In vivo proliferation of vascular smooth muscle cells
Extensive vascular remodelling occurs during development, in response to injury and recent studies have shown that vasculature formed from host cells perfuse cardiac grafts established from injected stem cell-derived cardiomyocytes (1). The origin of cells in new vessels in grafts is not clear. To investigate whether pre-existing vascular smooth muscle cells (VSMC) can be induced to stimulate neo-vascularisation after MI, we have used clonal VSMC lineage tracing in models where VSMCs proliferation is induced acutely. We found that whereas adult VSMCs are largely quiescent in healthy tissue, a small subset of VSMCs are activated and expand clonally after vascular injury. This observation suggests that there is an unexploited cellular reserve that potentially can be activated to improve re-vascularisation.
Chappell, J., Harman, J.L., Narasimhan, V.M., Yu, H., Foote, K., Simons, B.D., Bennett, M.R., and Jørgensen, H.F. (2016). Extensive Proliferation of a Subset of Differentiated, yet Plastic, Medial Vascular Smooth Muscle Cells Contributes to Neointimal Formation in Mouse Injury and Atherosclerosis Models. Circulation Research 119, 1313–1323.