A novel vasculo-angiogenic effect of cilostazol mediated by cross-talk between multiple signalling pathways including the ERK/p38 MAPK signalling transduction cascade

Abstract

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.

The phosphodiesterase 3 inhibitor cilostazol does not stimulate growth of colorectal liver metastases after major hepatectomy

“…In line with this, Wang et al also demonstrated a decrease of VEGF expression by cilostazol in streptozotocin-induced diabetic inflammation [40]. In contrast, several recent studies could show a stimulation of VEGF expression upon cilostazol treatment, including conditions of hind limb ischemia [41,42] and transient forebrain ischemia [43]. The latter results are in line with the results of the present study, indicating an increased VEGF expression in livers of cilostazol-treated, hepatectomized animals.…”

“…Accordingly, several reports are published, demonstrating that a cilostazolinduced increase of VEGF expression is associated with an increased vascularization [41][42][43]. Surprisingly, our data indicate a reduction of tumor vessel density (density of PECAM-1-positive cells) after cilostazol treatment, despite an increased VEGF expression.…”

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

“…It is indicated for peripheral artery disease-related intermittent claudication. 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 …”

“…[1][2][3] Diabetes mellitus is a significant risk factor for the development of atherosclerotic diseases and an increase in cardiovascular mortality. 4 Hyperglycemia decreases nitric oxide (NO) production, 5 and reduces vasculoangiogenesis with resultant impaired function of endothelial progenitor cells (EPCs) and less flow recovery after hind limb ischemia.…”

“…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.…”