Aldehyde Dehydrogenase as a Marker of Early Mesenchymal Progenitor Cells in Donor Bone Marrow Stroma

Abstract

Aim. To analyze the growth rate of mesenchymal stromal cell (MSC) culture depending on the aldehyde dehydrogenase-positive (ALDH+) cell count. Materials & Methods. The study involved bone marrow mesenchymal cell cultures of 10 donors (5 men and 5 women) with median age of 34.5 years (range 14-38 years). Nucleated cells were obtained by density gradient centrifugation. MSCs were cultivated according to the conventional protocol using platelet-rich donor plasma. Stromal cell identification and ALDH+ cell counting were performed by laser flow cytometry according to the criteria of the International Society for Cell Therapy. Results. The growth rate of MSC cultures and ALDH+ cell counts are maximum at primary and passage No. 1, becoming significantly lower by passage No. 3. The relationship between MSC culture growth rate and ALDH+ cell count was revealed. The older the donor, the lower MSC culture growth rate and ALDH+ cell count in bone marrow stroma. Conclusion. The data obtained indicate the relationship between bone marrow MSC culture growth rate, donor’s age, and ALDH+ cell count. ALDH-expressing cells proved to confer MSC population renewal. Based on the results acquired, we assume that the studied ALDH marker can serve as an objective criterion for placing mesenchymal cell elements into the category of early progenitor cells.