Morphological and functional characteristics of cell culture derived from the mouse nail unit

Abstract

Nail unit is a complex anatomical structure that is capable of rapid growth and regeneration throughout the life. Such significant reparative potential is associated with the presence different types of stem and progenitor cells, whose biology remains one of the fundamental issues today. Taking into account the active search for new stem cell sources for cell therapy, the view of the nail unit as a potential site for the localization of undifferentiated cells with stem potency is topical problem.Purpose. The study was conducted with an objective to establish the morphological, morphometric and proliferative characteristics of cultured cells isolated from the mouse nail unit.Materials and methods. Primary cultures of cells were obtained from tissue sampling, which included areas of the proximal nail fold, nail matrix and onychodermis of the FVB mouse nail organ. Cells were cultured in DMEM:F12 medium with 15 % fetal bovine serum during 6 passages. We determined the colony-forming activity, the population growth rate and doubling time, measured the area of cells, nuclei, and calculated the nuclear-cytoplasmic ratio. For cell morphology analysis, we used staining with Bemer’s hematoxylin and eosin, Heidenhain’s iron hematoxylin and May-Grünwald stain.Results. According to the morphological analysis in vitro the cells from mouse nail unit are heterogeneous with high synthetic activity and a low nuclear-cytoplasmic ratio – the features characteristic of the low-differentiated cells. The population doubling time of the culture was 80 ± 6.5 hours on average, the fastest growing cells were at the 4th passage (63 ± 7 hours). The specific growth rate for cell culture is low (0.01 ± 0.0007).The colony forming efficiency at the 5th passage was only 4 %. A significant number of colonies was small with large poorly proliferative cells, which may indicate a production of large numbers of transitional progenitor cells.Conclusion. The obtained cell culture from the mouse nail unit according to the analysis of their morphology, morphometry and proliferative potential is heterogeneous and requires the further development of pure culture technologies for the detailed characterization of separate subpopulations of cells.