Tracking phenotypic heterogeneity at the single cell level in populations of vascular cells through the development of microwell arrays

Significant remodelling of the vascular wall underlies cardiovascular disease resulting in the formation of atherosclerotic plaques populated with macrophage and smooth muscle cells (SMCs). These SMCs are thought to arise from the vessel wall, as mature SMCs de-differentiate from a contractile to a migratory,
proliferate phenotype. However, the remodelling process is not fully understood and uncertainties remain over the plasticity of cells within the wall. Both drug development and regenerative medicine have been restricted by these uncertainties. Recently, through a combination of time-lapse, high-speed fluorescence and 3D reconstruction microscopy, we demonstrated unambiguously [1] that freshly isolated mature, contractile SMCs can rapidly transform into not only a migratory but a phagocytic phenotype, a characteristic behaviour of macrophage. Results also showed strong heterogeneity in the proliferation of SMCs [2] and the presence of other highly proliferative cell types in vascular wall that readily interact with SMCs. To better understand vascular cell fate, including characterizing cell-cell phenotypic heterogeneity, we are developing strategies that enable screening at the single cell level of large numbers of freshly isolated vascular cells.