In vivo cellular imaging pinpoints the role of reactive oxygen species in the early steps of adult hematopoietic reconstitution.
Few techniques are available to characterize in vivo the early cellular dynamics of long-term reconstitution of hematopoiesis after transplantation of hematopoietic stem cells (HSCs) after lethal irradiation. Using a fiber-optic imaging system, we track the early steps of in vivo recruitment and proliferation of Lin(-)Sca-1(+)c-Kit(+)CD34(-) (LSKCD34(-)) HSCs highly enriched in HSCs and transplanted into lethally irradiated mice. Recruitment of the transplanted LSKCD34(-) hematopoietic cells first occurs in the femoral head and is continuous during 24 hours. Quantification of the fluorescence emitted by the transplanted hematopoietic cells shows that proliferation of LSKCD34(-) hematopoietic cells in the femoral head was potent 3 days after transplantation. Using a development of this fiber-optic imaging system, we show that the transplanted LSKCD34(-) hematopoietic cells are associated with vascularized structures as early as 5 hours after transplantation. This early association is dependent on reactive oxygen species (ROS) partly through the regulation of vascular cell adhesion molecule-1 expression on endothelial cells and is followed by a ROS-dependent proliferation of LSKCD34(-) hematopoietic cells. This new in vivo imaging technique permits the observation of the early steps of hematopoietic reconstitution by HSCs in long bones and shows a new role of ROS in the recruitment of HSCs by bone marrow endothelial cells.
Laboratoire de recherche sur la Réparation et la Transcription dans les cellules Souches, France.
Daniel
D
Lewandowski
Vilma
V
Barroca
Frédéric
F
Ducongé
Jan
J
Bayer
Jeanne Tran
JT
Van Nhieu
Carine
C
Pestourie
Pierre
P
Fouchet
Bertrand
B
Tavitian
Paul-Henri
PH
Roméo
D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D000950:Antigens, Ly / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D005269:Femur / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D005336:Fiber Optic Technology / Q000379:methods; D006410:Hematopoiesis / Q000187:drug effects* / Q000502:physiology; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D057054:Molecular Imaging / Q000379:methods*; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000494:pharmacology*; D054928:Validation Studies as Topic; D014916:Whole-Body Irradiation
D018952:Antigens, CD34; D000950:Antigens, Ly; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; D019009:Proto-Oncogene Proteins c-kit