IADR Abstract Archives
RAGE Deletion Suppresses Atherogenesis in P. gingivalis-infected ApoE-null Mice
Objectives: Periodontal infections increase the risk for atherosclerotic vascular disease. Porphyromonas gingivalis localizes in human atherosclerotic plaques and accelerates atherosclerosis in animal models. The receptor for advanced glycation endproducts (RAGE) is involved in atherogenesis and in P. gingivalis-mediated endothelial cell activation. We studied the contribution of RAGE to atherosclerotic plaque formation and vascular inflammation in hypercholesterolemic mice infected with P. gingivalis.
Methods: Double knock-out (DKO) mice, deficient in both the apolipoprotein E (apoE) gene and the RAGE gene were generated (ApoE-/- / RAGE-/-), and apoE-/- animals were used as controls. All mice were orally infected with P. gingivalis strain 381 over a three-week period. At age 20 weeks, 12 weeks after the last P. gingivalis inoculation, mice were euthanized and atherosclerotic lesion area was quantified at the aortic sinus. Pathway-focused gene expression profiling was assessed in excised aortas using Real-Time PCR array analysis, and Taqman Real-Time PCR was used for validation. Protein expression of molecules involved in atherogenesis was studied by immunoblotting and immunofluorescence.
Results: Atherosclerotic lesion areas at the aortic sinus were significantly lower in DKO infected mice (31,360±27,710 μm2, n=11) compared to control apoE-/- infected mice (62,350±33,350 μm2, n=9); p=0.015. PCR array profiling (n=3 arrays per group) revealed that RAGE deletion downregulated genes involved in proatherogenic responses. Specifically, out of the 84 atherosclerosis-related genes included in the focused array, 34 were identified that were either down- or upregulated by more than a 1.40-fold cut-off. These included genes involved in the remodeling of extracellular matrix, lipid transport and metabolism, cell growth and proliferation, apoptosis, and adhesion molecule genes. Results were consistent on the protein level.
Conclusions: Our findings demonstrate for the first time in vivo a protective role of RAGE deletion in the proatherogenic and proinflammatory systemic injury seen in P. gingivalis-infected apoE-/- mice.
Methods: Double knock-out (DKO) mice, deficient in both the apolipoprotein E (apoE) gene and the RAGE gene were generated (ApoE-/- / RAGE-/-), and apoE-/- animals were used as controls. All mice were orally infected with P. gingivalis strain 381 over a three-week period. At age 20 weeks, 12 weeks after the last P. gingivalis inoculation, mice were euthanized and atherosclerotic lesion area was quantified at the aortic sinus. Pathway-focused gene expression profiling was assessed in excised aortas using Real-Time PCR array analysis, and Taqman Real-Time PCR was used for validation. Protein expression of molecules involved in atherogenesis was studied by immunoblotting and immunofluorescence.
Results: Atherosclerotic lesion areas at the aortic sinus were significantly lower in DKO infected mice (31,360±27,710 μm2, n=11) compared to control apoE-/- infected mice (62,350±33,350 μm2, n=9); p=0.015. PCR array profiling (n=3 arrays per group) revealed that RAGE deletion downregulated genes involved in proatherogenic responses. Specifically, out of the 84 atherosclerosis-related genes included in the focused array, 34 were identified that were either down- or upregulated by more than a 1.40-fold cut-off. These included genes involved in the remodeling of extracellular matrix, lipid transport and metabolism, cell growth and proliferation, apoptosis, and adhesion molecule genes. Results were consistent on the protein level.
Conclusions: Our findings demonstrate for the first time in vivo a protective role of RAGE deletion in the proatherogenic and proinflammatory systemic injury seen in P. gingivalis-infected apoE-/- mice.