How arterial muscle cells transform into macrophages and accelerate atherosclerosis

A striking cellular mechanism explains why atherosclerosis advances unchecked: the smooth muscle cells surrounding blood vessels are not fixed structures but highly plastic, capable of mutating into macrophage-like, fibroblast-like, or foam cell-like states in response to the toxic plaque environment. This phenotypic plasticity represents the pathological core of cardiovascular disease, the leading global cause of mortality. Single-cell sequencing and lineage-tracing techniques have revealed unprecedented heterogeneity within atherosclerotic lesions, showing how specific clones of smooth muscle cells expand in coordinated fashion. The infiltrating macrophages, already inflammatory and dying within the plaque, recruit additional macrophages through biochemical signals, creating an accumulation cycle analogous to what we observe in tumors. Emerging therapeutic strategies—phenotype-specific modulation, immunotherapy, nanomedicine, and senolytics—point toward precision medicine that interrupts this cellular transformation before unstable plaques trigger heart attack or stroke.