C CellMatrix Interactions A How cells pull onto and deform the matrix to which they attach themselves B Cell-matrix interactions control the spontaneous closure of wounds in organs. C. What happens when regeneration is induced?
C. Cell-Matrix Interactions A. How cells pull onto and deform the matrix to which they attach themselves. B. Cell-matrix interactions control the spontaneous closure of wounds in organs. C. What happens when regeneration is induced?
C. What happens when regeneration is induced? Closure of a defect by contraction(and scar synthesis)appears to block regeneration in the adult Certain ECM analogs that selectively lock contraction have been shown to induce partial regeneration in adults skin, peripheral nerves, conjunctiva) Under the same conditions, neither addition of growth factors nor of cell suspensions have blocked contraction nor have they induced regeneration
C. What happens when regeneration is induced? • Closure of a defect by contraction (and scar synthesis) appears to block regeneration in the adult. • Certain ECM analogs that selectively lock contraction have been shown to induce partial regeneration in adults (skin, peripheral nerves, conjunctiva). • Under the same conditions, neither addition of growth factors nor of cell suspensions have blocked contraction nor have they induced regeneration
Hypothesis: Regeneration requires selective blocking of contraction
Hypothesis: Regeneration requires selective blocking of contraction
a brief review of the obvious effects of closure by contraction
A brief review of the obvious effects of closure by contraction
Isolated cell(fibroblast) contracts surface of thin silicone film, floating on oil. Buckling results Image removed due to copyright considerations See Figure 9. 1 in Yannas, L.V. Tissue and Organ Regeneration in Adults New York: Springer-Verlag, 2001
Isolated cell (fibroblast) contracts surface of thin silicone film, floating on oil. Buckling results. Image removed due to copyright considerations. See Figure 9.1 in Yannas, I. V. Tissue and Organ Regeneration in Adults. New York: Springer-Verlag, 2001. Image removed due to copyright considerations. See Figure 9.1 in Yannas, I. V. Tissue and Organ Regeneration in Adults. New York: Springer-Verlag, 2001
Burn patient has experienced closure by contraction Image removed due to copyright considerations of massive wounds in neck
Burn patient has experienced closure by contraction of massive wounds in neck Image removed due to copyright considerations. Image removed due to copyright considerations
Closure of dermis natural light free defect by contraction Image removed due to copyright considerations See Figure 9. 4 in [Yannas] induces scar synthesis polarized light
Closure of dermisfree defect by contraction induces scar synthesis natural light Image removed due to copyright considerations. See Figure 9.4 in [Yannas]. Image removed due to copyright considerations. See Figure 9.4 in [Yannas]. polarized light
Cell capsule round regenerated nerves mm gap normal rat sciatic Image removed due to copyright considerations nerve See Figure 10.7 in [Yannas 8-mm gap Regenerated across mm gap
Normal rat sciatic nerve Regenerated across 0-mm gap 4-mm gap 8-mm gap Cell capsule round regenerated nerves Image removed due to copyright considerations. See Figure 10.7 in [Yannas]. Image removed due to copyright considerations. See Figure 10.7 in [Yannas]
Contractile cells near original (brown) proximal ensheathe stump regenerating Image removed due to copyright considerations stump See Figure 4.6 in [Yannas] of transected rat sciatic nerve near original distal stump
near original proximal stump Contractile cells (brown) ensheathe regenerating stump of transected rat sciatic nerve Image removed due to copyright considerations. See Figure 4.6 in [Yannas]. Image removed due to copyright considerations. See Figure 4.6 in [Yannas]. near original distal stump
Partly regenerated rat sciatic cross-section nerve Image removed due to copyright considerations shows thick Tubulated See Figure 4.5 in [ Yannas sheath in silicone of contractile tube cells
Partly regenerated rat sciatic nerve. Tubulated in silicone tube. cross-section shows thick sheath of contractile cells Image removed due to copyright considerations. See Figure 4.5 in [Yannas]. Image removed due to copyright considerations. See Figure 4.5 in [Yannas]
