Figure 4. The loss of AREG and Egfr in pulmonary arterial endothelial cells recruits inflammatory myeloid cells into the lungs in hypoxic mice.

(A) Human pulmonary arterial endothelial cells were transfected with either scrambled siRNA (siCTL) or siRNA against AREG (siAREG) and placed in normoxic or hypoxic conditions. CCL1, CCL2, CXCL2, and CXCL3 expression was measured by qRT-PCR. (B) Cdh5^+/+ Egfr^fl/fl and Cdh5^cre/+ Egfr^fl/fl mice were placed in normoxic or hypoxic conditions for 21 d, and lungs were harvested. Cx3cr1, Ccr2, Ccr1, and Cxcr4 expression was assessed in whole lungs by qRT-PCR. (C, D, E, F) Number and frequency of alveolar macrophages (CD45⁺, CD11c⁺, CD103⁺, and CD64⁺) and monocytes (CD45⁺, Siglec F⁻, CD11b⁺, MHC-II⁻, and CD64⁻) were assessed in the lungs (C, D) and blood (E, F) of hypoxic Cdh5^+/+ Egfr^fl/fl and Cdh5^cre/+ Egfr^fl/fl mice by flow cytometry. (A, B, C, D, E, F) n = 5 replicates (A) and 5 mice (B, C, D, E, F) per condition. Data are shown as mean. *P < 0.05, **P < 0.01, ***P < 0.005, ****P < 0.001.