Integration of single and multicellular wound responses

Curr Biol. 2009 Aug 25;19(16):1389-95. doi: 10.1016/j.cub.2009.06.044. Epub 2009 Jul 23.

Abstract

Single cells and multicellular tissues rapidly heal wounds. These processes are considered distinct, but one mode of healing--Rho GTPase-dependent formation and closure of a purse string of actin filaments (F-actin) and myosin-2 around wounds--occurs in single cells and in epithelia. Here, we show that wounding of one cell in Xenopus embryos elicits Rho GTPase activation around the wound and at the nearest cell-cell junctions in the neighbor cells. F-actin and myosin-2 accumulate at the junctions and around the wound itself, and as the resultant actomyosin array closes over the wound site, junctional F-actin and myosin-2 become mechanically integrated with the actin and myosin-2 around the wound, forming a hybrid purse string. When cells are ablated rather than wounded, Rho GTPase activation and F-actin accumulation occur at cell-cell junctions surrounding the ablated cell, and the purse string closes the hole in the epithelium. Elevation of intracellular free calcium, an essential upstream signal for the single-cell wound response, also occurs at the cell-cell contacts and in neighbor cells. Thus, the single and multicellular purse string wound responses represent points on a signaling and mechanical continuum that are integrated by cell-cell junctions.

Publication types

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

MeSH terms

  • Actins / physiology*
  • Animals
  • Blastomeres
  • Calcium Signaling
  • Embryo, Nonmammalian / injuries
  • Embryo, Nonmammalian / metabolism
  • Enzyme Activation
  • Intercellular Junctions / physiology*
  • Myosin Type II / physiology*
  • Wound Healing / genetics
  • Wound Healing / physiology*
  • Xenopus laevis / embryology
  • rho GTP-Binding Proteins / physiology*

Substances

  • Actins
  • Myosin Type II
  • rho GTP-Binding Proteins