Congenital absence of nitric oxide synthase 3 potentiates cardiac dysfunction and reduces survival in doxorubicin- and trastuzumab-mediated cardiomyopathy.
BACKGROUND
Doxorubicin (DOX) and trastuzumab (TRZ) are highly effective chemotherapeutic agents in the breast cancer setting, limited by their cardiotoxic side effects. Among the potential mechanisms for this drug-induced cardiomyopathy, increased production of oxidative stress (OS) through a nitric oxide synthase 3 (NOS3)-dependent pathway has gained recent attention. The objective of the study was to determine the role of NOS3 and OS in a clinically relevant female murine model of DOX- and TRZ-induced heart failure.


METHODS
A total of 120 female mice (60 wild-type [WT] and 60 NOS3 knockout [NOS3(-/-)]) were treated with either 0.9% saline, DOX, TRZ, or DOX with TRZ (DOX+TRZ). Serial echocardiography was performed for a total of 10 days, after which the mice were euthanized for histological and biochemical analyses.


RESULTS
In WT female mice receiving DOX+TRZ, left ventricular ejection fraction (LVEF) decreased from 75 ± 3% at baseline to 46 ± 2% at day 10 (P < 0.05). In the NOS3(-/-) group, LVEF decreased from 72 ± 3% at baseline to 35 ± 2% at day 10 (P < 0.05). LVEF was significantly lower in NOS3(-/-) female mice receiving DOX+TRZ than WT mice at day 10 (P < 0.05). Compared with WT, NOS3(-/-) female mice also demonstrated increased mortality after treatment with DOX+TRZ, corroborating the echocardiographic findings. Histological analysis demonstrated increased myofibrillar degradation and loss of cell integrity in NOS3(-/-) female mice treated with DOX+TRZ. There was increased generation of oxidized phosphatidylcholine, a marker of OS, in NOS3(-/-) female mice receiving DOX+TRZ compared with control mice.


CONCLUSIONS
Congenital absence of NOS3 potentiates the cardiotoxic side effects of DOX+TRZ in an acute female murine model of chemotherapy-induced cardiomyopathy.
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Matthew
M
Zeglinski
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Sheena
S
Premecz
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Jordyn
J
Lerner
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Piotr
P
Wtorek
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Megan
M
Dasilva
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Devin
D
Hasanally
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Rakesh
R
Chaudhary
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Anita
A
Sharma
Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada.
James
J
Thliveris
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Section of Cardiology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Amir
A
Ravandi
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Pawan K
PK
Singal
Institute of Cardiovascular Sciences, St Boniface Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada; Section of Cardiology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Section of Oncology, Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Radiology, St Boniface General Hospital, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address: djassal@sbgh.mb.ca.
Davinder S
DS
Jassal
D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000633:toxicity; D015153:Blotting, Western; D009202:Cardiomyopathies / Q000139:chemically induced / Q000201:enzymology* / Q000401:mortality; D004195:Disease Models, Animal; D004317:Doxorubicin / Q000633:toxicity; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000201:enzymology*; D052250:Nitric Oxide Synthase Type III / Q000172:deficiency*; D018384:Oxidative Stress; D000068878:Trastuzumab; D018487:Ventricular Dysfunction, Left / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology
D061067:Antibodies, Monoclonal, Humanized; D004317:Doxorubicin; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D000068878:Trastuzumab