Osmosis Wound Healing
Channel: Health 4 YOU
Date: 2022-08-09

Osmosis Wound Healing

smotic cues from the environment mediate rapid detection of epithelial breaches by leukocytes in larval zebrafish tail fins. Using intravital luminescence and fluorescence microscopy, we now show that osmolarity differences between the interstitial fluid and the external environment trigger ATP release at tail fin wounds to initiate rapid wound closure through long-range activation of basal epithelial cell motility. Extracellular nucleotide breakdown, at least in part mediated by ecto-nucleoside triphosphate diphosphohydrolase 3 (Entpd3), restricts the range and duration of osmotically induced cell migration after injury. Thus, in zebrafish larvae, wound repair is driven by an autoregulatory circuit that generates pro-migratory tissue signals as a function of environmental exposure of the inside of the tissue.

Introduction
Rapid epithelial wound closure is essential for metazoan life, as it restricts exposure of the inside of an organism to the noxious outside environment. Wound closure mechanisms operate efficiently in animals that occupy different habitats (e.g., land/river/sea), and whose epithelia are exposed to vastly different physicochemical environments (air, fresh/salt water, etc.). Wound closure shows striking similarities to morphogenetic processes, such as dorsal closure in Drosophila melanogaster (Redd et al., 2004). These developmental events are thought to be regulated by organism-intrinsic cues; i.e., the external environment does not instruct them. Given its robust functionality throughout phyla, and analogy to developmental mechanisms, it is intuitive (and in fact common) to regard wound repair as an intrinsically guided, postdevelopmental program. Yet, it remains unclear whether the conserved function of wound repair derives from an insulation against extrinsic influences, or an adaption to them. The question arises whether epithelial wound detection and repair are obligatory tissue-intrinsic processes, or if they also integrate information from the environment.