Bovine CD49 positive-cell subpopulation remarkably increases in mammary epithelial cells that retain a stem-like
Diego Cravero1, Eugenio Martignani1, Silvia Miretti1
1Dept. Veterinary Science, University of Turin, Largo Braccini 2, 10095 Grugliasco, TO, Italy.
Insights
Adult bovine mammary stem cells retain regenerative potential in long-term culture. These CD49f-positive cells can form functional mammary outgrowths in vivo, confirming their multipotency.
Area of Science:
- Stem Cell Biology
- Mammary Gland Development
- Bovine Research
Background:
- Adult stem cells in the bovine mammary gland possess regenerative potential.
- Mammary stem-like cells were maintained in long-term culture for immunophenotyping.
Purpose of the Study:
- To investigate the immunophenotypic characteristics of bovine mammary stem-like cells during extended in vitro culture.
- To assess the regenerative capacity of cultured mammary stem cells in vivo.
Main Methods:
- Flow cytometry was used to analyze cell subpopulations over time.
- Mammary epithelial cells were cultured long-term.
- In vivo xenotransplantation into immunodeficient mice was performed.
Main Results:
- CD49f-positive cell populations significantly increased during culture (p<0.01).
- CD29 and ALDH1 positive cell populations showed similar trends.
- CD49f-positive cells retained regenerative capabilities after 35 days of culture, forming pseudo-alveoli in vivo.
Conclusions:
- A multipotent cell subpopulation with strong epithelial induction potential exists in the bovine mammary gland.
- Long-term in vitro culture may expand the primitive population of adult mammary stem cells.
- Cultured CD49f-positive cells demonstrate sustained regenerative capacity in vivo.
Abstract:
We previously proved that adult stem cells reside in the bovine mammary gland and possess an intrinsic potential to generate a functional mammary outgrowth. The aim of this study was to investigate on the immunophenotyping features retained by mammary stem-like cells detected in long term culture. Flow cytometry analysis showed different subpopulations of mammary epithelial cells emerging according to the timing of cell culture. CD49f(+)-cells significantly increased during the culture (p<0.01) and a similar trend was observed, even if less regular, for CD29(+) and ALDH1 positive cell populations. No difference during the culture was observed for CD24 positive cells but after 35 days of culture a subset of cells, CD49f positive, still retained regenerative capabilities in in vivo xenotransplants. These cells were able to form organized pseudo-alveoli when transplanted in immunodeficient mice. These results prove the presence of a multipotent cell subpopulation that retain a strong epithelial induction, confirmed in in vivo xenotransplants with a presumable in vitro expansion of the primitive population of adult mammary stem cells.
