Figure 5.

Alteration in laminar flow invokes changes in mechanoreceptors such as monocilia and integrins, followed by activation of e.g., the Mek/Erk-Mef2 cascade. Mef2 activates nuclear expression of Klf2 thereby influencing Et-1, eNos, Vegf, Smads (particularly P-Smad2, and Smad4/7) and probably Pdgf-B. Upregulation of Klf2 by changes in laminar flow (but also by Angiopoietin-activation of the Tie2 receptor and by statins) involves down-regulation of most of the latter genes. It is interesting to note that oxidative stress and cytokine but also oscillatory flow not sensed by monocilia downregulate Klf2 expression. Data mainly based on [3,5,63,105].