Modeling and Evaluation of Murine Diabetic Cardiomyopathy Model

Summary

This protocol outlines a method for inducing diabetic cardiomyopathy through a combination of high-fat diet feeding and streptozotocin injection. This approach aims to provide a reliable framework for scientific investigation into diabetic cardiomyopathy and to explore potential avenues for clinical treatment applications.

Abstract

The underlying pathophysiological mechanisms of diabetic cardiomyopathy (DbCM), a leading cause of mortality among patients with type 2 diabetes mellitus (T2DM), remain poorly understood. The myocardial toxicity associated with T2DM is attributed to factors such as lipotoxicity, glucotoxicity, oxidative stress, reduced cardiac efficiency, and lipoapoptosis. Compared to rats, mice offer greater accessibility, cost-effectiveness, and broader applicability for animal experiments. Insulin resistance and impaired insulin secretion are crucial factors in the pathophysiology of T2DM. We introduce a novel nongenetic murine model that replicates the progression of human DbCM induced by a combination of high-fat diet (HFD) feeding and streptozotocin (STZ) injection. In this study, we used wild-type C57BL/6J mice, administering an HFD regimen for 12 weeks, followed by intraperitoneal injections of STZ for an additional 12 weeks to induce characteristic manifestations of T2DM. We conducted oral glucose tolerance tests and measured serum insulin concentrations to confirm the development of insulin resistance and insufficient insulin secretion. Cardiac structure and function were rigorously assessed through noninvasive transthoracic echocardiography. Pathological characteristics were evaluated through Masson's trichrome staining and wheat germ agglutinin (WGA) staining, revealing pathological features related to DbCM. Therefore, we provide a robust and versatile method for establishing a nongenetic murine model of DbCM.

Introduction

Type 2 diabetes mellitus (T2DM) is a progressively escalating global health concern, standing as a leading cause of morbidity and mortality among affected individuals. The prevalence of T2DM is closely related to the rising epidemic of obesity^1,2. More than one-third of patients with T2DM exhibit a distinct cardiovascular phenotype termed diabetic cardiomyopathy (DbCM), characterized by myocardial dysfunction that occurs independently of coronary artery disease, hypertension, and valvular heart disease³. Emerging evidence suggests that approximately 20% of diabetic patients are predispo....

Protocol

All procedures followed institutional guidelines for animal research in accordance with the Guide for the Care and Use of Laboratory Animals outlined by the US National Institutes of Health (NIH Publication No. 85-23, revised in 1996). All animal experiments were approved by the Ethics Committee of Animal Care and the Ethics Committee of Sichuan University. Male C57BL/6J mice were purchased from Beijing Vital River Laboratory Animal Technology Co. (China). Throughout the experimental duration, mice were housed under controlled conditions of 24 °C and a regulated 12 h light/dark cycle, with ad libitum access to food and water.

Results

This study involved random allocation of mice into two groups: the ND group and the HFD/STZ group, with 6 mice in each group. Subsequent to the final echocardiography and OGTT tests 24 weeks after feeding, the mice were euthanatized to harvest their heart tissues for a histological assessment.

HFD/STZ caused an obvious body weight gain, reaching its peak in 12 weeks, and was significantly higher compared with the ND group. Following the administration of STZ, a notable decrease in body weight .......

Discussion

Given the widespread prevalence of diabetes mellitus and its associated cardiovascular complications globally, there is an urgent need to uncover the underlying molecular mechanisms and develop preventative and therapeutic strategies for this condition²⁰. The pathogenesis of DbCM, one of the cardiovascular complications for patients with T2DM, remains unclear, with no effective approaches to prevent and treat²¹. The absence of reliable preclinical models that accurately mim.......

Materials

Name	Company	Catalog Number	Comments
Animal ultrosound system	Fujifilm Visual Sonics	VEVO 3100	Echocardiography
Blood glucometer	Yuwell	GU100	Assess blood glucose level
Citric acid	Sigma-Aldrich	251275
Isoflurane	RWD life science	R510-22	Anesthesia
Isoflurane vaporizer	RWD life science	R500	Anesthesia
Mouse insulin (INS) ELISA Kit	Wuhan Feiyue Biotechnology Co.,Ltd	FY-EM14029	Assess serum insulin level
Nair hair removal cream	Nair	255g	Remove the fur of mouse
Rodent diet with 60% kcal fat	Research Diets Inc	D12492	High fat diet feeding
Sodium citrate	Sigma-Aldrich	S4641
Sterile filter	Merck Millipore	SLHV033N
Streptozocin	Solarbio	S8050
Ultrasound gel	Keppler	KL-250	Echocardiography
Workstation Dongle	Fujifilm Visual Sonics	Vevo LAB	Echocardiographic data analysis