The Transient Human Thyroid Progenitor Cell: Examining the Thyroid Continuum from Stem Cell to Follicular Cell

Thyroid ◽  
2021 ◽  
Author(s):  
Terry F. Davies ◽  
Rauf Latif ◽  
Ravi Sachidanandam ◽  
Risheng Ma
Keyword(s):  
Stem Cell ◽  
Progenitor Cell ◽  
Follicular Cell ◽  
Human Thyroid

Downregulation of c-kit (Stem Cell Factor Receptor) in Transformed Hematopoietic Precursor Cells by Stroma Cells

Blood ◽  
1999 ◽  
Vol 93 (2) ◽  
pp. 554-563 ◽  
Author(s):  
Christoph Heberlein ◽  
Jutta Friel ◽  
Christine Laker ◽  
Dorothee von Laer ◽  
Ulla Bergholz ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Line ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
Receptor Expression ◽  
General Mechanism ◽  
Ligand Interaction ◽  
Kit Ligand ◽  
Kit Receptor ◽  
Progenitor Cell Line

Abstract We show a dramatic downregulation of the stem cell factor (SCF) receptor in different hematopoietic cell lines by murine stroma. Growth of the human erythroid/macrophage progenitor cell line TF-1 is dependent on granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3). However, TF-1 cells clone and proliferate equally well on stroma. Independent stroma-dependent TF-1 clones (TF-1S) were generated on MS-5 stroma. Growth of TF-1S and TF-1 cells on stroma still requires interaction between c-kit (SCF receptor) and its ligand SCF, because antibodies against c-kit inhibit growth to less than 2%. Surprisingly, c-kit receptor expression (RNA and protein) was downregulated by 2 to 3 orders of magnitude in TF-1S and TF-1 cells grown on stroma. This stroma-dependent regulation of the kit receptor in TF-1 was also observed on exposure to kit ligand-negative stroma, thus indicating the need for heterologous receptor ligand interaction. Removal of stroma induced upregulation by 2 to 4 orders of magnitude. Downregulation and upregulation of c-kit expression could also be shown for the megakaryocytic progenitor cell line M-07e and was comparable to that of TF-1, indicating that stroma-dependent regulation of c-kit is a general mechanism. Downregulation may be an economic way to compensate for the increased sensitivity of the c-kit/ligand interaction on stroma. The stroma-dependent c-kit regulation most likely occurs at the transcriptional level, because mechanisms, such as splicing, attenuation, differential promoter usage, or mRNA stability, could be excluded.

Abstract 297: Nkx2–5 Transcriptionally Activates C-kit-ligand And Regulates Cardiac Progenitor Cell Populations

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rebecca L Scotland ◽  
Xiaozhong Shi ◽  
Anwarul Ferdous ◽  
Michael Kyba ◽  
Daniel J Garry
Keyword(s):  
Transcription Factor ◽  
Stem Cell ◽  
Progenitor Cell ◽  
Transcriptional Regulator ◽  
Luciferase Reporter ◽  
Transcriptional Networks ◽  
Cell Populations ◽  
Cardiac Progenitor Cell ◽  
Downstream Target ◽  
Kit Ligand

C-kit-ligand, also known as stem cell factor, is expressed broadly and has a functional role during hematopoesis, gametogenesis, melanogenesis, mast cell growth and differentiation. Although the receptor for c-kit-ligand, c-kit, has been utilized as a marker to identify cardiac stem cell and progenitor cell populations, the transcriptional regulation and biological function of c-kit-ligand during cardiogenesis has not been defined. Here we demonstrate that c-kit-ligand is a novel downstream target of Nkx2–5. The homeodomain transcription factor, Nkx2–5, is one of the earliest markers of the cardiac lineage and mice lacking this transcription factor are nonviable. To identify potential Nkx2–5 downstream target genes, we utilized ES/EBs that were engineered to overexpress Nkx2–5 and undertook transcriptome analysis of embyroid bodies with and without Nkx2–5 induction. We observed a significant increase in c-kit-ligand expression following Nkx2–5 induction suggesting a role for Nkx2–5 in the activation of c-kit-ligand. Furthermore, analysis of the c-kit-ligand promoter revealed three evolutionarily conserved Nkx2–5 response elements, supporting the notion that Nkx2–5 is a transcriptional regulator of gene expression. We undertook transcriptional assays and transfected the c-kit-ligand promoter-luciferase reporter in the absence and presence of increasing amounts of Nkx2–5. We observed that Nkx2–5, in a dose dependent fashion, was a potent transcriptional activator of c-kit-ligand. These studies enhance our understanding of Nkx2–5 mediated transcriptional networks and further emphasize that Nkx2–5 is an important transcriptional regulator of cardiac progenitor cell populations.

scholarly journals A model of intramedullary hematopoietic microenvironments based on stereologic study of the distribution of endocloned marrow colonies

Blood ◽  
1984 ◽  
Vol 63 (2) ◽  
pp. 287-297 ◽  
Author(s):  
RH Lambertsen ◽  
L Weiss
Keyword(s):  
Stem Cell ◽  
Progenitor Cell ◽  
Cell Replication ◽  
Detailed Model ◽  
Colony Cell ◽  
Central Regions ◽  
Granulocytic Colony ◽  
Progenitor Cell Proliferation ◽  
Macrophage Colony ◽  
Cell Commitment

Hematopoietic colonies were studied in the marrow of alternate fraction- irradiated mice by light microscopic stereology to investigate the microenvironmental organization of marrow. Separate analyses of the relative colony cell density of undifferentiated, granulocytic, erythrocytic, and macrophage colonies in four marrow zones were carried out at 3, 4, and 5 days postirradiation (PI) for all colonies, all periarterial colonies, and all non-periarterial colonies. The results demonstrate a differential colony cell distribution that does not appear to be due to a preferential distribution of certain colony types around arteries. Undifferentiated colony cells showed a consistent predilection for endosteal and periarterial regions, with the majority of colony cells occurring along bone. Erythrocytic colony cells proliferated initially in intermediate and central marrow zones and along arteries. Granulocytic colony cells occurred in all areas at 3 days PI, but increased in density along bone thereafter. Macrophage colony cells occurred in all zones at 4 days PI, but at 5 days were concentrated in subosteal and central regions. Macrophage colonies also occurred periarterially. To explain these findings and the organization of normal bone marrow, we present a detailed model of the microenvironmental organization of intramedullary hematopoiesis. This model portrays the stroma as engendering distinct microenvironments for stem cell replication, stem cell commitment, and early progenitor cell proliferation.

scholarly journals Nfatc1’s Role in Mammary Epithelial Morphogenesis and Basal Stem/progenitor Cell Self-renewal

2021 ◽  
Author(s):  
Melissa McNeil ◽  
Yingying Han ◽  
Peng Sun ◽  
Kazuhide Watanabe ◽  
Jun Jiang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mammary Gland ◽  
Progenitor Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Basal Layer ◽  
Mammary Epithelial ◽  
Epithelial Morphogenesis ◽  
Small Subset ◽  
Self Renewal

AbstractMammary gland is an outstanding system to study the regulatory mechanisms governing adult epithelial stem cell activity. Stem cells in the basal layer of the mammary gland fuel the morphogenesis and regeneration of a complex epithelial network during development and upon transplantation. The self-renewal of basal stem/progenitor cells is subjected to regulation by both cell-intrinsic and extrinsic mechanisms. Nfatc1 is a transcription factor that regulates breast tumorigenesis and metastasis, but its role in mammary epithelial development and stem cell function has not been investigated. Here we show that Nfatc1 is expressed in a small subset of mammary basal epithelial cells and its epithelial-specific deletion results in mild defects in side branching and basal-luminal cell balance. Moreover, Nfatc1-deficient basal cells exhibit reduced colony forming ability in vitro and somewhat compromised regenerative potential upon transplantation. Thus, our study provides evidence for a detectable yet non-essential role of Nfatc1 in mammary epithelial morphogenesis and basal stem/progenitor cell self-renewal.

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