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Adenosine signaling promotes hematopoietic stem and progenitor cell emergence.

Jing L, Tamplin OJ, Chen MJ, Deng Q, Patterson S, Kim PG, Durand EM, McNeil A, Green JM, Matsuura S, Ablain J, Brandt MK, Schlaeger TM, Huttenlocher A, Daley GQ, Ravid K, Zon LI - J. Exp. Med. (2015)

Bottom Line: A2b adenosine receptor activation induced CXCL8 via cAMP-protein kinase A (PKA) and mediated hematopoiesis.We further show that adenosine increased multipotent progenitors in a mouse embryonic stem cell colony-forming assay and in embryonic day 10.5 aorta-gonad-mesonephros explants.Our results demonstrate that adenosine signaling plays an evolutionary conserved role in the first steps of HSPC formation in vertebrates.

View Article: PubMed Central - HTML - PubMed

Affiliation: Stem Cell Program, Division of Hematology/Oncology, Boston Children's Hospital and Dana-Farber Cancer Institute, Boston, MA 02115 Harvard Stem Cell Institute, Howard Hughes Medical Institute, and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138.

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Adenosine signaling regulates hemogenic vascular endothelium. (A–C′) Confocal imaging of Tg(sclβ:d2eGFP; flk1:mcherry) embryos at 30 hpf. Control embryos (A and A′), embryos injected with A2b MO (B and B′), and embryos treated with 10 µM BAY 60-6583 (C and C′) are shown. Arrowheads indicate the hemogenic endothelial cells marked by sclβ:GFP+. Dashed lines mark the somite boundaries. (D–G) Expression of runx1/cmyb in the AGM of control embryos (D), embryos injected with A2b MO (E), and scl mRNA–injected (F) and A2b MO– and scl mRNA–co-injected embryos (G). The numbers are combined from multiple experiments. (H) Summary of the number of sclβ:GFP+ hemogenic endothelial cells per somite. The results are presented as mean ± SE (Student’s t test: *, P < 0.05; **, P < 0.01; n = 5–8 per group). (I) Quantification of the experiments in E and G. The results are presented as the mean percentage of embryos with runx1/cmyb staining as in G ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars, 100 µm.
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fig6: Adenosine signaling regulates hemogenic vascular endothelium. (A–C′) Confocal imaging of Tg(sclβ:d2eGFP; flk1:mcherry) embryos at 30 hpf. Control embryos (A and A′), embryos injected with A2b MO (B and B′), and embryos treated with 10 µM BAY 60-6583 (C and C′) are shown. Arrowheads indicate the hemogenic endothelial cells marked by sclβ:GFP+. Dashed lines mark the somite boundaries. (D–G) Expression of runx1/cmyb in the AGM of control embryos (D), embryos injected with A2b MO (E), and scl mRNA–injected (F) and A2b MO– and scl mRNA–co-injected embryos (G). The numbers are combined from multiple experiments. (H) Summary of the number of sclβ:GFP+ hemogenic endothelial cells per somite. The results are presented as mean ± SE (Student’s t test: *, P < 0.05; **, P < 0.01; n = 5–8 per group). (I) Quantification of the experiments in E and G. The results are presented as the mean percentage of embryos with runx1/cmyb staining as in G ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars, 100 µm.

Mentions: The abortive EHT of flk1:GFP cells could result from a lack of hemogenic potential in these cells. We then examined whether adenosine regulates HE specification, the onset of EHT. The master hematopoietic transcriptional regulator scl is critical for establishing the hematopoietic potential in aorta endothelial cells and plays its role before runx1 during definitive hematopoiesis. In zebrafish, an N-terminal truncated scl-β isoform is essential for HSPC emergence. The scl reporter line Tg(sclβ:d2eGFP) marks the hemogenic vascular endothelium, which is later transformed to HSPCs via EHT (Zhen et al., 2013). We altered adenosine signaling in Tg(sclβ:d2eGFP) embryos. In the absence of A2b, scl-β:GFP+ HE cell population was strongly reduced (1.6 ± 0.2/somite vs. 3.5 ± 0.3/somite [con]; Fig. 6, A–B′ and H). Addition of A2b receptor agonist BAY 60-6583 to wild-type embryos increased the number of scl-β:GFP+ in the AGM (4.6 ± 0.7/somite vs. 3.5 ± 0.5/somite [con]; Fig. 6, C, C′, and H). Overexpression of scl mRNA in zebrafish embryos partially rescued runx1+/cmyb+ HSPCs in A2b-deficient embryos (Fig. 6, D–G and I). These results indicate that adenosine signaling mediates scl+ hemogenic vascular endothelium. Together, our data suggest that adenosine mediates HSPC formation via regulation of hematopoietic commitment of endothelial cells.


Adenosine signaling promotes hematopoietic stem and progenitor cell emergence.

Jing L, Tamplin OJ, Chen MJ, Deng Q, Patterson S, Kim PG, Durand EM, McNeil A, Green JM, Matsuura S, Ablain J, Brandt MK, Schlaeger TM, Huttenlocher A, Daley GQ, Ravid K, Zon LI - J. Exp. Med. (2015)

Adenosine signaling regulates hemogenic vascular endothelium. (A–C′) Confocal imaging of Tg(sclβ:d2eGFP; flk1:mcherry) embryos at 30 hpf. Control embryos (A and A′), embryos injected with A2b MO (B and B′), and embryos treated with 10 µM BAY 60-6583 (C and C′) are shown. Arrowheads indicate the hemogenic endothelial cells marked by sclβ:GFP+. Dashed lines mark the somite boundaries. (D–G) Expression of runx1/cmyb in the AGM of control embryos (D), embryos injected with A2b MO (E), and scl mRNA–injected (F) and A2b MO– and scl mRNA–co-injected embryos (G). The numbers are combined from multiple experiments. (H) Summary of the number of sclβ:GFP+ hemogenic endothelial cells per somite. The results are presented as mean ± SE (Student’s t test: *, P < 0.05; **, P < 0.01; n = 5–8 per group). (I) Quantification of the experiments in E and G. The results are presented as the mean percentage of embryos with runx1/cmyb staining as in G ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars, 100 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4419349&req=5

fig6: Adenosine signaling regulates hemogenic vascular endothelium. (A–C′) Confocal imaging of Tg(sclβ:d2eGFP; flk1:mcherry) embryos at 30 hpf. Control embryos (A and A′), embryos injected with A2b MO (B and B′), and embryos treated with 10 µM BAY 60-6583 (C and C′) are shown. Arrowheads indicate the hemogenic endothelial cells marked by sclβ:GFP+. Dashed lines mark the somite boundaries. (D–G) Expression of runx1/cmyb in the AGM of control embryos (D), embryos injected with A2b MO (E), and scl mRNA–injected (F) and A2b MO– and scl mRNA–co-injected embryos (G). The numbers are combined from multiple experiments. (H) Summary of the number of sclβ:GFP+ hemogenic endothelial cells per somite. The results are presented as mean ± SE (Student’s t test: *, P < 0.05; **, P < 0.01; n = 5–8 per group). (I) Quantification of the experiments in E and G. The results are presented as the mean percentage of embryos with runx1/cmyb staining as in G ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars, 100 µm.
Mentions: The abortive EHT of flk1:GFP cells could result from a lack of hemogenic potential in these cells. We then examined whether adenosine regulates HE specification, the onset of EHT. The master hematopoietic transcriptional regulator scl is critical for establishing the hematopoietic potential in aorta endothelial cells and plays its role before runx1 during definitive hematopoiesis. In zebrafish, an N-terminal truncated scl-β isoform is essential for HSPC emergence. The scl reporter line Tg(sclβ:d2eGFP) marks the hemogenic vascular endothelium, which is later transformed to HSPCs via EHT (Zhen et al., 2013). We altered adenosine signaling in Tg(sclβ:d2eGFP) embryos. In the absence of A2b, scl-β:GFP+ HE cell population was strongly reduced (1.6 ± 0.2/somite vs. 3.5 ± 0.3/somite [con]; Fig. 6, A–B′ and H). Addition of A2b receptor agonist BAY 60-6583 to wild-type embryos increased the number of scl-β:GFP+ in the AGM (4.6 ± 0.7/somite vs. 3.5 ± 0.5/somite [con]; Fig. 6, C, C′, and H). Overexpression of scl mRNA in zebrafish embryos partially rescued runx1+/cmyb+ HSPCs in A2b-deficient embryos (Fig. 6, D–G and I). These results indicate that adenosine signaling mediates scl+ hemogenic vascular endothelium. Together, our data suggest that adenosine mediates HSPC formation via regulation of hematopoietic commitment of endothelial cells.

Bottom Line: A2b adenosine receptor activation induced CXCL8 via cAMP-protein kinase A (PKA) and mediated hematopoiesis.We further show that adenosine increased multipotent progenitors in a mouse embryonic stem cell colony-forming assay and in embryonic day 10.5 aorta-gonad-mesonephros explants.Our results demonstrate that adenosine signaling plays an evolutionary conserved role in the first steps of HSPC formation in vertebrates.

View Article: PubMed Central - HTML - PubMed

Affiliation: Stem Cell Program, Division of Hematology/Oncology, Boston Children's Hospital and Dana-Farber Cancer Institute, Boston, MA 02115 Harvard Stem Cell Institute, Howard Hughes Medical Institute, and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138.

Show MeSH
Related in: MedlinePlus