Abstract

Gene Expression and Proteomic Profiling of Lp (a)-Induced Signalling Pathways in Human Aortic Valve Interstitial Cells

Bin Yu, Hannah Kapur, Qutayba Hamid, Kashif Khan, George Thanassoulis, Renzo Cecere, Benoit de Varennes, Jacques Genest and Adel Schwertani

Aortic valve stenosis is one of the most common valve diseases in the world for which there is currently no pharmacological treatment to prevent or halt disease progression. Recent genetic research has demonstrated a causal association between elevated blood levels of lipoprotein (a) (Lp (a)) and aortic valve calcification, however, the mechanisms by which Lp (a) contributes to aortic valve calcification and stenosis, is unknown. In the present study, we aimed at determining Lp (a)-induced changes in human aortic valve interstitial cells using an integrated bioinformatics approach. The Lp (a)-induced cellular pathways were analysed using microarray gene expression and proteomic data from non-stenotic human aortic valve interstitial cells. Lp (a) treatment induced osteogenic differentiation, extracellular remodeling, extracellular vesicles biogenesis, and apoptosis of human aortic valve interstitial cells. In particular, the Wnt/ β-catenin signalling pathway, a known calcification pathway contributing to aortic valve stenosis, was differentially expressed compared to non-treated cells. Lp (a) also induced the expression of 14-3-3 proteins known to regulate various signalling pathway relevant to aortic valve disease. Elucidating the mechanisms and molecular players that Lp (a) induces in the early stages of the disease to initiate aortic valve calcification could provide insight into potential pharmacological targets for the treatment of this debilitating disease.