mRNA-seq analysis of RAGE knock-in (RageAHA/AHA) and RAGE-/- mice

Cell surface heparan sulfate (HS) plays an essential role in RAGE signaling by inducing RAGE oligomerization. To understand the physiological significance of HS-induced RAGE oligomerization in vivo, we generated RAGE knock-in mice (RageAHA/AHA) by introducing point mutations to specifically disrupt HS–RAGE interaction. The RAGE variant expressed by RageAHA/AHA mice demonstrated normal ligand-binding but greatly impaired capacity of HS-binding and oligomerization. To grasp the full scale of the alteration in gene expression caused by knocking out Rage, we performed a RNAseq analysis of mature neutrophils and lung from WT, RageAHA/AHA and Rage-/- mice. The overall number of differently regulated genes (DEGs) in Rage-/- neutrophils were almost 2.5 times higher than in RageAHA/AHA neutrophils (603 vs. 247). In contrast, the number of DEGs were much less in lungs compared to neutrophils in both strains (202 DEGs in Rage-/- lungs and merely 31 DEGs in RageAHA/AHA lungs), however the difference between the two genotypes was even more dramatic in lungs (7-fold) than we observed in neutrophils (2.5-fold). By comparing transcriptomes of neutrophils and lung tissues from RageAHA/AHA and Rage-/- mice, we present clear evidence that complete deficiency of RAGE had much broader impact on global gene expression compared to point mutations of RAGE. PMN and lung mRNA profiles of wild type (WT), RAGE knock-in (RageAHA/AHA) and RAGE-/- mice