cytochalasin-d and Dupuytren-Contracture

The anchored fibroblast-populated collagen matrix (aFPCM) is an appropriate model to study fibrocontractive disease mechanisms. Our goal was to determine if aFPCM height reduction (compaction) during development is sufficient to predict tension generation. Compaction was quantified daily by both traditional light microscopy and an optical coherence tomography (OCT) system. Contraction in aFPCM was revealed by releasing them from anchorage. We found that aFPCM contraction increase was correlated to the compaction increase. Cytochalasin D treatment reversibly inhibited compaction. Therefore, we demonstrated that aFPCM height reduction efficiently measures compaction, contraction, and relative maturity of the collagen matrix during development or treatment. In addition, we showed that OCT is suitable for effectively imaging the cross-sectional morphology of the aFPCM in culture. This study will pave the way for more efficient studies on the mechanisms of (and treatments that target) migration and contraction in wound healing and Dupuytren's contracture in a tissue environment.

Topics: Cell Movement; Cells, Cultured; Collagen; Connective Tissue; Cross-Sectional Studies; Cytochalasin D; Dupuytren Contracture; Fibroblasts; Humans; Microscopy; Stress, Physiological; Tomography, Optical Coherence; Wound Healing

Matrix metalloproteinases (MMPs) are expressed in Dupuytren's contracture and play a role in matrix remodeling. We tested the role of tension on contractility and MMP expression in Dupuytren's nodule and cord cells. Cells were subjected to pre-determined loading patterns of known repeatable magnitudes (static load, unloading, and overloading) and tested for MMP gene expression (MMP-1, -2, -9, -13, and TIMP-1, -2) and force generation using a tension-culture force monitor. Matrix remodeling was assessed by addition of cytochalasin D and residual matrix tension was quantified. Nodule compared to cord and control cells demonstrate greater force generation and remodeling (p < 0.05). Nodule cells subjected to a reduced load and overloading led to threefold increase of MMP-1, -2, and -9 compared to static load, whilst cord and control cells only showed a twofold increase of MMP-9. Nodule cells subjected to overloading showed a twofold increase in TIMP-2 expression, whilst cord and control cells showed a twofold increase in TIMP-1 expression. Nodule cells differ from cord cells by increased force generation in response to changes in the mechanical environment and related MMP/TIMP-mediated matrix remodeling. In turn this may lead to permanent matrix shortening and digital contracture. Interventional therapies should be aimed at nodule cells to prevent contraction and subsequent permanent matrix remodeling.

Topics: Aged; Cells, Cultured; Cytochalasin D; Dupuytren Contracture; Fibroblasts; Gene Expression; Humans; Matrix Metalloproteinases; Middle Aged; Muscle Contraction; Stress, Mechanical; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2

Mechanical tension and contracture are two related facets of tissue biology. This study assessed the effect of ilomastat, a broad-spectrum matrix metalloprotease (MMP) inhibitor, on generation of tension by Dupuytren's disease fibroblasts. Nodule and cord-derived fibroblasts were isolated from five patients with Dupuytren's disease; flexor retinaculum acted as the control. A culture force monitor (CFM) provided an in vitro model of tissue organization to assess development of mechanical tension, lattice contraction and spatial remodelling by fibroblasts. Responses to ilomastat were compared to treatment with a control peptide. Nodule and cord-derived fibroblasts exhibited a two-fold increase in tension compared with flexor retinaculum. Ilomastat significantly inhibited development of tension by nodule and cord but not flexor retinaculum derived fibroblasts at 100 microM. These results imply that MMP activity mediates regulation of tensile strength by Dupuytren's disease fibroblasts and may be an important therapeutic target in patients with Dupuytren's disease.

Topics: Cells, Cultured; Cytochalasin D; Dupuytren Contracture; Enzyme Inhibitors; Fibroblasts; Humans; Hydroxamic Acids; Indoles; Matrix Metalloproteinase Inhibitors; Nucleic Acid Synthesis Inhibitors