Abstract Title
Doxorubicin Modulates Autophagy in a Cell-Type Dependent Manner: A Potential Mechanism for Doxorubicin Induced Cardiotoxicity
Additional Funding Sources
This project is supported by a 2021-2022 STEM Undergraduate Research Grant from the Higher Education Research Council.We are supported by COBRE, INBRE, the HERC Fellowship, and have utilized Biomolecular Research Center resources. We acknowledge support from the Institutional Development Awards (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under Grant Nos. P20GM103408 and P20GM109095. We also acknowledge support from the Biomolecular Research Center at Boise State, BSU-Biomolecular Research Center, RRID:SCR_019174, with funding from the National Science Foundation, Grant Nos. 0619793 and 0923535, the M.J. Murdock Charitable Trust, Lori and Duane Stueckle, and the Idaho State Board of Education.
Abstract
Doxorubicin is a highly effective chemotherapeutic, but its use is limited due to dose-dependent cardiotoxicity, which can result in lethal cardiomyopathy. Although oxidative stress leading to apoptosis (cell death) is generally accepted as the principal mechanism for doxorubicin-induced cardiotoxicity, antioxidant interventions have largely failed in pre-clinical and clinical trials. Other novel mechanisms that could explain this effect include autophagy.
Autophagy is a highly conserved process of self-degradation of cellular components in response to cellular stress and signals such as starvation, growth factor deprivation, and pathogen infection. Interference with this process may also lead to the induction of apoptosis and downstream cardiotoxic symptoms. Previous studies have demonstrated doxorubicin influences autophagy in cardiomyocytes. However, little is known about the effects of this chemotherapeutic in fibroblasts. Fibroblasts are the largest cell population in the heart and the main cell type responsible for the synthesis, deposition, and degradation of cardiac extracellular matrix (ECM).
Through use of cell culture, western blotting, and reverse transcription quantitative polymerization chain reaction (RT-qPCR) techniques, we studied the effects of doxorubicin on autophagy by the monitored expression of known autophagy markers. Expression of autophagy markers P62 and LC3B analyzed by western blotting suggests doxorubicin induces autophagy in NIH 3T3 fibroblast cells. A similar trend was not obvious in mouse primary cardiac fibroblasts, signifying this effect may be cell-type dependent. Preliminary RT-qPCR analysis also indicates that doxorubicin modulates the expression of several genes in autophagy pathway. With further study, autophagy could be a potential target for mitigating doxorubicin-induced cardiotoxicity.
Doxorubicin Modulates Autophagy in a Cell-Type Dependent Manner: A Potential Mechanism for Doxorubicin Induced Cardiotoxicity
Doxorubicin is a highly effective chemotherapeutic, but its use is limited due to dose-dependent cardiotoxicity, which can result in lethal cardiomyopathy. Although oxidative stress leading to apoptosis (cell death) is generally accepted as the principal mechanism for doxorubicin-induced cardiotoxicity, antioxidant interventions have largely failed in pre-clinical and clinical trials. Other novel mechanisms that could explain this effect include autophagy.
Autophagy is a highly conserved process of self-degradation of cellular components in response to cellular stress and signals such as starvation, growth factor deprivation, and pathogen infection. Interference with this process may also lead to the induction of apoptosis and downstream cardiotoxic symptoms. Previous studies have demonstrated doxorubicin influences autophagy in cardiomyocytes. However, little is known about the effects of this chemotherapeutic in fibroblasts. Fibroblasts are the largest cell population in the heart and the main cell type responsible for the synthesis, deposition, and degradation of cardiac extracellular matrix (ECM).
Through use of cell culture, western blotting, and reverse transcription quantitative polymerization chain reaction (RT-qPCR) techniques, we studied the effects of doxorubicin on autophagy by the monitored expression of known autophagy markers. Expression of autophagy markers P62 and LC3B analyzed by western blotting suggests doxorubicin induces autophagy in NIH 3T3 fibroblast cells. A similar trend was not obvious in mouse primary cardiac fibroblasts, signifying this effect may be cell-type dependent. Preliminary RT-qPCR analysis also indicates that doxorubicin modulates the expression of several genes in autophagy pathway. With further study, autophagy could be a potential target for mitigating doxorubicin-induced cardiotoxicity.