Figure 4.

siRNA Internalization and Activity in Discrete Lung Cell Subpopulations

(A) FACS analysis of dissociated lung tissues before (total lung) and after separation into alveolar macrophages and dendritic cells (CD11c⁺), CD11c-depleted hematopoietic cells (CD45⁺), and non-hematopoietic cells (CD45^neg). AM, alveolar macrophages; D, dendritic cells; En, endothelial cells; Ep, epithelial cells. Numbers indicate percent of events gated in that area. (B) Plot represents Ctnnb1 mRNA in isolated cell subsets relative to Ppib mRNA control 72 h after 50 mg/kg siRNA intratracheal dosing. Numbers in the plot indicate Ctnnb1 mRNA knockdown relative to the respective PBS control. (C) siRNA content in isolated cell subsets was determined by stem-loop PCR. Lines indicate means ± SE. ****p < 0.0001 versus PBS-treated cell subset; ####p < 0.0001, #p < 0.05 versus total lung; †p < 0.05; n.s., not significant.