title: 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.
authors.affiliation: Medical Research Center for Ischemic Tissue Regeneration, Department of Pharmacology, School of Medicine, Pusan National University, Yangsan-si, Gyeongsangnam-do, Korea.
authors.forename: Dong Hyung
authors.initials: DH
authors.lastname: Lee
authors.forename: Hye Rin
authors.initials: HR
authors.lastname: Lee
authors.forename: Hwa Kyoung
authors.initials: HK
authors.lastname: Shin
authors.forename: So Youn
authors.initials: SY
authors.lastname: Park
authors.forename: Ki Whan
authors.initials: KW
authors.lastname: Hong
authors.forename: Eun Kyoung
authors.initials: EK
authors.lastname: Kim
authors.forename: Sun Sik
authors.initials: SS
authors.lastname: Bae
authors.forename: Won Suk
authors.initials: WS
authors.lastname: Lee
authors.forename: Byung Yong
authors.initials: BY
authors.lastname: Rhim
authors.forename: Chi Dae
authors.initials: CD
authors.lastname: Kim
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects* / Q000502:physiology; D000077407:Cilostazol; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004195:Disease Models, Animal; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D019012:Integrin beta1 / Q000502:physiology*; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D013777:Tetrazoles / Q000494:pharmacology* / Q000627:therapeutic use; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: C482601:Epac protein, mouse; D020662:Guanine Nucleotide Exchange Factors; D019012:Integrin beta1; D018696:Neuroprotective Agents; D047428:Protein Kinase Inhibitors; D013777:Tetrazoles; D017868:Cyclic AMP-Dependent Protein Kinases; D000077407:Cilostazol