The different roles of myosin IIA and myosin IIB in contraction of 3D collagen matrices by human fibroblasts.
Contraction of 3D collagen matrices by fibroblasts frequently is used as an in vitro model of wound closure. Different iterations of the model - all conventionally referred to as "contraction" - involve different morphological patterns. During floating matrix contraction, cells initially are round without stress fibers and subsequently undergo spreading. During stressed matrix contraction, cells initially are spread with stress fibers and subsequently undergo shortening. In the current studies, we used siRNA silencing of myosin IIA (MyoIIA) and myosin IIB (MyoIIB) to test the roles of myosin II isoforms in fibroblast interactions with 3D collagen matrices and collagen matrix contraction. We found that MyoIIA but not MyoIIB was required for cellular global inward contractile force, formation of actin stress fibers, and morphogenic cell clustering. Stressed matrix contraction required MyoIIA but not MyoIIB. Either MyoIIA or MyoIIB was sufficient for floating matrix contraction (FMC) stimulated by platelet-derived growth factor. Neither MyoIIA or MyoIIB was necessary for FMC stimulated by serum. Our findings suggest that myosin II-dependent motor mechanisms for collagen translocation during extracellular matrix remodeling differ depending on cell tension and growth factor stimulation.
Department of Cell Biology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9039, USA.
Zhenan
Z
Liu
Department of Cell Biology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9039, USA.
Chin-Han
CH
Ho
Department of Cell Biology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9039, USA. Electronic address: Frederick.grinnell@utsouthwestern.edu.
Frederick
F
Grinnell
D001696:Biomechanical Phenomena; D002448:Cell Adhesion / Q000502:physiology; D002449:Cell Aggregation / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D024507:Nonmuscle Myosin Type IIA / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D024501:Nonmuscle Myosin Type IIB / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D014945:Wound Healing / Q000502:physiology
D006576:Heterocyclic Compounds, 4 or More Rings; D034741:RNA, Small Interfering; C472645:blebbistatin; D003094:Collagen; D024507:Nonmuscle Myosin Type IIA; D024501:Nonmuscle Myosin Type IIB
3D collagen matrix; Cell contraction; Morphogenic cell clustering; Myosin; Wound repair