Dupuytren's fibroblast contractility by sphingosine-1-phosphate is mediated through non-muscle myosin II.
OBJECTIVE
Previous studies suggest that Dupuytren's disease is caused by fibroblast and myofibroblast contractility within Dupuytren's nodules; however, the stimulus for cell contractility is unknown. Sphingosine-1-phosphate (S1P) is a serum-derived lysophospholipid mediator that enhances cell contractility by activating the S1P receptor, S1P(2). It is hypothesized that S1P stimulates Dupuytren's fibroblast contractility through S1P(2) activation of non-muscle myosin II (NMMII). This investigation examined the role of S1P and NMMII activation in Dupuytren's disease progression and suggests potential targets for treatment.


METHODS
We enmeshed Dupuytren's fibroblasts into fibroblast-populated collagen lattices (FPCLs) and assayed S1P-stimulated FPCL contraction in the presence of the S1P(2) receptor inhibitor JTE-013, the Rho kinase inhibitor Y-27632, the myosin light chain kinase inhibitor ML-7, and the NMMII inhibitor blebbistatin. Tissues from Dupuytren's fascia (n = 10) and normal palmar fascia (n = 10) were immunostained for NMMIIA and NMMIIB.


RESULTS
Sphingosine-1-phosphate stimulated FPCL contraction in a dose-dependent manner. Inhibition of S1P(2) and NMMII prevented S1P-stimulated FPCL contraction. Rho kinase and myosin light chain kinase inhibited both S1P and control FPCL contraction. Dupuytren's nodule fibroblasts robustly expressed NMMIIA and NMMIIB, compared with quiescent-appearing cords and normal palmar fascia.


CONCLUSIONS
Sphingosine-1-phosphate promotes Dupuytren's fibroblast contractility through S1P(2), which stimulates activation of NMMII. NMMII isoforms are ubiquitously expressed throughout Dupuytren's nodules, which suggests that nodule fibroblasts are primed to respond to S1P stimulation to cause contracture formation. S1P-promoted activation of NMMII may be a target for disease treatment.
Komatsu
Issei
I
Division of Plastic and Reconstructive Surgery, Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA.
Bond
Jennifer
J
Selim
Angelica
A
Tomasek
James J
JJ
Levin
L Scott
LS
Levinson
Howard
H
D002460:Cell Line; D003094:Collagen; D018450:Disease Progression; D004387:Dupuytren Contracture / Q000378:metabolism*; D005347:Fibroblasts / Q000737:chemistry* / Q000502:physiology; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D007124:Immunoenzyme Techniques; D008246:Lysophospholipids / Q000378:metabolism*; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000737:chemistry*; D024462:Myosin Type II / Q000096:biosynthesis*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism
D006576:Heterocyclic Compounds, 4 or More Rings; D008246:Lysophospholipids; C472645:blebbistatin; C060506:sphingosine 1-phosphate; D003094:Collagen; D024462:Myosin Type II; D013110:Sphingosine