Angiogenesis induced by the injection of peripheral leukocytes and platelets.
BACKGROUND
Peripheral leukocytes and platelets (LAPs) contain many kinds of cells with the ability to secrete several growth factors and cytokines. We attempted to induce therapeutic angiogenesis by injecting self-LAPs into a rat ischemic hindlimb model.


METHODS
Supernatants from cultured LAPs were used for the endothelial cell (EC) proliferation assay, and LAPs were used in a cornea model to evaluate angiogenic potency. LAPs were injected directly into the male Dark Agouti rat ischemic hindlimb model, after which a microangiogram was done and the capillary/muscle fiber ratio was examined histologically. ELISA revealed the levels of contributing growth factors and cytokines present in the ischemic muscles.


RESULTS
The EC proliferation assay showed that the supernatants of LAPs accelerated proliferation and that the LAPs induced angiogenesis in the cornea model. The microangiograms and histological evaluation revealed that angiogenesis was induced more effectively in the rats injected with LAPs (LAP group) than in the those injected with phosphate-buffered saline (PBS group). The levels of basic fibroblast growth factor (bFGF) in the ischemia, PBS, and LAP groups were significantly increased compared to those in the sham group. The level of interleukin-1beta (IL-1beta) in the LAP group was significantly more elevated than in the other groups.


CONCLUSIONS
The injection of self-LAPs induced angiogenesis in a rat ischemic hindlimb model. Ischemia caused an elevation in the level of bFGF and also in IL-1beta derived from LAPs, which contributed to angiogenesis. This is a novel, yet simple and safe method of inducing therapeutic angiogenesis.
Kobayashi
Toshiro
T
First Department of Surgery, School of Medicine, Yamaguchi University, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan.
Hamano
Kimikazu
K
Li
Tao-Sheng
TS
Nishida
Masahiko
M
Ikenaga
Shigeru
S
Hirata
Ken
K
Zempo
Nobuya
N
Esato
Kensuke
K
D000818:Animals; D001792:Blood Platelets / Q000166:cytology / Q000502:physiology*; D002455:Cell Division; D017690:Cell Transplantation; D003315:Cornea / Q000098:blood supply; D017077:Culture Media, Conditioned; D016228:Endothelial Growth Factors / Q000032:analysis; D004730:Endothelium, Vascular / Q000166:cytology; D004797:Enzyme-Linked Immunosorbent Assay; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D006614:Hindlimb / Q000098:blood supply; D007375:Interleukin-1 / Q000032:analysis; D007511:Ischemia / Q000378:metabolism / Q000473:pathology; D007962:Leukocytes / Q000166:cytology / Q000502:physiology*; D008222:Lymphokines / Q000032:analysis; D008297:Male; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000098:blood supply / Q000737:chemistry; D018919:Neovascularization, Physiologic; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D017077:Culture Media, Conditioned; D016228:Endothelial Growth Factors; D007375:Interleukin-1; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2