People with type 1 diabetes have an above-average risk of developing heart disease, or atherosclerosis, and two related groups of inflammatory immune cells may be to blame.

Immune cells called monocytes and macrophages — which develop from bone marrow — from mice and humans with diabetes express unusually high levels of the enzyme ACSL1. This modifies fat molecules that then trigger inflammation, according to Karin Bornfeldt at the University of Washington in Seattle and her team. Diabetic mice that received transplanted bone-marrow cells lacking ACSL1 developed fewer and smaller blood-vessel lesions characteristic of atherosclerosis than did diabetic mice transplanted with normal cells.

Blocking this enzyme could prevent the accelerated atherosclerosis common in patients with diabetes, the authors suggest.

Proc. Natl Acad. Sci. USA http://dx.doi.org/10.1073/pnas.1111600109 (2012)