TLR2/6-dependent stimulation by MALP-2 promotes angiogenesis in vitro as well as proliferation and migration of endothelial cells. (A) Pictures represent fluorescence of BCECF-AM-stained tube-like structures of HUVECs 24 hours after the administration of MALP-2 (1 μg/mL). Representative pictures are shown (Zeiss Axiovert 200M microscope, 20×/0.50 NA dry objective, Zeiss AxioCam MRc camera, AxiVision Version 4 software). (B) Quantification of the numbers (#) of tube-like structures of HUVECs. bFGF (100 ng/mL) was used as positive control. Unspecific IgG (50 μg/mL) was used as antibody control (n = 3-5). AB indicates antibody (25 μg/mL each). *P < .05, **P < .01 vs control. #P < .05 vs MALP-2. (C) Proliferation of HUVECs was determined by BrdU incorporation for 16 hours after stimulation with different concentrations of MALP-2 as indicated; 10% FCS was used as positive control (n = 6). *P < .05, **P < .01 vs control. (D) Migration of HUVECs (1 × 105) was carried out in transwell cell culture inserts for 24 hours after stimulation with different concentrations of MALP-2 as indicated; 10% FCS was used as positive control (n = 5-7). **P < .01 vs control. (E) Migration of HUVECs (1 × 105) was carried out in transwell cell culture inserts for 24 hours. As chemoattractant, supernatants from HUVECs after 24-hour stimulation with MALP-2 (1 μg/mL) were used and compared with control supernatant from unstimulated HUVECs (n = 5). *P < .05 vs control. (B-E) Error bars represent mean ± SEM.
