Background and purpose: Age is still the major independent risk factor for the pathogenesis of cardiovascular diseases (CVD) mainly due to the limited vascular regeneration capacity as well as the development of an endothelial dysfunction. The accumulation of senescent cells in the vasculature over the lifespan is a key process contributing to these processes. Senescent cells are characterized by impaired functional properties as proliferation and an enhanced inflammatory phenotype. These aspects encourage the usage of senescent cells as a target for further therapeutical strategies to restore vascular integrity and to increase health and lifespan.

Here, we aimed to establish a treatment to target senescent endothelial cells and restore their cellular functions by a partial, non-genetic reprogramming strategy involving three FDA-approved pharmacological substances.

Methods and Results: Working with primary vascular cells, methods to describe the effect of the treatment on cellular characteristics mainly included gene and protein expression analysis as well as assessment of cellular function by proliferation and scratch wound assays. Further experiments included determination of telomere length and immunofluorescence staining’s to study cell morphology.

Treatment of previously characterized senescent endothelial cells resulted in a significant up-regulation of reprogramming associated genes, namely Oct3/4, Sox2, Klf4 and c-Myc (OSKM) for the duration of the treatment (P<0.05). Additionally, siRNA-knockdown prior to the treatment confirmed the correlation between OSKM upregulation and pharmacological treatment. Staining’s for cell morphology for cellular and nuclear size as well as cell identity as endothelial cells did not show any alterations due to the treatment confirming the hypothesis of only a partial and not complete reprogramming process. However, cellular functions as proliferation (P<0.001), metabolic activity (P<0.05) and migration capacity (P<0.001) were significantly improved by the treatment of the senescent cells compared to an untreated senescent control. Further, endothelial cell function as endothelial sprouting (P<0.001) and tube formation (P<0.01) showed a significant improvement by the treatment. Moreover, expression of typical markers for senescent cells as p14arf (P<0.01) were significantly downregulated by the treatment. In contrast to the senescent cells, non-senescent endothelial cells were not influenced by the treatment. First in vivo experiments in a hind-limb ischemia model hint towards a promising approach to improve angiogenic capacities.