Figure 2.

Chronic Downregulation of Ubr-Ubiquitin Ligases in the Liver Induces Inflammation

Mice were treated with LNP-siRNA for 4 weeks, 2 times/week. The combined dose of LNP-siUbr siRNA was 0.3 mg/kg for Ubr1, -2, and -5 and 0.5 mg/kg for Ubr4, for a total of 1.4 mg/kg. Mice treated with LNP-siCtrl (luciferase) received 1.4 mg/kg. (A) mRNA and (B) protein levels of Ubr1, Ubr2, Ubr4, and Ubr5 in the liver of LNP-treated mice. Protein levels of UBR5 are undetectable in the liver. (C) Weight curve of animals treated with LNPs, measured before each injection and averaged for the group. Measures were compared as a percentage of change from day 0. (D) Analysis of cell death by the TUNEL assay in livers of LNP-treated mice. Red nuclei represent TUNEL-positive cells. Scale bar, 100 μm. p values were determined by a Mann-Whitney test (*p < 0.05). (E) H&E stain of mice treated with LNPs or vehicle. Scale bars, 200 μm (10 times) and 100 μm (20 times). (F) Representative flow cytometry analysis of neutrophil, macrophage, and eosinophil populations in the liver of mice treated with LNPs. (G) Percent of neutrophil, Ly6C^high macrophage, or eosinophil populations in the livers of LNP or vehicle-treated mice, gated on CD45⁺ cells. Results show mean ± SEM; n = 5 mice per group.