Microtubule dynamics control the direction of cardiomyocyte growth
Summary
The adult heart grows by the addition of sarcomeres along the length or width of individual cardiomyocytes, yet how directional growth is spatially coordinated remains unclear. We found that microtubule dynamics could act as a toggle to direct cardiomyocyte growth. Increasing microtubule stability drove cellular widening, concomitant with redirecting messenger RNA (mRNA) export and translation along the width of the cell and reinforcement of the intercalated disc. Conversely, decreasing mi
Content
# Microtubule dynamics control the direction of cardiomyocyte growth
*Published: 2026 May 14*
The adult heart grows by the addition of sarcomeres along the length or width of
individual cardiomyocytes, yet how directional growth is spatially coordinated
remains unclear. We found that microtubule dynamics could act as a toggle to
direct cardiomyocyte growth. Increasing microtubule stability drove cellular
widening, concomitant with redirecting messenger RNA (mRNA) export and
translation along the width of the cell and reinforcement of the intercalated
disc. Conversely, decreasing microtubule stability promoted cellular
lengthening, disrupting the intercalated disc and biasing translation and
incorporation of new sarcomeric protein toward this structure. Notably,
disrupting intercalated disc adhesion was sufficient for cardiomyocyte
elongation yet dispensable for cardiomyocyte widening. Thus, the heart
coordinates local translation and structural remodeling to orchestrate
bidirectional growth.
DOI: 10.1126/science.adz1970