VEGF controls lung Th2 inflammation via the miR-1–Mpl (myeloproliferative leukemia virus oncogene)–P-selectin axis

S Takyar, H Vasavada, J Zhang, F Ahangari… - Journal of Experimental …, 2013 - rupress.org
S Takyar, H Vasavada, J Zhang, F Ahangari, N Niu, Q Liu, CG Lee, L Cohn, JA Elias
Journal of Experimental Medicine, 2013rupress.org
Asthma, the prototypic Th2-mediated inflammatory disorder of the lung, is an emergent
disease worldwide. Vascular endothelial growth factor (VEGF) is a critical regulator of
pulmonary Th2 inflammation, but the underlying mechanism and the roles of microRNAs
(miRNAs) in this process have not been defined. Here we show that lung-specific
overexpression of VEGF decreases miR-1 expression in the lung, most prominently in the
endothelium, and a similar down-regulation occurs in lung endothelium in Th2 inflammation …
Asthma, the prototypic Th2-mediated inflammatory disorder of the lung, is an emergent disease worldwide. Vascular endothelial growth factor (VEGF) is a critical regulator of pulmonary Th2 inflammation, but the underlying mechanism and the roles of microRNAs (miRNAs) in this process have not been defined. Here we show that lung-specific overexpression of VEGF decreases miR-1 expression in the lung, most prominently in the endothelium, and a similar down-regulation occurs in lung endothelium in Th2 inflammation models. Intranasal delivery of miR-1 inhibited inflammatory responses to ovalbumin, house dust mite, and IL-13 overexpression. Blocking VEGF inhibited Th2-mediated lung inflammation, and this was restored by antagonizing miR-1. Using mRNA arrays, Argonaute pull-down assays, luciferase expression assays, and mutational analysis, we identified Mpl as a direct target of miR-1 and showed that VEGF controls the expression of endothelial Mpl during Th2 inflammation via the regulation of miR-1. In vivo knockdown of Mpl inhibited Th2 inflammation and indirectly inhibited the expression of P-selectin in lung endothelium. These experiments define a novel VEGF–miR-1–Mpl–P-selectin effector pathway in lung Th2 inflammation and herald the utility of miR-1 and Mpl as potential therapeutic targets for asthma.
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