Gene expression levels of the intracellular localized TLRs <i>Tlr3</i>, <i>Tlr7</i>, <i>Tlr8</i>, and <i>Tlr9</i> in different HF models of diverse etiology.

<p>Cardiac tissue of healthy and diseased C57BL/6J mice was used for TaqMan based gene expression analysis of the plasma membrane localized TLRs <i>Tlr3</i>, <i>Tlr7</i>, <i>Tlr8</i>, and <i>Tlr9</i>. Expression levels of cardiac tissue from control mice are shown as white boxes, from diseased animals as red, blue, green, or yellow boxes corresponding to the analyzed heart failure model. In viral-induced myocarditis (shown in red), gene expression of <i>Tlr3</i>, <i>Tlr7</i>, <i>Tlr8</i>, and <i>Tlr9</i> was highly increased 7 days after infection compared to healthy controls. However, <i>Tlr3</i>, <i>Tlr7</i> and <i>Tlr9</i> displayed the highest increase during acute myocarditis and the initially increased gene expression levels returned almost with exception to basal levels 28 days after infection. Moreover, in the model of myocardial infarction (shown in blue), gene expression of <i>Tlr3</i>, <i>Tlr7</i>, <i>Tlr8</i>, and <i>Tlr9</i> was highly increased 5 days post infarction in the infarct zone when compared to the remote zone. In addition, the TLRs <i>Tlr7</i>, <i>Tlr8</i>, and <i>Tlr9</i> showed the highest increase in gene expression levels after myocardial ischemia. In the remote zone, no increased TLR gene expression was observed. In STZ-induced diabetic cardiomyopathy (shown in green), a decreased gene expression of <i>Tlr8</i> in comparison to their healthy controls was detected; the remaining TLRs displayed no changes in gene expression levels. In the heart failure model caused by chronic AngII-infusion for 21 days (shown in yellow) only the intracellular localized <i>Tlr3</i> displayed a significant decrease when compared to their controls. Data are presented as relative mRNA expression in fold change to the corresponding untreated control using the formula 2^−ΔΔCt. * = significantly different compared to corresponding control; ^# = significantly different compared to VM (acute—7 days) or RZ (remote zone).