Prioritization of Candidate Biomarkers for Degenerative Aortic Stenosis through a Systems Biology-Based In-Silico Approach

Abstract

Degenerative aortic stenosis is the most common valve disease in the elderly and is usually confirmed at an advanced stage when the only treatment is surgery. This work is focused on the study of previously defined biomarkers through systems biology and artificial neuronal networks to understand their potential role within aortic stenosis. The goal was generating a molecular panel of biomarkers to ensure an accurate diagnosis, risk stratification, and follow-up of aortic stenosis patients. We used in silico studies to combine and re-analyze the results of our previous studies and, with information from multiple databases, established a mathematical model. After this, we prioritized two proteins related to endoplasmic reticulum stress, thrombospondin-1 and endoplasmin, which have not been previously validated as markers for aortic stenosis, and analyzed them in a cell model and in plasma from human subjects. Large-scale bioinformatics tools allow us to extract the most significant results after using high throughput analytical techniques. Our results could help to prevent the development of aortic stenosis and open the possibility of a future strategy based on more specific therapies.

Keywords: aortic valve; biomarkers; endoplasmic reticulum; in silico models; systems biology.

Figure 1

Mathematical model pipeline. Aortic stenosis was defined at molecular level through bibliography and database revision, a biological map was built, and mathematical models were trained. Then, candidate proteins were prioritized according to the functional relationship with the disease.

Figure 2

Verification of the osteoblastic differentiation through alizarin red staining (a) and α-SMA (b) and Western blot confirmation of thrombospondin-1 (c) and endoplasmin (d) levels in HAVICs treated with FIB medium (C) and osteogenic medium (Ost) after 7 and 14 days of culture. Data from western blots were normalized to total protein level (Ponceau S stain, Figure S1).*= p < 0.05.

Figure 3

Western blot confirmation of thrombospondin-1 (a) and endoplasmin (b) levels in the plasma samples (control and severe AS subjects), with the corresponding p-values (Student’s t-test) for each protein analyzed: *= p < 0.05; RI, relative intensity.