Cilostazol enhances integrin‐dependent homing of progenitor cells by activation of camp‐dependent protein kinase in synergy with Epac1

Abstract

Recruitment and adhesion of exogenous endothelial progenitor cells (EPCs) or endogenously mobilized bone marrow mononuclear cells (BM MNCs) to the sites of ischemia is an important focus of cell therapy. This study sought to determine whether cilostazol enhances integrin-dependent homing of progenitor cells both in vitro and in vivo. In the in vitro experiments with human umbilical cord blood (HUCB)-derived EPCs, cilostazol (10 μM) stimulated up-regulation of integrins β1, α1, and αv as well as 8-pCPT-2'-O-Me-cAMP (100 μM; 8-pCPT, Epac activator). Cilostazol and 8-pCPT significantly enhanced migration and adhesion of HUCB EPCs to a fibronectin-coated plate and endothelial cells, which were inhibited by KT5720 (PKA inhibitor, 1 μM) and GGTI-298 (Rap1 inhibitor, 20 μM). Cilostazol stimulated Epac1 expression and up-regulated the active Rap1, as did 8-pCPT, and they were suppressed by KT5720 (P < 0.001) and GGTI-298 (P < 0.001). 8-pCPT increased p-CREB expression and stimulated PKA activity, which was inhibited by KT5720, Rp-cAMPS, and GGTI-298. In addition, N(6)-benzoyl-cAMP (100 μM) increased Rap1 GTP expression, as did 8-pCPT; they were suppressed by Rp-cAMPS and GGTI-298. The in vivo experiments showed that cilostazol (30 mg/kg/day, orally for 7 days) significantly enhanced the integrin β1 expression in the molecular layer and up-regulated homing of BM MNCs to the injured molecular layer with increased capillary density in mouse brain subjected to transient forebrain ischemia (n = 6, P < 0.001). In conclusion, cilostazol stimulated integrin expression and enhanced migration and adhesion of progenitor cells through cooperative activation of PKA and Epac signals; such activity may improve the efficacy of cell therapy for ischemic disease.

Cilostazol improves high glucose-induced impaired angiogenesis in human endothelial progenitor cells and vascular endothelial cells as well as enhances vasculoangiogenesis in hyperglycemic mice mediated by the adenosine monophosphate-activated protein kinase pathway

“…This is the first report indicating a pivotal role for AMPK in modulating the effects of cilostazol on EPCs. Previous studies conducted in glucose-free conditions have shown that cilostazol might produce beneficial effects to EPCs via activation of cAMP/PKA, 3,16 Akt/ eNOS, and mitogen-activated protein kinase pathways, 3 and by increasing the expression and secretion of some chemokines and their receptors capable of mobilizing bonemarrow derived stems cells. 15 Furthermore, our previous clinical study revealed that cilostazol could enhance mobilization and proliferation of EPCs and collateral formation by modifying vasculoangiogenic biomarkers in peripheral arterial disease.…”

“…3,8 Interestingly, the compound has been reported to have a number of additional effects, including protecting endothelial cells from apoptosis, 9 preventing monocyte adhesion to endothelial cells, 10,11 stimulating the release of angiogenic factors, 12 and activating endothelial NO synthase (eNOS) expression and NO release. 13,14 In addition, we and others have found that cilostazol may have beneficial effects on EPCs 3,15,16 and has vasculoangiogenic effects in a murine hind limb-ischemia model. 3 Furthermore, cilostazol has been reported to activate peroxisome proliferator-activated receptor-g, 17 and treatment with cilostazol is associated with marked cardiovascular benefits in patients with diabetes.…”

Combination of Cilostazol and <smlcap>L</smlcap>-Carnitine Improves Walking Performance in Peripheral Arterial Disease Model Rats

“…Recently, several studies have demonstrated the angiogenic effect of cilostazol, such as promoting endothelial progenitor cell migration [7] and angiogenesis [8] .…”

Loss of phosphodiesterase 4D mediates acquired triapine resistance via Epac-Rap1-Integrin signaling

“…Interestingly, the adhesion-mediating but also tumor-promoting functions of cAMP-Rap1 signaling have been repeatedly linked to its impact on integrin expression and activity [61, 62]. Therefore, we decided to investigate whether triapine resistance is based on integrin-mediated survival signaling.…”