The early wound signals

Abstract

Wounding of tissue barriers, such as epithelia, disrupts homeostasis and allows infection. Within minutes, animals detect injury and respond to it by recruitment of phagocytes and barrier breach closure. The signals that activate these first responses are scarcely known. Commonly considered are cytoplasmic factors released into the extracellular space by lysing cells (Damage Associated Molecular Patterns, DAMPs). DAMPs activate transcription through pattern recognition receptors. But the promptness of wound responses is difficult to explain by transcriptional mechanisms alone. This review highlights the emerging role of nonlytic stress signals in the rapid detection of wounds.

Amputation‐induced reactive oxygen species signaling is required for axolotl tail regeneration

“…In the context of tissue damage or injury, ROS can modulate injury‐induced gene expression responses and regulate proteins involved in wound signaling and regeneration (Enyedi and Niethammer, ; Neithammer, ; Lessi et al, ). Our results show that ROS signaling and NOX activity are required for axolotl spinal cord and tail regeneration.…”

Hydrogen peroxide as a central redox signaling molecule in physiological oxidative stress: Oxidative eustress

“…Cell proliferation subsequent to amputation of the tail of tadpoles involves increases in H 2 O 2 concentration, as indicated by the HyPer probe (assuming that pH effects do not contribute significantly to the signal) [95]. The transients in H 2 O 2 are embedded in concerted action with other signals in the process of wound responses mentioned in the Introduction above [96]·H 2 O 2 controls axon pathfinding of retinal ganglion cells projecting towards the tectum in zebrafish [97].…”

Regeneration Genetics

“…Mechanical properties of epithelial cells are likely to mobilize epithelial cell sheets (16), but the molecular basis of their differential motility and its significance are unclear. Studies of wound healing responses in zebrafish larvae and Drosophila embryos indicate clues to early molecular responses (83; 95). At the onset of wounding, initial tissue damage is thought to be detected by osmotic surveillance (28; 33).…”

“…Among several known early wound-released signals (83), the production of hydrogen peroxide along the wound edge can recruit leukocytes to sites of tissue damage by activation of the redox sensor Lyn, a Src family kinase (84; 137). In addition to transient activation at the early phase of wounding (< 2 hours) for recruiting immune cells, ROS remain elevated at the wound edge for days in both zebrafish and Xenopus models (34; 72).…”