Real-Time Monitoring of Intraplaque Furin in Atherosclerotic Mice during Pneumonia and Dexamethasone Treatment

Atherosclerotic plaque destabilization during acute infections such as pneumonia represents a critical clinical challenge, yet the underlying molecular dynamics remain poorly characterized. This study introduces a furin-responsive photoacoustic/fluorescence dual-modal probe (FRP) to investigate intraplaque furin activity in ApoE^-/^- mice with pneumonia-complicated atherosclerosis. The FRP, integrating photoacoustic and fluorescence imaging modalities, enabled comprehensive longitudinal monitoring of plaque furin dynamics both in vitro and in vivo. Notably, dexamethasone treatment effectively reduced plaque furin content, demonstrating the reversibility of this inflammatory response. Histopathological analysis confirmed that furin upregulation correlated with increased plaque inflammation, extracellular matrix degradation, and necrotic core expansion. These findings establish in vivo furin imaging as a valuable approach for elucidating the mechanistic links between systemic inflammation and plaque vulnerability and for evaluating therapeutic interventions aimed at plaque stabilization.