Metabolic activity of OECs and adult stem cells culture in transwell systems and in monoculture. Metabolic activity of (A) adipose-derived adult stem cells (ASCs), (B) bone marrow mesenchymal stem cells (bmMSCs), and (C) human umbilical cord perivascular cells (HUCPVCs) in monoculture or in co-culture with OECs. Metabolic activity of OECs in monoculture or in co-culture with (D) ASCs, (E) bmMSCs, and (F) HUCPVCs. Values are shown as mean±standard deviation (n=3 samples of 2×104 adult stem cells and 1×105 OECs/sample, *P<0.05; **P<0.01; ***P<0.001).