Regulation of endothelial cell and endothelial progenitor cell survival and vasculogenesis by integrin-linked kinase.
OBJECTIVE
New vessel formation is a dynamic process of attachment, detachment, and reattachment of endothelial cells (ECs) and endothelial progenitor cells (EPCs) with each other and with the extracellular matrix (ECM). Integrin-linked kinase (ILK) plays a pivotal role in ECM-mediated signaling. Therefore, we investigated the role of ILK in ECs and EPCs during neovascularization.


RESULTS
In human umbilical cord vein ECs and EPCs, endogenous ILK expression, along with subsequent cell survival signals phospho-Akt and phospho-glycogen synthase kinase 3beta, was reduced after anchorage or nutrient deprivation. Even brief anchorage deprivation resulted in retarded capillary tube formation by ECs. Adenoviral ILK gene transfer in ECs and EPCs reversed the decrease in cell survival signals after anchorage or nutrient deprivation, leading to enhanced survival, reduced apoptosis, and significantly accelerated the functional recovery after reattachment. And ILK overexpressing EPCs significantly improved blood flow recovery and prevented limb loss in nude mice hindlimb ischemia model. Furthermore, the efficacy of systemic delivery was equivalent to local injection of ILK-EPCs.


CONCLUSIONS
ILK overexpression protects ECs and EPCs from anchorage- or nutrient-deprived stress and enhances neovascularization, suggesting that ILK is an optimal target gene for genetically modified cell-based therapy. Neovascularization is a dynamic process of detachment and reattachment of ECs and EPCs. Endogenous ILK expression was decreased in various stress conditions, and the gene transfer of ILK protected ECs and EPCs from temporary anchorage or nutrient deprivation. Furthermore, ILK gene transfer in EPCs significantly enhanced neovascularization in vivo.
Cho
Hyun-Jai
HJ
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Youn
Seock-Won
SW
Cheon
Soo-In
SI
Kim
Tae-Youn
TY
Hur
Jin
J
Zhang
Shu-Ying
SY
Lee
Seung Pyo
SP
Park
Kyung-Woo
KW
Lee
Myoung-Mook
MM
Choi
Yun-Shik
YS
Park
Young-Bae
YB
Kim
Hyo-Soo
HS
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology* / Q000201:enzymology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D018014:Gene Transfer Techniques; D006801:Humans; D007511:Ischemia / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013234:Stem Cells / Q000166:cytology* / Q000201:enzymology*; D014471:Umbilical Veins / Q000166:cytology; D000099200:Scaffold Protein ILK
D017346:Protein Serine-Threonine Kinases; D000099200:Scaffold Protein ILK