Study reveals mural cell morphology and vessel coverage as key regulators of vessel diameter
A zebrafish study published on bioRxiv found that vascular mural cells regulate blood vessel diameter primarily through changes in cell morphology and vessel coverage, rather than contractility alone. Researchers used live imaging and single-cell morphometric analysis to track how vascular smooth muscle cells and pericytes retract their processes during vascular remodeling. The findings challenge the prevailing view that contractile force is the dominant mechanism controlling vessel diameter, with implications for understanding vascular disease.
Using high-resolution live imaging and single-cell morphometric analysis in zebrafish, researchers demonstrated that vascular smooth muscle cells (vSMCs) and pericytes progressively reduce in size by retracting actin-rich cellular processes during vascular remodeling. By manipulating RhoA activity to alter mural cell contractility and shape, the team identified vessel-specific roles: vSMC contractility was found to be dispensable for the initial constriction of the dorsal aorta but necessary to stabilize its diameter afterward and maintain vascular tone. Pericyte contractility, by contrast, was dispensable for both constriction and stabilization of intersegmental vessels. In brain vasculature specifically, vessel diameter was governed by the balance between contractile force and the extent of vessel coverage by vSMCs. The study concludes that cell morphology and vessel coverage are key determinants of vascular diameter in vivo, redefining how mural cell function is understood in vascular biology.
What's missing
As a preprint posted on bioRxiv, this study has not yet undergone peer review, and its findings should be interpreted with caution. The study relies entirely on zebrafish as a model organism, and it remains unclear how directly these mechanisms translate to mammalian or human vascular physiology.
What different sources said
- bioRxivCenter
Mural cell contractility regulates vessel diameter by controlling cell morphology and vessel coverage
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