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Updated: Jul 6, 2026
A Doxorubicin-Induced Murine Model of Dilated Cardiomyopathy In Vivo
Published on: May 16, 2020
Toll-like receptor-4 deficiency attenuates doxorubicin-induced cardiomyopathy in mice
Alexander Riad1, Sandra Bien, Matthias Gratz
1Charité - Universitätsmedizin Berlin, Germany, Campus Benjamin Franklin, Department of Cardiology and Pneumology, Hindenburgdamm 30, 12200 Berlin, Germany.
Background:
Cardiac inflammation and generation of oxidative stress are known to contribute to doxorubicin (Dox)-induced cardiomyopathy. Toll-like receptors (TLRs) are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signalling, we investigated whether or not TLR4 is involved in Dox-induced cardiotoxicity.
Methods And Results:
Five days after a single injection of Dox (20 mg/kg; i.p.), left ventricular pressure-volume loops were measured in wild-type and TLR4-deficient mice (TLR4-/-) Dox-treated and control mice. Analyses of possible pathophysiological mechanisms were performed in left ventricular tissue and isolated myocytes, respectively. Dox injection resulted in an impairment of left ventricular function and neurohumoral activation, indexed by increased ET-1 expression. This was further associated with an increase in cardiac oxidative stress, inflammation and apoptosis, as indicated by an up-regulation of cardiac lipid peroxidation, TNF-alpha expression and enhanced content of TUNEL-positive cells. In contrast, TLR4-/- Dox mice showed improved left ventricular function with reduced oxidative and inflammatory stress response including reduced cardiac apoptosis. These results were found to be associated with an increase of GATA-4 expression.
Conclusions:
TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in Dox-induced cardiomyopathy.
Insights
Toll-like receptor 4 (TLR4) deficiency protects against doxorubicin-induced cardiomyopathy by reducing cardiac inflammation and oxidative stress. This study demonstrates TLR4 plays a key role in doxorubicin cardiotoxicity.
Area of Science:
- Cardiovascular Biology
- Immunology
- Pharmacology
Background:
- Doxorubicin (Dox)-induced cardiomyopathy is linked to cardiac inflammation and oxidative stress.
- Toll-like receptors (TLRs) are involved in innate immunity and cardiac stress responses.
- TLR4's potential role in cardiac inflammatory signaling warrants investigation in Dox-induced cardiotoxicity.
Purpose of the Study:
- To investigate the role of TLR4 in doxorubicin-induced cardiotoxicity.
- To determine if TLR4 deficiency impacts the development of Dox-induced cardiomyopathy.
Main Methods:
- Comparison of left ventricular function in wild-type and TLR4-deficient mice post-doxorubicin injection.
- Assessment of cardiac oxidative stress, inflammation, and apoptosis markers.
- Analysis of neurohumoral activation and gene expression (ET-1, GATA-4).
Main Results:
- Doxorubicin impaired left ventricular function, increased oxidative stress, inflammation, and apoptosis in wild-type mice.
- TLR4-deficient mice exhibited improved left ventricular function with reduced oxidative and inflammatory stress.
- TLR4 deficiency was associated with reduced cardiac apoptosis and increased GATA-4 expression.
Conclusions:
- TLR4 deficiency significantly improves left ventricular function in the context of doxorubicin-induced cardiomyopathy.
- Attenuating TLR4 signaling mitigates key pathophysiological mechanisms of doxorubicin cardiotoxicity, including inflammation and oxidative stress.
