Mesenchymal stem cell-based gene therapy with prostacyclin synthase enhanced neovascularization in hindlimb ischemia.
OBJECTIVE
Bone marrow cell therapy contributes to collateral formation through the secretion of angiogenic factors by progenitor cells and muscle cells per se, thereby presenting a novel option for patients with critical limb ischemia. However, some cases are refractory to this therapy due to graft failure. Therefore, we used genetic modification of mesenchymal stem cells (MSCs) to overexpress a vasoregulatory protein, prostacyclin (PGI(2)), to examine whether it could enhance engraftment and neovascularization in hindlimb ischemia.


RESULTS
We engineered the overexpression of PGI(2) synthase (PGIS) within MSCs, which resulted in higher expression levels of phosphorylated Akt and Bcl-2 than in control. Under hypoxic conditions, the overexpression of PGIS led to upregulated expression of cyclooxigenase-2 and peroxisome proliferator-activated receptor delta, following a 40% increased rate of proliferation in MSCs. We then produced unilateral hindlimb ischemia in C57BL6/J mice, which were injected either with MSCs transfected with GFP, with MSCs overexpressing PGIS, or with vehicle. Laser Doppler analyses demonstrated that the administration of MSCs effectively recovered blood perfusion, and that the peak blood flow was reached within 7 days of surgery in mice with MSCs overexpressing PGIS, which was earlier than that in mice with MSCs transfected with GFP. This beneficial effect was correlated to enhanced collateral formation and muscle bundle proliferation.


CONCLUSIONS
Sustained release of PGI(2) enhanced the proangiogenic function of MSCs and subsequent muscle cell regrowth in the ischemic tissue suggesting potential therapeutic benefits of cell-based gene therapy for critical limb ischemia.
Department of Medical Science of Proteases, Nagoya University School of Medicine, Nagoya, Japan.
Masakazu
M
Ishii
Yasushi
Y
Numaguchi
Kenji
K
Okumura
Ryuji
R
Kubota
Xiuyang
X
Ma
Ryuichiro
R
Murakami
Keiji
K
Naruse
Toyoaki
T
Murohara
D000818:Animals; D049109:Cell Proliferation; D003577:Cytochrome P-450 Enzyme System / Q000627:therapeutic use*; D015316:Genetic Therapy; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000627:therapeutic use*; D007511:Ischemia / Q000628:therapy; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018919:Neovascularization, Physiologic / Q000235:genetics / Q000502:physiology*; D047494:PPAR delta / Q000235:genetics
D047494:PPAR delta; D003577:Cytochrome P-450 Enzyme System; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase