Increased CCT-eta expression is a marker of latent and active disease and a modulator of fibroblast contractility in Dupuytren's contracture

Cell Stress Chaperones. 2013 Jul;18(4):397-404. doi: 10.1007/s12192-012-0392-9. Epub 2013 Jan 6.

Abstract

Dupuytren's contracture (DC) is a fibroproliferative disorder of unknown etiology characterized by a scar-like contracture that develops in the palm and/or digits. We have previously reported that the eta subunit of the chaperonin containing T-complex polypeptide (CCT-eta) is increased in fibrotic wound healing, and is essential for the accumulation of α-smooth muscle actin (α-SMA) in fibroblasts. The purpose of this study was to determine if CCT-eta is similarly implicated in the aberrant fibrosis seen in DC and to investigate the role of CCT-eta in the behavior of myo/fibroblasts in DC. Fibroblasts were obtained from DC-affected palmar fascia, from adjacent phenotypically normal palmar fascia in the same DC patients (PF), and from non-DC palmar fascial tissues in patients undergoing carpal tunnel (CT) release. Inherent contractility in these three populations was examined using fibroblast-populated collagen lattices (FPCLs) and by cell traction force microscopy. Expression of CCT-eta and α-SMA protein was determined by Western blot. The effect of CCT-eta inhibition on the contractility of DC cells was determined by deploying an siRNA versus CCT-eta. DC cells were significantly more contractile than both matching palmar fascial (PF) cells and CT cells in both assays, with PF cells demonstrating an intermediate contractility in the FPCL assay. Whereas α-SMA protein was significantly increased only in DC cells compared to PF and CT cells, CCT-eta protein was significantly increased in both PF and DC cells compared to CT cells. siRNA-mediated depletion of CCT-eta inhibited the accumulation of both CCT-eta and α-SMA protein in DC cells, and also significantly decreased the contractility of treated DC cells. These observations suggest that increased expression of CCT-eta appears to be a marker for latent and active disease in these patients and to be essential for the increased contractility exhibited by these fibroblasts.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Biomarkers / metabolism
  • Cells, Cultured
  • Chaperonin Containing TCP-1 / antagonists & inhibitors
  • Chaperonin Containing TCP-1 / genetics
  • Chaperonin Containing TCP-1 / metabolism*
  • Dupuytren Contracture / metabolism
  • Dupuytren Contracture / pathology
  • Fascia / cytology
  • Fibroblasts / cytology
  • Fibroblasts / physiology*
  • Humans
  • Muscle Contraction / physiology
  • RNA Interference
  • RNA, Small Interfering / metabolism

Substances

  • ACTA2 protein, human
  • Actins
  • Biomarkers
  • RNA, Small Interfering
  • Chaperonin Containing TCP-1