Thrombotic occlusion of inflammatory plaque in coronary arteries causes
myocardial infarction. Treatment with emergent balloon angioplasty (BA) and
stent implant improves survival, but restenosis (regrowth) can occur. Periodontal
bacteremia is closely associated with
inflammation and native arterial
atherosclerosis, with potential to increase restenosis. Two virus-derived anti-inflammatory
proteins, M-T7 and Serp-1, reduce
inflammation and plaque growth after BA and transplant in animal models through separate pathways. M-T7 is a broad spectrum C, CC and
CXC chemokine-
binding protein. Serp-1 is a
serine protease inhibitor (
serpin) inhibiting thrombotic and thrombolytic pathways. Serp-1 also reduces
arterial inflammation and improves survival in a mouse herpes virus (MHV68) model of lethal
vasculitis. In addition, Serp-1 demonstrated safety and efficacy in patients with unstable
coronary disease and
stent implant, reducing markers of myocardial damage. We investigate here the effects of Porphyromonas gingivalis, a periodontal pathogen, on restenosis after BA and the effects of blocking
chemokine and
protease pathways with M-T7 and Serp-1.
ApoE-/- mice had aortic BA and oral P. gingivalis
infection. Arterial plaque growth was examined at 24 weeks with and without anti-inflammatory
protein treatment. Dental plaques from mice infected with P. gingivalis tested positive for
infection. Neither Serp-1 nor M-T7 treatment reduced
infection, but
IgG antibody levels in mice treated with Serp-1 and M-T7 were reduced. P. gingivalis significantly increased monocyte invasion and arterial plaque growth after BA (P<0.025). Monocyte invasion and plaque growth were blocked by M-T7 treatment (P<0.023), whereas Serp-1 produced only a trend toward reductions. Both
proteins modified expression of TLR4 and MyD88. In conclusion, aortic plaque growth in
ApoE-/- mice increased after angioplasty in mice with chronic oral P. gingivalis
infection. Blockade of
chemokines, but not
serine proteases significantly reduced arterial plaque growth, suggesting a central role for
chemokine-mediated
inflammation after BA in P. gingivalis infected mice.