Blocking H1R signal aggravates atherosclerosis by promoting inflammation and foam cell formation.

Abstract

Atherosclerosis (AS) is a chronic inflammatory arterialdisease, in which abnormal lipid metabolism and foam cell formation play key roles. Histamine is a vital biogenic amine catalyzed by histidine decarboxylase (HDC) from L-histidine. Histamine H1receptor (H1R)antagonist is a commonly encountered anti-allergic agent in theclinic. However, the role and mechanism of H1R in atherosclerosis have not been fully elucidated. Here, we explored the effect of H1R on atherosclerosis using ApolipoproteinE-knockout (ApoE-/-)mice with astemizole (AST, a long-acting H1R antagonist) treatment. The results showed that AST increased atherosclerotic plaque area and hepatic lipid accumulation in mice. The result of microarray study identified a significant change of endotheliallipase (LIPG) in CD11b+ myeloid cells derived from HDC-knockout (HDC-/-) mice compared to WT mice. Blocking H1R promoted the formation of foam cells from bone marrow-derived macrophages (BMDMs) of mice by up-regulating p38mitogen-activatedproteinkinase (p38 MAPK) and LIPG signalingpathway. Taken together, these findings demonstrate that blocking H1R signal aggravates atherosclerosis by promoting abnormal lipid metabolism and macrophage-derived foam cell formation via p38 MAPK-LIPG signalingpathway. KEY MESSAGES: Blocking H1R signal with AST aggravated atherosclerosis and increased hepatic lipid accumulation in high-fatdiet (HFD)-fed ApoE-/- mice. Blocking H1R signal promoted macrophage-derived foam cell formation via p38 MAPK-LIPG signalingpathway.