Caught in the act: In vivo molecular imaging of the transcription factor NF-κB after myocardial infarction

Nuclear factor κB (NF-κB) is a ubiquitous transcription factor activated by various stimuli implicated in heart failure progression. However, its activation in heart failure has not been well defined yet. Therefore, we investigated activation of NF-κB after myocardial infarction. For the first time, we performed serial, non-invasive in vivo molecular imaging of transcription factor activation in the heart. We used mice expressing a luciferase reporter whose transcription is dependent upon NF-κB activation for up to 8 weeks after myocardial infarction. There was a significant increase of NF-κB activity with a maximum at day 3 after myocardial infarction when compared to sham controls. Thus, in vivo measurement of the activation of NF-κB is feasible. NF-κB activity might play an important role for the remodeling process.