title: Prx-1 expression in Xenopus laevis scarless skin-wound healing and its resemblance to epimorphic regeneration.
abstract: Despite a strong clinical need for inducing scarless wound healing, the molecular factors required to accomplish it are unknown. Although skin-wound healing in adult mammals often results in scarring, some amphibians can regenerate injured body parts, even an amputated limb, without it. To understand the mechanisms of perfect skin-wound healing in regenerative tetrapods, we studied the healing process in young adult Xenopus "froglets" after experimental skin excision. We found that the excision wound healed completely in Xenopus froglets, without scarring. Mononuclear cells expressing a homeobox gene, prx1, accumulated under the new epidermis of skin wounds on the limb and trunk and at the regenerating limb. In transgenic Xenopus froglets expressing a reporter for the mouse prx1 limb-specific enhancer, activity was seen in the healing skin and in the regenerating limb. Comparable activity did not accompany skin-wound healing in adult mice. Our results suggest that scarless skin-wound healing may require activation of the prx1 limb enhancer, and competence to activate the enhancer is probably a prerequisite for epimorphic regeneration, such as limb regeneration. Finally, the induction of this prx1 enhancer activity may be useful as a reliable marker for therapeutically induced scarless wound healing in mammals.
authors.affiliation: Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan. yokoyoko@biology.tohoku.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Tamae
authors.initials: T
authors.lastname: Maruoka
authors.forename: Akio
authors.initials: A
authors.lastname: Aruga
authors.forename: Takanori
authors.initials: T
authors.lastname: Amano
authors.forename: Shiro
authors.initials: S
authors.lastname: Ohgo
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shiroishi
authors.forename: Koji
authors.initials: K
authors.lastname: Tamura
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002921:Cicatrix / Q000235:genetics; D005121:Extremities / Q000502:physiology; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D009000:Monocytes / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012867:Skin / Q000378:metabolism; D014945:Wound Healing / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics*; D014982:Xenopus laevis
chemical_list: D018398:Homeodomain Proteins; C489937:PRRX1 protein, Xenopus; C489936:Prrx1 protein, mouse; D029867:Xenopus Proteins