Tannerella forsythia BspA increases the risk factors for atherosclerosis in ApoE−/− mice

Objective The aim of this study was to evaluate the effects of Tannerella forsythia and its major surface virulence factor, BspA, on the progression of atherosclerosis in ApoE−/− mice and the expression of lipid metabolism-related genes. Methods PMA-differentiated THP-1 cells were treated with BspA to detect foam cell formation. The proximal aortas of ApoE−/− mice injected with T. forsythia or BspA were stained with oil red O to examine lipid deposition. The serum levels of CRP, HDL, and LDL were detected by ELISA. The liver tissue of T. forsythia- or BspA-injected ApoE−/− mice was examined for mRNA expression of lipid metabolism-related genes, such as liver X receptors (LXRα and LXRβ) and ATP-binding cassette transporter A1 (ABCA1). Results Tannerella forsythia and BspA induced foam cell formation in THP-1 cells and accelerated the progression of atherosclerotic lesions in ApoE−/− mice. Mouse serum levels of CRP and LDL were increased, and HDL was decreased by T. forsythia and BspA. The expression levels of LXRα and LXRβ, and ABCA1 in liver tissue were decreased by T. forsythia and BspA. Conclusions Tannerella forsythia and BspA augmented atherosclerotic lesion progression in ApoE−/− mice. This process may be associated with downregulation of lipid metabolism-related gene expression.