Fig. 1

HUVEC culture system consisted of HUVECs seeded on surface of six-well culture plate in complete HUVEC culture medium alone (untreated HUVECs) (a), or with 100 mM glucose (b), or with 100 mM glucose and 25% conditioned medium (CM) obtained from unstimulated pMSCs (c), and ICpMSC (intercellular direct contact experiment) culture system consisted of pMSCs seeded on reverse side of membrane of chamber and HUVECs seeded on upper side of membrane (d). For ICpMSC, 0.4-μm pore size transwell chamber membranes were used. In ICpMSC culture system, cells cultured at a ratio of 1 HUVEC:1 pMSC in HUVEC culture medium in presence of 100 mM glucose. In all culture systems, cells incubated for 24, 48, and 72 h at 37 °C in a cell culture incubator. CMpMSC conditioned medium of unstimulated pMSCs, HUVEC human umbilical vein endothelial cell, pMSC placental mesenchymal stem cell