Lgr6 marks nail stem cells and is required for digit tip regeneration

Area of Science:

• Regenerative biology
• Mammalian development
• Stem cell biology

Background:

• Digit tip regeneration in mammals is a complex process.
• It relies on the nail organ and a proliferative blastema.
• Wnt/β-catenin signaling is essential for this regeneration.

Purpose of the Study:

• Investigate the roles of Lgr5 and Lgr6 (leucine-rich repeat-containing G protein-coupled receptor 5 and 6) in digit tip regeneration.
• Identify stem cell populations involved in this process.
• Determine the function of Lgr6-expressing cells.

Main Methods:

• Expression analysis of Lgr5 and Lgr6.
• Genetic lineage tracing.
• Analysis of Lgr6-deficient mice.

Main Results:

• Lgr5 is expressed in the dermis but does not contribute to the blastema.
• Lgr6 is expressed in the nail matrix, bone, and sweat glands.
• Lgr6 marks nail stem cells and contributes to the blastema.
• Lgr6-deficient mice exhibit defects in nail and bone regeneration.

Conclusions:

• Lgr6 is a key marker for nail stem cells.
• Lgr6-expressing cells play a direct role in digit tip regeneration.
• The nail organ is critical for mammalian digit regeneration.