Cholesterol poses a cardiovascular risk once it becomes transformed into an inflammatory building block of artery-clogging plaque. That process, which happens all the time, is triggered by oxidation. A new study finds that breathing nanoscale particles spewed by diesel-fuel combustion—also a common occurrence—may turn on genes that multiply cholesterol's inflammatory and atherosclerotic risks.
André Nel of the David Geffen School of Medicine at the University of California, Los Angeles and his colleagues subjected cells from the lining of human arteries to oxidized cholesterol or diesel particulates. Some 2,500 genes changed their activity in response to both insults. Among this group, the researchers discerned what Nel calls "a genetic footprint" of heightened activity by genes whose activity promotes inflammation.
Pairing a low concentration of diesel particles with a high concentration of oxidized cholesterol ratcheted up the unwanted activity of s