Apolipoprotein E Negatively Regulates House Dust Mite-induced Asthma via a Low-Density Lipoprotein Receptor-mediated Pathway

摘要

Rationale. Distinct sets of corticosteroid-unresponsive genes modulate disease severity in asthma. Objectives: To identify corticosteroid-unresponsive genes that provide new insights into disease pathogenesis and asthma therapeutics. Methods: Experimental murine asthma was induced by nasal administration of house dust mite for 5 days per week. Dexametha-sone and apolipoprotein E (apo E) mimetic peptides were administered via osmotic minipumps. Measurements and Main Results: Cenome-wide expression profiling of the lung transcriptome in a house dust mite-induced model of murine asthma identified increases in apo E mRNA levels that persisted despite corticosteroid treatment. House dust mite-challenged apo E~(-/-) mice displayed enhanced airway hyperreactivity and goblet cell hyperplasia, which could be rescued by administration of an apo E(130-149) mimetic peptide. Administration of the apo E(130-149) mimetic peptide to house dust mite-challenged apo E~(-/-) mice also inhibited eosinophilic airway inflammation, IgE production, and the expression of Th2 and Th17 cytokines. House dust mite-challenged low-density lipoprotein receptor (LDLR) knockout mice displayed a similar phenotype as apo E~(-/-) mice with enhanced airway hyperreactivity, goblet cell hyperplasia, and mucin gene expression, but could not be rescued by the apo E(130-149) mimetic peptide, consistent with a LDLR-dependent mechanism. Conclusions: These findings for the first time identify an apo E-LDLR pathway as an endogenous negative regulator of airway hyperreactivity and goblet cell hyperplasia in asthma. Furthermore, our results demonstrate that strategies that activate the apo E-LDLR pathway, such as apo E mimetic peptides, might be developed into a novel treatment approach for patients with asthma.