Risk-factor dependant regulation of the miR-483-3p in metabolic HFpEF and pre-diabetes

Abstract Background Prediabetes and the metabolic phenotype of heart failure with preserved ejection fraction (HFpEF) are two related diseases with high metabolic predisposition and prevalence. We previously described an increase in the micro-RNA miR-483-3p in M2-type macrophages and in endothelial cells in human patients with type 2 diabetes mellitus (T2DM) associated with reduced endothelial regenerative capacity. The miR-483-3p may also be relevant in metabolic HFpEF, but individual cardio-metabolic risk factors causing the upregulation of miR-483-3p have not been specified. Purpose We aimed to understand the relevance of the miR-483-3p in metabolic HFpEF and to identify the cardiovascular risk factors causing miR-483-3p upregulation in humans and in a large animal model of metabolic HFpEF. Methods M2-type macrophages were cultured from blood samples of healthy donors, individuals with prediabetes and patients with established T2DM (n=51, 63% female, age 41-75 years). Expression of hsa-miR-483-3p and hsa-miR-21-5p (housekeeping control) were determined by reverse transcription quantitative real time polymerase chain reaction (RT-qPCR) and correlated with donor characteristics (age at inclusion, biological sex, systolic and diastolic blood pressure, glycated haemoglobin (HbA1C), fasting glucose, fasting triglycerides (TG), high- and low-density lipoproteins, waist circumference). Cultured human aortic endothelial cells (EC) and M2-type primary macrophages were exposed to the fatty acid palmitate, bacterial lipopolysaccharides (LPS), tumour necrosis factor alpha (TNF-α) for 24 h prior to analysis of expression of the miR-483-3p. Results M2 macrophages of individuals with fasting plasma TG levels above 170mg/dL expressed more miR-483-3p (2.0±0.4-fold versus individuals below 170mg/dL TG, p=0.04). Consistently, miR-483-3p was upregulated in M2 macrophages and ECs by palmitic acid (M2: 13.5±7.1-fold versus control; EC: 1.7±0.3-fold versus control, p=0.01). In a porcine model of metabolic HFpEF, the miR-483-3p increased steadily over the initial 12 weeks of high sucrose/high cholesterol diet and subcutaneous deoxycorticosterone acetate application, maintaining a plateau for the following 2 months (57-fold to 300-fold of baseline, n=3). Higher cellular expression of the miR-483-3p in response to TNF-α (M2: 35.5±16.2-fold versus control, p=0.001; EC: 2.2±0.7-fold versus control, p=0.01) and LPS (M2: 31.1±13.4-fold versus control, p=0.005; EC: 1.7±0.4-fold versus control, p=0.01) indicate a potential role of inflammation. Conclusion The miR-483-3p is upregulated in individuals of the human pre-diabetic continuum, associated with triglyceride/fatty acid levels, as well as in a porcine model of metabolic HFpEF. Future studies need to evaluate whether miR-483-3p is a treatable target for maintaining endothelial function under pro-inflammatory and dyslipidaemic conditions in human patients at risk to develop HFpEF and T2DM.