JNK Pathway-Associated Phosphatase Deficiency Facilitates Atherosclerotic Progression by Inducing T-Helper 1 and 17 Polarization and Inflammation in an ERK- and NF-κB Pathway-Dependent Manner.

Aim: JNK pathway-associated phosphatase (JKAP) regulates T cell-mediated immunity and inflammation, which are involved in atherosclerosis pathogenesis. This study investigated the effects of JKAP on T-helper (Th) cell polarization, inflammation, and atherosclerotic progression.

Methods: Serum JKAP levels were measured in 30 patients with coronary heart disease (CHD) and 30 controls. CHD blood naïve CD4^＋ T cells were acquired, followed by JKAP overexpression and knockdown with or without treatment with PD98059 (ERK inhibitor) or BAY-11-7082 (NF-κB inhibitor) in vitro. CD4^＋ T-cell conditional JKAP ablation mice were established in vivo, followed by the construction of an atherosclerosis model.

Results: JKAP was reduced and negatively correlated with the Gensini score, CRP, Th1 cells, Th17 cells, and proinflammatory cytokines in patients with CHD. In vitro, JKAP overexpression suppressed Th1 and Th17 cell differentiation and proinflammatory cytokines, whereas JKAP knockdown exerted the opposite effect; however, JKAP modification did not affect Th2 cell differentiation. Interestingly, JKAP negatively regulated the ERK and NF-κB pathways; meanwhile, the PD98059 and BAY-11-7082 treatments repressed Th1 and Th17 cell differentiation, and attenuated the effect of JKAP knockdown on these indices. In vivo, conditional CD4^＋ T-cell JKAP ablation increased Th1 and Th17 cell polarization in the spleen, lymph node, blood, and/or aortic root. Furthermore, CD4^＋ T-cell conditional JKAP ablation exaggerated atherosclerotic lesions in the aorta, elevated CD4⁺ cell infiltration and proinflammatory cytokines in the aortic root, and activated the ERK and NF-κB pathways in the aortic root.

Conclusion: JKAP ablation facilitates atherosclerosis progression by promoting Th1 and 17 polarization and inflammation through regulation of the ERK and NF-κB pathways.