Customized laboratory TLR4 and TLR2 detection method from peripheral human blood for early detection of doxorubicin-induced cardiotoxicity

Abstract

Cancer treatments can have significant cardiovascular adverse effects that can cause cardiomyopathy and heart failure with reduced survival benefit and considerable decrease in the use of antineoplastic therapy. The purpose of this study is to assess the role of TLR2 and TLR4 gene expression as an early marker for the risk of doxorubicin-induced cardiomyopathy in correlation with early diastolic dysfunction in patients treated with doxorubicin. Our study included 25 consecutive patients who received treatment with doxorubicin for hematological malignancies (leukemia, lymphomas or multiple myeloma), aged 18-65 years, with a survival probability>6 months and with left ventricular ejection fraction>50%. Exclusion criteria consisted of the following: previous anthracycline therapy, previous radiotherapy, history of heart failure or chronic renal failure, atrial fibrillation, and pregnancy. In all patients, in fasting state, a blood sample was drawn for the assessment of TLR2 and TLR4 gene expression. Gene expression was assessed by quantitative reverse transcription PCR (qRT-PCR) using blood collection, RNA isolation, cDNA reverse transcription, qRT-PCR and quantification of the relative expression. At enrollment, all patients were evaluated clinically; an ECG and an echocardiography were performed. The average amount of gene expression units was 0.113 for TLR4 (range 0.059-0.753) and 0.218 for TLR2 (range 0.046-0.269). The mean mRNA extracted quantity was 113 571 ng/μl. As for the diastolic function parameters, criteria for diastolic dysfunction were present after 6 months in 16 patients (64%). In these patients, the mean values for TLR4 were 0.1198625 and for TLR2 were 0.16454 gene expression units. As for the diastolic function parameters, criteria for diastolic dysfunction were present after 6 months in 16 patients (64%). In these patients, the mean value for TLR2 was 0.30±0.19 and for TLR4 was 0.15±0.04. The corresponding values for the patients who did not develop diastolic dysfunction were 0.16±0.07 for TLR2 (P=0.01) and 0.11±0.10 for TLR4 (P=0.2). Our study suggests that TLR4 and TLR2 expression is higher in patients under doxorubicin therapy who develop diastolic dysfunction. This may suggest a predisposition to myocardial involvement, a higher sensitivity to doxorubicin cardiac effects.

Updates in Anthracycline-Mediated Cardiotoxicity

“…DOX also up-regulates the expression of cell surface membrane death receptors (DR), such as Fas cell surface death receptors, DR4, and DR5, TNF receptor 1 (TNFR1) in cardiomyocytes ( Zhao and Zhang, 2017 ). In addition, DOX induces the expression of toll-like receptors (TLR) that play an important role in cardiac damage via activating pro-inflammatory NFκB ( Pop-Moldovan et al, 2017 ). All these DOX-induced immune responses contribute to the activation of a caspase cascade.…”

Toll-Like Receptors 2 and 4 Predict New-Onset Atrial Fibrillation in Acute Myocardial Infarction Patients

“…We speculate that TLR2 and TLR4 have the same signal (MyD88-dependent) pathway in new-onset atrial fibrillation patients after acute myocardial infarction. 28,29) As past studies have indicated, new-onset AF after MI is most dependent on infarction size, and AF also could cause harmful cardiovascular events and high mortality. A blood sample is collected before reperfusion therapy and patients only received aspirin, plavix, and statins.…”

Toll-like receptor 4 (TLR4) expression is correlated with T2* iron deposition in response to doxorubicin treatment: cardiotoxicity risk assessment

“…TLRs are members of the interleukin-1 receptor family (IL1) and are involved in the ability to react to molecular triggers associated with pathogenic microorganisms. Recent studies have shown that TLRs are activated by endogenous signals, such as heat shock proteins and oxidative stress, which can contribute to congestive heart failure 6 .…”

“…Oxidative stress is one of the major effects in Dox-induced cardiac dysfunction. In a previous study, we hypothesized and showed that TLRs contribute to the pathogenesis of Dox-induced cardiac dysfunction via an inflammation-induced mechanism 6 . These studies also indicate that free radicals play an important role in Dox-induced CTX.…”