Limits...
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.

Show MeSH

Related in: MedlinePlus

Adenosine signaling is required for EHT in zebrafish. (A and B) Still images from in vivo time-lapse confocal imaging of Tg(flk1:GFP) embryos between 32 and 48 hpf. Embryos are either uninjected (A) or injected with A2b MO (B). Numbers indicate recording time in hours and minutes. Arrows in A point to three aorta cells undergoing successful EHT. Cells 2a and 2b are the daughter cells of cell 2. The two dorsal aorta cells 1′ and 2′ in B initiate EHT and burst into pieces (marked by circles). (C) Quantification of the number of flk1:GFP+ cells per somite undergoing burst during the 16-h time-lapse period. The results are presented as mean ± SE (Student’s t test: **, P < 0.01; n = 6–8 embryos per group). (D) Tg(hsp70:runx1) embryos stained for runx1 without heat shock (HS) induction or after heat shock induction. (E–H) Expression of cmyb at 36 hpf in Tg(hsp70:runx1) embryos. Embryos were either uninjected (E and F) or injected with A2b MO (G and H). Embryos either received no heat shock treatment (E and G) or received heat shock induction (F and H). The numbers are combined from multiple experiments. (I) Quantification of the experiments in G and H. The results are presented as the mean percentage of embryos with rescued cmyb staining as in H ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars: (A and B) 50 µm; (D) 250 µm; (E–H) 100 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4419349&req=5

fig5: Adenosine signaling is required for EHT in zebrafish. (A and B) Still images from in vivo time-lapse confocal imaging of Tg(flk1:GFP) embryos between 32 and 48 hpf. Embryos are either uninjected (A) or injected with A2b MO (B). Numbers indicate recording time in hours and minutes. Arrows in A point to three aorta cells undergoing successful EHT. Cells 2a and 2b are the daughter cells of cell 2. The two dorsal aorta cells 1′ and 2′ in B initiate EHT and burst into pieces (marked by circles). (C) Quantification of the number of flk1:GFP+ cells per somite undergoing burst during the 16-h time-lapse period. The results are presented as mean ± SE (Student’s t test: **, P < 0.01; n = 6–8 embryos per group). (D) Tg(hsp70:runx1) embryos stained for runx1 without heat shock (HS) induction or after heat shock induction. (E–H) Expression of cmyb at 36 hpf in Tg(hsp70:runx1) embryos. Embryos were either uninjected (E and F) or injected with A2b MO (G and H). Embryos either received no heat shock treatment (E and G) or received heat shock induction (F and H). The numbers are combined from multiple experiments. (I) Quantification of the experiments in G and H. The results are presented as the mean percentage of embryos with rescued cmyb staining as in H ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars: (A and B) 50 µm; (D) 250 µm; (E–H) 100 µm.

Mentions: It is known that HSCs originate from HE via EHT. Recent time-lapse imaging studies have directly captured the emergence of HSPCs from flk1:GFP+ aortic endothelial cells in live zebrafish embryos (Bertrand et al., 2010; Kissa and Herbomel, 2010). To examine whether adenosine regulates the EHT, we injected A2b MO into Tg(fk1l:GFP) embryos and used time-lapse imaging to track the formation of HSPCs between 32 and 60 hpf, as previously described (Kissa and Herbomel, 2010). As shown in Fig. 5 and Videos 1 and 2, in A2b-deficient embryos, flk1:GFP+ endothelial cells initiated bending, and sometimes contraction, normally, albeit more rarely than in control embryos. We noticed that as the flk1:GFP+ cells rounded up to become HSCs, a subset of these cells burst into small cellular pieces (Fig. 5, A–C). The bursting is very similar to the events seen in runx1-deficient embryos, in which the EHT event of flk1:GFP+ cells abort into cell death (Kissa and Herbomel, 2010). These results suggested that adenosine signaling is required to achieve successful EHT.


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 is required for EHT in zebrafish. (A and B) Still images from in vivo time-lapse confocal imaging of Tg(flk1:GFP) embryos between 32 and 48 hpf. Embryos are either uninjected (A) or injected with A2b MO (B). Numbers indicate recording time in hours and minutes. Arrows in A point to three aorta cells undergoing successful EHT. Cells 2a and 2b are the daughter cells of cell 2. The two dorsal aorta cells 1′ and 2′ in B initiate EHT and burst into pieces (marked by circles). (C) Quantification of the number of flk1:GFP+ cells per somite undergoing burst during the 16-h time-lapse period. The results are presented as mean ± SE (Student’s t test: **, P < 0.01; n = 6–8 embryos per group). (D) Tg(hsp70:runx1) embryos stained for runx1 without heat shock (HS) induction or after heat shock induction. (E–H) Expression of cmyb at 36 hpf in Tg(hsp70:runx1) embryos. Embryos were either uninjected (E and F) or injected with A2b MO (G and H). Embryos either received no heat shock treatment (E and G) or received heat shock induction (F and H). The numbers are combined from multiple experiments. (I) Quantification of the experiments in G and H. The results are presented as the mean percentage of embryos with rescued cmyb staining as in H ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars: (A and B) 50 µm; (D) 250 µm; (E–H) 100 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4419349&req=5

fig5: Adenosine signaling is required for EHT in zebrafish. (A and B) Still images from in vivo time-lapse confocal imaging of Tg(flk1:GFP) embryos between 32 and 48 hpf. Embryos are either uninjected (A) or injected with A2b MO (B). Numbers indicate recording time in hours and minutes. Arrows in A point to three aorta cells undergoing successful EHT. Cells 2a and 2b are the daughter cells of cell 2. The two dorsal aorta cells 1′ and 2′ in B initiate EHT and burst into pieces (marked by circles). (C) Quantification of the number of flk1:GFP+ cells per somite undergoing burst during the 16-h time-lapse period. The results are presented as mean ± SE (Student’s t test: **, P < 0.01; n = 6–8 embryos per group). (D) Tg(hsp70:runx1) embryos stained for runx1 without heat shock (HS) induction or after heat shock induction. (E–H) Expression of cmyb at 36 hpf in Tg(hsp70:runx1) embryos. Embryos were either uninjected (E and F) or injected with A2b MO (G and H). Embryos either received no heat shock treatment (E and G) or received heat shock induction (F and H). The numbers are combined from multiple experiments. (I) Quantification of the experiments in G and H. The results are presented as the mean percentage of embryos with rescued cmyb staining as in H ± SE (Student’s t test: *, P < 0.05; n = 3 experiments, around 20 embryos per experiment). Bars: (A and B) 50 µm; (D) 250 µm; (E–H) 100 µm.
Mentions: It is known that HSCs originate from HE via EHT. Recent time-lapse imaging studies have directly captured the emergence of HSPCs from flk1:GFP+ aortic endothelial cells in live zebrafish embryos (Bertrand et al., 2010; Kissa and Herbomel, 2010). To examine whether adenosine regulates the EHT, we injected A2b MO into Tg(fk1l:GFP) embryos and used time-lapse imaging to track the formation of HSPCs between 32 and 60 hpf, as previously described (Kissa and Herbomel, 2010). As shown in Fig. 5 and Videos 1 and 2, in A2b-deficient embryos, flk1:GFP+ endothelial cells initiated bending, and sometimes contraction, normally, albeit more rarely than in control embryos. We noticed that as the flk1:GFP+ cells rounded up to become HSCs, a subset of these cells burst into small cellular pieces (Fig. 5, A–C). The bursting is very similar to the events seen in runx1-deficient embryos, in which the EHT event of flk1:GFP+ cells abort into cell death (Kissa and Herbomel, 2010). These results suggested that adenosine signaling is required to achieve successful EHT.

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