Dataset Information

Extracellular matrix-modulated Heartless signaling in Drosophila blood progenitors regulates their differentiation via a Ras/ETS/FOG pathway and target of rapamycin function.

ABSTRACT: Maintenance of hematopoietic progenitors ensures a continuous supply of blood cells during the lifespan of an organism. Thus, understanding the molecular basis for progenitor maintenance is a continued focus of investigation. A large pool of undifferentiated blood progenitors are maintained in the Drosophila hematopoietic organ, the larval lymph gland, by a complex network of signaling pathways that are mediated by niche-, progenitor-, or differentiated hemocyte-derived signals. In this study we examined the function of the Drosophila fibroblast growth factor receptor (FGFR), Heartless, a critical regulator of early lymph gland progenitor specification in the late embryo, during larval lymph gland hematopoiesis. Activation of Heartless signaling in hemocyte progenitors by its two ligands, Pyramus and Thisbe, is both required and sufficient to induce progenitor differentiation and formation of the plasmatocyte-rich lymph gland cortical zone. We identify two transcriptional regulators that function downstream of Heartless signaling in lymph gland progenitors, the ETS protein, Pointed, and the Friend-of-GATA (FOG) protein, U-shaped, which are required for this Heartless-induced differentiation response. Furthermore, cross-talk of Heartless and target of rapamycin signaling in hemocyte progenitors is required for lamellocyte differentiation downstream of Thisbe-mediated Heartless activation. Finally, we identify the Drosophila heparan sulfate proteoglycan, Trol, as a critical negative regulator of Heartless ligand signaling in the lymph gland, demonstrating that sequestration of differentiation signals by the extracellular matrix is a unique mechanism employed in blood progenitor maintenance that is of potential relevance to many other stem cell niches.

SUBMITTER: Dragojlovic-Munther M

PROVIDER: S-EPMC4256155 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Extracellular matrix-modulated Heartless signaling in Drosophila blood progenitors regulates their differentiation via a Ras/ETS/FOG pathway and target of rapamycin function.

Dragojlovic-Munther Michelle M Martinez-Agosto Julian A JA

Developmental biology 20130418 2

Maintenance of hematopoietic progenitors ensures a continuous supply of blood cells during the lifespan of an organism. Thus, understanding the molecular basis for progenitor maintenance is a continued focus of investigation. A large pool of undifferentiated blood progenitors are maintained in the Drosophila hematopoietic organ, the larval lymph gland, by a complex network of signaling pathways that are mediated by niche-, progenitor-, or differentiated hemocyte-derived signals. In this study we ...[more]

PMID: 23603494

Similar Datasets

Project description:This study was undertaken to identify how gene expression of the RT4 bladder papilloma cells respond to extracellular matrics (ECM) Matrigel. Gene expression profile of RT4 cells grown on Plastic was compared with expression profiles of RT4 cells grown on Matriges over 12 hours-9 days timecourse. Total 5881 hypervariable (HV) genes were found to vary significantly over the time points, indicating a response to matrix change. Correlational clustering showed these HV genes fell into distinct families, predominantly genes which became highly expressed on ECM. Another cluster show genes expressed at 12 hours after grown on Matrigel and third cluster show genes whose expression decreased below noise level on Matrigel. This indicate that processes responsible for cell adaptation to ECM happen within first 12 hours and the second cluster form last response of those active processes. Over 1-9 days of cell grows on Matrigel those genes are constantly expressed. Cell signaling and cellular growth and proliferation accounted for major functions for those genes. G-protein signaling, immune response and NF-kB signaling accounted for most dramatically affected canonical pathways. Genes sharing similar ontologies also share several overrepresented transcription regulatory elements confirmed by independent experiment on Panomics platform.Thus, rapid response for ECM orchestrated by several transcription factors was observed. Identified canonical pathways indicate possible targets for manipulating cell phenotype on ECM. Keywords: extracellular matrix, gene expression, RT4, Matrigel, microarray, time course Three dimensional gel cultures with Matrigel were performed by layering 0.8 mls of ice cold Matrigel onto polyethylene terephthalate membranes of 6-well cell culture inserts (Falcon, Becton-Dickinson Labware, Franklin Lakes, NJ). Gels were solidified at 37Âº C. RT4 cells were trypsinized, brought up on 20 mls McCoys media with 10% Fetal Calf Serum (FCS). Cells were centrifuged then brought up in McCoys media with 10% FCS to a concentration of 500,000 cells/250Âµl. 250Âµl added on top of each solidified matrigel disc and 2mls of McCoys with 10% FCS layered underneath each culture insert. Cells were maintained for 10 days and media replenished underneath the insert twice a week. Cells were harvested at 12 hrs, 24hrs, 2 days, 3 days, 4days, 6 days, 7 days, 8 days, and 9 days of growth in culture using Matrisperse (Falcon, Becton-Dickinson Labware, Franklin Lakes, NJ) and RNA collected. Data were normalized as was described previously in Dozmorov I et al., Nucleic Acids Res. 2004 Oct 28;32(19). In general, intensities were converted to expression and normalized to low-expressed genes, which provide possible technical noise level. The arrays are then adjusted to each other by robust linear regression and this Log10 transformed data presented for each sample. Group of low-expressed genes is selected by normal distribution fitting. This group provides internal standard of measurement noise (ISMN). Genes above 5SD from mean of ISMN were selected as expressed

Dataset Information

Extracellular matrix-modulated Heartless signaling in Drosophila blood progenitors regulates their differentiation via a Ras/ETS/FOG pathway and target of rapamycin function.

Publications

Extracellular matrix-modulated Heartless signaling in Drosophila blood progenitors regulates their differentiation via a Ras/ETS/FOG pathway and target of rapamycin function.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure