By Guest Bloggers Han Peng, PhD & Robert M. Lavker, PhD
Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
“Stop biting your nails!” parents scold their children.
Now we have more evidence why parents are correct in this admonishment. Nail biters, here is the latest scientific warning: Do not bite your nails too deeply; otherwise, you may lose the ability to regenerate the nail (and digit, if you are an Olympic nail-biter), according to Takeo et al in a recent article published in Nature.
The ability to regenerate nails and digit-tips in mice requires wnt signals initiated by the nail distal matrix; this is supported by evidence that loss of wnt signal (by either conditional knockout of β-catenin or removal of the distal matrix) results in failure of nail differentiation and bone regeneration.
Given the wnt signaling links between nail differentiation and digit regeneration, Takeo and colleagues investigated whether giving a wnt signal to nail epithelium can overcome the limitation of regeneration after removal of the distal matrix. Indeed, stabilization of β-catenin in the basal nail epithelium, which includes the nail epithelial stem cells, leads to regeneration of wnt-active distal nail matrix, formation of an innervated blastema, bone regeneration, and nail regrowth. Therefore, from the bench-to-bedside of view, nail epithelial stem cells may have the potential for the development of a stem cell therapy for amputees, if the proper signals were given. In the short-term, congenital nail biters might have a way out; a nail polish containing slow release, activated, Wnt nanoparticles, which could penetrate the nail plate and maintain nail viability.