Fig. 2.

Quantification of human growth factor secretions expressed in the culture of FM and BM of hUC-MSC. A. The culture medium of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in the flask is “FM” and that of hUC-MSCs in the bioreactor is “BM.” Cytokines released from hUC-MSCs's conditioned media (FM and BM) were detected using the RayBio C-Series human growth factor antibody kit. Cytokines are spotted and those released from conditioned media appear as black dots. Each antibody was spotted in duplicate. Of the total 41 cytokines, 18 cytokines with significant differences in expression between FM and BM were selected (red box). All 41 antibodies were more strongly expressed in BM than in FM. Among them: blue box – positive spot (controlled amount of biotinylated antibody printed of non-specific onto the array; used for normalization and to orientate the arrays); green box – negative spot (no antibodies used to measure the baseline responses; used for determining the level binding of the samples); red box – 1: AR, 2: bFGF, 3: EGF, 4: GDNF, 5: HGF, 6: IGFBP-4, 7: IGFBP-6, 8: IGF-1, 9: IGF-1R, 10: M-CSFR, 11: NT-4, 12: PDGFR-beta, 13: PDGF-AA, 14: SCRF, 15: TGF-beta2, 16: TGF-beta3, 17: VEGFR3, 18: VEGF-D. Cytokines presenting a detectable black spot signal are indicated. The human growth factor antibody array was used to detect paracrine effect in hUC-MSCs-conditioned media in FM (left panel) and BM (right panel). B. The result confirmed that 18 cytokines, which had a significant impact on stem cell growth, were more strongly expressed in BM than in FM. The control has nothing in it. Experiments were performed in triplicate. The experimental significance was determined by Student's t-test. Significantly differences between FM and BM were evaluated at ∗P < 0.05; ∗∗P < 0.01; and ∗∗∗P < 0.001.