Haeme oxygenase promotes progenitor cell mobilization, neovascularization, and functional recovery after critical hindlimb ischaemia in mice.
OBJECTIVE
Neovascularization is an important element of long-term functional recovery during chronic ischaemia. We postulated that haeme oxygenase (HO) is required for progenitor cell recruitment, neovascularization, and blood flow recovery after critical hindlimb ischaemia (HLI).


RESULTS
The femoral artery was ligated in FVB/N mice proximal to its superficial and deep branches. Blood flow in the ischaemic hindlimb was determined by laser Doppler perfusion imaging. Capillary density was measured by isolectin staining, and mobilization of Sca-1(+)/Kdr(+) progenitor cells by FACS analysis. Progenitor cell recruitment to the ischaemic hindlimb was assessed after Tie2-lacZ transgenic bone marrow transplantation. Blood flow recovery after femoral artery ligation was significantly blunted in mice treated with the HO inhibitor tin protoporphyrin-IX (25 mg/kg i.p., every other day). HO-inhibited mice developed more pronounced limb necrosis, associated with impaired hindlimb motor function. Capillary density in the ischaemic hindlimb and mobilization of Sca-1(+)/Kdr(+) progenitor cells were significantly reduced after HO inhibition. After transplantation of Tie2-lacZ transgenic bone marrow cells into lethally irradiated wild-type mice, fewer LacZ(+) cells were detected in the ischaemic hindlimb muscle of HO-inhibited mice. Mechanistically, HO inhibition prevented the establishment of a stromal cell-derived factor-1 gradient for progenitor cell mobilization between the ischaemic hindlimb and bone marrow.


CONCLUSIONS
HOs are required for progenitor cell recruitment, neovascularization, and functional recovery after HLI.
Tongers
Jörn
J
Department of Cardiology and Angiology, Hannover University Medical School, 30625 Hannover, Germany.
Knapp
Julia-Marie
JM
Korf
Mortimer
M
Kempf
Tibor
T
Limbourg
Anne
A
Limbourg
Florian P
FP
Li
Zhixiong
Z
Fraccarollo
Daniela
D
Bauersachs
Johann
J
Han
Xiaoqiang
X
Drexler
Helmut
H
Fiedler
Beate
B
Wollert
Kai C
KC
D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D001783:Blood Flow Velocity; D016026:Bone Marrow Transplantation; D002196:Capillaries / Q000378:metabolism / Q000503:physiopathology; D002465:Cell Movement / Q000187:drug effects; D054377:Chemokine CXCL12 / Q000378:metabolism; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051547:Heme Oxygenase-1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006614:Hindlimb; D007511:Ischemia / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008665:Metalloporphyrins / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000098:blood supply*; D018919:Neovascularization, Physiologic / Q000187:drug effects; D011524:Protoporphyrins / Q000494:pharmacology; D042787:Receptor, TIE-2 / Q000235:genetics / Q000378:metabolism; D012039:Regional Blood Flow; D013234:Stem Cells / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D013997:Time Factors; D014463:Ultrasonography
D020533:Angiogenesis Inhibitors; D054377:Chemokine CXCL12; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D008665:Metalloporphyrins; D011524:Protoporphyrins; C032628:tin protoporphyrin IX; D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D042787:Receptor, TIE-2