TY - JOUR
T1 - Regulation of corneal fibroblast morphology and collagen reorganization by extracellular matrix mechanical properties
AU - Karamichos, Dimitris
AU - Lakshman, Neema
AU - Petroll, W. Matthew
PY - 2007/11
Y1 - 2007/11
N2 - PURPOSE. To investigate how extracellular matrix mechanical properties influence cell and matrix patterning in three-dimensional culture. METHODS. Human corneal fibroblasts were seeded within 30 X 10 mm collagen matrices that were unconstrained (UN), fully constrained (CO) along the long axis by attaching the construct to two immobilized plastic bars, or partially constrained (PC) by allowing linear elastic displacement of one bar. After 24 hours, constructs were labeled with phalloidin and were imaged using fluorescent and reflected light (for collagen) confocal microscopy. Cell morphology and local collagen fibril density and alignment were measured using digital image processing. RESULTS. Corneal fibroblasts in UN matrices were less elongated (UN < PC < CO; P < 0.05) than those in constrained matrices. Cells were aligned parallel to the long axis in the anisotropic region of constrained matrices but were randomly aligned in unconstrained (isotropic) matrices (UN < PC = CO; P < 0.05). Both the local collagen density and the degree of cell/collagen coalignment were higher in constrained matrices (UN < PC < CO; P < 0.05). In regions of higher cell density, additional bands of aligned collagen were often observed between individual cells. CONCLUSIONS. These data suggest that cell spreading, alignment, and contractile force generation are directly influenced by the mechanical properties of the surrounding extracellular matrix (ECM). Corneal fibroblasts generally align and compact collagen parallel to the axis of greatest ECM stiffness. Mechanical cross-talk between adjacent cells leads to enhancement of matrix reorganization, and results in additional, more complex matrix patterning.
AB - PURPOSE. To investigate how extracellular matrix mechanical properties influence cell and matrix patterning in three-dimensional culture. METHODS. Human corneal fibroblasts were seeded within 30 X 10 mm collagen matrices that were unconstrained (UN), fully constrained (CO) along the long axis by attaching the construct to two immobilized plastic bars, or partially constrained (PC) by allowing linear elastic displacement of one bar. After 24 hours, constructs were labeled with phalloidin and were imaged using fluorescent and reflected light (for collagen) confocal microscopy. Cell morphology and local collagen fibril density and alignment were measured using digital image processing. RESULTS. Corneal fibroblasts in UN matrices were less elongated (UN < PC < CO; P < 0.05) than those in constrained matrices. Cells were aligned parallel to the long axis in the anisotropic region of constrained matrices but were randomly aligned in unconstrained (isotropic) matrices (UN < PC = CO; P < 0.05). Both the local collagen density and the degree of cell/collagen coalignment were higher in constrained matrices (UN < PC < CO; P < 0.05). In regions of higher cell density, additional bands of aligned collagen were often observed between individual cells. CONCLUSIONS. These data suggest that cell spreading, alignment, and contractile force generation are directly influenced by the mechanical properties of the surrounding extracellular matrix (ECM). Corneal fibroblasts generally align and compact collagen parallel to the axis of greatest ECM stiffness. Mechanical cross-talk between adjacent cells leads to enhancement of matrix reorganization, and results in additional, more complex matrix patterning.
UR - http://www.scopus.com/inward/record.url?scp=38449099430&partnerID=8YFLogxK
U2 - 10.1167/iovs.07-0443
DO - 10.1167/iovs.07-0443
M3 - Article
C2 - 17962454
AN - SCOPUS:38449099430
SN - 0146-0404
VL - 48
SP - 5030
EP - 5037
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 11
ER -