Cyclic stretch reveals a mechanical role for intermediate filaments in a desminopathic cell model

Abstract

Mechanics is now recognized as crucial in cell function. To date, the mechanical properties of cells have been inferred from experiments which investigate the roles of actin and microtubules ignoring the intermediate filaments (IFs) contribution. Here, we analyse myoblasts behaviour in the context of myofibrillar myopathy resulting from p.D399Y desmin mutation which disorganizes the desmin IF network in muscle cells. We compare the response of myoblasts expressing either mutated or wild-type desmin to cyclic stretch. Cells are cultivated on supports submitted to periodic uniaxial stretch of 20% elongation amplitude and 0.3 Hz frequency. We show that during stretching cycles, cells expressing mutated desmin reduce their mean amplitude both for the elongation and spreading area compared to those expressing wild-type desmin. Even more unexpected, the reorientation angles are altered in the presence of p.D399Y desmin. Yet, at rest, the whole set of those parameters are similar for the two cell populations. Thus, we demonstrate that IFs affect the mechanical properties and the dynamics of cell reorientation. Since these processes are known due to actin cytoskeleton, these results suggest the IFs implication in mechanics signal transduction. Further studies may lead to better understanding of their contribution to this process.

Effects of oxidative stress-induced changes in the actin cytoskeletal structure on myoblast damage under compressive stress: confocal-based cell-specific finite element analysis

“…This seemed to be consistent with an earlier observation that microtubules disruption apparently had little effect on the elastic moduli of myoblasts measured using atomic force microscopy (AFM) (Collinsworth et al 2002). Intermediate filaments seemed to play significant roles when cells were being stretched (Leccia et al 2013) and under large deformation (Wang and Stamenovic 2000).…”

N-Acetyl-L-Cysteine Prevents Stress-Induced Desmin Aggregation in Cellular Models of Desminopathy

“…Cell stretching is supposed to mimic muscle contraction/shrinkage. Here, stretching conditions of 20% elongation and 6 hours’ duration were based on previous experiments on cell reorientation dynamics [29]. Other authors found increased cell death and substrate detachment with 30% elongation and similar frequency [23].…”

“…Cells were stretched as described previously [29]. Briefly, cells were plated on elastomeric strips of poly-dimethylsiloxane (PDMS) (Sylgard 184, Corning) coated with fibronectin (Sigma-Aldrich) at 2 x 10 3  cells/cm 2 and cultured for 72 h before stretching.…”

Condensed desmin and actin cytoskeletal communication in lipid droplets

“…To begin to understand intercytoskeletal communications, we focused on muscle desmin and actin, which are involved in force‐related events and in the scaffolding of the complex muscle architecture (Charrier et al, ; Leccia et al, ; Palmisano et al, ). The interaction of desmin filaments with muscle proteins of nebulin and nebulette contributes to the organization of the Z‐disk structure, and the modulation of their affinity by desmin mutations can induce dysfunction of striated muscle cells (Baker et al, ; Hernandez et al, ).…”

“…To begin to understand intercytoskeletal communications, we focused on muscle desmin and actin, which are involved in forcerelated events and in the scaffolding of the complex muscle architecture (Charrier et al, 2016;Leccia et al, 2012;Palmisano et al, 2015).…”