Suppression of hepatocyte growth factor production impairs the ability of adipose-derived stem cells to promote ischemic tissue revascularization.
The use of adipose-derived stem/stromal cells (ASCs) for promoting repair of tissues is a promising potential therapy, but the mechanisms of their action are not fully understood. We and others previously demonstrated accelerated reperfusion and tissue salvage by ASCs in peripheral ischemia models and have shown that ASCs secrete physiologically relevant levels of hepatocyte growth factor (HGF) and vascular endothelial growth factor. The specific contribution of HGF to ASC potency was determined by silencing HGF expression. RNA interference was used to downregulate HGF expression. A dual-cassette lentiviral construct expressing green fluorescent protein (GFP) and either a small hairpin RNA specifically targeted to HGF mRNA (shHGF) or an inactive control sequence (shCtrl) were used to stably transduce ASCs (ASC-shHGF and ASC-shCtrl, respectively). Transduced ASC-shHGF secreted >80% less HGF, which led to a reduced ability to promote survival, proliferation, and migration of mature and progenitor endothelial cells in vitro. ASC-shHGF were also significantly impaired, compared with ASC-shCtrl, in their ability to promote reperfusion in a mouse hindlimb ischemia model. The diminished ability of ASCs with silenced HGF to promote reperfusion of ischemic tissues was reflected by reduced densities of capillaries in reperfused tissues. In addition, fewer GFP(+) cells were detected at 3 weeks in ischemic limbs of mice treated with ASC-shHGF compared with those treated with ASC-shCtrl. These results indicate that production of HGF is important for the potency of ASCs. This finding directly supports the emerging concept that local factor secretion by donor cells is a key element of cell-based therapies. Disclosure of potential conflicts of interest is found at the end of this article.
Cai
Liying
L
Indiana Center for Vascular Biology & Medicine, Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 975 W. Walnut Street IB 441, Indianapolis, Indiana 46202, USA.
Johnstone
Brian H
BH
Cook
Todd G
TG
Liang
Zhong
Z
Traktuev
Dmitry
D
Cornetta
Kenneth
K
Ingram
David A
DA
Rosen
Elliot D
ED
March
Keith L
KL
D017667:Adipocytes / Q000378:metabolism / Q000473:pathology; D000273:Adipose Tissue / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics; D005260:Female; D017228:Hepatocyte Growth Factor / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D006614:Hindlimb / Q000098:blood supply / Q000502:physiology; D006801:Humans; D007511:Ischemia / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D011897:Random Allocation; D013234:Stem Cells / Q000378:metabolism* / Q000473:pathology; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D014161:Transduction, Genetic
D017228:Hepatocyte Growth Factor