Epidermal Wound Healing in the Nematode Caenorhabditis elegans.

Significance: Healing of epidermal wounds is a fundamentally conserved process found in essentially all multicellular organisms. Studies of anatomically simple and genetically tractable model invertebrates can illuminate the roles of key genes and mechanisms in wound healing. Recent Advances: The nematode skin is composed of a simple epithelium, the epidermis (also known as hypodermis), and an associated extracellular cuticle. Nematodes likely have a robust capacity for epidermal repair; yet until recently, relatively few studies have directly analyzed wound healing. Here we review epidermal wound responses and repair in the model nematode Caenorhabditis elegans. Critical Issues: Wounding the epidermis triggers a cutaneous innate immune response and wound closure. The innate immune response involves upregulation of a suite of antimicrobial peptides. Wound closure involves a Ca2+-triggered rearrangement of the actin cytoskeleton. These processes appear to be initiated independently, yet, their coordinated activity allows the animal to survive otherwise fatal skin wounds. Future Directions: Unanswered questions include the nature of the damage-associated molecular patterns sensed by the epidermis, the signaling pathways relaying Ca2+ to the cytoskeleton, and the mechanisms of permeability barrier repair.