Vascular macrophages can sense octanal, triggering dangerous inflammation and atherosclerosis

Amazing stuff! If you can smell it, you can treat it?

"... The new study, published in Science, shows that this inflammation can lead to cardiovascular disease and atherosclerosis in mice. The researchers reversed this inflammation by blocking immune cells called macrophages from sensing a compound called octanal. ...
Everyone has a small amount of octanal in their blood, but LJI scientists have shown that people with markers of cardiovascular disease, such as high LDL cholesterol, also have higher levels of octanal. This extra octanal can end up in blood due to diet or a phenomenon in cells called oxidative stress. ..."

"... vascular macrophages involved in the pathogenesis of atherosclerosis express multiple subtypes of olfactory receptors. ..."

From the abstract:

"Atherosclerosis is an inflammatory disease of the artery walls and involves immune cells such as macrophages. Olfactory receptors (OLFRs) are G protein–coupled chemoreceptors that have a central role in detecting odorants and the sense of smell. We found that mouse vascular macrophages express the olfactory receptor Olfr2 and all associated trafficking and signaling molecules. Olfr2 detects the compound octanal, which activates the NLR family pyrin domain containing 3 (NLRP3) inflammasome and induces interleukin-1β secretion in human and mouse macrophages. We found that human and mouse blood plasma contains octanal, a product of lipid peroxidation, at concentrations sufficient to activate Olfr2 and the human ortholog olfactory receptor 6A2 (OR6A2). Boosting octanal levels exacerbated atherosclerosis, whereas genetic targeting of Olfr2 in mice significantly reduced atherosclerotic plaques. Our findings suggest that inhibiting OR6A2 may provide a promising strategy to prevent and treat atherosclerosis."

» Macrophages in the artery wall ‘smell’ their surroundings Immune cells can sniff out octanal in blood, triggering dangerous inflammation and atherosclerosis

Olfactory receptor 2 in vascular macrophages drives atherosclerosis by NLRP3-dependent IL-1 production