Suppression of ischemia in arterial occlusive disease by JNK-promoted native collateral artery development

Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. Collaterals are artery-to-artery or arteriole-to-arteriole interconnections that can bypass an occlusion by providing an alternative route for blood flow to the affected tissue. The increased flow and sheer stress initiate processes that result in the remodeling (arteriogenesis) of these vessels into efficient conductance arteries. Here we report that the mixed-lineage kinase (MLK) pathway activates cJun NH2-terminal kinase (JNK) in endothelial cells. Disruption of Mlk2/3 or Jnk1/2 genes caused severe blockade of blood flow and failure to recover in the femoral artery ligation model of hindlimb ischemia because of abnormal collateral arteries. We show that the MLK-JNK pathway is essential for patterning and maturation of collateral arteries during development, but this pathway is not required for angiogenesis or arteriogenesis in adults. JNK in endothelial cells promotes Delta-like 4-induced Notch signaling and suppresses excessive sprouting angiogenesis during development. This function of the MLK-JNK pathway contributes to normal formation of native collateral arteries. The MLK-JNK pathway is therefore a key regulatory mechanism for vascular development. These data highlight the crucial importance of the collateral circulation in the response to arterial occlusive diseases. Overall design: RNA-seq analysis of mouse lung endothelial cells (MLEC) of the following genotypes Cdh5-Cre+ Jnk1+/+ Jnk2+/+ Jnk3-/-(ECtrl), Cdh5-Cre- Jnk1LoxP/LoxP Jnk2LoxP/LoxP Jnk3-/- (EfCtrl), and Cdh5-Cre+ Jnk1LoxP/LoxP Jnk2LoxP/LoxP Jnk3-/- (E3KO). Three separate samples from mouse lung endothelial cells of each genotype were analyzed.

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Ramo K, Sugamura K, Craige S, Keaney JF, Davis RJ