Multiomics coupled with vibrational spectroscopy identify early mechanisms of experimental aortic valve stenosis [miRNA]

Calcific aortic valve stenosis (CAVS), characterized by calcium deposition in the aortic valve in a multiannual process, is associated with high mortality and morbidity. To understand phenomena at its early stages, reliable animal models are needed. Here, we used a critically revised high-fat vitamin D2 diet rabbit model to unveil the earliest in vivo-derived mechanisms linked to CAVS progression. We modeled the inflammation-calcification temporal pattern seen in human disease and investigated molecular changes before inflammation. Coupling comprehensive multiomics and vibrational spectroscopy revealed that among the many procedures involved, mechanotransduction, peroxisome activation, DNA damage-response, autophagy, phospholipid signaling, native ECM proteins upregulation, protein cross-linking and self-folding, are the most relevant driving mechanisms. Activation of Complement 3 receptor, Immunoglobulin J and TLR6 were the earliest signs of inflammation. Among several identified key genes were AXIN2, FOS, and JUNB. Among 10 identified miRNAs, miR-21-5p and miR-204-5p dominated fundamental cellular processes, phenotypic transition, inflammatory modulation, and were validated in human samples. The enzymatic biomineralization process mediated by TNAP was complemented by V-type proton ATPase overexpression, and the substitution of Mg-pyrophosphate with Ca-pyrophosphate. These data extend our understanding on CAVS progression, facilitate the refinement of pathophysiological hypotheses and provide a basis for novel pharmaceutical therapy investigations. Overall design: New Zealand male rabbits received a diet supplemented by 1% cholesterol plus 3500 International Units ergocalciferol per Kg per day, or normal diet. The experimental groups were: E (experimentals, having received the experimental diet) obtained after 2 weeks, 4 weeks, and 7 weeks of diet, and C (controls, having received regular diet), which are pooled from 2 weeks and 4 weeks. Before the analysis, to account for possible minimal myocardial contamination in the aortic valve dataset, we extracted RNA from the left ventricular myocardium and ascending aorta (just below the head and neck vessels) and sequenced the RNA (from 3 control and 3 experimental animals), filtered out the genes that were present in both the myocardium and the aortic valve but not in the ascending aorta (2.22% of genes).