The role of immunoglobulin E and mast cells in hypertension

Aims Hypertension is the major cause of cardiovascular diseases and global mortality. Immunoglobulin E (IgE), which plays crucial roles in allergic diseases, has been implicated in the pathogenesis of vascular and cardiac remodelling via its receptor (Fc epsilon R1). In this study, we aimed to reveal the role of IgE and Fc epsilon R1 in hypertension. Methods and results Herein, we reported that IgE levels were significantly increased in hypertensive patients as well as in hypertensive mice induced by angiotensin II (Ang II). Ang II-induced vascular remodelling and hypertension were significantly alleviated in Fc epsilon R1 genetic knockout mice or in mice treated with anti-IgE monoclonal antibody. Similarly, treatment with omalizumab (a clinical IgE antagonist) also markedly inhibited Ang II-induced hypertension. Furthermore, the cellular contribution of IgE-Fc epsilon R1 in hypertension was evaluated in mice with Fc epsilon R1 conditional knockout in mast cell (MC), smooth muscle cell (SMC), or endothelial cell (EC). Our data revealed that IgE-mediated hypertension is largely dependent on Fc epsilon R1 in MCs but not SMCs and ECs. Finally, RNA-seq and signalling pathway analyses of mouse bone marrow-derived MCs suggested that interleukin 6 (IL-6) is one of critical mediators in IgE-mediated hypertension. IL-6 derived from IgE-stimulated MCs promoted reactive oxygen species production and decreased the levels of phosphorylated endothelial nitric oxide synthase in ECs, leading to endothelial dysfunction. Conclusion Our findings reveal that IgE contributes to the pathogenesis of hypertension, at least partially through activating the IgE-Fc epsilon R1 signalling in MCs. Thus, IgE may represent a new therapeutic target for IgE-mediated hypertension.