MPTAG restores PKA activity in TNFα-stimulated HUVECs.

<p>(A) The cells were treated with media (control), MPTAG, SQ 22536, H-89 or their indicated combinations in absence and presence of TNF-α stimulation. PKA activity was assessed in the cell lysates. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046528#s2" target="_blank">Results</a> are expressed as mean ± sem of three independent experiments. *p<0.05 vs. control. <b>Proposed model of MPTAG action in TNF-α-stimulated HUVECs.</b> (B) In TNF-α-stimulated HUVECs (without MPTAG treatment), PI-3K-regulated Akt is activated (indicated by solid line arrow) resulting in NF-κB activation. On the other hand, PKA activity remained repressed (indicated by broken line arrow) under these conditions. (C) MPTAG pretreatment to TNF-α-stimulated HUVECs restored the repressed activity of PKA. Thus, derepression of PKA activity resulted in inhibition of Akt and overall inhibition of NF-κB in these cells.