Doxorubicin-Induced Cardiotoxicity Is Mediated By Neutrophils Through Release Of Neutrophil Elastase
Author ORCID Identifier
https://orcid.org/0000-0003-2392-1489
Date of Graduation
12-2022
Document Type
Dissertation (PhD)
Program Affiliation
Immunology
Degree Name
Doctor of Philosophy (PhD)
Advisor/Committee Chair
Dr Eugenie Kleinerman
Committee Member
Dr Gheath Al-Atrash
Committee Member
Dr Joya Chandra
Committee Member
Dr Michelle Hildebrandt
Committee Member
Dr Keri Schadler
Committee Member
Dr Stephanie Watowich
Abstract
Doxorubicin (Dox) is one of the most effective chemotherapy agents that is used for the treatment of childhood cancer. Unfortunately Dox treatment can cause damage to the heart. Indeed, childhood cancer survivors are at a higher risk of developing a cardiovascular disease at an earlier age. The mechanisms by which Dox causes acute and late cardiotoxicity are not completely understood. One understudied area in Dox-induced cardiotoxicity is the contribution of inflammation and innate immune cells, in particular neutrophils. Recognizing that neutrophils have been implicated in a number of heart diseases, we evaluated the role of neutrophils in Dox-induced cardiotoxicity. Here, using echocardiography, flow cytometry and immunofluorescence staining, we demonstrated increased infiltration of neutrophils that correlated with decreased heart function (as defined by a decrease in ejection fraction and fractional shortening), disruption of vascular structures and increased collagen deposition in the heart after Dox treatment. Depleting neutrophils protected the heart from Dox-induced cardiotoxicity and changes in vascular structure both in the acute (24 hours after therapy) and late stages (12 weeks after therapy). Furthermore, our data using neutrophil elastase (NE) knock-out mice and the NE inhibitor AZD9668 suggest that neutrophils induce cardiac damage by releasing NE and that inhibiting NE can prevent both acute and late Dox-induced cardiotoxicity. Taken together, this data indicates the contribution of neutrophils and NE in Doxorubicin-induced cardiotoxicity. This is the first demonstration of the importance of neutrophils and NE in heart damage caused by Dox and suggests a potential new therapeutic intervention.
Keywords
Cardiotoxicity, Doxorubicin, Doxorubicin-induced cardiotoxicity, Neutrophils, neutrophil elastase