Rowe Researcher: Mesenchymal Progenitors

Spring 2008: Characterization of Mesenchymal Progenitors from Bone Marrow and Adipose Tissue

By Shawnet K. Jones, Katie Lamothe, Ivo Kalajzic and H.Leonardo Aguila

In the lab of Dr. H. Leonardo Aguila we aimed to find markers that would allow for the characterization and isolation of mesenchymal progenitors from different sources. This project focused mostly on progenitors isolated from bone marrow and adipose tissue, two sites containing cells with recognized ability to form bone. In addition this project aimed to determine if there was a differential distribution of progenitor cells amongst males and females.

The distribution of cell surface markers, evaluated by flow cytometry, made us appreciate the cellular heterogeneity between different organs. Our an-alysis of hematopoietic elements showed that adipose tissue contains an elevated number of T cells. The comparison of bone marrow and adipose tissue showed distinct distribution of markers in their non-hematopoietic compartment, indicating that cells with osteogenic potential may have different phenotypes in each organ.

Differences between genders were observed in the distribution of cell surface markers in non-hematopoietic compartments. This could represent differences induced by hormonal regulation that could translate in differential regenerative potentials.

The dissection of populations by cell surface markers is an important tool to define cell populations with progenitor activity. We found that a combination of two cell surface markers, known to be expressed in hematopoietic progenitors (Sca-1 and CD90), can also be used to define heterogeneity of non-hematopoietic progenitors.