Cardiotoxicity of anthracycline: Novel approach through down regulation of TLR-3 via TRAF/MAPK signaling pathway

Abstract

Cardiotoxicity is one of the most important complications doxorubicin (DOX) and its pathomechanisms are not completely elucidated. We hypothesize that signaling via toll-like receptor (TLR)-3, a receptor that is activated upon binding of double-stranded nucleotides, might play a crucial role in the pathogenesis of cardiac-toxicity following DOX treatment. Male adult C57BL6 wild-type mice and TLR-3 knock-out (-/-) mice were subjected to 20 mg/kg; administered intraperitoneally. TLR-3 down-stream signaling was activated in WT mice lead to strong pro-inflammatory response with significant monocyte cells invasion. In contrast, this effect was attenuated in TLR-3-/- mice. Moreover, the TLR-3 activation resulted in cardiac damage that was associated with significantly reduced LV function and increased monocyte chemoattractant protein-1 (MCP)-1 expression in WT mice. This finding was confirmed by increased MAPK and TRIF protein expression in WT mice. This study confirmed that the absence of TLR-3 is associated with lower heart injury and maintained LV function. Thus, we conclude that TLR-3 seems to participate in the pathogenesis of cardiotoxicity of DOX.