Figure 5. BRG1 expression influences Mrtf transcription.

(A,B): Luciferase reporter constructs containing no promoter (negative control) or fragments of the Mrtfa (1.5 kb), Mrtfb (2.5 kb) or Srf (1.5 kb) promoters upstream of the respective transcription start sites were stably expressed in HEK293T cells. Stable lines were transfected with nonspecific control (NS) or BRG1 siRNA oligos (A) or with a BRG1 expression plasmid or its relevant empty vector control (B). Luciferase activity was measured 24 hr post-transfection and was normalized to activity from control samples. Error bars represent S.D. of results from three independent experiments (with triplicate samples). Statistical calculations were performed using a two-tailed Student’s t test (*, P<0.05). (C): C166 endothelial cells were transfected with nonspecific control or BRG1 siRNA oligos plus an empty vector (EV) or expression plasmids for murine MRTF-A, MRTF-B, and/or SRF for 24 hr. RNA was harvested, and qPCR was performed to detect expression of Brg1, Srf, β-actin, and Zo-1. Data shown represent BRG1 knockdown samples, which were normalized to the relative expression of control nonspecific knockdown samples (dotted line). Error bars represent S.D. of results from three independent experiments. Statistical calculations were performed using a one-way ANOVA comparing overexpression plasmid transfections against EV transfections for each transcript analyzed (*, P<0.05).