title: CCN1 secreted by tonsil-derived mesenchymal stem cells promotes endothelial cell angiogenesis via integrin αv β3 and AMPK.
abstract: CCN1 is highly expressed in cancer cells and has been identified in the secretome of bone marrow-derived mesenchymal stem cells (BM-MSC). Although secreted CCN1 is known to promote angiogenesis, its underlying mechanism remains unclear. Here, we examined whether our recently-established tonsil-derived MSC (T-MSC) secrete CCN1 and, if any, how CCN1 promotes the angiogenesis of human umbilical vein endothelial cells (HUVEC). Compared with untreated control T-MSC, a higher level of CCN1 was secreted by T-MSC treated with activin A and sonic hedgehog, drugs known to induce endodermal differentiation. Expectedly, conditioned medium collected from differentiated T-MSC (DCM) significantly increased HUVEC migration and tube formation compared with that from control T-MSC (CCM), and these stimulatory effects were reversed by neutralization with anti-CCN1 antibody. Treatment with recombinant human CCN1 (rh-CCN1) alone also mimicked the stimulatory effects of DCM. Furthermore, treatment with either DCM or rh-CCN1 increased the phosphorylation of AMP kinase (AMPK), and ectopic expression of siRNA of the AMPK gene inhibited all observed effects of both DCM and rh-CCN1. However, no alteration of intracellular ATP levels or phosphorylation of LKB1, a well-known upstream factor of AMPK activation, was observed under our conditions. Finally, the neutralization of integrin α(v) β(3) with anti-integrin α(v) β(3) antibody almost completely reversed the effects of CCN1 on AMPK phosphorylation, and EC migration and tube formation. Taken together, we demonstrated that T-MSC increase the secretion of CCN1 in response to endodermal differentiation and that integrin α(v) β(3) and AMPK mediate CCN1-induced EC migration and tube formation independent of intracellular ATP levels alteration.
authors.affiliation: Department of Molecular Medicine, School of Medicine, and Global Top 5 Research Program, Ewha Womans University, Mok-6-dong, Yangcheon-gu, Seoul 158-710, Republic of Korea.
authors.forename: Yoon Shin
authors.initials: YS
authors.lastname: Park
authors.forename: Soojin
authors.initials: S
authors.lastname: Hwang
authors.forename: Yoon Mi
authors.initials: YM
authors.lastname: Jin
authors.forename: Yeonsil
authors.initials: Y
authors.lastname: Yu
authors.forename: Sung-Ae
authors.initials: SA
authors.lastname: Jung
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Jung
authors.forename: Kyung-Ha
authors.initials: KH
authors.lastname: Ryu
authors.forename: Han Su
authors.initials: HS
authors.lastname: Kim
authors.forename: Inho
authors.initials: I
authors.lastname: Jo
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D028341:Activins / Q000494:pharmacology; D000906:Antibodies / Q000276:immunology; D001854:Bone Marrow Cells / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D055515:Cysteine-Rich Protein 61 / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D042783:Endothelial Cells / Q000378:metabolism; D053823:Hedgehog Proteins / Q000494:pharmacology; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology*; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000276:immunology; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D014066:Palatine Tonsil / Q000166:cytology*; D010766:Phosphorylation; D034622:RNA Interference; D034741:RNA, Small Interfering; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D014470:Umbilical Cord / Q000166:cytology
chemical_list: D000906:Antibodies; C501848:CCN1 protein, human; D017077:Culture Media, Conditioned; D055515:Cysteine-Rich Protein 61; D053823:Hedgehog Proteins; D039302:Integrin alphaVbeta3; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C422405:activin A; D028341:Activins; D055372:AMP-Activated Protein Kinases