Early Development of Calcific Aortic Valve Disease and Left Ventricular Hypertrophy in a Mouse Model of Combined Dyslipidemia and Type 2 Diabetes Mellitus
Objective—This study aimed to determine the potential impact of type 2 diabetes mellitus on left ventricular dysfunction and the development of calcified aortic valve disease using a dyslipidemic mouse model prone to developing type 2 diabetes mellitus.
Approach and Results—When compared with nondiabetic LDLr−/−/ApoB100/100, diabetic LDLr−/−/ApoB100/100/IGF-II mice exhibited similar dyslipidemia and obesity but developed type 2 diabetes mellitus when fed a high-fat/sucrose/cholesterol diet for 6 months. LDLr−/−/ApoB100/100/IGF-II mice showed left ventricular hypertrophy versus C57BL6 but not LDLr−/−/ApoB100/100 mice. Transthoracic echocardiography revealed significant reductions in both left ventricular systolic fractional shortening and diastolic function in high-fat/sucrose/cholesterol fed LDLr−/−/ApoB100/100/IGF-II mice when compared with LDLr−/−/ApoB100/100. Importantly, we found that peak aortic jet velocity was significantly increased in LDLr−/−/ApoB100/100/IGF-II mice versus LDLr−/−/ApoB100/100 animals on the high-fat/sucrose/cholesterol diet. Microtomography scans and Alizarin red staining indicated calcification in the aortic valves, whereas electron microscopy and energy dispersive x-ray spectroscopy further revealed mineralization of the aortic leaflets and the presence of inflammatory infiltrates in diabetic mice. Gene expression studies showed upregulation of hypertrophic markers (anp, bnp, b-mhc) in myocardial tissues and of osteogenic markers (spp1, bglap, runx2) in aortic tissues of diabetic mice.
Conclusions—We have established the diabetes mellitus –prone LDLr−/−/ApoB100/100/IGF-II mouse as a new model of calcified aortic valve disease. Our results are consistent with the growing body of clinical evidence that the dysmetabolic state of type 2 diabetes mellitus contributes to early mineralization of the aortic valve and calcified aortic valve disease pathogenesis.
- Received January 10, 2014.
- Accepted July 24, 2014.
- © 2014 American Heart Association, Inc.