Highlights. Notch signaling is known to be important regulator of endothelium homeostasis and cardiovascular disease. Particularly, Notch seems to be associated with pathological changes in endothelium epigenome although no such Notch effects have been found. We have discovered that activation of Notch signaling alters histone 1 repertoire in the human endothelial cells and this is the first example of epigenomic Notch targets.Aim. The disturbance of blood flow and alteration of physiological shear stress is one of the main reasons for endothelial dysfunction. Mechanosensitive and dosedependent Notch pathway is assumed to be an important player of endothelial dysfunction progression, but the molecular mechanisms of the influence of Notch dysregulation on endothelium are still not understood. In particular, there is no data about possible targets of Notch in the endothelial epigenome.Methods. Here we focused on the analysis of changes in histone code of human umbilical vein endothelial cells (HUVEC) after activation of Notch. For this purpose, we transduced cells by lentiviruses with construction for Notch 1 intracellular domain (N1ICD) overexpression or by empty vector (control). Then we isolated histone enriched fraction and secretome proteins and performed their shotgun proteomics analysis on timsToF Pro instrument. Proteomics data are available via ProteomeXchange with identifier PXD032978.Results. We found the shift in proteomics profile of HUVEC caused by Notch activation and, particularly, the increase in the levels of N-terminal acetylated forms of histone 1: H1-0, H1-3, H1-4, H1-5, H1-10. We also found changes in the cell secretome profile which are associated with the decrease in proangiogenic effect of HUVEC secretome.Conclusion. Our data identified epigenomic Notch targets and we assume that changes in H1 repertoire might be associated with cardiovascular disease progression in vivo.