Imaging Pulmonary NF-kappaB Activation and Therapeutic Effects of MLN120B and TDZD-8

NF-κBactivation is a critical signaling event in the inflammatory response and has been implicated in a number of pathological lung diseases. To enable the assessment of NF-κBactivity in the lungs, we transfected a luciferasebased NF-κBreporter into the lungs of mice or into Raw264.7 cells in culture. The transfected mice showed specific luciferaseexpression in the pulmonary tissues. Using these mouse models, we studied the kinetics of NF-κBactivation following exposure to lipopolysaccharide (LPS). The Raw264.7 cells expressed a dose-dependent increase in luciferasefollowing exposure to LPS and the NF-κBreporter mice expressed luciferasein the lungs following LPS challenge, establishing that bioluminescence imagingprovides adequate sensitivity for tracking the NF-κBactivation pathway. Interventions affecting the NF-κBpathway are promising clinical therapeutics, thus we further examined the effect of IKK-2 inhibition by MLN120B and glycogen synthasekinase 3 beta inhibition by TDZD-8 on NF-κBactivation. Pre-treatment with either MLN120B or TDZD-8 attenuated NF-κBactivation in the pulmonary tissues, which was accompanied with suppression of pro-inflammatory chemokine MIP-1s and induction of anti-inflammatory cytokine IL-10. In summary, we have established an imaging based approach for non-invasive and longitudinal assessment of NF-κBactivation and regulation during acute lung injury. This approach will potentiate further studies on NF-κBregulation under various inflammatory conditions.