Therapeutic angiogenesis with intramuscular injection of low-dose recombinant granulocyte-colony stimulating factor.
OBJECTIVE
In vivo administration of granulocyte colony-stimulating factor (G-CSF) has been shown to facilitate regeneration of cardiovascular tissues. However, G-CSF causes marked leukocytosis that potentially induces adverse cardiovascular events. Earlier studies showed that G-CSF had direct stimulatory actions on mature endothelial cells, resulting in promotion of angiogenesis. We thus examined whether low doses of recombinant human G-CSF (rhG-CSF) locally injected into ischemic tissues would stimulate angiogenesis without inducing severe leukocytosis.


RESULTS
Reverse-transcription polymerase chain reaction (PCR) revealed expression of G-CSF receptor in human umbilical vein endothelial cells (HUVECs). rhG-CSF (100 ng/mL) enhanced migration and tube formation but not proliferation of HUVECs in vitro. We then examined the effects of rhG-CSF on angiogenesis in a rat model of hindlimb ischemia. Nude rats received in their ischemic skeletal muscles either rhG-CSF (2, 10, 20 microg/kg per day) or saline (control) for 6 days. Laser Doppler blood flowmetry (LDBF) revealed an augmented ischemic/normal limb LDBF ratio and an increased capillary density in the rhG-CSF-treated groups compared with the control at days 14, 21, and 28 (P<0.05). These doses of rhG-CSF induced only mild leukocytosis ( approximately 1.4-fold increases versus baseline).


CONCLUSIONS
rhG-CSF promoted endothelial migration and tube formation in vitro. Local injection of low doses rhG-CSF effectively augmented ischemia-induced angiogenesis in vivo. This treatment regimen of low-dose rhG-CSF may become a new and safe modality for therapeutic angiogenesis.
Lee
Mejeong
M
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Aoki
Mika
M
Kondo
Takahisa
T
Kobayashi
Koichi
K
Okumura
Kenji
K
Komori
Kimihiro
K
Murohara
Toyoaki
T
D000818:Animals; D002196:Capillaries / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D007511:Ischemia / Q000188:drug therapy* / Q000503:physiopathology*; D007958:Leukocyte Count; D008297:Male; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011923:Rats, Nude; D016188:Receptors, Granulocyte Colony-Stimulating Factor / Q000235:genetics; D011994:Recombinant Proteins; D014471:Umbilical Veins / Q000166:cytology; D014657:Vasculitis / Q000503:physiopathology
D012333:RNA, Messenger; D016188:Receptors, Granulocyte Colony-Stimulating Factor; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor