Impact of a CD36 Inhibitor on Porphyromonas gingivalis Mediated Atherosclerosis

Objectives: To determine if AP5055 drug prevents the increase in Porphyromonas gingivalis (Pg) mediated atherosclerosis in low density lipoprotein receptor knock out mice (Ldlr Ko) by targeting CD36.
Methods: Male Ldlr Ko mice were orally lavaged with Pg every other day for two weeks to induce periodontal disease (PD) and fed a western diet for 16 weeks to induce atherosclerosis. Mice were treated with the AP5055 (1mg/kg) or vehicle (10% DMSO) every other day for 16 weeks. At sacrifice, entire aorta was dissected and stain with lipophilic stain for morphometric analysis, collect blood/plasma to determine markers of inflammation, by cytokine array and cholesterol levels. Mandibles were preserved for assessment of periodontal disease using micro CT. To determine if AP5055 specifically affected CD36-mediated signalling, murine macrophages of the RAW Blue cell line were pre-treated with AP5055 followed by PgLPS and nuclear factor-kappa B (NF-κB) activity measured by secreted embryonic alkaline phosphatase (SEAP) reporter assay. Cytokine array using cell culture supernatants of macrophages isolated from wild type mice was also performed.
Results: Based on a power calculation, 15 mice/group were enrolled. Lesion burden analysis of the isolated aortas showed a significant (p=0.0018) decrease in lesion area in the AP5055 treated group as compared to the control groups. In vitro analysis showed that AP5055 inhibited the transcriptional activity of NF-κB and the cytokine array exhibited a decrease (p <0.001) in the expression of pro-inflammatory cytokines. The drug treated group also had significantly (p=0.0040) decreased levels of plasma cholesterol as compared to the non-treated group. Micro CT measurements of bone loss was not significant between the two groups.
Conclusions: Targeting CD36 abrogates atherosclerotic lesion burden associated with PD, accompanied by a reduction in markers of inflammation. These experiments may support development of drugs targeting CD36 for human disease.