Newly Discovered Mouse Digit Tip Derived Precursors Are Associated With Digit Regeneration

Objective The aim of this project was to identify and characterize the putativestem/progenitor cells from mouse digit tip and analyze the role of novel cellpopulation during mouse digit tip regeneration.Methods1. The putative stem/progenitor cells were isolated from neonatal mice,expended in DMEM/F12medium, differentiated in conditional medium andcharacterized by PCR, immunofluorescent staining and immunocytochemical stainingtechnologies.2. The postnatal day3(PN3) mice were anesthetized with an intraperitonealinjection of pentobarbital (50mg/kg), amputation was performed in the distal one-halfof the terminal phalanx by using microdissection scissors. In all mice, the centralthree digits of right hindlimbs were amputated as experimental groups while lefthindlimb digits were intact as control groups. Entire digit tissues were removed fromhindlimbs at different times after amputation for immunohistochemistry staining.Results1. we employed a SKP sphere culture condition to isolate putativestem/progenitor cells from neonatal mice digits[1]. Interestingly, we found that thenovel cells were Sox-2positive, and expressing other stem cell markers. In addition,these cells have the capabilities of self-renewing and multiple differentiation in someextent, which can steadily subcultured for3to5times, and differentiate to neuron,schwann, cartilage, and other types of cells， so we name it Digit Tip DerivedPrecursors(DTDPs).2. About4weeks after amputation, the amputated digits were observed toregenerate closely completely. Staining results showed that during the regenerationthe number of Sox-2positive cells located in the dermis and subcutaneous around thedigit tip was increased. Conclusion In the present study, we found that DTDPs have some capabilities ofstem cells, and they are associated with the wound repair or regeneration of digit.