Loss of E3 ubiquitin protein ligase Cbl-b provides protection against UVB-induced cytotoxicity and inflammation.. Mus musculus

The exposure of skin to ultraviolet (UV) radiation results in sunburn cell (SBC) and cyclobutane pyrimidine dimer (CPD) formation and local immune suppression. However, the pathways that regulate these events are poorly understood. Here, we exposed mice to UVB to study the early cytotoxic effects in absence of E3 ubiquitin protein ligase Cbl-b. We observed that Cbl-b-/- mice developed significantly less SBCs and CPDs compared to WT mice. In addition, microarray analysis revealed that loss of Cbl-b-induced cell tolerance genes rather than DNA repair genes. Taken together, our results suggest a novel role of Cbl-b in regulating UV cytotoxicity. Overall design: Samples of dorsal skin were collected from UV-exposed clb-b -/- (group 1) and wild type (group 2) mice 24 hours after exposure. The number of animals was 3 per experimental group.