Bacterial lipopolysaccharides can initiate regeneration of the Xenopus tadpole tail

Tadpoles of the frog Xenopus laevis can regenerate tails except for a short refrac-tory period in which they heal rather than regenerate. Rapid and sustained pro-duction of ROS by NADPH oxidase (Nox) is critical for regeneration. Here, we show that tail amputation results in rapid, transient activation of the ROS-activated transcription factor NF-kappa B and expression of its direct target cox2 in the wound epithelium. Activation of NF-kappa B is also sufficient to rescue refractory tail regeneration. We propose that bacteria on the tadoole's skin could influence tail regenerative outcomes, possibly via LPS-TLR4-NF-kappa B signaling. When raised in antibiotics, fewer tadpoles in the refractory stage attempted regeneration, whereas addition of LPS rescued regeneration. Short-term activation of NF-kappa B using small molecules enhanced regeneration of tadpole hindlimbs, but not froglet forelimbs. We propose a model in which host microbiome contributes to creating optimal conditions for regeneration, via regulation of NF-kappa B by the innate immune system.

Automated summary

The regeneration of tadpole tails is regulated by ROS, NF-kappa B, and the host microbiome, possibly through the LPS-TLR4-NF-kappa B signaling pathway. Activation of NF-kappa B can rescue refractory tail regeneration.