

Combined Single Cell Lineage and Transcriptome Sequencing Unveils Cell-Autonomous Regulators of Hematopoietic Stem Cell Fate

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 446-446
Author(s):  
Alejo E Rodriguez-Fraticelli ◽  
Caleb S Weinreb ◽  
Allon Moshe Klein ◽  
Shou-Wen Wang ◽  
Fernando D Camargo
Keyword(s):  
Single Cell ◽  
Cell Fate ◽  
Conflicts Of Interest ◽  
Large Fraction ◽  
Cell Lineage ◽  
Gene Signature ◽  
Hematopoietic Stem ◽  
Cell State

Blood regeneration upon transplantation relies on the activity of long-term repopulating hematopoietic stem cells (LT-HSCs). One of the major controversies in hematopoiesis relates to the apparently different properties that HSCs have in transplantation versus unperturbed settings. In unperturbed steady state hematopoiesis, the most potent HSCs appear to be mostly dormant, and only producing platelet-lineage cells. In turn, upon transplant, even a single transplanted HSC can actively divide and regenerate hundreds of millions of blood progenitors of all lineages. It would thus appear that HSCs have different fundamental properties in each study system. However, most transplantation studies have only tracked the lineage output of the transplanted HSC clones, and rarely the regeneration of the HSC compartment itself. In addition, clonal assays have not been performed at sufficient resolution to fully capture the diversity and clonal complexity of the regenerated HSC compartment. Here, we have used expressible barcodes, which can be sequenced in conventional single cell RNAseq assays, to simultaneously record the functional outcomes and transcriptional states of thousands of HSCs. Our analysis revealed multiple clonal HSC behaviors following transplantation that drastically differ in their differentiation activity, lineage-bias and self-renewal. Surprisingly, we witnessed a large fraction of clones that efficiently repopulate the HSC compartment but show limited contribution to differentiated progeny. Furthermore, these inactive clones have increased competitive multilineage serial repopulating capacity, implying that shortly after transplant a subset of clones reestablishes the native-like LT-HSC behaviors. Our results also argue that this clonal distribution of labor is controlled by cell autonomous, heritable properties (i.e. the epigenetic cell state). Then, using only our clonal readouts to segregate single HSC transcriptomes, we unveiled the transcriptional signatures that associated with unique HSC outcomes (platelet bias, clonal expansion, dormancy, etc.) and unraveled, for the first time, a gene signature for functional long-term serially repopulating clones. We interrogated the drivers of this cell state using an in vivo inducible CRISPR screening and identified 5 novel regulators that are required to regenerate the HSC compartment in a cell autonomous fashion. In conclusion, we demonstrate that functional LT-HSCs share more similar properties in native and transplantation hematopoiesis than previously expected. Consequently, we unveil a definition of the essential, common functional properties of HSCs and the molecular programs that control them. Figure 1 Disclosures No relevant conflicts of interest to declare.

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