Identification of potential biomarkers for predicting the early onset of diabetic cardiomyopathy in a mouse model

Abstract

Type 2 diabetes (T2D) is characterized by metabolic derangements that cause a shift in substrate preference, inducing cardiac interstitial fibrosis. Interstitial fibrosis plays a key role in aggravating left ventricular diastolic dysfunction (LVDD), which has previously been associated with the asymptomatic onset of heart failure. The latter is responsible for 80% of deaths among diabetic patients and has been termed diabetic cardiomyopathy (DCM). Through in silico prediction and subsequent detection in a leptin receptor-deficient db/db mice model (db/db), we confirmed the presence of previously identified potential biomarkers to detect the early onset of DCM. Differential expression of Lysyl Oxidase Like 2 (LOXL2) and Electron Transfer Flavoprotein Beta Subunit (ETFβ), in both serum and heart tissue of 6-16-week-old db/db mice, correlated with a reduced left-ventricular diastolic dysfunction as assessed by high-resolution Doppler echocardiography. Principal component analysis of the combined biomarkers, LOXL2 and ETFβ, further displayed a significant difference between wild type and db/ db mice from as early as 9 weeks of age. Knockdown in H9c2 cells, utilising siRNA of either LOXL2 or ETFβ, revealed a decrease in the expression of Collagen Type I Alpha1 (COL1A1), a marker known to contribute to enhanced myocardial fibrosis. Additionally, receiver-operating curve (ROC) analysis of the proposed diagnostic profile showed that the combination of LOXL2 and ETFβ resulted in an area under the curve (AUC) of 0.813, with a cutoff point of 0.824, thus suggesting the favorable positive predictive power of the model and further supporting the use of LOXL2 and ETFβ as possible early predictive DCM biomarkers. Diabetes affects 463 million people worldwide and this number is said to increase to 700 million by 2045 1. Diabetes and its complications are inextricably linked to cardiovascular dysfunction, which is currently the leading cause of mortality worldwide, affecting 17.9 million individuals 2. This association was first reported in the Framingham Heart study and since then numerous reports have come to the forefront, confirming a 2-4 times increased susceptibility of diabetic individuals to heart failure (HF) 3,4. Coronary artery disease (CAD) is the major type of CVD responsible for HF in diabetic individuals, however diabetic cardiomyopathy (DCM) is an established complication of diabetes mellitus (DM) existing in the absence of CAD or hypertension 5. Furthermore, DCM is referred to as the silent killer, due to the manifestation of a long subclinical period in which the disease exists with no overt clinical symptoms 6-8 .

Moderate- and High-Intensity Endurance Training Alleviate Diabetes-Induced Cardiac Dysfunction in Rats

“…Here, the exercise-induced decrease in fibrosis was accompanied by, even if not significant, clear lower protein levels of LOX following MIT. In silico predictive methods support that LOX-like 2, a LOX isoform known to play an important role in ECM cross-linking, can be used as an early biomarker for diabetic cardiomyopathy [ 98 ]. Contrary to our findings, 26 weeks of voluntary treadmill running by hypertensive rats induced increased gene and protein expression of LOX in the heart accompanied by diastolic dysfunction [ 99 ].…”

Chronic Ethanol Exposure Induces Deleterious Changes in Cardiomyocytes Derived from Human Induced Pluripotent Stem Cells

“…In view of the remarkable changes of collagen matrix proteins in EtOH-treated hiPSC-CMs, these proteins could be potential biomarkers for alcoholic cardiomyopathy diagnosis. Indeed, growing evidence demonstrated that COL1A1 could serve as a biomarker candidate in a variety of cardiac diseases, such as diabetic cardiomyopathy and heart failure [60,61].…”

Diabetic cardiomyopathy: the need for adjusting experimental models to meet clinical reality

“…Using this approach and exploiting meta-analysis of transcriptomic datasets, differential expression levels of lysyl oxidase like 2 (LOXL2) and electron transfer flavoprotein beta subunit (ETFβ) in serum and heart tissue of 6-16-week-old db/db mice correlated closely with a reduced LV diastolic dysfunction, supporting the use of LOXL2 and ETFβ as early predictive biomarkers for diabetic CM. 126 Moreover, systematic multiorgan biobanking of porcine models of diabetes and obesity subjected to molecular profiling by transcriptomics, proteomics and metabolomics has been proposed to better understand tissue specific pathogenic mechanisms and organ crosstalk with the prospect of revealing novel molecular targets. 127 In the field of imaging technologies, the development of machine learning algorithms aims to provide more accurate biomarkers.…”