Determining the Chronological Onset of Senescence in the Aging Vasculature

National Institute On Aging

Investigators

Abstract

To track senescent cells in the vasculature, we will utilize a combination of approaches including immunofluorescence, western blotting, and high-throughput proteomics and spatial transcriptomics. First, we employed irradiated and control p16tdTomato mice to determine whether immunostaining of the aortic root would be an effective way to assess senescence. We have demonstrated that mice irradiated with 6Gy begin to develop plaque in their aortic root, despite being fed a normal diet. Additionally, immunofluorescent staining of the same aortic root revealed p16 and tdTomato-positive cells, suggesting the presence of senescent cells where plaque accumulates. Further, protein lysates prepared from the descending aortas of mice expressed less Lamin B1 (LMNB1), a protein strongly reduced during senescence, in old and IR-treated animals. Using SLAM mice from ages ranging from 6 to 36 months, we can systematically determine the onset of cellular senescence in the vascular wall to identify the optimal time point for interventional therapy. Further, we can leverage unbiased techniques, such as mass spectrometry and spatial sequencing, to elucidate the protein and RNA changes that govern alterations in cell function and ultimately promote functional decline in the vasculature during aging.