Key result
Microtubule depolymerization prevents stiffness-induced T-tubule remodeling and calcium handling impairment in cardiomyocytes.
Why the study?
Disruption of T-tubule structure contributes to contractile dysfunction in heart failure, but the mechanisms driving this remodeling remain poorly understood.
Pathological mechanical stiffness alone is sufficient to induce T-tubular remodeling and Ca2+ handling dysfunction in cardiomyocytes via a microtubule-dependent mechanism.
Mechanical load alone drives T-tubule remodeling in isolated cardiomyocytes; leaves open in vivo relevance and therapeutic targeting.
T-tubules are invaginations of the cardiomyocyte sarcolemma, essential for excitation–contraction coupling and calcium-induced calcium release. Disruption of T-tubule structure contributes to contractile dysfunction in heart failure, yet the mechanisms driving this remodeling remain poorly understood. Here, we investigated whether mechanical load alone, independent of neurohormonal signals and extracellular matrix cues, is sufficient to induce pathological remodeling of T-tubules in isolated cardiomyocytes. Using a magnetorheological elastomer (MRE) culture system with tunable stiffness, we subjected adult rat cardiomyocytes to mechanical microenvironments spanning that of healthy (10 kPa) and diseased (50 kPa) myocardium. We assessed Ca 2+ -handling, T-tubule architecture, and the localization of key structural and functional proteins, as well as evaluated the role of the microtubule cytoskeleton using nocodazole-mediated depolymerization. We found that pathological substrate stiffness impaired Ca 2+ -transients, increased Ca 2+ -release dyssynchrony, and disrupted T-tubule organization, causing a shift from transverse to longitudinal orientation. We found no differences in key T-tubule total protein levels between experimental groups but observed spatial reorganization of TCAP in response to substrate stiffening. Microtubule depolymerization with nocodazole prevented pathological t-tubule remodeling, suggesting that microtubules act as mechanotransducers that orchestrate subcellular reorganization in response to mechanical cues. Our findings highlight the intrinsic ability of cardiomyocytes to remodel in response to mechanical load in the form of extracellular mechanical stiffness, in the absence of external hormonal influences, other cell types, the extracellular matrix, and other compensatory systemic responses, and that this is largely mediated by the microtubular network.
No takes yet. Share an insight, caveat, or question.
Ibrahim et al. (2026) studied Pathological mechanical stiffness / Heart failure. Pathological substrate stiffness (50 kPa) vs. Healthy substrate stiffness (10 kPa) was evaluated on Ca2+-handling, T-tubule architecture, and localization of key structural and functional proteins. Pathological substrate stiffness impaired Ca2+-transients and disrupted T-tubule organization in adult rat cardiomyocytes, a remodeling process prevented by microtubule depolymerization.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: