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bioRxiv · 10.1101/413377

Cytoskeleton mechanics determine resting size and activation dynamics of platelets.

Mathur, A.·Correia, S. R.·Dmitrieff, S.·Gibeaux, R.·Kalinina, I.·Quidwai, T.·Ries, J.·Nedelec, F.
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Abstract

Platelets are cell fragments of various size that help maintain hemostasis. The way platelets respond during a clotting process is known to depend on their size, with important physiological consequences. We characterized the cytoskeleton of platelets as a function of their size. In resting Human and Mice platelets, we find a quadradic law between the size of a platelet and the amount of microtubule polymer it contains. We further estimate the length and number of microtubules in the marginal band using Electron and Super-resolution microscopy. In platelets activated with ADP, the marginal band coils as a consequence of cortical contraction driven by actin. We observe that this elastic coiling response is accompanied by a reversible shortening of the marginal band. Moreover, larger platelets have a higher propensity to coil. These results establish the dynamic equilibrium that is responsible for platelet size and differential response on a more quantitative level.\n\nHighlightsO_LIPlatelet size scales consistently with amount of polymerized tubulin in both mouse and human.\nC_LIO_LIPolymerized actin is required for ADP-induced marginal band coiling.\nC_LIO_LIUpon activation, the marginal band exhibits a reversible visco-elastic response involving shortening.\nC_LIO_LILarger marginal bands have a higher propensity to coil than shorter ones.\nC_LI\n\nIn briefThe cytoskeleton is adapted to platelet size and its mechanical properties determine propensity of a platelet to undergo morphological changes in response to agonists.

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Mathur, A., Correia, S. R., Dmitrieff, S., Gibeaux, R., Kalinina, I., Quidwai, T., Ries, J., Nedelec, F.. 2018-09-10. Cytoskeleton mechanics determine resting size and activation dynamics of platelets.. https://doi.org/10.1101/413377

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