Angiogenic cytokines produced by MACs. (A) A human angiogenesis proteome profiler array was used to identify soluble factors released by cells to the medium. RMECs secrete minimal amounts of ET-1, and medium from a MAC and RMEC coculture system showed significant expression of proangiogenic proteins such as MMP-9, IL-8, and MCP-1. Three pairs of positive controls are included in the top corners and bottom left corner. A pair of negative control spots in the bottom right corner indicates very low background levels. (B) IL-8 proteome array assessment of conditioned media of RMECs, MACs and RMECs + MACs. (C) Quantification of proteome profiler shown in (B) by densitometry (O. D., optical density); N = 6. (D) ELISA quantification of IL-8 in conditioned media of RMECs, MACs and RMECs + MACs. N = 4. Data in (C) and (D) expressed as mean ± SEM. ***P < 0.001 versus RMECs; *P < 0.05 versus RMECs; ns, not significant.