A Doxorubicin-Induced Murine Model of Dilated Cardiomyopathy In Vivo

Summary

Described is a protocol to establish a Doxorubicin-induced dilated cardiomyopathy (DCM) model in mice via long-term intraperitoneal injection of Doxorubicin.

Abstract

Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed cardiac performance in the absence of hypertension, valvular, congenital, or ischemic heart diseases, and which may be related to infection, autoimmune or metabolic abnormalities, or family inheritance. It can progress into congestive heart failure with a poor prognosis. Doxorubicin (Dox) is widely employed as a chemotherapeutic drug, but its use is limited because it causes DCM-like changes of the myocardium. Its myocardial toxicity is attributed to oxidative stress, chronic inflammation, and cardiomyocyte apoptosis. A model of DCM exploiting these Dox-induced DCM symptoms has not been established.

Introduction

One of the most common causes of heart failure, DCM is characterized by ventricular dilatation and decreased cardiac function and is the most common reason for heart transplantation worldwide¹. In order to further investigate its pathogenesis and find effective treatments, access to mature animal models is especially important. The purpose of the described experiments is to establish a stable mouse model of DCM that resembles human DCM.

Due to the complex pathogenesis of DCM, there are many different methods to make corresponding animal models. Spontaneous DCM models² are relatively stable, bu....

Protocol

Animal experiments were approved by Institutional Animal Care and Use Committee (IACUC) of Nanjing Drum Tower Hospital.

1. Preparation of the reagents and animals

1. Dissolve doxorubicin hydrochloride (Pfizer, USA) in sterilized water. Vortex to obtain a Dox solution of 1 mg/mL and keep at 4 °C.
2. Use C57BL/6 mice (8–10 weeks old; 25–30 g weight). For this study, mice were purchased from the Model Animal Research Center of Nanjing University and kept in the animal room of Nanjing Drum Tower Hospital.
3. Pathogen-free mouse cages were maintained under a 12 h light/dark cycle at a constant temperature ....

Results

Cardiac function
Dilated cardiomyopathy is characterized by progressive ventricular dilatation and contractile dysfunction. Figure 2 shows representative echocardiographic images of the two groups. Dox-treated mice showed markedly reduced left ventricular ejection fraction and left ventricular fractional shortening (Figure 3A,B). The LV diameter also increased in both the diastolic and systolic phases (F.......

Discussion

Dox is a nonspecific periodic antitumor chemotherapy drug commonly used in clinical practice¹². Its main side effect is cardiotoxicity, characterized by cardiomyopathy and subsequent heart failure¹³. The underlying mechanism includes damage of myocardial lipid peroxidation, inhibition of myocardial sarcoplasmic reticulum Ca²⁺-ATPase activity, and activation of the myocardial local renin-angiotensin system, resulting in increased AT II production and intracellular.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
4% paraformaldehyde	servicebio	CAS30525-89-4
C57BL/6 mice	Model Animal Research Center of Nanjing University	\
Doxorubicin hydrochloride	Pfizer	CAS25316-40-9
echocardiography	Visualsonics	\
Hematoxylin and Eosin staining kit	Solarbio	G1120
Masson staining kit	Solarbio	G1343
phosphate buffer solution	Sigma	P5368
potassium chloride	Sigma	CAS7447-40-7
sterilized syringe	Millipore	SLGP033RB