Influence of endothelial Cx40 under atheroprone and atheroprotective flow

High laminar shear stress (HLSS), as observed in straight parts of arteries, assures a quiescent non-activated endothelium through the induction of the Krüppel-like transcription factors KLF2 and KLF4. Cx40-mediated gap junctional communication contributes to a healthy endothelium by propagating adenosine-evoked anti-inflammatory signals between endothelial cells. As the promoter of the Cx40 gene contains KLF consensus binding sites, we hypothesize that HLSS through the modulation of KLF4, may affect Cx40 expression in ECs, which may affect the quiescent non-activated state of the endothelium. Overall design: Mouse ECs (bEnd.3) were exposed to static conditions, high LSS (HLSS; 20 dynes/cm2), or oscillatory SS (OSS; 5 dynes/cm2, 1Hz) for 48 hours using an Ibidi flow system. Knock-down of KLF4 or Cx40 was performed using siRNA.

高层流切应力（High laminar shear stress, HLSS）存在于动脉直管段中，其可通过诱导Krüppel样转录因子（Krüppel-like transcription factors）KLF2与KLF4的表达，使血管内皮维持静息非活化状态。Cx40介导的间隙连接通讯可通过在血管内皮细胞间传递腺苷诱发的抗炎信号，助力维持健康的内皮状态。由于Cx40基因的启动子区域含有KLF结合共识序列，本研究推测HLSS可通过调控KLF4的表达，影响内皮细胞（endothelial cells, ECs）中Cx40的表达水平，进而改变内皮细胞的静息非活化状态。实验设计：使用Ibidi流体系统将小鼠内皮细胞系bEnd.3分别置于静态培养环境、高切应力（HLSS；20 dynes/cm²）以及振荡切应力（OSS；5 dynes/cm²，1Hz）中培养48小时，并通过小干扰RNA（siRNA）技术敲低KLF4或Cx40的表达。