Figure 2.

S1PR1 is required for HLMVEC migration in response to impinging flow. (a) HLMVECs treated with 1 µM W146 do not migrate against the flow direction in response to impinging flow. Live cell image at t = 20 h near the jet centre. The migration trajectories of five cells are shown as coloured lines, starting at t = 0 with the dot indicating its final location at t = 20 h. Scale bar, 100 µm. (b) Box-and-whisker plots showing the radial migration distance of tracked cells that were untreated (−) or treated with 1 µM W146 (+), binned by initial starting position in response to 20 h of impinging flow at a maximum WSS of 9 dynes cm⁻². Here, a positive migration distance indicates migration away from the jet centre, while negative migration distance indicates migration towards the jet centre. N = 200 cells per condition, taken from two independent experiments. (c) HLMVECs treated with siRNA for S1PR1 do not migrate against the flow direction in response to impinging flow. Live cell image at t = 20 h around the jet centre. The migration trajectories of five cells are shown as coloured lines, starting at t = 0 with the dot indicating its final location at t = 20 h. Scale bar, 100 µm. (d) Relative S1PR1 mRNA expression (referenced to scrambled siRNA control) for HLMVECs after 24 and 48 h. (e) Box-and-whisker plots showing the radial migration distance of tracked cells both treated with scrambled siRNA (−) and treated with siRNA targeting S1PR1 (+), binned by initial starting position in response to 20 h of impinging flow at a maximum WSS of 9 dynes cm⁻². N = 200 cells per condition, taken from two independent experiments.